Loading...
HomeMy WebLinkAboutNCG020735_COMPLETE FILE - HISTORICAL_20141231PERMIT NO. DOC TYPE DOC DATE STORMWATER DIVISION CODING SHEET NCG PERMITS /v �� oaro�35 HISTORICAL FILE Li MONITORING REPORTS o C)ulyja31 YYYYM M DD Compliance Inspection Report Permit: NCG020735 Effective: 05/13/10 Expiration: 12/31/14 Owner: Martin Marietta Materials Inc SOC: Effective: Expiration: Facility: Martin Marietta -Selma Quarry County: Johnston Bear Farm Rd Sr 1914 Region: Raleigh Smithfield NC 27577 Contact Person: Steve Whitt Title: Phone: Directions to Facility: System Classifications: Primary ORC: Certification: Phone: Secondary ORC(s): On -Site Representative(s): 24 hour contact name Steve Whitt Phone: 919-783-4630 Related Permits: Inspection Date: 01/20/2011 Ent Time: 02:00 M Exit Time: 02:30 PM Primary Inspector: Mitchell S Hayes i�1 Phone: 919-791-4200 Secondary Inspector(s): Reason for Inspection: Routine Inspection Type: Compliance Evaluation Permit Inspection Type: Mining Activities Stormwater Discharge COC Facility Status: ■ Compliant Q Not Compliant Question Areas: E Storm Water (See attachment summary) Page: 1 Permit: NCG020735 Owner - Facility: Martin Marietta Materials Inc Inspection Date: 01/2012011 Inspection Type: Compliance Evaluation Reason for Visit: Routine Inspection Summary: This site has not been mined for approximately 20 years. The site is currently inactive and not developed. There are no empolyees or equipement on site. Owner does not expect any activity for 2011. Owner maintains the SPPP according to permit requirements. This site currently has no external discharge outfalls. Dispersal pads 1 rip rap will be constructed to slow stormwater so that it will soak into the ground. Stormwater Pollution Prevention Plan Yes No NA NE Does the site have a Stormwater Pollution Prevention Plan? ■ ❑ ❑ ❑ # Does the Plan include a General Location (USGS) map? ■ n ❑ ❑ # Does the Plan include a "Narrative Description of Practices"? ■ n Q ❑ # Does the Plan include a detailed site map including outfall locations and drainage areas? ■ ❑ ❑ n # Does the Plan include a list of significant spills occurring during the past 3 years? ❑ ❑ ■ ❑ # Has the facility evaluated feasible alternatives to current practices? ■ ❑ Q n # Does the facility provide all necessary secondary containment? n n ■ o # Does the Plan include a BMP summary? ■ n ❑ n # Does the Plan include a Spill Prevention and Response Plan (SPRP)? ■ ❑ n ❑ # Does the Plan include a Preventative Maintenance and Good Housekeeping Plan? ■ ❑ 17 n # Does the facility provide and document Employee Training? n r-1 ■ ❑ # Does the Plan include a list of Responsible Party(s)? ■ Cl Q 0 # Is the Plan reviewed and updated annually? ■ ❑ ❑ ❑ # Does the Plan include a Stormwater Facility Inspection Program? ■ n n ❑ Has the Stormwater Pollution Prevention Plan been implemented? ■ n ❑ 0 Comment: This site has not been mined for approximately 20 years. The site is currently inactive and not developed. There are no empolyees or equipement on site. Owner does not expect any activity for 2011. Owner maintains the SPPP according to permit requirements, This site currently has no external discharge outfalls. Dispersal pads 1 rip rap slow stormwater to allow any stormwater to soak into ground. Permit and Outfalls Yes No NA NE # Is a copy of the Permit and the Certificate of Coverage available at the site? ■ 0 0 n # Were all outfalls observed during the inspection? rl 1=l ■ n # If the facility has representative outfall status, is it properly documented by the Division? ❑ ❑ ■ ❑ # Has the facility evaluated all illicit (non stormwater) discharges? ■ n n Cl Comment: This site currently has no external discharge outfalls. Dispersal pads 1 rip rap slow stormwater to allow any stormwater to soak into ground. Page: 2 ®� Kimley-Horn \Val ® and Associates; Inc. T e c h n i c a l M e m o r a n d u m 9 � Ada ��IIIIIIIfRAII IIRIII�C'~` �O To: Mr. Steven S. Whitt Martin Marietta Materials��/ Prepared by: Chad Evenhouse, PWS; Josh Allen, EIT, Todd St. John, PE Kimley-Horn.and Associates, Inc. (KHA) Date: September 1, 2009 Subject: Selma Quarry NPDES Operations and Maintenance Plan (amended) Introduction Kimley Horn and Associates, Inc (KHA) reviewed the Martin Marietta Materials (MMM) Mine Plan for the proposed Selma Quarry in Johnston County, NC to address discharge questions raised by the NC Division of Water Quality (NCDWQ) in their review of the National Pollution Discharge Elimination System (NPDES) permit application. KHA and MMM met with NCDWQ on December 19, 2008 to discuss their comments, and the discussions focused on two aspects of the project: 1) Stormwater runoff and nutrient treatment to meet requirements for the Neuse River Basin, and 2) Potential dewatcring impacts on surrounding waters (wetlands and streams) associated with the proposed mine, In order to address these issues, NCDWQ requested that MMM prepare and submit an NPDES Operation and Maintenance (O&M) Plan. MMM and KHA met again with NCDWQ on July 24, 2009 to discuss the O&M plan (dated April 16 , 2009) and provided continents and requests for more information. This memorandum is an amended O&M plan per the project discussions with NCDWQ, MMM, and KHA. Site Description The proposed mine site is located in the Town of Selma, Johnston County, North Carolina adjacent to the Neuse River near US 70 (Figure 1). The area for the proposed pit is agricultural (cattle pasture) adjacent to forested areas along the Neuse River floodplain. Topographically, the proposed hard rock mine site is Selma Quarry NPDES Operudons and Maintenance Plan Page 1 _f located on a lull in between two headwater streams and the Neuse River floodplain. A berth is proposed between the future pit and the Neuse River floodplain (figure 2) On the southern portion of the site there is an old borrow pit. This area was not considered "Waters of the U.S." by the U.S. Army Corps of Engineers (404 permit approved 5/28/2008, 1D: SAW-2007-01798), or "Waters of the State" by NCDWQ (401 Water Quality Certification approved 8/3/2007, NCDWQ #20070861). There is a permanent water level in the borrow pit, but no outlet or connection to surface waters. The location and proximity to the boundary of the site to the floodplain wetlands provide evidence of the water table in adjacent wetland areas along the Neuse River floodplain. The proposed development for other aspects of the mine (plant, stockpiles, shop, scale house, etc.) is located in the managed agricultural fields and flat pasture areas further from the river. The site is located in the Piedmont physioQ aphic province just west of the fall line between the Piedmont and Coastal Plain (Giese et al. 1997). The mine will be a hard rock (granite) operation where the pit will deepen with a series of benches or ledges. Compared to a typical coastal plain mine limestone operation where the urine expands laterally with the rock layer being trained, the hard rock operation develops vertically. Groundwater flow in this area is likely typical of the Piedmont where flow direction is towards streams (discharge areas) and the shape of the water table mimics the topography of the land surface. Most of the groundwater flow is located within the upper 30 feet of the more densely fractured rock and transitional zones (saprolite and surficial sediments) (blamed, 1989). Hydrology and Hydrogeology Evaluation This evaluation focuses on the proposed'development potential impact to site hydrology and groundwater in two separate components: stormwater treatment for the developed areas, and groundwater pumping and discharge. These two components are separated by the nature of the development (i.e. pit and plant areas), and are discussed separately below. Groundwater Dewatering Dewatering volume associated with development of the pit will increase as the pit deepens through the more conductive upper surface, and the cone of influence will expand as the footprint of the pit grows to its built -out footprint. Once the mine expands to its footprint and then develops vertically, it is not anticipated that there will be a significant increase in dewatering discharge with depth. This has been observed at MMM's Benson Quarry which is similarly situated (geographically, topographically, hydrologically) and is also a hard rock operation. fn addition, MMM has conducted a hydrogeology study to determine typical hydrologic influence from dewatering in piedmont quarries. Based on that study, MMM assumes that the limit for surficial hydrology influence adjacent to a piedmont quarry is 500 feet. This study has been submitted to NCDWQ for the Selma Quarry NPDES permit application in conjunction with this memorandum. Selma Quarry NPDES Operations and Maintenance Plan Page 2 Therefore, wetlands and streams within 500 feet from the pit may be affected by dewatering, however those adjacent to the Neuse River, and others further from the pit (but closer to the plant areas) will not likely be affected. The delineated streams acid wetlands are shown in Figure 3. Of these, the Stream 2/Wetland 7 system and Wetland 2/Stream 3/Wetland 3 system may be affected by dewatering and the cone of influence of the pit. Hydrology in these systems will be managed and monitored under the O&M plan utilizing dewatering discharge to maintain aquatic functions while dewatering activities are on- going. Figure 5 shows the location of pit dewatering ponds and discharge locations to the two systems to be maintained and monitored. It is intended that the Wetland 2/Stream 3 system will receive most of the dewatering discharge through a diffuse flow outlet (i.e. plunge pool) upslope of the headwater wetland. Stream 2 will receive less discharge since the stream is intermittent and has less capacity to handle sustained discharge. This system will receive hydration from the clarification pond through infiltration to the strewn. Wetland 4 will not be hydrologically affected by the initial development of the pit since water table will be sustainer) by the Neuse Rivet'. It is anticipated that as the pit expands, groundwater may flow from the floodplain towards the pit; however this groundwater will be discharged directly back to the river/floodplain system through the discharge discussed above and it is anticipated that there will be no impact to stream flow in the Neuse River, or hydrology of wetlands in the Neuse River floodplain. It was agreed by MMM and NCDWQ to install additional wetland monitoring gages along; Wetland 4 in the Neuse River floodplain as the pit expanded. The three additional gages would be installed along the wetland boundary of Wetland 4 and would be installed once the pit had expanded to within 600 feet of the permitted limit (for the pit). This is approximately 1,000 feet from the wetland boundary. The old borrow pit is in a location that will allow for observation of the water table adjacent to the Neuse River floodplain wetlands as the mining pit develops and expands. The water level in the borrow pit will be observed as a qualitative groundwater reference as the mine develops, however it will not need to be monitored using a continuously monitoring water Ievel gauge at this point since the mining pit will not expand to this portion of the site until later. Additional monitoring may be considered when the NPDES permit is renewed. Wetland 1 is beyond the 500-foot cone of influence for the pit, however, NCDWQ expressed concern that that the development of the berm/stockpile area adjacent to this wetland would reduce overland flow to the wetland and therefore reduce wetland hydrology. It was agreed that a monitoring gage would be installed at this location to provide wetland hydrology monitoring prior to construction of the berm/stockpile area. Wetland 6 and Stream 1 are not within the cone of influence of dewatering, However, these areas will receive additional hydration from the Best Management Practices (BMPs) and stormwater treatment discharge discussed below. Impacts to Wetlands 5, 8, 9, and 10 have been permitted for the development of the pit. As such, these wetlands will not be monitored. Selma Quarry NPDES Operations and Maintenance Plan Page 3 Stormwater A stormwater analysis was completed to determine the stormwater treatment requirements for the future permanent plant (plant) and stockpile area for the proposed development. The Neuse River which is adjacent to the site is classified by the North Carolina Division of Water Quality (NC NCDWQ) as nutrient sensitive water (NSW) and Water Supply Watershed (WS IV). Also the site is located in Johnston County, which is subject to Neuse Basinwide Stormwater Requirements (15A NCAC 2B .0235) and are administered by Johnston County (NCDENR NCDWQ 2007). However, most of the site is located within Selma which administers the water supply watershed stormwater requirements. Selma's stormwater program is not on NCDWQ's list of approved local programs, whereas Johnston County's program is. As such, if Johnston County does not review the stormwater plan, NCDWQ's 401 Unit will. Additionally, the approved 401 Water Quality Certification states the following regarding stormwater requirements. "If conventional engineered stormwater BMPs are used, they must be designed, at a minimum, to remove 85 percent of Total Suspended Solids (TSS). in addition to controlling 85 percent of TSS, all projects requiring stormwater management and located in watersheds that drain directly to waters containing these supplemental classifications shall meet the following requirements: for Nutrient Sensitive Waters a minimum of 30 percent total phosphorus and 30 percent total nitrogen removal." If Johnston County's Stormwater Management Ordinance applies, the requirements for nutrient reduction involving new development are as follows: "Stormwater shall be conveyed from a development in an adequately designed drainage system of natural drainageways, grass swales, storm sewers, culverts, inlets, and channels. Drainage systems shall be designed, constructed, and maintained to encourage natural infiltration, control velocity, control flooding, and extend the time of concentration of stormwater runoff. The post -development runoff rate for the one-year storm event shall be attenuated to the predevelopment runoff rate for the one-year storm. . The nitrogen loading contributed by new development shall be restricted to 3.6 pounds of nitrogen per acre per year. Methodologies for determining nitrogen loading are outlined in the stormwater design manual. A developer has the option of offsetting the nitrogen loading from a development by paying into the state wetlands restoration program. Procedures for offset payments are outlined in the stormwater design manual. When using the offset payment, the total nitrogen loading from a development shall not exceed six pounds per acre per year for residential development and ten pounds per acre per year for nonresidential development." If Selma's water supply watershed requirements apply, these requirements are typically based on state minimum requirements_ Such requirements include 30-Foot or 100-foot stream buffers (based on the project built -upon area). They also require stormwater best management practices (BMP) that capture and treat the first one inch of rain and remove 85% total suspended solids (TSS) for high density projects. These criteria would be less stringent than those set forth in the 401 Water Quality Certification (WQC). As such, meeting the 401 WQC requirements would likely suffice for meeting Selma's water supply watershed stormwater requirements. Selma Quarry NPDES Operations and Maintenance Plan Page 4 Assuming a conservative impervious surface percentage of 50% (100% built -out condition of the 27.1 acre plant site); the amount of runoff for a I -inch rain is 49,000 cubic feet, In order to treat this runoff sufficiently (85% TSS Removal) with a stormwater wetland OMP, the minimum required surface area for the wetlands would be 49,000 square feet (1.l Acres). Including a 30 foot buffer surrounding the wetland (for berms, access, etc.), the total surface area required is equal to approximately 1,9 acres. Location for the stormwater wetland BMP is shown in figure 4. The nitrogen loading was calculated for the site at its final built -out condition (based on 27.1 acres of developed area at 50% imperviousness). The nitrogen load was calculated to be 11.20 pounds per acre per year. After treatment by the stormwater wetland the resulting nitrogen load would be 6.72 lbs/actyr. This would be below the maximum of 10 Ibs/ac/year, but above the required 3.6 Ibs/ac/yr. MMM would be able to provide 2 (approximate) additional BMPs in series to decrease the nitrogen load export; however if the impervious surface percentage for the plant and stockpile area exceeds 44% (11.9 acres of development), MMM may need to "buy down" the excess loading from 4.03 lbs/ae/yr to 3.6 lbs/ae/yr. However, expanding the plant site beyond 27.1 acres may also be a means of increasing the impervious acreage without exceeding 3.6 lbs/adyr. This would require increasing the size of the existing BMPs or the addition of BMPs. Johnston County and Selma both have indicated that they are willing to allow fora phased development approach. This would mean if 6.5 of the 27 acres were made impervious in the first phase then the wetland alone would meet the 3.6 Ibs/ac/yr nitrogen loading requirement. Once development surpassed 6.5 acres, the addition of a wet pond in series with the wetland would allow another 2.7 acres of development, for a total of 9.2 acres of impervious cover. Once development exceeded the 9.2 acre threshold, the addition of a forested filter strip in series with the wet pond and wetland would allow MMM to develop up to 11.9 acres without exceeding 3.6 ibs/ac/yr of nitrogen. However, if Johnston County's nutrient reduction program does not apply, then the development will need to meet NCDWQ's 401 WQC requirements as described above. In any event, the development can be designed to comply with the applicable state, county, or local government requirements. The use of stormwater wetland will alone meet the 30% Nitrogen and Phosphorus removal required by the 401 Water Quality Certification for the built -out condition. Calculations for nutrient loading and BMP sizing are included in Appendix A. Monitoring Monitoring at the Selma Quarry site will focus on the two drainage systems nearest to the pit (Stream 2/Wetland 7 and Wetland 2/Stream 3/Wetland 3). These systems will be hydrated using dewatering discharge from the mine pit's clarification ponds. This discharge will only include mine dewatering water extracted from the pit. The primary clarification pond will discharge through a diffuse flow structure (i.e. plunge pool) upslope from Wetland 2 above the headwaters of Stream 3. The secondary clarification pond will also be fed by the dewatering discharge, however not on a regular basis such as the primary clarification pond. This Selma Quarry NPDES Operations and Maintenancc Plan Page 5 pond will allow infiltration to Stream 2 and will periodically be tilled to maintain a permanent water level for hydration, A water level monitoring gage will be installed in Wetland 2 to document that wetland hydrology is sustained while dewatering activities are on -going. Since the drainage system below Wetland 2 is a surface hydrology wetland/streani system, hydration of Wetland 2 will demonstrate that the system is functioning with appropriate hydrologic functions. A flow meter will be installed in Stream 2 to document discharge and low and duration in the intermittent stream. In addition, a water level monitoring gage will be installed downstream in Wetland 7 at the property boundary to document wetland hydrology where Stream 2 confluences with the Neuse River floodplain wetland area. These gages will record water table levels on a daily basis for the wetlands, and flow volume and duration by event in Stream 2. A staff gage will be installed in the borrow pit area and, will be observed periodically by the on -site plant manager. An on -site rain sago will be installed and will collect daily rainfall measurements. Monitoring locations are shown in Figure 6. The frequency of data collection will be evaluated and discussed at the completion of Year l monitoring. Recornrnendation to change monitoring frequency will be addressed at that time. An annual monitoring report will be prepared and submitted to NCDWQ. The report will include: o Summary of the mine development o Summary of hydrologic monitoring data (daily gage measurements, and monthly observations) o Summary of on -site rainfall o Visual assessment of all wetlands and streams shown in Figure 3 o Visual assessment of 13MP function and copies of any Operations and Maintenance Reporting if required by Johnston County. o Recommendations for corrective measures of accessary) It is intended that the first annual report will evaluate the effectiveness of on -site stormwater treatment and managing dewatering discharge in relation to the progress of site development and expansion of the pit. Recommendations for additional monitoring and implementation of future stormwater treatment will be presented as needed. Selma Quarry NPDES Operations and Maintenance Plan Page 6 References Giese, G.L., Eimers, J.L., and Coble, R.W. 1997. Simulation of ground -water flow in the Coastal Plain aquifer system of North Carolina, in Regional Aquifer -System Analysis -Northern Atlantic Coastal Plain: U.S. Geological Survey Professional Paper 1404-M, 142 p. Harned, Douglas A. 1989. The Hydrogeologic Framework and a Reconnaissance of Ground -water Quality in the Piedmont Province of North Carolina, With a Design for Future Study (Water Resources Investigations Report 88-4130). U.S. Geologic Survey, Raleigh, NC. NCDENR NCDWQ (North Carolina Department of Environment and Natural Resources Division of Water Quality). 2007. Administrative Code Section:15A NCAC 213.0200 Classifications and Water Quality Standards Applicable to Surface Waters and Wetlands. N.C. Environmental Management Commission. Raleigh, NC. Selma Quar y NPr)ES operations and Mainteamtec Plan Page 7 FIGURES Title I Vicinity Map hcpwed For Project I Selma Quarry — NPDES Operations and Maintenance Plan Johnston County, North Carolina Date Project Number 9/i/09 1 011185026 Figure KARAL E.vuaomrm"I I I85OU MHW Sd n*SEL IA O&M K. FWURESAd Prcl wM by Joshw Allm CMFI !=. t 'dr, .M I L S y � s � eat a .. ; ��� ��� r1 � ',r �•0 • ,` ~'� .SAS 'f i . • .1 .. - =��� �• �•' 'y ` \ R�'}'i� � �..[= " �'` Imo. 5 � 1 f � Sena and Gravel 03�1 psonUnit �.. �f" ��-�NJ P,Cf _` _ ,(� +. Legend ;I �� -�, 0 1,000 2,000 4,000 Project Boundary �- Feet Tide USGS Topographic Map (USGS Quad: Selma, NC: 1964, revised 1988) Project Selma Quarry NPDES Operations and Maintenance Plan Nr pa,cd For: Johnston County,North Carolina v Date Project Plumber Figure 911/09 011185026 2 K:VtAL F.ntiiranmusieRPl11530?6 h�M1�M SdmatsFl,l�lq RG, Plan FIOIIRES,doc Picpwed try Joshua Allrn tmn •.r=. "The stormwater wetland will treat approximately the first 6.5 acres of development in MMM's Future Plant and Stockpile Area. Any development beyond this can be treated by the addition of other BMPs in series with the existing stormwater wetland. Watershed: / \ Approx.27.11 Potential Futurall BMP Location I R LEGEND C3 Proposed Wetland Proposed Wetland Buffer C3 Potential Future BMP Locations -Ro— Delineated Streams 96 Delineated Wetlands ® Future Plant and Stockpile Area R 4 R N 0 250 500 I I I Feet O ` .r Stormwater Wtedand': Title Proposed Stormwater Treatment for Future Plant and Stockpile Area Project Selma Quarry - NPDES Operations and Maintenance Plan Prepared r.r. Johnston County, North Carolina RI..., Rl�ILLI. r.w.re. nn y: Date Project ]Number Figure 911 /09 011185026 4 K,VU[. I'n,irmmau.il'l111 M026 MMM Sdm,r S[LMA CAM Km RKAIRI-S dw Prepumd by Joshua All- [ 2` Fll�gp I r a Y U N 0 250 500 r f I I AFeet — { Y r / Y "Ifand 2 Sfieam 3 i Y Ile I • LEGEND • f p r ® Mine Water Clarification Pond r lAktiand Delineated Streams �- —��� • Delineated Wetlands Title Mine Dewatering Locations Project Selina Quarry -PDES Operations and Maintenance Plan ft�a For: Johnston County, North Carolina A Date Project Number Figure 911/09 011185026 5 KARAt_F•vho•n f.Wf J 185026 MMM Sd.MSMsn 08M Pimp HOUMA- Prqued by Joshua Allen EW A ,Yr. . N 0 375 750 Permitted Stream I i I Impact Area Feet lht+tland ti \ 0.02 ac Stream 2 0.48 ac velbclty Flow Meter , ` Stream Gauge ' • Depth �. Water • ' r Z Wtetland Gauge Water Depth ' Mbtland Gauge ,: • Water Depth Wetland Gauge • ! • WbBand Z Permitted Wetland lmpad Area t� Water Depth \ ` • , Wetland Gauge Wetland Permitted !m act Area Stream 3 Water Depth LEGEND , Kttttand Gauge Proposed Monitoring Locations Gage Location letter Depth e Future Wetland Ga 9' Vlletland Gauge • Initial Wetland Gauge Location a Velocity Meter Location ® Mine Water Clarification Pond Delineated Streams Delineated Wetlands Tide Proposed Monitoring Locations Project Selma Quarry NPDES Operations and Maintenance Plan Prepued r�r Johnston County,North Carolina ;AA Date Project Number Figure 9/I/09 011185026 6 V--%AL EnYlra LaNJ I ILWXMMSd..accru. O&M M= MRSAs P+C Pd by lostma Aff a r.Mn Zi=k APPENDIX A Kimsey -loom C �,1 and Associates, Inc. PROPOSED WETLAND (BASED ON 50% IMPERVIOUS COVER) Project Information Project Name: Martin Marietta Materials - Selma Quarry KNA Project k: 011185026 Designed by: JCA Date: 4114/2009 Revised by: TSJ Date: 4/1412009 Revised by: Date: Design Resource: NCDENR - Stormwater Best Management Practices (April 1999) NCDENR - Updated Draft Manual of Stormwater Best Management Practices ( July2005) Site Information Sub Area Location: Future Permanent Plant and Stockpile Area Drainage Area (DA) = 27.05 Acres Impervious Area (IA) = 13.53 Acres Percent Impervious (1) = 50-0 Required Storage Volume (Water Quality): Design Storm = 1 inch Determine Rv Value = o,05 + .009 (1) = 0.50 infin Storage Volume Required = 49,098 of (above Permanent Poot) Temporary Pool Depth = 12 Inch Maximum Surface Area Required = 49,098 sf Required Forbay Sizing Required Volume = 10.00% of Parmenant Pool Required Forbay V01ume = 4,910 cf Kimley-Horn ! I , and Associates, Inc. NUTRTIENT LOADING CALCULATIONS (BASED ON 50% Project information Project Name: MMM Selma Quarry - Built Out Conditions KHA Project M 011185026 Designed by. JCA Date_ Revised by: TSJ Data: _ Revised by: Data. WP-1 (Wet Pond) Site TN Export TN Export Area Coeff. by Land Use Dralne a Area Conditions (Acres) (lbslacl r) (Ibslyr) Permanently protected undisturbed 0.000 0.6 0.00 opens ace forest, unmown, meadow Permanently protected managed 13.526 1.2 16,23 open space rass, landscaping. etc.) Proposed: Impervious surfaces {roads, parking 13.526 21.2 286.74 tots, driveways. roofs, paved storage areas, etc. Totals 27.051 302.97 SW-1 (Stormwater Wetland) Site TN Export TN Export Area Coeff. by Land Use Drainage Area Conditions (Acres) (Ibslavyr} (lbs(yr) Permanently protected undisturbed 0.000 U.6 LJ open space forest. unmown. meadow Permanently protected managed 13.626 1.2 12.17 open space rass, landscaping, etc.) Proposed: Impervious surfaces (roads, parking 13.526 21.2 215.06 lots, drrvewe s. roofs, paved storage areas, 91c.) Totals 27.051 227.23 FS-1 (Forested Filter Strip) BMP BMP BMP Remaining Site TN Export TN Export TN Export TN Removal TN Reduction TN Reduction Nitrogen Area Coeff, by Land Use From Site Efficiency by Land Use From Site Load Drainage Area Conditions Acres Ibslacl r (lbsJ r) (Ibslaclyr) %) (Ibslyr) (Ibslaclyr) (Ibslaclyr) Permanently protected undisturbed 0.000 0.6 0.00 20.0 % 0.1c 1. a en space forest, unmowr., meadow) Permanently protected managed 13.526 1.2 7.30 20.0% 1.46 opens ace rass, landscaping, etc.) Proposed: impervious surfaces (roads. parking 13.526 21.2 129,02 20.0% 25.81 lots, drivews s, roofs, paved storage areas, etc - Totals 27.031 13t1.34 5.04 27.27 1.01 4.03 TOTAL TN LOAD FOR ENTIRE PROJECT = 11.20 LBSIACIYR TOTAL TN REDUCTION FOR ENTIRE PROJECT = 7.17 LSSIACIYR TOTAL POST CONSTRUCTION TN LOAD = 4.03 LBSIAC,YR % TN REDUCTION FOR ENTIRE SITE - 64.00% 4 Kimiey-Horn ►I and Associates, Inc. T e c h n i c a l M e m o r a n d u m To: Mr. Steven S. Whitt Martin Marietta Materials Prepared by: Chad Evenhouse, PWS; Josh Allen, EIT, Todd St. John, PE Kimley-Horn and Associates, Inc. (KHA) Date: September 1, 2009 Subject: Selma Quarry NPDES Operations and Maintenance Plan (amended) Introduction Kimley Horn and Associates, Inc (KHA) reviewed the Martin Marietta Materials (MMM) Mine Plan for the proposed Selma Quarry in Johnston County, NC to address discharge questions raised by the NC Division of Water Quality (NCDWQ) in their review of the National Pollution Discharge Elimination System (NPDES) permit application. KHA and MMM met with NCDWQ on December 19, 2008 to discuss their comments, and the discussions focused on two aspects of the project; 1) Stormwater runoff and nutrient treatment to meet requirements for the Neuse River Basin, and 2) Potential dewatering impacts on surrounding waters (wetlands and streams) associated with the proposed mine. In order to address these issues, NCDWQ requested that MMM prepare and submit an NPDES Operation and Maintenance (O&M) Plan. MMM and KHA met again with NCDWQ on July 24, 2009 to discuss the O&M plan (dated April 16 , 2009) and provided comments and requests for more information. This memorandum is an amended O&M plan per the project discussions with NCDWQ, MMM, and KHA. Site Description The proposed mine site is located in the Town of Selma, Johnston County, North Carolina adjacent to the Neuse River near US 70 (Figure 1). The area for the proposed pit is agricultural (cattle pasture) adjacent to forested areas along the Neuse River floodplain. Topographically, the proposed hard rock mine site is SeEma Quarry NPDFS Operations and Maintenance flan Page t located on a hill in between two headwater streams and the Neuse River floodplain. A berm is proposed between the future pit and the Neuse River floodplain (Figure 2) On the southern portion of the site there is an old borrow pit. This area was not considered "Waters of the U.S." by the U.S. Army Corps of Engineers (404 permit approved 5/28/2008,1D: SAW-2007-01798), or "Waters of the State" by NCDWQ (401 Water Quality Certification approved 8/3/2007, NCDWQ #20070861). There is a permanent water level in the borrow pit, but no outlet or connection to surface waters. The location and proximity to the boundary of the site to the floodplain wetlands provide evidence of the water table in adjacent wetland areas along the Neuse River floodplain. The proposed development for other aspects of the mine (plant, stockpiles, shop, scale house, etc.) is located in the managed agricultural fields and flat pasture areas further from the river. The site is located in the Piedmont physiographic province just west of the fall line between the Piedmont and Coastal Plain (Giese et al. 1997). The mine will be a hard rock (granite) operation where the pit will deepen with a series of benches or ledges. Compared to a typical coastal plain mine limestone operation where the mine expands laterally with the rock layer being mined, the hard rock operation develops vertically. Groundwater flow in this area is likely typical of the Piedmont where flow direction is towards streams (discharge areas) and the shape of the water table mimics the topography of the land surface. Most of the groundwater flow is located within the upper 30 feet of the more densely fractured rock and transitional zones (saprolite and surficial sediments) (Harped, 1989). Hydrology and Hydrogeology Evaluation This evaluation focuses on the proposed development potential impact to site hydrology and groundwater in two separate components: stormwater treatment for the developed areas, and groundwater pumping and discharge. These two components are separated by the nature of the development (i.e. pit and plant areas), and are discussed separately below. Groundwater Dewatering Dewatering volume associated with development of the pit will increase as the pit deepens through the more conductive upper surface, and the cone of influence will expand as the footprint of the pit grows to its built -out footprint. Once the mine expands to its footprint and them develops vertically, it is not anticipated that there will be a significant increase in dewatering discharge with depth. This has been observed at MMM's Benson Quarry which is similarly situated (geographically, topographically, hydrologically) and is also a hard rock operation. In addition, MMM has conducted a hydrogeology study to determine typical hydrologic influence from dewatering in piedmont quarries. Based on that study, MMM assumes that the limit for surficial hydrology influence adjacent to a piedmont quarry is 500 feet. This study has been submitted to NCDWQ for the Selma Quarry NPDES permit application in conjunction with this memorandum. Selma Quarry NPDES Operations and Maintenance Plan Page 2 Therefore, wetlands and streams within 500 feet from the pit may be affected by dewatering, however those adjacent to the Neuse River, and others further from the pit (but closer to the plant areas) will not likely be affected. The delineated streams and wetlands are shown in Figure 3. Of these, the Stream 2/Wetland 7 system and Wetland 2/Stream 3/Wetland 3 system may be affected by dewatering and the cone of influence of the pit. Hydrology in these systems will be managed and monitored under the O&M plan utilizing dewatering discharge to maintain aquatic functions while dewatering activities are on- going. Figure 5 shows the location of pit dewatering ponds and discharge locations to the two systems to be maintained and monitored. It is intended that the Wetland 2/Stream 3 system will receive most of the dewatering discharge through a diffuse flow outlet (i.e. plunge pool) upslope of the headwater wetland. Stream 2 will receive less discharge since the stream is intermittent and has less capacity to handle sustained discharge. This system will receive hydration from the clarification pond through infiltration to the stream. Wetland 4 will not be hydrologically affected by the initial development of the pit since water table will be sustained by the Neuse River. It is anticipated that as the pit expands, groundwater may flow from the floodplain towards the pit; however this groundwater will be discharged directly back to the river/floodplain system through the discharge discussed above and it is anticipated that there will be no impact to stream flow in the Neuse River, or hydrology of wetlands in the Neuse River floodplain. It was agreed by MMM and NCDWQ to install additional wetland monitoring gages along Wetland 4 in the Neuse River floodplain as the pit expanded. The three additional gages would be installed along the wetland boundary of Wetland 4 and would be installed once the pit had expanded to within 600 feet of the permitted limit (for the pit). This is approximately 1,000 feet from the wetland boundary. The old borrow pit is in a location that will allow for observation of the water table adjacent to the Neuse River floodplain wetlands as the mining pit develops and expands. The water level in the borrow pit will be observed as a qualitative groundwater reference as the mine develops, however it will not need to be monitored using a continuously monitoring water level gauge at this point since the mining pit will not expand to this portion of the site until later. Additional monitoring may be considered when the NPDES permit is renewed. Wetland 1 is beyond the 500-foot cone of influence for the pit, however, NCDWQ expressed concern that that the development of the berm/stockpile area adjacent to this wetland would reduce overland flow to the wetland and therefore reduce wetland hydrology. It was agreed that a monitoring gage would be installed at this location to provide wetland hydrology monitoring prior to construction of the berm/stockpile area. Wetland 6 and Stream 1 are not within the cone of influence of dewatering. However, these areas will receive additional hydration from the Best Management Practices (BMPs) and stormwater treatment discharge discussed below. Impacts to Wetlands 5, &, 9, and 10 have been permitted for the development of the pit. As such, these wetlands will not be monitored. Selm Quarry NPDES Operations and Maintenance Plan Page 3 Stormwater A stormwater analysis was completed to determine the stormwater treatment requirements for the future permanent plant (plant) and stockpile area for the proposed development. The Neuse River which is adjacent to the site is classified by the North Carolina Division of Water Quality (NC NCDWQ) as nutrient sensitive water (NSW) and Water Supply Watershed (WS IV). Also the site is located in Johnston County, which is subject to Neuse Basinwide Stormwater Requirements (15A NCAC 2B .0235) and are administered by Johnston County (NCDENR NCDWQ 2007). However, most of the site is located within Selma which administers the water supply watershed stormwater requirements. Selma's stormwater program is not on NCDWQ's list of approved local programs, whereas Johnston County's program is. As such, if Johnston County does not review the stormwater plan, NCDWQ's 401 Unit will. Additionally, the approved 401 Water Quality Certification states the following regarding stormwater requirements. "If conventional engineered stormwater BMPs are used, they must be designed, at a minimum, to remove 85 percent of Total Suspended Solids (TSS). In addition to controlling 85 percent of TSS, all projects requiring stormwater management and located in watersheds that drain directly to waters containing these supplemental classifications shall meet the following requirements: for Nutrient Sensitive Waters a minimum of 30 percent total phosphorus and 30 percent total nitrogen removal." If Johnston County's Stormwater Management Ordinance applies, the requirements for nutrient reduction involving new development are as follows: "Stormwater shall be conveyed from a development in an adequately designed drainage system of natural drainageways, grass swales, storm sewers, culverts, inlets, and channels. Drainage systems shall be designed, constructed, and maintained to encourage natural infiltration, control velocity, control flooding, and extend the time of concentration of stormwater runoff. The post -development runoff rate for the one-year storm event shall be attenuated to the predevelopment runoff Date for the one-year storm. The nitrogen loading contributed by new development shall be restricted to 3.6 pounds of nitrogen per acre per year. Methodologies for deternuning nitrogen loading are outlined in the stormwater design manual. A developer has the option of offsetting the nitrogen loading from a development by paying into the state wetlands restoration program. Procedures for offset payments are outlined in the stormwater design manual. When using the offset payment, the total nitrogen loading from a development shall not exceed six pounds per acre per year for residential development and ten pounds per acre per year for nonresidential development." If Selma's water supply watershed requirements apply, these requirements are typically based on state minimum requirements. Such requirements include 30-foot or 100-foot stream buffers (based on the project built -upon area). They also require stormwater best management practices (BMP) that capture and treat the first one inch of rain and remove 85% total suspended solids (TSS) for high density projects. These criteria would be less stringent than those set forth in the 401 Water Quality Certification (WQC). As such, meeting the 401 WQC requirements would likely suffice for meeting Selma's water supply watershed stormwater requirements. Selma Quarry NIPDES operations and Maintenance Plan Page 4 Assuming a conservative impervious surface percentage of 50% (100% built -out condition of the 27.I acre plant site); the amount of runoff for a 1-inch rain is 49,000 cubic feet. In order to treat this runoff sufficiently (85% TSS Removal) with a stormwater wetland BMP, the minimum required surface area for the wetlands would be 49,000 square feet (L I Acres). Including a 30 foot buffer surrounding the wetland (for berms, access, etc.), the total surface area required is equal to approximately 1.9 acres. Location for the stormwater wetland BMP is shown in Figure 4. The nitrogen loading was calculated for the site at its fmal built -out condition (based on 27.1 acres of developed area at 50% imperviousness). The nitrogen load was calculated to be 11.20 pounds per acre per year. After treatment by the stormwater wetland the resulting nitrogen load would be 6.72 lbs/ac/yr. This would be below the maximum of 10 Ibs/ae/year, but above the required 3.6 lbs/ac/yr. MMM would be able to provide 2 (approximate) additional BMPs in series to decrease the nitrogen load export; however if the impervious surface percentage for the plant and stockpile area exceeds 44% (11.9 acres of development), MMM may need to "buy down" the excess Ioading from 4.03 Ibs/ae/yr to 3.6 lbs/ac/yr. However, expanding the plant site beyond 27.1 acres may also be a means of increasing the impervious acreage without exceeding 3.6 lbs/ac/yr. This would require increasing the size of the existing BMPs or the addition of BMPs. Johnston County and Selma both have indicated that they are willing to allow for a phased development approach. This would mean if 6.5 of the 27 acres were made impervious in the first phase then the wetland alone would meet the 3.6 lbs/ac/yr nitrogen loading requirement. Once development surpassed 6.5 acres, the addition of a wet pond in series with the wetland would allow another 2.7 acres of development, for a total of 9.2 acres of impervious cover. Once development exceeded the 9.2 acre threshold, the addition of a forested filter strip in series with the wet pond and wetland would allow MMM to develop up to 11.9 acres without exceeding 3.6 lbs/ae/yr of nitrogen. However, if Johnston County's nutrient reduction program does not apply, then the development will need to meet NCDWQ's 401 WQC requirements as described above. In any event, the development can be designed to comply with the applicable state, county, or local government requirements. The use of stormwater wetland will alone meet the 30% Nitrogen and Phosphorus removal required by the 401 Water Quality Certification for the built -out condition. Calculations for nutrient loading and BMP sizing are included in Appendix A. Monitoring Monitoring at the Selma Quarry site will focus on the two drainage systems nearest to the pit (Stream 2/Wetland 7 and Wetland 2/Stream 3/Wctland 3). These systems will be hydrated using dewatering discharge from the mine pit's clarification ponds. This discharge will only include mine dewatering water extracted from the pit. The primary clarification pond will discharge through a diffuse flow structure (i.e. plunge pool) upslope from Wetland 2 above the headwaters of Stream 3. The secondary clarification pond will also be fed by the dewatering discharge, however not on a regular basis such as the primary clarification pond. This Selma Quarry NPDES Operations and Maintenance Plan Page 5 pond will allow infiltration to Stream 2 and will periodically be filled to maintain a permanent water level for hydration. A water level monitoring gage will be installed in Wetland 2 to document that wetland hydrology is sustained while dewatering activities are on -going. Since the drainage system below Wetland 2 is a surface hydrology wetland/stream system, hydration of Wetland 2 will demonstrate that the system is functioning with appropriate hydrologic functions. A flow meter will be installed in Stream 2 to document discharge and flow and duration in the intermittent stream. In addition, a water level monitoring gage will be installed downstream in Wetland 7 at the property boundary to document wetland hydrology where Stream 2 confluences with the Neuse River floodplain wetland area. These gages will record water table levels on a daily basis for the wetlands, and flow volume and duration by event in Stream 2. A staff gage will be installed in the borrow pit area and will be observed periodically by the on -site plant manager. An on -site rain gage will be installed and will collect daily rainfall measurements. Monitoring locations are shown in Figure 6. The frequency of data collection will be evaluated and discussed at the completion of Year l monitoring. Recommendation to change monitoring frequency will be addressed at that time. An annual monitoring report will be prepared and submitted to NCDWQ. The report will include: o Summary of the mine development Summary of hydrologic monitoring data (daily gage measurements, and monthly observations) o Summary of on -site rainfall e Visual assessment of all wetlands and streams shown in Figure 3 Visual assessment of BMP function and copies of any Operations and Maintenance Reporting if required by Johnston County. • Recommendations for corrective measures (if necessary) It is intended that the first annual report will evaluate the effectiveness of on -site stormwater treatment and managing dewatering discharge in relation to the progress of site development and expansion of the pit. Recommendations for additional monitoring and implementation of future stormwater treatment will be presented as needed. Selma Quarry NPDES operations and Maintenance Plan Page 6 References Giese, G.L., Eimers, J.L., and Coble, R.W. 1997. Simulation of ground -water flow in the Coastal Plain aquifer system of North Carolina, in Regional Aquifer -System Analysis -Northern Atlantic Coastal Plain: U.S. Geological Survey Professional Paper 1404-M, 142 p. Harned, Douglas A. 1989. The Hydrogeologic Framework and a Reconnaissance of Ground -water Quality in the Piedmont Province of North Carolina, With a Design for Future Study (Water Resources Investigations Report 884130). U.S. Geologic Survey. Raleigh, NC. NCDENR NCDWQ (North Carolina Department of Environment and Natural Resources Division of Water QuaIity). 2007. Administrative Code Section:I SA NCAC 2B .0200 Classifications and Water Quality Standards Applicable to Surface Waters and Wetlands. N.G.. Environmental Management Commission. Raleigh, NC. Selina Quarry NPDES Operations and Maintenance Plan Page 7 FIGURES Title I Vicinity Map Project Selma Quarry — NPDES Operations and Maintenance Plan Johnston County, North Carolina v Date Project Number Figure 911109 01118502E 1 IL^RAL�ffisvmmmahQl llewre MMM Sdft4%SELay OEA1 Plr FKRWcca„ PrepuW by Joshua Anon can 7-. t 0/ 1po� V 0C 46 % 4, N 0 toe 41' Y 03 Sand and Gravel1!1%GA nit its Legend I " : Project Boundary .a lion ; C 0 1,000 2,000 4,000 Feet I Tide I USGS Topographic Map (USGS Quad. Selma, NC: 1964, revised 1988) 1 Project Selma Quarry — NPDES Operations and Maintenance Plan Prefm�d For: Johnston County, Noah Carolina Date Project Number Figure 9/l/09 1 011185026 2 IMRAL.En-wim—iiaA)t 1125026 MMM Sd,0SELVA 0&1.1 Plan FICURES.ft PmTarcd by Joshua AM- r M—ri k ♦ r " p M r- M'r w r a l41(r �' ells dk WE AY Legend Project Boundary we ^�-'- Jurisdictional Stream Channel ,. - (%`j Jurisdictional Wetlands Jurisdictional Open Waters 0 600 1,200 Z400 50' Neuse River Buffer I 1 Feel Title Delineation of Waters of the U.S. Project Selma Quarry PD1 S Operations and Maintenance Plan Nq� -d For Johnston County,North Carolina I�Iw IfrML Ya1wYa A A Date Project Number Figure 9/1/09 011185026 3 K!UL41.. F135M WAYASd,..ISF.WA 6fi.M ►1s FWAAFS.d. P[cjwed by losbud Aka cmn ==,r 'The stormwater wetland will treat approximately the first 5.5 acres of development in MMM's Future Plant and Stockpile Area. Any development beyond this can be treated by the addition of other BMPs in series with the existing stormwater wetland. /r�appmx.271 Potential Future( BMP Location I LEGEND a Proposed Wetland Proposed Wetland Buffer C3 Potential Future BMP Locations -%— Delineated Streams le Delineated Wetlands ® Future Plant and Stockpile Area N 0 250 500 A Feet \ \'A , \ ■ r / Sfomnvater Weiland•: / Approx. 1.9 ac a Title Proposed Stormwater Treatment for Future Plant and Stockpile Area Project Sclma Quarry -NPDES Operations and Maintenance Plan Prcpmcd For: Johnston County, North Carolina A Date Project Number Figure 9/1/09 011185026 4 K:Wt._r—IMN)i 1 IM26 AAM Sd-Y4SM%UO&M PL• MU Md., Prcparrd by Joshua An= r---" .+.rR~k . N 0 250 500 A ! I Feet . — . V011 rary "at rrroauw . ■ Pond A _ Stream + " I i LEGEND " i� i ftVand f p Mine Water ClarficaUcin Pond f t • ��__ �] ,ow.• Delineated Streams Delineated Wetlands Title I Mine Dewatering Locations Project Selina Quarry — NPDES Operations and Maintenance Plan Pry For: Johnston County, North Carolina Date Project Number Figure 9/1/09 011185026 5 K AL_E.vuo caufal I I ISM MMM S61.inL4ELMA O&M Plm FIGLMS.6. Prepared by Joshua Allrn cc r I 0-4=. Permitted Stream Impact Area VekwJty Flow Meter Stream Gauge Water Depth Wetland Gauge Water Depth Welland Gauge Permitted Weiland j Impact Area I Stream 31 LEGEND Proposed Monitoring Locations • Future Wetland Gage Location • Initial Wetland Gauge Location 0 Velocity Meter Location ® Mine Water Clarification Pond •w• Delineated Streams Delineated Wetlands N 0 375 750 A I I I Feet WaHand 6 0.02 ac TOA8w tfand Stream2 ! �� � Water Depth / ` \ Wetland Gauge Water De Wand Gauge Wfatland 2 Permitted Wetland �\ 0.8 ac ImpactArea J 4 J • � I' Water Depth fttfand Gauge Water Depth Wiafland Gauge Title Proposed Monitoring Locations Project Selma Quarry— NPDES Operations and Maintenance Plan r:e Fnr. Johnston County, North Carolina -yv Date Project Number Figure 9/1/09 011185026 6 k'RAL_E--i tat 1115M MMM Sd—m SELMA O&M Aa• 1IMMFS.d- PrepwcJ by Joshua AV= [ mn = k A1F"PFNV)flX f� rI n IGmley Horn ® _,_ and Associates, Inc. Project Information PROPOSED WETLAND (BASED ON 50% IMPERVIOUS COVER) Project flame: Martin Marietta Materials - Selma Quarry KHA Project #: 011185026 Designed by: JCA Date- 4114f2009 Revised by: TSJ Date: 411412009 Revised by. Date: Design Resource: NCDENR - Slormwater Best Management Practices (April 1999) NCDENR - Updated Draft Manual of Stormwater Best Management Practices ( July 2005) Site Information Sub Area Location: Future Permanent Plant and Stockpile Area Drainage Area (DA) = 27.05 Acres Impervious Area (IA) = 1353 Acres Percent Impervious (1) - 50.0 % Required Storage Volume (Water Quality): Design Storm � 1 inch Determine RV Value = 0,05 + .009 (1) 0.50 iahn Storage Volume Required = 49,098 cf (above Permanent Pool) Temporary Pool Depth = 12 Jnch Maximum Surfaco Area Required = 49,098 Sf Required Forbay Sizing Required Volume = 10.00% of Pormenant Pool Required Forbay Volume = 4,910 cf C®FI Kimley-Horn ® and Associates, Inc. NUTRTIENT LOADING CALCULATIONS (BASED ON 50% IMPERVIOUS COVER) Project Information Project Name: MMM Selma Quarry - Su4t Out Conditions KHA Project M 011185026 Designed by. JCA Date: 4/14/2009 Revised by: TSJ Date: 4/14/2009. Revised by: Date: WP-1 (Wet Pond) BMP BMP BMP Remaining Site TN Export TN Export TN Export TN Removal TN Reduction TN Reduction Nitrogen Area Coeff. by Land Use From Site Efficiency by Land Use From Site Load Drainage Area Conditions (Acres) {Ibslacl r) (Ibslyr) {Ibslaclyr) (% (Ibslyr) (Ibslac! ) (lbslacJyr Permanently protected undisturbed 0.000 0.6 0.00 25.0% 0.00 opens ace forest, unmown, meadow Permanently protected managed 13.526 1.2 18.23 25.0% 4.06 i a ens ace(grass. landscaping. etc. Proposed: Impervious surfaces (roads, parking 13.526 21.2 286.74 25.0% 71.69 i lots, drWeways, roofs, Mod Storage areas, etc. V Totals 27.051 302.97 11.20 75.74 2.80 8.40 SWA (Stormwater Watland) BMP BMP BMP Remaining Site TN Export TN Export TN Export TN Removal TN Reduction TN Reduction Nitrogen Area Coeff. by Land Use From Site Efficiency by Land Use From Site Load Drainage Area Conditions (Acres) (IbslaWyr) (Ibslyr) (1waclyr) (%) (lbslyr) (lbslaclyr) (Ibslaclyr) Permanently protected undisturbed 0.000 0.6 0.00 40.0% 0.00 i o n space forest, unmown, meadow Permanently protected managed 13.626 1.2 12.17 40.0% 4.87 open space(grass, landscaping, etc. Proposed: Impervious surfaces (roads, parking 13.526 21.2 215,06 1 1 40.0% 1 86.02 1 i lots, driveways, roofs, payed storage areas, etc.} 1 V Totals 27.051 227.23 1 8.40 90.89 3.36 5.04 FS-1 (Forested Filter Strip) 8MP BMP BMP Remaining Site TN Export TN Export TN Export TN Removal TN Reduction TN Reduction Nitrogen Area Coeff. by Land Use From Site Efficiency by Land Use From Site Load Drainage Area Conditions (Acres) (lbslacJyr) Ibsl r) (lbsiaclyr) (%) Ibslyr Ibslac! r lbslaclyr) Permanently protected undisturbed 0.000 0.6 0.00 20.0% 0.00 open space forest, unmown, meadow Permanently protected managed 13,526 1.2 7.30 20.0% 1.46 o ens ace rass, landscaping. etc. Proposed: Impervious surfaces (roads, parking 13.526 21.2 129.03 20.0% 25.81 lots, drivemmys, roofs._paved store a areas, etc.) V Totals 27.051 136.34 5.04 27.27 1.01 4.03 TOTAL TN LOAD FOR ENTIRE PROJECT = 11.20 LBSIACIYR TOTAL TN REDUCTION FOR ENTIRE PROJECT = 7.17 LBSIACIYR TOTAL POST CONSTRUCTION TN LOAD = 4.03 LBSIACNR % TN REDUCTION FOR ENTIRE SITE = 64.00 % Martini Marietta Materials P.O. Box 30013 Raleigh, North Carolina 27622-0013 Telephone (919) 781-4550 Hand Delivered (in the care of Mr. Ken Piciclel August 31, 2009 Ms. Jennifer Jones NC Division of Water Quality 512 N. Salisbury St. Raleigh, NC 2.7604 Subject: Request for Additional Information General Permit No. NCG020000 Martin Marietta Materials Inc, — Selma Quarry, NCG020735 Johnston County Dear Ms. Jones: Firstly we would like to thank you, Lauren Witherspoon, and Danny Smith for meeting with us on July 24, 2009 to discuss your concerns raised in your letter to our office dated June 30, 2009. We believe the meeting was productive and helped for all parties to come to an understanding and agreement as to what would truly be required for the O&M plan for the site. To this end please find attached the following documents: - Memo responding to your letter dated June 30, 2009. We have gone through the 4- page request for additional information item by item. - Revised O&M plan. - Hydrogeotogy study demonstrating expected cone of influence. - Revised maps: Site Plan, Details Sheet. We believe we have been very thorough in our response and trust that it satisfactorily addresses all of your concerns. Sincerely, Nuwan Wijesuriya Environmental Engineer Attachments CC: Lauren Witherspoon, Danny Smith — DWQ, Raleigh Regional Office 4K Car-1 Kimley-Horn and Associates Inc. T e c h n 1 c a l M e m o r a n d u m IV Mr. Steven S. Whitt; Mr. Nuwan Wijesusiya Martin Marietta Materials Prepared by: Chad Evenhouse, PWS; Kimley-Horn and Associates, Inc. Date: August 31, 2009 Subject: Response to NCDWQ Request for Information (June 6, 2009) and Sup1mary of NCDWQ meeting on July 24, 2009 regarding NCG020735 Selma Quarry, Johnston County 1 nl roil uction The following; memorandum is prepared to address the North Carolina Division of Water Quality (NCDWQ) request for more information regarding the Selma Quarry NPDES permit application (GP No. NCG020735, letter dater) .Tune 30, 2009) and the subsequent project meeting held between NCDWQ staff (Jennifer Jones, Danny Smith, Lauren Witherspoon), Martin Marietta Materials (MMM) staff (Steve Whitt, Nuwan Wijerusiya) and Kimley-Horn and Associates, Inc. (KHA) staff (Chad Evcnhouse, Todd St. John) on July 24, 2009 to discuss NCDWQ's questions. Response to Comments The following underlined items follow the bulleted and numbered questions/requests listed in the June 30, 2009 letter. "rhe discussion and response includes the discussion and resolution for each issue per the project meeting held on July 24, 2009 with NCDWQ. Calculations to show the cone influence As was discussed at the July 24, 2009 meeting with NCDWQ, the cone of the Selma Quarry is expected to be limited and similar to other hard -rock quarries located in the North Carolina Piedmont Physiographic Region. Martin Marietta Materials (MMM) utilized the attached hydrogeologic study, which was prepared to evaluate cone of influence of piedmont hard -rock quarries. MMM proposes to plan a 500-ft radius from the pit as an appropriate approximation of influence to surficial hydrology. Settling Pond Sizing — (MMM) Pond sizing; and information and calculations are included in the Mine Plan details submitted with the permit application. Selma O&M Plan_response_9-3l 2009.doc Page I A Level Spreader Design and Calculations Level spreader design and locations are included with the Mine Plan details for sediment basins. Level spreaders necessary to meet Neusc River Riparian Buffer requirements and 401 Water Quality Certification requirements will be presented to the Town of Selma and Atny Chapman with the NCDWQ 401 Unit for review and approval. Per the July 24, 2009 meeting, all submittals and approvals will be copied to Lauren Witherspoon for inclusion in the NPDES permit project file. Description of measures to prevent erosion and flooding The Mine Plan includes measures for sediment and erosion control for land disturbance activities per Division of Land Resources requirements. With regards to potential erosion due to dewatering discharge, the Mine Plan designates two areas for pit clarification ponds which will receive mine dewatering water. Pond I is located upslope of Wetland 2, a headwater wetland associated with Stream 3. Pond 2 is located upslope of Stream 2. It is anticipated that most of the water in the clarification ponds will be utilized for operations of the plant (i.e. dust suppression) for the initial years of mine development. Surplus dewatering water will discharge from Pond I via a spillway/control structure and into a plunge pool to provide diffuse flow towards the headwater wetland. Pond 2 will be maintained as an infiltration basin (i.e. no surface discharge) providing hydration to Stream 2. The management of dewatering water and discharge/seepage from these clarification ponds will use an adaptive management plan (Appendix A) depending on the actual volume of water generated from dewatering and amount needed for plant operations. MMM anticipates two scenarios: Scenario 1 — '['lie volume of water needed for the plant operations exceeds volume of water generated from dewatering. Under this condition, the adaptive management plan will require that the pit clarification ponds be maintained at a minimum level to allow for seepage from the ponds to the adjacent stream or wetland system. Scenario 2 — The volume of water from dewatering exceeds the water needs for the plant operation. Under this condition, Pond 2 water level will be maintained at a constant level via a diversion valve from Pond Iin order to maintain infiltration and hydration towards Stream 2. Pond 1 will discharge all surplus water through an energy dissipater/plunge pool providing diffuse flow into Weiland 2. if the volume of discharge into Wetland 2 is too great and/or constant, this could potentially cause concentrated flow and erosion of a channel, or channels through the wetland. If so, under the adaptive management plan, MMM will expand the clarification ponds for additional storage and infiltration, and/or provide for surplus water to be discharged to the abandoned borrow pit within the southern portion of the property, or other appropriate areas within the property. The adaptive management plan is attached (Appendix A), and a summary of the management activities per the plan, as well as condition of the discharge locations and monitoring areas, and volume of discharge will be included in the annual report. Selma O&M Plan_ resp6nse_8.31-2009.doc Pagc 2 With regards to potential flooding, a flood study was prepared for the project and presented to the Town of Selina demonstrating that the proposed project complies with City and County floodplain development ordinances. A copy of the flood study can be provided upon request. Annual Report An annual report will be submitted to NCDWQ within the first quarter of the following year (i.e. prior to March 31), summarizing the monitoring; results and adaptive management activities throughout the previous year. Monitoring gage data logger's will collect daily measurements and will be down loadcd/inspected periodically throughout the year. A qualitative assessment of the monitoring locations, clarification ponds, and outlet structures will be performed during all inspections. A summary of all monitoring data and site assessment inspections will be provided in the annual report. Restoration Plan Wetlands and streams adjacent to the mine will be hydrated through the adaptive management plan and management of mine dewatering discharge while dewatering activities are on -going. Once the dewatering ceases and the mine is abandoned, MMM will implement the approved Mine Reclamation Nan per North Carolina Division of Land Resources (NCDLR) requirements. 0&M Plan Comments Wetland 4 Wetland 4 is a broad wetland within the Neuse River floodplain that ties adjacent to the toc- of-slope of an upland terrace along a significant meander bend of the river. Hydrology of this large wetland system is likely dominated by flooding and flood storage associated with the river. The initial pit development within the project area is approximately 2,500 feet from the nearest portion of this wetland boundary. Therefore, the initial pit shown in the Mine PIan and initial dewatering activities are not likely to affect the water balance of Wetland 4 considering the available source hydrology from the river, and distance of groundwater influence from the wetland. However, at the July 24, 2009 meeting, MMM was agreed, that once the pit advanced to within 500 feet of the wetland, then the dcwatering from the pit may have a hydrologic effect on the adjacent wetland. Therefore, MMM proposed, and NCDWQ agreed that MMM would install three wetland monitoring gages in Wetland 4 once the pit had advanced to within 600 feet from the permitted pit limit (approximately 1,000 feet from the wetland boundary). These future monitoring locations will be added to the Mine Plan. a. Monitoring for wetland hydrology will be initiated once the pit is within 600 feet from the permitted pit limit in the direction of Wctland 4. This will provide for sufficient background data before the pit advances within 500 feet from the wetland. In the future, the annual report will document installation of these monitoring wells and will include recommendations for adaptive management measures for dewatering discharge as needed at that time. Selina 0&M Plan_responsc_8-3 ] ?009.doc Page 3 b. The intent for monitoring at the Selma Quarry will be to demonstrate that the adjacent stream and wetland features will continue to maintain hydrologic functions during the life of mining and dewatering activities. All wetland monitoring wells will be installed per U.S. Army Corps of Engineers (Corps) guidance for evaluating wetland hydrology (ERDC-TN-WRAP-05-2, June 2005), These wells will typically be three to three and a half feet deep, screened to within the upper six inches, and capped with a bentonite seal. A monitoring gage/data logger will be used to collect daily water level measurements. The gages will be inspected and downloaded on a quarterly basis. Sununary analysis and qualitative assessment will be provided in the annual report, A flow meter to record base flow and/or periodic flow events will be installed in the upper portion of Stream 2 to demonstrate that the intermittent stream maintains hydrologic functions. Corps guidance and technical specifications for a representative monitoring gage are included in Appendix B. c. All mine dewatering will be pumped by sump from the pit and directed to the pit clarification ponds as described above. Stream 1, Wetland 1, Wetland G 1. As discussed at the July 24, 2009 meeting, MMM will provide a copy of the hydrogeologic Study supporting the assumption that the cone of influence in the upper surface adjacent to the pit will be 500 feet, typical of other piedmont hard -rock quarry operations. 2. As discussed at the July 24, 2009 meeting with NCDWQ, Wetland 6 is a portion of a broader wetland area within the Neuse River floodplain and is hydrated by flooding and flood storage, The pit wall is not planned to ever be within 1,000 feet from this area. Also, Stream 2, which will receive hydration through the management of dewatering discharge, will provide an effective hydraulic barrier to groundwater influence. With these considerations, it was agreed that monitoring at this location would not be necessary. Wetland 1 is located more than 2,000 feet from the proposed pit limit, however, NCDWQ expressed concern that the construction of the stockpile area/berm adjacent to the wetland would effectively cut off surface runoff towards this area and would negatively affect wetland hydrology. MMM agreed that a wetland monitoring well would be installed at the wetland boundary in this area prior to the construction of the berm. The installation, monitoring, and documentation of this monitoring location would be included in the monitoring program discussed above. The future location for monitoring in this area will be shown in the Mine Plan. Wetland 2/Stream 3/Wetland 3 1. Wetland 2/Stream 2 will be hydrated by the adaptive management plan for dewatering discharge as discussed above. a. Discharge will be dissipated using a plunge pool at the outlet of Pool 1 providing diffuse overland flow upslope of Wetland 2. If site inspections demonstrate that the volume of water discharged into the system is likely to cause degradation, then the discharge Selma O&M Plan_responsc_8-31-2009.doc Page 4 volume to Pond 1 will be reduced through expanding clarification pond capacity, and/or directing flow to other areas within the project as discussed above. b. Sufficient hydrology provided to the wetland (i.e. wetland/stream hydrologic functions are sustained) will be demonstrated through the monitoring program, and any identified deficiencies will be addressed through the adaptive management plan as discussed above. c. Calculations are unknown at this time since the actual volume of dewatering is unknown and will change as the mine site develops depending on the rate of expansion of the pit and water needs of the operation. MMM's adaptive management plan will maintain hydrologic function in the adjacent strea►n/wetland systems per NCDWQ's requirements, however, actual quantity of discharge and water use are unknown at this time. 2. Wetland monitoring locations will be added to the Mine Plan map as discussed at the July 24, 2009 meeting with NCDWQ. Process Area The discharge from the process area will be addressed through the Stormwater Plan and developed with review from the Town of Selma and NCDWQ 401 Unit. As currently shown, the discharge from the process area will be treated through a constructed wetland stormwater BMP and will provide diffuse flow upslope of the regulated buffer. Additional future BMP locations are show to demonstrate that treatment areas will be added in the future as needed to meet stormwater requirements as the site expands and develops. Constructed Wetland The proposed constructed wetland is located upslope of Wetland 6. There is an area shown as a potential future BMP location in this area, however, the Mine Plan will be amended to remove this area from the Mine Plan. Future BMP locations will be added as needed and the Mine Plan amended through coordination with NCDLR as the mine develops I the future. Level Spreaders 1. Level spreaders are incorporated with sediment basins per NCDLR requirements and are shown in the Mine Plan. Stormwater discharge will be addressed through the Stormwater Permit review process with the Town of Selma and the NCDWQ 401 Unit. Diffused flow for mine dewatering discharge will be accomplished through the use of the dissipater/plunge pool upslope of Wetland 2 as discussed above. 2. Level spreader and plunge pool calculations and details are included in the Mine Plan. 3. Compliance with riparian buffer regulations will be addressed through the stormwater review process with the Town of Selma and NCDWQ 401 Unit. 4, Discharge from the clarification ponds will be directed as discussed above. Initial plans are for Pond 1 to be an infiltration basin only and will not discharge surface water. Pond 2 will discharge diffused flow towards Wetland 2 as discussed. Sehnia 0&M Plan_response 8-31-2009.doc Pagc 5 Large -Scale Plans 1. Monitoring gage locations have been added to the Mine Plan. 2. All discharge from the plant area will be addressed through the Stormwater Plan review with the Town of Selma and the NCDWQ 401 Unit. The discharge will likely be directed to Stream I and/or the floodplain area near Wetland 6 and will comply with all applicable Neuse River nutrient requirements and buffer rules. 3. Discharge locations for the clarification ponds as discussed above have been added to the Mine Plan. 4. The constructed wetland has been sized and located to treat the initial 27.1 acres of development for the plant and stockpile area (Phased development). The constructed wetland is shown in uplands and does not impact Wetland 6. There is a future BM.P location shown in the area of Wetland 6. This future BM will be moved to another location and the Mine Plan has been amended. 5. The labels of wetlands and stream have been added to the Mine Plan consistent with the 0&M plan. 6. The monitoring locations (initial and future) have been added to the Mine Plan. Stream 3 shown in the Mine Plan has been amended to be consistent with the Corps' approved delineation. Other 1. Vehicle maintenance areas have been noted on the Mine Plan. A flood study demonstrating that the proposed project meets local floodplain development ordinances has been completed, and MMM coordinated with Town of Selina and FEMA through the zoning process for the property. A copy of the flood study is available upon request. 3. The Stormwater Plan is in development and will be reviewed by the local approved stormwater program (Town of Selma) and the NCDWQ 401 Unit. A copy of the approved Stormwater Plan and agency correspondence will be provided to Lauren Witherspoon for the NPDES permit file. 4. The Selma Quarry site does not include asphalt or ready -mix concrete operations. 5. The project boundary shown in the Mine Plan is the correct boundary. The 0&M plan is amended to show the correct area. 27.1 acres represents the initial portion of development of the plant area. This area represents the impervious area to be initially developed through a phased development process. MMM will provide additional water quality treatment to meet stormwater requirements for the site as the site develops. This will be addressed through the Stormwater Plan review process with the Town of Selma and the NCDWQ 401 Unit. Sclma O&M Plan_responsc_8-31-2009.doc Pagc 6 7. There will be non -erosive velocities to all wetlands and streams from stormwatcr and mine dewatering discharge. S. The closed -loop system shown is for plant processes, and was discussed at the December 19, 2008 meeting with NCDWQ (Ken Pickle, Jennifer Jones, Danny Smith, Lauran Witherspoon, and Ian McMillan). It was agreed that this area would not be considered an "other" type of recycle system and would not require Authorization to Construct. 9. Monitoring will be conducted per the adaptive management plan (Appendix A) and will be documented in the annual report submitted to NCDWQ. a. Monitoring gage installation for the initial locations will be implemented upon approval of the NPDES permit. Future locations will be installed per the adaptive management plan as discussed above. b. Wells will be monitored as long as dewatering activities are on -going at the site and will be documented per the adaptive management plan. If changes to the monitoring program are identified through implementation of the adaptive management plan, MMM will coordinate with NCDWQ to modify the monitoring program as needed. c. Monitoring data will be maintained and documented per the adaptive management plan as discussed above. d. Monitoring data will be summarized and an annual report submitted to the region as discussed above. 10. Discharge rates and calculations have been previously provided by MMM in the original NPDES permit application. The Mine Plan has been amended to clearly show all outfalls. End Solnu O&M Plan_responsc_8-31-2009.doc 11age 7 Adaptive Management Plan - Selma (quarry The following Adaptive Management Plan for the Selma Quarry is prepared to meet the following requirements: 1. Maintain hydrologic functions of wetlands and streams within 500 feet from the pit so that these features are not adversely affected by dewatering activities associated with the aline operation. 2. Maintain water level in pit clarification ponds, as needed, to provide hydration to designated wetlands/streams as shown in the Mine Plan. 3. Maintain non -erosive discharge to receiving wetlands and streams per the Operation and Maintenance (O&M) Plan, NPDES permit, and Mine Plan. 4. Maintain hydrologic monitoring per the O&M plan. During initial site development but prior to excavation of consolidated material in the initial pit area, MMM will implement hydrologic monitoring per the O&M plan. MMM will perform the following on a quarterly basis: a Hydrologic Monitoring Locations o Manual Download of monitoring gages (gages collect daily water level or periodic flow measurements as noted in O&M Plan) o Visual inspection of monitoring area to identify any changes to the natural community. Once excavation of consolidated material begins and the pitlplant areas have been established, the on -site Plant Manager will be inspect the following on a mo_ nthly basis: a Clarification portd(s) water level o Maintained at designated levels for hydration a Clarification pond and stormwater BMP outlet structures o Stability at the structure, and non -erosive flows to down slope areas. If the Plan Manager identifies any areas of concern related to the requirements above, he/she will notify MMM Environmental Staff to implement corrective actions. Corrective Actions -- All corrective actions will be approved by MMM Environmental Staff to be consistent with the O&M plan and NPDES/Stormti.ater Permit requirements. Corrective actions will be documented to the file for inclusion in the annual report. Wetlands Regulatory Assistance Program ERDC TN-WRAP-05-2 .tune 2005 Technical Standard for Water -Table Monitoring of Potential Wetland Sites by U.S. Army Corps of Engineers PURPOSE: This technical note describes national standards for the collection, analysis, interpretation, and reporting of hydrologic data, which may be used to help determine whether wetlands are present on disturbed or problematic sites that may be subject to Clean Water Act regulatory jurisdiction. "These standards may be supplemented or superseded by locally or regionally developed standards at the discretion of the appropriate Corps of Engineers District. BACKGROUND: Wetland determinations in the majority of cases are based on the presence of readily observable field indicators of hydrophytic vegetation, hydric soils, and wetland hydrology, according to procedures given in the Corl)s of Engineers Wetlands Delineation iVfanual (environmental Laboratory 1987) (hereafter called the Corps Manual). These three characteristics are the best available evidence that an area has performed in the past, and continues to perform, the functions associated with wetland ecosystems. The Corps Manual (Part IV, Section F, Atypical Situations) recognizes that wetland determinations on some sites may be diliicult because of human disturbance that may have altered or destroyed wetland indicators. In addition, some naturally occurring wetland types may lack indicators or may have indicators present only at certain times of year or during certain years in a multi -year cycle (Part IV, Section G, Problem Areas). Wetland determinations in these atypical and problem situations increasingly involve the use of direct hydrologic monitoring to confirm the presence of wetlands in cases where soils or vegetation have been significantly disturbed or are naturally problematic, or where the hydrology of the site has been altered recently such that soil and vegetation indicators may give a misleading impression of the site's current wetland status. The Corps Manual provides only a general discussion of wetland hydrology concepts and does not provide a suitable standard that can be used to design a hydrologic monitoring study or interpret hydrologic data, particularly in cases where groundwater is an important water source. Therefore, the purpose of this Technical Standard is to provide a minimum standard for the design, construction, and installation of water -table monitoring wells, and for the collection and interpretation of groundwater monitoring data, in cases where direct hydrologic measurements are needed to determine whether wetlands are present on highly disturbed or problematic sites. USE OF THE TECHNICAL STANDARD: The Technical Standard is intended for use in atypical and problem situations as described in the Corps Manual. Atypical situations are broadly defined as any wetlands where indicators of hydrophytic vegetation; hydric soil, or wetland hydrology may be lacking due to recent human activities or natural events. Problem areas are wetlands that may lack wetland indicators at certain times due to normal variations in environmental conditions. '['his standard is designed to determine a site's current hydrologic status and may not be appropriate for evaluating past or pre -disturbance conditions. ERDC TN-WRAP-05-2 June 2005 This standard should not be used to overrule a wetland determination based on indicators of hydrophytic vegetation, hydric soil, and wetland hydrology on sites that are not significantly disturbed or problematic. Wetland indicators reflect natural processes that occur in wetlands and generally provide the best evidence that functioning wetlands are present on a site. The actual hydrologic regime required to produce and maintain a wetland may vary locally and regionally due to climate. landforms, geology, soils, and plant and animal adaptations. Therefore, any wetland hydrologic standard is necessarily an approximation and should be used only when an indicator - based wetland determination is not possible or would give misleading results. In addition, this standard is not intended to overrule other scientific evidence that particular regional or local wetland types may be associated with hydrologic conditions different from those described here, including the seasonal timing, depth, duration, and frequency of saturation. Standards used to verify wetland hydrology in such cases should be based on the best available scientific information concerning a particular local or regional wetland type. The Technical Standard is designed solely to determine the location of the water table for wetland jurisdictional purposes. It should not be used for water -duality monitoring or other purposes. This national standard may be supplemented or superseded by locally or regionally developed standards at the discretion of the District, and well -documented and justi f ied deviations from the standard are acceptable with the approval of the District. It is always good practice to discuss the goals and design of the monitoring study with Corps regulatory personnel before initiating work. This may help to avoid disagreements and problems of interpretation later. This standard is subject to periodic review and revision as better scientific information becomes available. SITE CHARACTERIZATION: A detailed site characterization should be completed before initiating the groundwater monitoring program. Site information is needed to determine appropriate well locations; installation depths, and other design features. The site characterization should begin with a review of all pertinent off -site information including county soil surveys, topographic maps, aerial photographs, and National Wetland Inventory (NWI) maps, if available. This review should be lollowed by afield investigation to verify the off -site information and gather additional data. At a minimum, the following site information should be collected (see Warne and Wakeley (2000) for detailed guidance): • Detailed site map showing the location of property and project -area bollllCarieS (determine coordinates of boundary points and landmarks, if possible). • Topographic map showing the watershed boundary, water features (e.g., lakes, streams, minor drainages), and direction of water movement across the site. • Current vegetation and land use. • Detailed description of any modifications to site hydrology (e.g., water diversions or additions including ditches; subsurface drains. dams. berms, channelized streams; irrigation. modified surface topography, etc.). • Soil profile descriptions including locations of soil test pits (indicate on site map and determine coordinates, if possible). ERDC TN-WRAP-05-2 June 2005 Soil profile descriptions are an important part of the site characterization because they may dictate appropriate depths for installation of water -table monitoring wells. Of critical importance is the identification of soil strata that can restrict downward water movement and create a perched water table. Examples of soil strata that may produce perched water tables include fragipans, spodic horizons, argillic horizons, and shallow bedrock. Ilia shallow restrictive soil layer is identified, care must be taken during well installation to ensure that the layer is not penetrated. Penetration of the restrictive layer may result in misleading water -level readings. Sol] profile descriptions should include horizon depths and (for each horizon) information about texture, color, induration (cementation), redoximorphic features, and roots, so that significant differences in permeability can be evaluated (Sprecher 2000). A blank Soil Characterization Data Form is provided for this purpose (Appendix A). Soil profiles must be described at least to the anticipated installation depth of the wells; profile descriptions to 24 in. or more are rccommended. Several soil characteristics indicate that downward water flow may be impeded and that perched water tables may exist. Features to note include the following (Sprecher 2000): • Abrupt change from many roots to few or no roots. • Abrupt change in soil texture. • Abrupt change in ease of excavation. • Abrupt change in water content, such as presence of saturated soil horizons immediately above soil horizons that are dry or only moist. • Redoximorphic features at any of the distinct boundaries listed above. WELL PLACEMENT: A detailed discussion of monitoring well placement within the project site is beyond the scope of this Technical Standard. In general, well placement depends on the objectives of the investigation and characteristics of the site. If the objective is to determine whether wetland hydrology is present at a particular point, a single well may be sufficient. However, multiple wells may be necessary to determine if wetland hydrology occurs on a complex site where topography and human alterations (e.g., road construction, ditching) have produced considerable hydrologic variation. Well locations and depths are dictated by site conditions including topographic relief and the depth and continuity of restrictive soil layers. Portions of a site that are most likely to meet wetland hydrology standards (e.g., low-lying areas such as depressions, floodplain backwaters, swales and washes, fringes of lakes and ponds, toes of slopes, or other areas with shallow restrictive soil layers) should be identified during site characterization and considered for well placement. If the objective is to confirm wetland boundaries based on groundwater measurements, then multiple wells installed along transects perpendicular to the expected wetland boundary are needed (Figure 1). The number and spacing of wells along each transect depend on the topographic gradient and the precision needed in defining the wetland boundary. Other site information that may help in placing wells and identifying boundaries includes changes in topographic gradient, proximity to hydrologic alterations (e.g., ditches), and changes in soil characteristics or vegetation. 3 ERDC TN-WRAP-05-2 June 2005 T9 — — — Expected Boundary Transect �` 0 Monitodnq Well T7 N ♦ T2 ♦ B 1 T6* A ` I � � > T3 i T5 � r T4 Figure 1. Example of monitoring wells located along transects across the expected wetland boundary. Transects extend from obvious upland to obvious wetland. Two or more wells are needed along each transect (e.g., at locations A and B). MONITORING WELL CONSTRUCTION: Inmost cases, a standard monitoring well installed to a depth of 15 in. below the soil surface should be used to measure water -table depth on potential wetland sites. Shallower installation depths may be needed if restrictive soil layers exist within 15 in. of the surface. Monitoring wells must not penetrate any such restrictive layer. The standard design is for a well installed by angering. Depending upon site conditions, wells installed by driving may also be acceptable (see the section on Monitoring Well Installation). Installation of one or more additional deeper (4-5 ft) wells at each site is also encouraged to help in interpreting water -table fluctuations and warn of sudden changes in water -table depth. Deeper wells are not required but; if used, should not penetrate any restrictive soil layers. The performance of all wells must be tested and verified before use. Monitoring Well Components. A standard monitoring well installed by augering is shown in Figure 2 and consists of the following main components: well screen, riser, well caps, sand filter pack, and bentonite sealant. Specifications for each of these components are given below. 4 ERDC TN-WRAP-05-2 June 2005 Vented Well Cap (Loosely 1-inch Fitted) Diameter Well Stock Bentonite/Soil Mixture Ground Surface J Riser a inches ' Bentonite Seal 1 1 1 1 1 11 1 1 1 Inch I111111t 111111,' 11 1 1 1 1 1 1 1 Augered Hole 11 1 1 1 1 1 7 1 411l1l1l1 1lf if �It illll1111 1111111/ f I'IEll it 1lftll!! 1IFI!lFkE I,111111 I I,�,�fll 11111111 Well Screen 1;I;lil;l t,tlllll ' 15 inches 11111�111 I�fll�ll I l l l l I I 1 1 , 111111[t ,II11111 I l l l i I I 1 1 11'f'!IE I'r /'tl f t ! E 1 ! Sand Filter rack I il'1'1'1 1'I/f 1' 1;1 1 �1111111 Ill�lifl 111111111 I1111111 111 IIIFIFII I I11f �111 11111111 1!! 4 l I I 1 1 f; 1; I t Well Cap with I�t'teF 1,'ll{' Drain Hole E 1'1'1'1 1 1 1 1 1 1 1'1'III 11111111111111111lltllllllll I llllllllllllllli'Itllllllll 3 inches Figure 2. Standard 15-in. monitoring well installed by augering 61 ERDC TN-WRAP-05-2 June 2005 Well Stock. Shallow monitoring wells should be made from commercially manufactured well stock. Schedule 40, ]-in. inside diameter PVC pipe is recommended. The diameter of the pipe allows sufficient room for hand measurement of water levels while minimizing well volume and maximizing responsiveness to water -table changes. The small diameter also minimizes auger hole diameter, volume of the filter pack, and the quantity of' bentonite needed to seal the bore hole. However, ifsrequired by automated water -level recorders; then 2-in.-diam pipes can be substituted. Well stock larger than 2 in. in diameter should be avoided. Well Screen and Bottom Cap. Recommended slot opening and slot spacing for the well screen are 0.010 in. and 0.125 in., respectively. The slotted screen should extend from approximately 5 in. below the ground surface down to the bottom of the well. Hand -slotted or drilled well screens Should not be used. One problem with the use of commercial well screen for very shallow monitoring wells is that there often is a length of unslotted pipe and joint or threads below the screen. In shallow monitoring situations, this extra length often must be inserted into underlying soil material that should be left undisturbed. In combination with a commercial well point, this extra length also provides a reservoir where water can remain trapped after the outside groundwater has dropped, resulting in the potential ofmisleading or incorrect readings during water -table drawdown. To avoid this problem, commercial well screen should be cut to the desircd length within the slotted portion of the pipe. A PVC cap should be glued at the bottom of the screen and a small drain hole should be drilled in the bottom cap (Figure 2). Riser. The riser is the unslotted PVC pipe that extends from the top of the wel I screen to above the ground surface (Figure 2). The riser should extend far enough above the ground to allow easy access but not so high that the leverage of normal handling will crack below -ground seals. In locations that do not pond or flood, 9 to 12 in. above the ground surface is usually sufficient. A longer riser may be needed on inundated sites or where automatic recording devices are used. Well Top Cap. A well cap is required to protect the top of the well from contamination and rainfall. Caps should be attached loosely so they can be removed easily without jarring ordislodging the well, or cracking the bentonite seal. Tiglit-fitting caps, either threaded or unthreaded, should be avoided because they may seize to the riser and require rough handling to remove. A suitable well cap can be constructed from a short length of PVC pipe of a larger diameter than the riser, with a glued PVC cap at one end (Sprecher 2000). The constructed well cap can be attached loosely to the riser by drilling a hole through both the cap and the riser and connecting the two with a wire lock pin. The cap should be vented to allow equilibration of air pressure inside and outside of the well. Filter Pack. A filter pack is placed around the well screen to remove fine particles and provide a zone of high hydraulic conductivity that promotes water movement toward the well (Figure 2). Filter packs can be classified into two major categories, natural and artificial. Natural packs are created by manually repacking any excavated soil around the well screen, ensuring that large voids are absent. Natural packs are recommended in coarse -textured, sandy soils. In fine -textured soils, an artificial pack should be used. See 'fable I for recommendations on the use of Filter packs f-or soils of different textures. A Commercially available silica sand is recommended for use as artificial pack material and is usually well - sorted, well-rounded, clean, chemically inert, and free of all fine-grained clays, particles, and organic material. Silica sand is available from water -well supply houses in uniformly graded sizes. Sand that passes a 20-mesh screen and is retained by a 40-mesh screen (20-40 sand) is recommended with a 0.010-in. well screen. Bentonite Sealant. Bentonite is a type of clay that absorbs large quantities of water and swells when wetted. It is used in well installation to form a tight seal around the riser to prevent water from running down the outside of the pipe to the well screen. With this protective plug, only groundwater enters the slotted well screen. When installing a monitoring well, 4 in, of bentonite should be placed around the riser immediately at and below the ground surface (Figure 2). This 4-in. ring of bentonite rests directly on top of the filter pack ERDC TN-WRAP-05-2 June 2005 Table 1 USDA Soil Texture Classes and Recommendations for Sand Filter Packs USDA Soil Texture Sand Pack Muck, Mucky Peat, Peat None Coarse Sand None Medium Sand None Fine Sand None Loamy Sand None Sandy Loam Recommended Loam Recommended Silt Loam Recommended Silt Recommended Sandy Clay Loam Required Silty Clay Loam Required Clay Loam Required Sandy Clay Required Silty Clay Required Clay I Required around the well screen. Above the bentonite ring, additional bentonite mixed with natural soil material should be mounded slightly and shaped to slope away from the riser so that surface water will run away from the pipe rather than pond around it at the ground surface. Bentonite is available from well drilling supply companies in powder, chip, or pellet form. Chips are easiest to use in the field. They can be dropped directly down the annular space above the sand filter pack. If this zone is already saturated with water, the chips will absorb water in place, swell tight, and seal off the sand filter from above. 1 f the bentonite chips are dropped into a dry annular space, they should be packed dry and then water should be added down the annular space so the clay can swell shut. Modified Well Design for Clay Soils. In heavy clay soils, such as Vertisols. water movement occurs preferentially along cracks and interconnected large pores. These cracks may deliver water to a standard monitoring- well through its vertical. slotted walls. Even when the surrounding soil is unsaturated, water may remain in the well for days due to impeded drainage into the slowly permeable clay. This problem can be reduced, but not eliminated, by using a well that is slotted or open only at the bottom. In addition, the sand filter pack should be installed only around the immediate well opening and should not extend up the riser. The annular space around the riser should be packed with the natural clay soil material or filled with bentonite. Because Vertisols in wetland situations tend to be episaturated (i.e., they perch water at or near the surface but may remain unsaturated below), monitoring should focus on detection of surface ponding 7 ERDC TN-WRAP-05-2 June 2005 and saturation in the upper few inches of the so I. For this purpose, wells shorter than 15 in. may be needed. MONITORING WELL INSTALLATION Installation Methods. The recommended method for installing shallow monitoring wells involves the use ofa bucket auger with an outside diameter 2 in. greater than the well diameter (e.g., 3 in. for a standard I -in. well). As an alternative, wells may be installed by driving them into the ground. Driven wells may be preferred in areas with noncohesive coarse -grained (sandy) soils, rocky soils (e.g., glacial tills), or in saturated organic materials (i.e., mucks or peats). Procedures for both installation methods are given below. No matter which installation method is selected, wells must be tested for performance before being used. These procedures assume that the soil profile at the well location has already been described and that the appropriate wel I depth (i.e., 15 in. or less) has been determined based on the presence or absence of'restrictive soil layers. A Monitoring Well Installation Data Form (Appendix 13) should be completed to document the design and installation of` each well (Sprecher 2000). Augering. Recommended equipment includes a bucket auger 2 in. larger than the diameter ofthe well being installed. a tamping tool (e.g., wooden or metal rod), bentonite chips, silica sand, and the constructed monitoring well. A pump or bailer may be needed to test the well after instal lation. ']'he following procedure is used to install the well: 1. Auger a hole in the ground to a depth approximately 2 in. deeper than the bottom of the well. Be sure the hole is vertical. 2. Scarify the sides of the hole if it was smeared during angering. 3. Place 2 to 3 in. of silica sand in the bottom of the hole. 4. Fora 15-in. well with 10 in. of well screen, make a permanent mark on the well riser 5 in. Above the top of the screen. Insert the well into the hole to the proper depth; the permanent mark oil the riser should be even with the soil surface. Do not insert through the sand. 5. Pour and gently tamp more of the same sand in the annular space around the screen and i in. above the screen. 6. Pour and gently tamp 4 in. of bentonite chips above the sand to the ground surface. I f necessary, add water to cause the bentonite sealant to expand. 7. Form a low mound of`a soil/bentonite mixture on the ground surface around the base of the riser to prevent surface water from puddling around the pipe. Driving. Well installation by driving is recommended when site conditions prevent angering (e.g., noncohesive sandy soils, soils with many coarse fragments; saturated organic soils). in addition, driven wells are acceptable whenever their performance can be shown to be equivalent to that of an angered well. Plans to use driven wells for regulatory purposes should be discussed in advance with the appropriate Corps of Engineers District office. ERDC TN-WRAP-05-2 June 2005 A driven well is similar in design and construction to the angered well described previously, with the addition of a well point in place of the bottom cap (Figure 3). Well points arc commercially available and can be vented to permit draining by drilling a hole in the bottom. A special driving tool may be needed to install the well without damaging the PVC pipe. 1-inch Diameter Well Stock r Ground Surface � ✓ice 4 inches 15 inches Vented Well Cap (Loosely Fitted) Bentonite/Soil Mixture � `` �'� � Riser Bentonite Seat Well Screen Well Point with Drain Hole Figure 3. Standard 15-in. monitoring well installed by driving ERDC TN-WRAP-05-2 June 2005 Required materials include bentonite chips and the constructed monitoring well with vented well point. A pump or bailer may be needed to test the well after installation and, depending on site conditions, a driving device may be required. The following procedure is used to install the well: . For a standard 15-in, well, make a permanent mark on the riser 15 in. above the bottom of the well screen. With the well cap removed, use a driving device to drive the well vertically into the ground until the mark is at the ground surface. Inorganic soil materials, the well may simply be pushed into the ground. 2. Dig out a ring of soil around the well riser to a depth of in. Fill this space with bentonite chips and add water; if necessary, to form a tight seal. 3. Form a low mound of a soil/bentonite mihture on the ground surface around the base of the riser to prevent surface water from puddling around the pipe. Establishing Riser Height. Water -level measurements are typically recorded as the "depth to water" from the top of the well riser. The depth of the water table below the ground surface is determined by subtracting the riser height from the "depth to water" measurement. Therefore, after installing the well, measure and permanently record the height of the riser above the ground surface. if automated water -level recording devices are used, follow the manufacturer's instructions for calibration of water -level readings relative to the ground surface. Riser height should be checked after soils have thawed in spring, and should be re -checked periodically when water -table measurements are taken or electronic data are downloaded. Surface Water. In areas subject to flooding or ponding, a separate staff' gauge or automated device is required to measure the depth of surface water. MONITORING WELL TESTING AND MAINTENANCE: During well installation, particularly with driven wells, tine soil particles may clog the well screen, impeding water flow and increasing the response time ofthe well. The performance of the well should be tested by (i) emptying the well by pumping or bailing and monitoring how quickly the water level returns to the initial level, or (2) if the well is dry, filling it with water and monitoring the rate of outflow. The water level in the well Should reestablish itself at approximately the same rate as it would in a freshly dug hole without any pipe. In soils with a high percentage of clay, this could require several hours. if the water does not return to the initial level in a reasonable amount of time, pull the instrument out of the ground, clean it, reinstall it, and retest it. If water -table readings are questionable at any time during the monitoring period, one option is to move some distance away from the well location, auger to the depth in question, and determine whether the water level in the auger hole is the same as that indicated by the monitoring well. Routine Maintenance. Monitoring well responsiveness should be tested at the beginning of the monitoring period and at least every 2-3 months thereafter by the procedure described above, because wells can plug over time due to bacterial growth and movement of fine soil particles. Well performance can also be affected by cracking of the bentonite seal, sediment deposition in the well, and movement of the ground surface and/or monitoring well due to frost heaving or shrink -swell action. To ensure accurate water -level readings, check for vertical displacement of the well after spring thaw and periodically during sampling by re -measuring the height of the riser above the ground surface and adjusting water -table measurements or resetting the well, as needed. 10 ERDC TN-WRAP-05-2 June 2005 MAKING WATER -LEVEL MEASUREMENTS: Water levels in monitoring wells should be measured with an accuracy of t0.25 in., if possible. Measurements may be made manually or with automated equipment- The use of automated water -level recorders is recommended unless an uninterrupted schedule of frequent site visits can be maintained. Automated recorders are also recommended in areas with highly variable or flashy hydrology. Whichever method is selected, it should be used consistently throughout the duration of the monitoring study. Manual Readings. Water -level measurements can be made easily with a steel measuring tape marked with chalk or a water-soluble marker. Another approach is to use an electric device that sounds or flashes when the sensor, attached to the end of a graduated tape, makes contact with the water. Measurement devices that displace large amounts of water (e.g., dowel rods) should not be used. Automated Readings. Automated recording devices record water levels with down -well transducers or capacitance -based sensors. An important consideration when purchasing automatic recording devices is the ability to compensate internally for variations in barometric pressure. These variations can be significant in wetland determinations. Automated equipment is more costly than hand measurement, but the devices can be used again in future studies. The credibility of monitoring results is enhanced with the high frequency of water -level readings that automated wells allow. Automated water -level recorders should be checked frequently for accuracy by comparison with manual readings. if automated readings are not within instrument specifications, the device should be recalibrated. Required Timing, Frequency, and Duration of Readings. Water -level measurements must be taken at least once each day, beginning 5-7 days before the first day of the growing season and continuing until the end of the growing season or until the minimum standard for wetland hydrology is met that year. I f automated recorders are used, readings four times per day are recommended (use the lowest reading; cacti day). On sites subject to flooding or ponding, depth of surface water must be measured each day that water -table readings are made. Growing season beginning and ending dates shall be based on the median dates (i.e.. 5 years in 10. or 50 percent probability) of 28 OF air temperatures in spring and fall as reported in WETS tables provided by the USDA-NRCS national Water and Climate Center. WETS tables are based on long- term temperature data collected at National Weather Service (N WS) cooperative weather stations throughout the United States and are available on the Internet at http:f/www.wee.nres.usda.Bov/ climate/wetlands.html. For a particular project site, growing season information from the nearest available weather station should be used unless, due to elevation or other factors, a more distant weather station is considered to be more representative of conditions at the project site. Alternative local or regional procedures for determining growing season dates may be used at the District's discretion. 4 Because hydrologic conditions are naturally variable, many years of groundwater monitoring data may be needed to establish what is typical for a given site. This is particularly true in the arid western United States where rainfall can be sparse, unpredictable, and Highly localized, In general, ten or more years of water -table monitoring data may be needed to determine whether minimum standards for water -table depth, duration, and frequency in wetlands are met. However, because long; -term monitoring is often impractical in a regulatory context. short-term studies may provide 11 ERDC TN-WRAP-05-2 .tune 2005 sufficient information if the normality of precipitation during the monitoring period is considered. Determining `'normal" rainfall is addressed in the following section. ANALYSIS AND INTERPRETATION OF MONITORING DATA Technical Standard for Wetland Hydrology. Wetland hydrology is considered to be present on an atypical or problem site if the following standard is met: The site is inundated (flooded or ponded) or the water table is <_12 inches heloii, the soil surface for >J4 conseculive days during the growing season at a minimum_fYequency of 5 years in 10 (>_50% probahilily). Any combination of inundation or shallow 14'aler table is acceptable in meeting,=!hc 14-day minimum requirement. Shorl-term monitoring data may he used to address the frequency requirement if the normality ofrainfall occurring prior to and during- the monitoring period each year is considered The Corps Manual discusses wetland hydrology in general, but does not provide a wetland hydrology criterion suitable for use in interpreting monitoring well data. The standard given above is based on recommendations by the National Academy of Sciences (National Research Council 1995). By requiring a water table within 12 in. of the surface, this standard ensures that saturation by free water or the capillary fringe occurs within the "t-najor portion of the root zone" described in the Manual. A 14-day minimum duration standard is assumed to apply nationwide unless Corps Districts have adopted a different standard at the local or regional level. The Corps Manual addresses the need for long-term data (10 or more years) in analyses of stream -gauge data but does not consider the use of short-term data in wetland determinations, nor does it address the frequency issue in relation to water -table monitoring. This Technical Standard allows the use of short-term monitoring data to address the frequency requirement for wetland hydrology, if the normality of rainfall is considered. The depth to saturation depends both on the position of the water table and the height of the tension - saturated capillary fringe (National Research Council 1995). While its presence has an influence on both plant growth and soil features, the upper limit of the capillary fringe is difficult to measure in the field and impractical as a basis for hydrologic monitoring. The Technical Standard for Wetland Hydrology is based on the depth of the water table because, in most cases, water -table depth can be monitored readily and consistently through the use of shallow wells with either manual or automated data collection. Water -table measurements should not be corrected for a capillary fringe unless other evidence, such as tensiometer readings, laboratory analysis of soil water content, or evidence ofsoil anoxia, indicates that the height of the saturated capillary fringe is greater than a few inches. Determining Normal Precipitation. Short-term water -table monitoring data (i.e., <10 years) must be interpreted in relation to the amount of precipitation that fell during and for at least 3 months prior to the monitoring period each year. This is done by comparing the precipitation record for a given year with the normal range of precipitation based on long-term records collected at the nearest appropriate NWS cooperative weather station. The USDA-NRCS National Water and Climate Center calculates normal precipitation ranges for each month (defined as between the 30"' and 701" percentiles of monthly precipitation totals) for NWS stations throughout the United States. The information is published in WETS tables available on the Internet (http://www.wcc.nros. usda.govlcI imatelwedand s.htm l). 12 J ERDC TN-WRAP-05-2 June 2005 Sprecher and Warne (2000, Chapter 4) describe three methods for evaluating precipitation normality within a given year. The First method is taken from the NRCS Engineering Field Handbook (Natural Resources Conservation Service 1997) and involves the direct application of WETS tables in relation to monthly rainfall totals at the project site. At a minimum, this method shall be used to determine whether rainfall was normal immediately before and during a groundwater monitoring study. The analysis should focus on the period leading up to and during the time when water tables are usually high in that climatic region. In many parts of the country, this is at the beginning of'the growing season, when precipitation is abundant and evapotranspiration is relatively low. The second method described by Sprecher and Warne (2000) evaluates daily precipitation data on the basis of 30-day rolling stuns, and the third method combines the two procedures, if daily precipitation data are available, the combined method is recommended. The evaluation of precipitation normality should include the three months prior to the start of the growing season and extend throughout the entire monitoring period each year. For many wetlands, water tables in a given year may be affected by precipitation that occurred in previous years, especially if monitoring occurs after an extended period of drought or precipitation excess. After a series of dry years, for example, it may take several years of normal or above -normal rainfal I to recharge groundwater and return water tables to normal levels. 'Therefore, in evaluating wetland hydrology based on short-term monitoring, it is necessary to consider the normality of rainfall over a period of years prior to the groundwater study. Recent precipitation trends can be determined by comparing annual rainfall totals at the monitoring site with the normal range given in WETS tables for two or more years prior to the monitoring study, or by examining trends in drought indices, such as the Palmer Drought Severity Index (Sprecher and Warne 2000). This issue may not be important in soils with perched water tables that respond to the current year's rainfall and dry out seasonally. Interpreting Results. Iften or more years of water -table monitoring data are available for a site, the long-term record probably includes years of normal, below normal, and above normal precipitation and thus reflects the average hydrologic conditions on the site. Therefore, wetland hydrology can be evaluated directly by the following procedure: l . For each year, determine the maximum number of consecutive days that the site was either inundated or the water table was <_12 in. from the ground surface during the growing season. Wetland hydrology occurred in a given year if the number of consecutive days of inundation or shallow water tables was >_14 days. 2. The Technical Standard for Wetland Hydrology was met if wetland hydrology occurred in at least 50 percent of years (i.e., >_5 years in 10). This procedure may not be appropriate during extended periods of drought or precipitation excess. Furthermore, in some regions with highly variable precipitation patterns (e.g., the arid West) more than ten years of groundwater monitoring data may be needed to capture the typical hydrologic conditions on a site. If fewer than ten years of water -table data are available, then the normality of precipitation preceding and during the monitoring period must be considered. One option is to apply the procedures described in the section on "Determining Normal Precipitation" foreach yearthat water tables were monitored. In addition, annual precipitation or drought severity indices should be 13 ERDC TN-WRAP-05-2 June 2005 evaluated for two or more years prior to the monitoring period on any site that lacks a perched water table. Wetland hydrology can then be evaluated by the following procedure: I . Select those years of monitoring data when precipitation was normal, or select an equal number of wetter -than -normal and drier -than -normal years. 2. 1 f'wetland hydrology (i.e., any combination of inundation or water tablc <l 2 in. from the surface for >_l4 consecutive days during the growing season) occurred in �:50 percent of years (e.g... 3 years in 5), then the site most likely meets the Technical Standard for Wetland Hydrology. It is important to remember that, even in normal rainfall years, many wetlands will lack wetland hydrology in some years due to annual differences in air temperatures (which affect evapotranspiration rates) and the daily distribution of rainfal I that are not considered in this analysis. This is particularly true of borderline wetlands that may have shallow water tables in only 50-60 percent of years. Therefore, this procedure may fail to identify some marginal wetlands. Another option, particularly for very short -duration monitoring studies (e.g., <_3 years), is to evaluate water -table measurements in conjunction with groundwater modeling. Hunt ct al. (200I) described one such approach, called the Threshold Wetland Simulation (TWS), which uses the DRAINMOD model. Actual water -table measurements in a given year are compared with those of a simulated, threshold wetland (i.e., one that meets wetland hydrology requirements in exactly 50 percent of years). The TWS approach requires detailed long-term precipitation and temperature data, soil characteristics, and considerable expertise with the DRAINMOD program. No method to determine wetland hydrology based on short-term water -table measurements is entirely reliable or free of assumptions. 'Therefore, ultimate responsibility for the interpretation of water -table monitoring data rests with the appropriate Corps District. REPORTING OF RESULTS. Warne and Wakeley (2000) provided a comprehensive checklist of information that should be included in the report of a groundwater monitoring study. The report should also include a justification for any deviations from procedures given in this Technical Standard. The report should include a clear, graphical presentation of daily water -table levels at each well plotted over time and shown in relation to the soil surface and the 12-in. depth, the depth of the monitoring wel L growing season starting and ending dates, local precipitation that year, and normal precipitation ranges based on WETS tables. Another useful feature is a diagram of the soil profile at the well location including depths and textures ofeach major horizon. An example graph with many of these features is shown in Figure 4 (Sprecher 2000). ACKNOWLEDGMENTS: The initial outline for this Technical Standard was developed at a workshop in Decatur. GA, in September 2003. Participants (in alphabetical order) were Mr. William Ainslie, U.S. Environmental Protection Agency (USEPA), Region 4; Mr. Bradley Cook. Minnesota State University, Mankato; Mr. Jason Hill, 'Tennessee Tech University (7"TU); Ms. Julie Kelley, Geotechnical and Structures Laboratory (GSL), U. S. Army Engineer Research and Development Center (ERDC); Dr. Barbara Kleiss; Environmental Laboratory (EL), ERDC; Dr. Vincent Neary, TTU; Mr. Chris Noble, EI_-ERDC; Dr. Bruce Pruitt, Nutter and Associates. Inc.; Dr. Thomas Roberts, TTU; Mr. Paul Rodrigue, USDA Natural Resources Conservation Service (NRCS); 14 • ERDC TN-WRAP-05-2 June 2005 Monitoring Well Record Columbus OH Area Wetland Site 1997 "aa name: CdurrMra OH Range of Nw" Pradpnadon: Columbus Airport, Franklin County OH WETS Tabu General location: ♦ Moodily Predpltatian Totals from Cdumbus Airport wS Statlon Ffr" County, OH J D*y PredpiMon flan CA.M.rs Airport WS Sfaban Well nAnWnumbcr: 3 a Y"r. Tg97 Number ofyears of record: 3.5 Frowency of water level readinpa: Twin daily Organization responsible for water level readings: Y Local Consufring Rim t Description of well: 1 Automefed "N,, ?' IO PVC, -43' deep P�+e rlaftad Ihrorrglforrt, with n annulus era bantanka alai of surface srr "I Delpbon: Gro Eldeen Sill t. u AP: 7iW Wm � � Lsvel A. Sla bem IN an: Cif loam M. cloybam BC: Gov"a� �yOrhm. yyd1q�,; Jan Feb Mar Apr May Jun Jul Aug Sop od Nov Dec •�`in: t GrowingSeason --�� A. Example filled out 0 cad I 30-0Day Rolling Figure 4. Example of graphical presentation of water -table monitoring data (Note that this example uses a deeper well than the 15 in. specified in this Technical Standard) Dr. Steven Sprecher; U. S. Army Engineer (USAE) District, Detroit, and Dr. James Wakeley, EL- ERDC. The first draft was written by Drs. Ncary and Wakeley and Messrs. Hill and Noble. Technical reviewers included Harry Baij, Jr., USAE District. Anchorage: Mark Clark,.-NRCS: David D'Amore, U. S. Forest Service (USES); Jackie DeMontigny, USES; Michiel Holley, USAE District, Anchorage; Wesley Miller, NRCS; James Miner. Illinois State Geological Survey; Joe Moore, NRCS; Dr. Chien-LLI Ping, University of Alaska, Fairbanks; Ann Puffer, USFS; and Ralph Rogers, USEPA Region 10. A subcommittee of the National "Technical Committee i'or I-lydric Soils (NTCHS) provided an independent peer review in accordance with Oft -ice of Management and Budget guidelines. The authors are grateful to NTCHS members Drs. Michael Vepraskas and R. Wayne Skaggs, North Carolina State University: and Mr. Ed Blake, Mr. 1". Michael Whited, Ms. Lenore Vasilas, and Mr. G. Wade Hurt, NRCS, for their comments and suggestions. The work was supported by Headquarters, U. S. Army Corps of Engineers through the Wetlands Regulatory Assistance Program (WRAP). POINTS OF CONTACT: For additional information, contact Dr. James S. Wakeley, U. S. Army Engineer Research and Development Center (ERDC), Vicksburg, MS, (601-634-3702, ,Iames,S,Wakele a,erdc.rrscrce.army.mio or the Program Manager of the Wetlands Regulatory 15 ERDC TN-WRAP-05-2 June 2005 Assistance Program, Mr. Bob Lazor (601-634-2935. Bob. L.La, ora,erdc,usace.armu.mi!). This technical note should be cited as follows: U. S. Army Corps of Engineers. (2005). "Technical Standard for Water -''able Monitoring of Potential Wetland Sites," WRAP Technical Noles Collection (ERDC TN- WRAP-05-2), U. S. Army Engineer Research and Development Center, Vicksburg; MS. REFERENCES Environmental Laboratory. (1987). "Corps of Engineers Wetlands Delineation Manual," Technical Report Y-87-1, U.S. Army Engineer Waterways Experiment Station, Vicksburg. MS. (Annotated on-line version available at http://el.erdc.usace.army.mil/elptibs/12df/wltnan87.pdD Hunt, W. F., III, Skaggs, R. W. Chescheir, G. M., and Amatya, D. M. (2001). "Examination of the Wetland Hydrologic Criterion and its Application in the Determination of Wetland Hydrologic Status," Report No. 333, Water Resources Research Institute of the University of North Carolina, North Carolina State Univ._- Raleigh. National Research Council. (1995). "Wetlands: Characteristics and Boundaries," National Academy Press. Washington, DC. Natural Resources Conservation Service. (1997), "Hydrology tools for wetland determination," Chapter 19, Engineering field handhook, Donald E. Woodward, ed., USDA-NRCS, I ort Worth. TX. (littp://www.infO.usda.gov/Cl ❑/ftpICED/EFH-CliI9.pdD Sprecher, S. W. (2000). "Installing monitoring wells/piezometers in wetlands," WRAP Technical Notes Collection, ERDC TN-WRAP-00-02, U.S. Army Engineer Research and Development Center, Vicksburg, MS. (httpJ/el.erdC._usace.army,mil/Cl2Libs/pdf/tnwrap00-2.p.df) Sprecher, S. W., and Warne. A. G. (2000). "Accessing and using meteorological data to evaluate wetland hydrology," Technical Reporl TR-WRA P-00- I, U.S. Army Engineer Research and Development Center, Vicksburg, MS. (http://el.erde.usace.army.mil/elaubslndfhvra_p00-I/wrap00-Lyd-O Warne, A. G., and Wakeley, J. S. (2000). "Guidelines for conducting and reporting; hydrologic assessments of potential wetland sites;" 111R,4P 'Technical A'otes Collection, ERDC TN-WRAP-00-01, U.S. Army Engineer Research and Development Center, Vicksburg, MS. (htip://el.erdc.usace.ann, e1 pubs/pdf/tnwrap00-1. pd f) NOTE': The contents of this technical note are not to be userlfor ach,ertising. publication, or pronrolional purposes. Citation of trade names does not constitute an ofticial endorsement or approval of the use of such products. 16 ERDC TN-WRAP-05-2 June 2005 APPENDIX A. SOIL CHARACTERIZATION DATA FORM Soil Characterization Data Form Project Name Personnel Date Soil Pit ID Horizon Depths (inches) Texture Matrix Color (Munsell moist) Redoximor hic Features Induration (none, weak, strop) Roots Color Abundance Comments: 17 ERDC TN-WRAP-05-2 June 2005 APPENDIX B. MONITORING WELL INSTALLATION DATA FORM Monitoring Well Installation Data Form Project Name Date of Installation Project Location Personnel Well Identification Code Attach map of project, showing well locations and significant topographic and hydrologic features. Characteristics of Instrument: Source of instrurrent/well stock Material of well stock Slot width Kind of well cap Installation: Was well installed by augering or driving? Kind of filter sand Depth to lowest screen slots Was bentonite wetted for expansion? Method of measuring water levels in instrument How was instrument checked for clogging after installation? Diameter of pipe Slot spacing Kind of well point/end plug Kind of bentonite Riser height above ground Instrument Diagram' Soil Characteristics Texture Matrix Color Redoximorphic Features Induration (none, weak, strop Roots Color Abundance aShow depths (heights) of riser, well screen, sand pack, and bentonite in relation to soil horizons. 18 ®®Kimley-Horn and Associates, Inc. T e c h n i c a l M e m o r a n d u m To: Mr. Steven S. Whitt; Mr. Nuwan Wijesuriya Martin Marietta Materials Prepared by: Chad Evenhouse, PWS; Kimley-Horn and Associates, Inc. Date: August 31, 2009 Subject: Response to NCDWQ Request for Information (June G, 2009) and Summary of NCDWQ meeting on July 24, 2009 regarding NCG020735 Selma Quarry, Johnston County Introduction The following ]memorandum is prepared to address the North Carolina Division of Water Quality (NCDWQ) request for more information regarding the Selma Quarry NPDES permit application (GP No. NCG020735, letter dated June 30, 2009) and the subsequent project meeting held between NCDWQ staff (Jennifer Jones, Danny Smith, Lauren Witherspoon), Martin Marietta Materials (MMM) staff (Steve Whitt, Nuwan Wijerusiya) and Kimley-Horn and Associates, Inc. (KHA) staff (Chad Evenhouse, Todd St. John) on July 24, 2009 to discuss NCDWQ's questions. Response to Comments The following; underlined items follow the bulleted and numbered questions/requests listed in the June 30, 2009 letter. The discussion and response includes the discussion and resolution for each issue per the project meeting held on July 24, 2009 with NCDWQ. Calculations to show the cone influence As was discussed at the July 24, 2009 meeting with NCDWQ, the cone of the Selina Quarry is expected to be limited and similar to other hard -rock quarries located in the North Carolina Piedmont Physiographic Region. Martin Marietta Materials (MMM) utilized the attached hydrogeologic study, which was prepared to evaluate cone of influence of piedmont hard -rock quarries. MMM proposes to plan a 500-ft radius from the pit as an appropriate approximation of influence to surficial hydrology. Settling Pond Sizing — [MMM] Pond sizing and information and calculations are included in the Mine Plan details submitted with the permit application. Selma O&M Plan_response_B-31-2009.doc Page ] Level Spreader Design and Calculations Level spreader design and locations are included with the Mine Plan details for sediment basins. Level spreaders necessary to meet Meuse River Riparian Suffer requirements and 401 Water Quality Certification requirements will be presented to the Town of Selma and Amy Chapman with the NCDWQ 401 Unit for review and approval. Per the July 24, 2009 meeting, all submittals and approvals will be copied to Lauren Witherspoon for inclusion in the NPDES permit project file. Description of measures to prevent erosion and flooding The Mine Plan includes measures for sediment and erosion control for land disturbance activities per Division of Land Resources requirements. With regards to potential erosion due to dewatering discharge, the Mine Plan designates two areas for pit clarification ponds which will receive mine dewatering water. Pond 1 is located upslope of Wetland 2, a headwater wetland associated with Stream 3. Pond 2 is located upslope of Stream 2. It is anticipated that most of the water in the clarification ponds will be utilized for operations of the plant (i.e. dust suppression) for the initial years of mine development. Surplus dewatering water will discharge from fond 1 via a spillway/control structure and into a plunge pool to provide diffuse flow towards the headwater wetland. Pond 2 will be maintained as an infiltration basin (i.e. no surface discharge) providing hydration to Stream 2. The management of dewatering water and dischargelscepage from these clarification ponds will use an adaptive management plan (Appendix A) depending on the actual volume of water generated from dewatering and amount needed for plant operations. MMM anticipates two scenarios: Scenario I —The volume of water needed for the plant operations exceeds volume of water generated from dewatering. Under this condition, the adaptive management plan will require that the pit clarification ponds be maintained at a minimum level to allow for seepage from the ponds to the adjacent stream or wetland system. Scenario 2 —The volume of water from dewatering exceeds the water needs for the plant operation. Under this condition, Pond 2 water level will be maintained at a constant level via a diversion valve from Pond I in order to maintain infiltration and hydration towards Stream 2. Pond 1 will discharge all surplus water through an energy dissipater/plunge pool providing diffuse flow into Wetland 2. If the volume of discharge into Wetland 2 is too great and/or constant, this could potentially cause concentrated flow and erosion of a channel, or channels through the wetland. If so, under the adaptive management plan, MMM will expand the clarification ponds for additional storage and infiltration, and/or provide for surplus water to be discharged to the abandoned borrow pit within the southern portion of the property, or other appropriate areas within the property. The adaptive management plan is attached (Appendix A), and a summary of the management activities per the plan, as well as condition of the discharge locations and monitoring areas, and volume of discharge will be included in the annual report. Selma 0&M Nan_response_8-31-2009.doe Page 2 With regards to potential flooding, a flood study was prepared for the project and presented to the Town of Selina demonstrating that the proposed project complies with City and County floodplain development ordinances. A copy ofthe stood study can be provided upon request. Annual Report An annual report will be submittcd to NCDWQ within the first quarter of the following year (i.e. prior to March 31), summarizing the monitoring results and adaptive management activities throughout the previous year. Monitoring gage data loggers will collect daily measurements and will be downloaded/inspected periodically throughout the year. A qualitative assessment of the monitoring locations, clarification ponds, and outlet structures will be performed during all inspections. A sununary of all monitoring data and site assessment inspections will be provided in the annual report. Restoration Plan Wetlands and streams adjacent to the mine will be hydrated through the adaptive management plan and management of mine dewatering discharge while dewatering activities are on -going. Once the dewatering ceases and the mine is abandoned, MMM will implement the approved Mine Reclamation Plan per Forth Carolina Division of Land Resources (NCDLR) requiremcnts. O&N4 flan Comments Wetland 4 1. Wetland 4 is a broad wetland within the Neuse River floodplain that lies adjacent to the toc- of-slope of an upland terrace along a significant meander bend of the river. Hydrology of this large wetland system is likely dominated by flooding and flood storage associated with the river. The initial pit development within the project area is approximately 2,500 feet frorn the nearest portion of this wetland boundary. Therefore, the initial pit shown in the Mine flan and initial dewatering activities are not likely to affect the water balance of Weiland 4 considering the available source hydrology from the river, and distance of groundwater influence from the wetland. However, at the July 24, 2009 meeting, MMM was agreed, that once the pit advanced to within 500 feet of the wetland, then the dewatering from the pit may have a hydrologic effect on the adjacent wetland. Therefore, MMM proposed, and NCDWQ agreed that MMM would install three wetland monitoring gages in Wetland 4 once the pit had advanced to within 600 feet from the permitted pit limit (approximately 1,000 feet from the wetland boundary). These future monitoring locations will be added to the Mine flan. a. Monitoring for wetland hydrology will be initiated once the pit is within 600 feet from the permitted pit limit in the direction of Wetland 4. This will provide for sufficient background data before the pit advances within 500 feet from the wetland. In the future, the annual report will document installation of these monitoring wells and will include recommendations for adaptive management measures for dewatering discharge as needed at that time. Selma O&M Plan_response_8-33-2009.doc Page The intent for monitoring at the Selma Quarry will be to demonstrate that the adjacent stream and wetland features will continue to maintain hydrologic functions during the life of mining and dewatcring activities. All wetland monitoring wells will be installed per U.S. Army Corps of Engineers (Corps) guidance for evaluating wetland hydrology (ERDC-TN-WRAP-05-2, June 2005). These wells will typically be three to three and a half feet deep, screened to within the upper six inches, and capped with a bentonite seal. A monitoring gagc/data logger will be used to collect daily water level measurements. The gages will be inspected and downloaded on a quarterly basis. Summary analysis and qualitative assessment will be provided in the annual report. A flow meter to record base flow and/or periodic flow events will be installed in the upper portion of Stream 2 to demonstrate that the intermittent stream maintains hydrologic functions. Corps guidance and technical spccilications for a representative monitoring gage are included in Appendix B. c. All mine dewatering will be pumped by sump from the pit and directed to the pit clarification ponds as described above. Stream 1. Wetland 1, Wetland 6 1. As discussed at the July 24, 2009 meeting, MMM will provide a copy of the hydrogeologic study supporting the assumption that the cone of influence in the upper surface adjacent to the pit will be 500 feet, typical of other piedmont hard -rock quarry operations. As discussed at the July 24, 2009 meeting with NCDWQ, Wetland 6 is a portion of a broader wetland area within the Neuse River floodplain and is hydrated by flooding and flood storage. The pit wall is not planned to ever be within 1,000 feet from this area. Also, Stream 2, which will receive hydration through the management of dewatering discharge, will provide an effective hydraulic barrier to groundwater influence. With these considerations, it was agreed that monitoring at this location would not be necessary. Wetland 1 is located more than 2,000 feet from the proposed pit limit, however, NCDWQ expressed concern that the construction of the stockpile area/berm adjacent to the wetland would effectively cut off surface runoff towards this area and would negatively affect wetland hydrology. MMM agreed that a wetland monitoring well would be installed at the wetland boundary in this area prior to the construction of the berm. The installation, monitoring, and documentation of this monitoring location would be included in the monitoring program discussed above. The future location for monitoring in this area will be shown in the Mine Plan. Wetland 2/Stream 3/Wetland 3 1. Wetland 2/Stream 2 will be hydrated by the adaptive management plan for dewatering discharge as discussed above. a. Discharge will be dissipated using a plunge pool at the outlet of Pool 1 providing diffuse overland flow upslope of Wetland 2. If site inspections demonstrate that the volume of water discharged into the system is likely to cause degradation, then the discharge Selma O&M Plan_response_8-31 2009,dor Page 4 volume to Pond l will be reduced through expanding clarification pond capacity, and/or directing flow to other areas within the project as discussed above. b. Sufficient hydrology provided to the wetland (i.e. wetland/stream hydrologic functions are sustained) will be demonstrated through the monitoring program, and any identified deficiencies will be addressed through the adaptive management plan as discussed above. c. Calculations are unknown at this time since the actual volume of dewatering is unknown and will change as the mine site develops depending on the rate of expansion of the pit and water needs of the operation. MMM's adaptive management plan will maintain hydrologic function in the adjacent stream/wetland systems per NCDWQ's requirements, however, actual quantity of discharge and water use are unknown at this time. 2. Wetland monitoring locations will be added to the Mine Plan map as discussed at the July 24, 2009 meeting with NCDWQ. Process Area The discharge from the process area will be addressed through the Stormwater Plan and developed with review from the Town of Selma and NCDWQ 401 Unit. As currently shown, the discharge from the process area will be treated through a constructed wetland storin water BMP and will provide diffuse flow upslope of the regulated buffer. Additional future BMP locations are show to demonstrate that treatment areas will be added in the future as needed to mcet stormwater requirements as the site expands and develops. Constructed Wetland The proposed constructed wetland is located upslope of Wetland 6. There is an area shown as a potential future BMP location in this area, however, the Mine Plan will be amended to remove this area from the Mine Plan. Future BMP locations will be added as needed and the Mine Plan amended through coordination with NCDLR as the mine develops I the future. Level Spreaders 1. Level spreaders are incorporated with sediment basins per NCDLR requirements and are shown in the Mine Plan. Stormwater discharge will be addressed through the Stormwater Permit review process with the Town of Selma and the NCDWQ 401 Unit. Diffused flow for mine dewatering discharge will be accomplished through the use of the dissipater/plunge pool upslope of Wetland 2 as discussed above. 2. Level spreader and plunge pool calculations and details are included in the Mine Plan. 3. Compliance with riparian buffer regulations will be addressed through the stormwater review process with the Town of Selma and NCDWQ 401 Unit. 4. Discharge from the clarification ponds will be directed as discussed above. Initial plans are for Pond I to be an infiltration basin only and will not discharge surface water. Pond 2 will discharge diffused flow towards Wetland 2 as discussed. Selma 0&M Plan_responsc_8-31-2004.doc Page 5 Laree-Scale Plans 1. Monitoring gage locations have been added to the Mine Plan. All discharge from the plant area will be addressed through the Stormwater Plan review with the Town of Selina and the NCDWQ 401 Unit. The discharge will likely be directed to Stream 1 and/or the floodplain area near Wetland 6 and will comply with all applicable Neuse River nutrient requirements and buffer rules. 3. Discharge locations for the clarification ponds as discussed above have been added to the Mine Plan. 4. The constructed wetland has been sized and located to treat the initial 27.1 acres of development for the plant and stockpile area (Phased development). The constructed wetland is shown in uplands and does not impact Wetland 6. There is a future BMP location shown in the area of Wetland 6. This future BMP will be moved to another location and the Mine Plan has been amended. 5. The labels of wetlands and stream have been added to the Mine Plan consistent with the O&M plan. 6. The monitoring locations (initial and fixture) have been added to the Mine Plan. 7. Stream 3 shown in the Mine Plan has been amended to be consistent with the Corps' approved delineation. Other 1. Vehicle maintenance areas have been noted on the Mine Plan. A flood study demonstrating that the proposed project meets local floodplain development ordinances has been completed, and MMM coordinated with Town of Selma and FEMA through the zoning process for the property. A copy of the flood study is available upon request. The Stormwater Plan is in development and will be reviewed by the local approved stormwater program (Town of Selma) and the NCDWQ 401 Unit. A copy of the approved Stormwater Plan and agency correspondence will be provided to Lauren Witherspoon for the NPDLS permit file. 4. The Selma Quarry site does not include asphalt or ready -mix concrete operations. 5. The project boundary shown in the Mine Plan is the correct boundary. The O&M plan is amended to show the correct area. 27.1 acres represents the initial portion of development of the plant area. This area represents the impervious area to be initially developed through a phased development process. MMM will provide additional water quality treatment to meet stormwater requirements for the site as the site develops. This will be addressed through the Stormwater Plan review process with the Town of Selma and the NCDWQ 401 Unit. Selma O&M Plan_responsc_8-31-2009.doc Page 6 7. "There will be non -erosive velocities to all wetlands and streams from stormwater and mine dewatering discharge. 8. The closed -loop system shown is for plant processes, and was discussed at the December 19, 2008 meeting with NCDWQ (Ken Pickle, Jennifer Jones, Danny Smith, Lauran Witherspoon, and Ian McMillan). It was agreed that this area would not be considered an "other" type of recycle system and would not require Authorization to Construct. 9. Monitoring will be conducted per the adaptive management plan (Appendix A) and will be documented in the annual report submitted to NCDWQ. a. Monitoring gage installation for the initial locations will be implemented upon approval of the NPDES permit. Future locations will be installed per the adaptive management plan as discussed above. b. Wells will be monitored as long as dewatering activities are on -going at the site and will be documented per The adaptive management plan. If changes to the monitoring program are identified through implementation of the adaptive management plan, MMM will coordinate with NCDWQ to modify the monitoring program as needed. c. Monitoring data will be maintained and documented per the adaptive management plan as discussed above. d. Monitoring data will be summarized and an annual report submitted to the region as discussed above. 10. Discharge rates and calculations have been previously provided by MMM in the original NPDES permit application. The Mine Plan has been amended to clearly show all outfalls. End Selma O&M Plan_responsc_6-31.2009.doc Page 7 Adaptive Management Plan - Selma Quarry The following Adaptive Management flan for the Selma Quarry is prepared to meet the following requirements: 1. Maintain hydrologic functions of wetlands and streams within 500 feet from the pit so that these features are not adversely affected by dewatering activities associated with the mine operation. 2. Maintain water level in pit clarification ponds, as needed, to provide hydration to designated wetlands/streams as shown in the Mine Plan, 3. Maintain non -erosive discharge to receiving; wetlands and streams per the Operation and Maintenance (O&M) Plan, NPDES permit, and Mine Plan. 4. Maintain hydrologic monitoring per the O&M plan. During initial site development but prior to excavation of consolidated material in the initial pit area, MMM will implement hydrologic monitoring per the O&M plan. MMM will perform the following on a quarterly basis: o Hydrologic Monitoring Locations o Manual Download of monitoring gages (gages collect daily water level or periodic flow measurements as noted in O&M Plan) o Visual inspection of monitoring area to identify any changes to the natural community. Once excavation of consolidated material begins and the pit/plant areas have been established, the on -site Plant Manager will be inspect the following on a monthly basis: G Clarification pond(s) water level o Maintained at designated levels for hydration Y Clarification pond and storunwater BMP outlet structures o Stability at the structure, and non -erosive flows to down slope areas. Ifthe Plan Manager identifies any areas of concern related to the requirements above, he/she will notify MMM Environmental Staff to implement corrective actions. Corrective Actions — All corrective actions will he approved by MMM Environmental Staff to be consistent with the O&M plan and NPDES/Stormwater Permit requirements. Corrective actions will be documented to the file for inclusion in the annual report. Wetlands Regulatory Assistance Program ERDC TN-WRAP-05-2 June 2005 Technical Standard for Water -Table Monitoring of Potential Wetland Sites by U.S. Army Corps of Engineers PURPOSE: This technical note describes national standards for the collection, analysis, interpretation, and reporting of hydrologic data, which may be used to help determine whether wetlands are present on disturbed or problematic sites that may be sr.ibjcct to Clean Water Act regulatory jurisdiction. These standards maybe supplemented or superseded by locally or regionally developed standards at the discretion of the appropriate Corps of Engineers District. BACKGROUND: Wetland determinations in the majority of cases are based on the presence of readily observable field indicators of hydrophytic vegetation, hydric soils, and wetland hydrology, according to procedures given in the Corps ref Engineer's P"ellancls Delineation Mannal (Cnvironmental Laboratory 1987) (hereafter called the Corps Manual). These three characteristics are the best available evidence that an area has performed in the past, and continues to perlorm, the functions associated with wetland ecosystems. The Corps Manual (Part IV, Section l=, Atypical Situations) recognizes that wetland determinations on some sites may be diffiClllt because of human disturbance that may have altered or destroyed wetland indicators. In addition, some naturally occurring wetland types may lack indicators or may have indicators present only at certain times of year or during certain years in a multi -year cycle (Part IV, Section G, Problem Areas). Wetland determinations in these atypical and problem situations increasingly involve the use of direct hydrologic monitoring to confirm the presence of wetlands in cases where soils or vegetation have been significantly disturbed or are naturally problematic, or where the hydrology of the site has been altered recently such that soil and vegetation indicators may give a misleading impression of the site's current wetland status. The Corps Manual provides only a general discussion of wetland hydrology concepts and does not provide a suitable standard that can be used to design a hydrologic monitoring study or interpret hydrologic data, particularly in cases where groundwater is an important water source. Therefore, the purpose of this Technical Standard is to provide a minimum standard for the design, construction, and installation of' water -table monitoring wells, and for the collection and interpretation oi�groundwater monitoring data, in cases where direct hydrologic measurements are needed to determine whether wetlands are present on highly disturbed or problematic sites. USE OF THE TECHNICAL STANDARD: The Technical Standard is intended for use in atypical and problem situations as described in the Corps Manual. Atypical situations are broadly defined as any wetlands where indicators of hydrophytic vegetation, hydric soil, or wetland hydrology may be lacking due to recent human activities or natural events. Problem areas are wetlands that may lack wetland indicators at certain times due to normal variations in environmental conditions. This standard is designed to determine a site's current hydrologic status and may not be appropriate for evaluating past or pre -disturbance conditions. ERDC TN-WRAP-05-2 June 2005 `I'his standard should not be used to overrule a wetland determination based on indicators of hydrophytic vegetation, hydric soil, and wetland hydrology on sites that are not significantly disturbed or problematic. Wetland indicators reflect natural processes that occur in wetlands and generally provide the best evidence that functioning wetlands are present on a site. The actual hydrologic regime required to produce and maintain a wetland may vary locally and regionally due to climate, landforms, geology, soils, and plant and animal adaptations. Therefore, any wetland hydrologic standard is necessarily an approximation and should be used only when an indicator - based wetland determination is not possible or would give misleading results. In addition, this standard is not intended to overrule other scientific evidence that particular regional or local wetland types may be associated with hydrologic conditions different from those described here, including the seasonal timing, depth, duration, and frequency of saturation. Standards used to verify wetland hydrology in such cases should be based on the best available scientific Inlormatlon concerning a particular local or regional wetland type. The Technical Standard is designed solely to determine the location of the water table for wetland jurisdictional purposes. it should not be used for water -quality monitoring orother purposes. ']'his national standard may be supplemented or superseded by locally or regionally developed standards at the discretion of the District, and well -documented and justif led deviations from the standard are acceptable with the approval of the District. It is always good practice to discuss the goals and design of the monitoring study with Corps regulatory personnel before initiating work. This may help to avoid disagreements and problems of interpretation later. This standard is subject to periodic review and revision as better scientific information becomes available. SITE CHARACTERIZATION: A detailed site characterization should be completed before initiating the groundwater monitoring program. Site information is needed to determine appropriate well locations, installation depths, and other design features. The site characterization should begin with a review of all pertinent off -site information including county soil surveys, topographic maps, aerial photographs, and National Wetland Inventory (NWi) maps, if available. This review should be followed by a field investigation to verify the off -site information and gather additional data. At a minimum, the following site information should be collected (see Warne and Wakeley (2000) for detailed guidance): • Detailed site map showing the location of property and project -area boundaries (determine coordinates of boundary points and landmarks, if possible). • Topographic map showing the watershed boundary, water features (e.g., lakes, streams, minor drainages), and direction of water movement across the site. • Current vegetation and land use. • Detailed description ofany modifications to site hydrology (e.g., water diversions or additions including ditches, subsurface drains, dams, berms, channelized streams., irrigation, modified surface topography, etc.). • Soil profile descriptions including locations of soil test pits (indicate on site map and determine coordinates, if possible). ERDC TN-WRAP-05-2 June 2005 Soil profile descriptions are an important part of the site characterization because they may dictate appropriate depths for installation of water -table monitoring wells. Of critical importance is the identification of soil strata that can restrict downward water movement and create a perched water table. Examples of soil strata that may produce perched water tables include fragipans, spodic horizons, argil lic horizons, and shal low bedrock. l f a shallow restrictive soi I layer is identified, care must be taken during well installation to ensure that the layer is not penetrated. Penetration of the restrictive layer may result in misleading water-lcvel readings. Soil profile descriptions should include horizon depths and (for each horizon) information about texture, color,, induration (cementation), redoximorphic features, and roots, so that significant differences in permeability can be evaluated (Sprecher 2000). A blank Soil Characterization Data Form is provided for this purpose (Appendix A). Soil profiles must be described at least to the anticipated installation depth of the wells; profile descriptions to 24 in. or more are recommended. Several soil characteristics indicate that downward water flow may be impeded and that perched water tables may exist. Features to note include the following (Sprecher 2000): • Abrupt change from many roots to few or no roots. • Abrupt change in soil texture. • Abrupt change in case of excavation. • Abrupt change in water content, such as presence ofsaturated soil horizons immediately above soil horizons that are dry or only moist. • liedoximorphic features at any of the distinct boundaries listed above. WELL PLACEMENT: A detailed discussion of monitoring well placement within the pro icct site is beyond the scope of this Technical Standard. in general, well placement depends on the objectives of the investigation and characteristics of the site_ 1 f the objective is to determine whether wetland hydrology is present at a particular point, a single well may be sufficient. However, multiple wells may be necessary to determine if wetland hydrology occurs on a complex site where topography and human alterations (e.g., road construction, ditching) have produced considerable hydrologic variation. Well locations and depths are dictated by site conditions including topographic relief and the depth and continuity of restrictive soil layers. Portions of a site that are most likely to meet wetland hydrology standards (e.g., low-lying areas such as depressions, floodplain backwaters, swales and washes, fringes of lakes and ponds, toes ol'slopes, or other areas with shallow restrictive soil lavers) should be identified during site characterization and considered for well placement. I f the objective is to confirm wetland boundaries based on groundwater measurements, then multiple wells installed along transccts perpendicular to the expected wetland boundary are needed (Figure 1). The number and spacing of wells along each transect depend on [fie topographic gradient and the precision needed in defining the wetland boundary. Other site information that may help in placing wells and identifying boundaries includes changes in topographic gradient, proximity to hydrologic alterations (e.g., ditches), and changes in soil characteristics or vegetation. ERDC TN-WRAP-05-2 June 2005 T1 Tl l T6 I — — — Expected Boundary Transect • Monitoring Well T2 '� B A l � i T3 T5 TA Figure 1. Example of monitoring wells located along transects across the expected wetland boundary. Transects extend from obvious upland to obvious wetland. Two or more wells are needed along each transect (e.g., at locations A and B). MONITORING WELL CONSTRUCTION: In most cases, a standard monitoring well installed to a depth of 15 in. below the soil surface should be used to measure water -table depth on potential wetland sites. Shallower installation depths may be needed i frestrictive soil layers exist within 15 in. ofthe surface. Monitoring wells must not penetrate any such restrictive layer. The standard design is for a well installed by angering. Depending upon site conditions, wells installed by driving may also be acceptable (see the section on Monitoring; Well Installation). Installation of one or more additional deeper (4-5 ft) wells at each site is also encouraged to help in interpreting; water -table fluctuations and warn of sudden changes in water -table depth. Deeper wells are not required but, if used, should not penetrate any restrictive soil layers. The performance ofali wells must be tested and verified before use. Monitoring Well Components. A standard monitoring well installed by augering is shown in Figure 2 and consists of the following main components: well screen, riser, well caps, sand filter pack, and bentonite sealant. Specifications for each of these components are given below. 2 10 ERDC TN-WRAP-05-2 June 2005 Vented Well Cap (Loosely 1-inch Fitted) Diameter Well Stock Bentonite/Soil Mixture Ground Surface a Riser 4 inches Bentonite Seal 1 inch 11 1 1 1 1 1 1 1 Augered Hole 1 1 1 1 1 1 1 1 1 Well Screen 1,lI1, 1,1 1, 1, I11, 15 inches 1 1 1 1 1 I r l l rll'I'I'1 r'1'I'I' I l r l l 1 1 1 1 1 FI'1'I'I 1'1'I'1' Sand Filter Pack 1 1 1 1 1 1 1 1 1 I I I I I 1 1 1 1 I II, 1, 1,1 IIIIIIII 11 1 1 1 4 l 1 1 Well Cap with 1 1 1 Drain Hole I l l l l 1 f i 1 1 1 1 1 1 3 inches Figure 2. Standard 15-in. monitoring well installed by augering 5 ERDC TN-WRAP-05-2 June 2005 Well Stock. Shallow monitoring wells should be made from commercially manufactured well stock. Schedule 40, 1-in. inside diameter PVC pipe is recommended. The diameter of the pipe allows sufficient room for hand measurement of water levels while minimizing well volume and maximizing responsiveness to water -table changes. The small diameter also minimizes auger hole diameter, volume of the filter pack, and the quantity of bentonite needed to seal the bore hole. However, if required by automated water -level recorders, then 2-in.-diam pipes can be substituted. Well stock larger than 2 in. in diameter should be avoided. Well Screen and Bottom Cap. Recommended slot opening and slot spacing for the well screen are 0.010 in. and 0.125 in., respectively. The slotted screen should extend from approximately 5 in, below the ground surface down to the bottom of the well. Hand -slotted or drilled well screens Should not be used. One problem with the use of commercial well screen for very shallow monitoring wells is that there often is a length of unslotted pipe and joint or threads below the screen. In shallow monitoring situations, this extra length often must be inserted into underlying soil material that should be left undisturbed. In combination with a commercial well point, this extra length also provides a reservoir where water can remain trapped after the outside groundwater has dropped, resulting in the potential of misleading or incorrect readings during water -table drawdown. To avoid this problem, commercial well screen should be cut to the desired length within the slotted portion ofthe pipe. A PVC cap should be glued at the bottom of the screen and a small drain hole should be drilled in the bottom cap (Figure 2). Riser. The riser is the unslotted PVC pipe that extends from the top of'the well screen to above the ground surface (Figure 2). The riser should extend far enough above the ground to allow easy access but not so high that the leverage of normal handling will crack below -ground seals. In locations that do not pond or flood, 9 to 12 in. above the ground surface is usually sufficient. A longer riser may be needed on inundated sites or where automatic recording devices are used. Well Top Cap. A well cap is required to protect the top off the well from contamination and rainfall. Caps should be attached loosely so they can be removed easily without jarring or dislodging the well, or cracking the bentonite seal. Tight -fitting caps, either threaded or unthreaded, should he avoided because they may seize to the riser and require rough handling to remove. A suitable well cap can be constructed from a short length of INC pipe of a larger diameter than the riser, with a glued PVC cap at one end (Sprecher 2000). The constructed well cap can be attached loosely to the riser by drilling a hole through both the cap and the riser and connecting the two with a wire lock pin. The cap should be vented to allow equilibration of air pressure inside and outside of the well. Filter Pack. A filter pack is placed around the well screen to remove fine particles and provide a zone of high hydraulic conductivity that promotes water movement toward the well (Figure 2). Filter packs can be classified into two major categories, natural and artificial. Natural packs are created by manually repacking any excavated soil around the well screen, ensuring that large voids are absent. Natural packs are recommended in coarse -textured, sandy soils. In Cne-textured soils, an artificial pack should be used. Sec Table 1 for recommendations on the use of filter packs for soils of different textures. 0 Commercially available silica sand is recommended for use as artificial pack material and is usually well - sorted; well-rounded, clean, chemically inert, and free of all fine-grained clays, particles, and organic material. Silica sand is available from water -well supply houses in uniformly graded sizes. Sand that passes a 20-mesh screen and is retained by a 40-mesh screen (20-40 sand) is recommended with a 0.010-in. well screen. Bentonite Sealant. Bentonite is a type of clay that absorbs large quantities of' water and swells when wetted. It is used in well installation to form a tight seal around the riser to prevent water frorn running down the outside of the pipe to the well screen. With this protective plug, only groundwater enters the slotted well screen. When installing a monitoring well. 4 ii}. of bentonite should be placed around the riser immediately at and below the ground surface (Figure 2). This 4-in. ring of bentonite rests directly on top of the filter pack ERDC TN-WRAP-05-2 June 2005 Table 1 USDA Soil Texture Classes and Recommendations for Sand Filter Packs USDA Soil Texture Sand Pack Muck, Mucky Peat, Peat None Coarse Sand Norte Medium Sand None Fine Sand None Loamy Sand Norte Sandy Loam Recommended Loam Recommended Silt Loam Recommended Silt Recommended Sandy Clay Loam Required Silty Clay Loam Required Clay Loam Required Sandy Clay Required Silty Clay Required Clay Required around the well screen. Above the bentonite ring, additional bentonite mixed with natural soil material should be mounded slightly and shaped to slope away from the riser so that surface water will run away from the pipe rather than pond around it at the ground surface. Bentonitc is available from well drilling supply companies in powder, chip, or pellet form. Chips are easiest to use in the field. They can be dropped directly down the annular space above the sand filter pack. If this zone is already saturated with water, the chips will absorb water in place, swell tight, and seal off the sand filter from above.. ifthe bentonitc chips are dropped into a dry annular space, they should be packed dry and then water should be added down the annular space so the clay can swell shut. Modified Well Design for Clay Soils. In heavy clay soils, such as Vcrtisols, water movement occurs preferentially along cracks and interconnected large pores. These cracks may deliver water to a standard monitoring well through its vertical, slotted walls. Even when the surrounding soil is unsaturated, water may remain in the well for days due to impeded drainage into the slowly permeable clay. This problem can be rcduced, but not eliminated, by using a well that is slotted or open only at the bottorn. In addition, the sand filter pack should be installed only around .the immediate well opening and should not extend up the riser. The annular space around the riser should be packed with the natural clay soil material or filled with bentonite. Because Vertisols in wetland situations tend to be episaturated (i.e., they perch water at or near the surface but may remain unsaturated below), monitoring should focus on detection of surface ponding 7 ERDC TN-WRAP-05-2 June 2005 and saturation in the upper few inches of the soil. For this purpose, wells shorter than 15 in. may be needed. MONITORING WELL INSTALLATION Installation Methods. The recommended method for installing shallow monitoring wells involves the use of a bucket auger with an outside diameter 2 in. greater than the well diameter (e.g., 3 in. for a standard 1-in. well). As an alternative, wells may be installed by driving them into the ground. Driven wells may he preferred in areas with noncohesive coarse -grained (sandy) soils, rocky soils (e.g., glacial tills), or in saturated organic materials (i.e., mucks or petits). Procedures for both installation methods are given below. No matter which installation method is selected, wells must be tested for performance before being used. These procedures assume that the soil profile at the well location has already been described and that the appropriate well depth (i.e., 15 in. or less) has been determined based on the presence or absence of restrictive soil layers. A Monitoring Well Installation Data Form (Appendix 13) should be completed to document the design and installation of each well (Sprccher 2000). Augering. Recommended equipment includes a bucket auger 2 in. larger than the diameter of the well being; installed, a tamping too] (e.g., wooden or metal rod), bentonite chips, silica sand, and the constructed monitoring; well. A pump or bailer maybe needed to test the well after installation. The following] procedure is used to install the well; . Auger a hole in the ground to a depth approximately 2 in. deeper than the bottom of the well. Be sure the hole is vertical. 2. Scarify the sides of the hole if it was smeared during augering. 3. Place 2 to 3 in. of silica sand in the bottom of the hole. 4. For a 15-in. well with 10 in. of wel I screen, make a permanent mark on the well riser 5 in. above the top ofthe screen. Insert the well into the hole to the proper depth; the permanent mark on the riser should be even with the soil surface. Do not insert through the sand. 5. Pour and gently tamp more of the same sand in the annular space around the screen and I in. above the screen. G. Pour and gently tamp 4 in. of bentonite chips above the sand to the ground surface. If -necessary, add water to cause the bentonite sealant to expand. 7. Form a low mound of a soil/bentonite mixture on the ground surface around the base of the riser to prevent surface water from puddling around the pipe. Driving. Well installation by driving is recommended when site conditions prevent augering (e.g., noncohesive sandy soils, soils with many coarse fragments, saturated organic soils). In addition, driven wells are acceptable whenever their performance can be shown to be equivalent to that of an augered well. Plans to use driven we] Is for regulatory purposes should be discussed in advance with the appropriate Corps of Engineers District office. • ERDC TN-WRAP-05-2 June2005 A driven well is similar in design and construction to the augered well described previously, with the addition of a well point in place of the bottom cap (Figure 3). Well points are commercially available and can be vented to permit draining by drilling a hole in the bottom. A special driving tool may be needed to install the well without damaging the PVC pipe. 1-inch Diameter Well Stock � Ground Surface 4 inches 15 inches Vented Well Cap (Loosely Pitted) Bentonite/Soil Mixture t Riser Bentonite Seal Well Screen Well Point with Drain Hole Figure 3. Standard 1 5-in_ monitoring well installed by driving 9 ERDC TN-WRAP-05-2 June 2005 Required materials include bentonite chips and the constructed monitoring well with vented well point. A pump or bailer may be needed to test the well after installation and, depending on site conditions, a driving device may be required. The following procedure is used to install the well: 1. For a standard 15-in. well, make a permanent mark on the riser 15 in. above the bottom of the well screen. With the well cap removed, use a driving device to drive the well vertically into the grottrid until the mark is at the ground surface. In organic soil materials, the wc11 may simply be Pushed into the ground. 2. Dig out a ring of soil around the well riser to a depth of 4 in. Fill this space with bentonite chips and add water, if necessary, to form a tight seal. 3. Form a low mound of a soil/bentonite mixture on the ground surface around the bast of the riser to prevent surface water from puddling around the pipe. Establishing Riser Height. Water -level measurements are typically recorded as the "depth .to water" from the top of the well riser. The depth of the water table below the ground surface is determined by subtracting the riser height from the "depth to water' measurement. Therefore, after installing the well, measure and permanently record the height of the riser above the ground surface. If automated water -level recording devices are used, follow the manufacturer's instructions for calibration of•water-level readings relative to the ground surface. Riscr height should be checked after soils have thawed in spring, and should be re -checked periodically when water -table measurements are taken or electronic data are downloaded. Surface Water. In areas subject to flooding or ponding, a separate staff gauge or automated device is required to measure the depth of surface water. MONITORING WELL TESTING AND MAINTENANCE: Duringwcll installation, particularly with driven wells, fine soil particles may clog the well screen, impeding water flow and increasing the response time of the well. The performance of the well should be tested by (1) emptying the well by pumping or bailing and monitoring how quickly the water level returns to the initial level, or (2) if the well is dry, filling it with water and monitoring the rate of outflow. The water level in the well should reestablish itself atapproximately the same rate as itwould in a freshly dug hole With Litany pipe. In soils with a high percentage of clay, this could require several hours. If the waterdoes not return to the initial level in a reasonable arzIount ol'time, pull the instrument out ofthe ground, clean it, reinstall it, and retest it. If' water -table readings are questionable at any time during the monitoring period, one option is to move some distance away from the well location, auger to the depth in question, and determine whether the water level in the auger hole is the same as that indicated by the monitoring well. Routine Maintenance. Monitoring well responsiveness should be tested at the beginning of the monitoring period and at ]cast every 2-3 months thereafter by the procedure described above, because wells can plug over tithe due to bacterial growth and movement of fine soil particles. Well performance can also be affected by cracking of the bentonite seal, sediment deposition in the well, and movement of the ground surface and/or monitoring well due to frost heaving or shrink -swell action. To ensure accurate water -level readings, check for vertical displacement of the well after spring thaw and periodically during sampling by re-rneasuring the height of the riser above the ground surface and adjusting water -table measurements or resetting the well, as needed. 10 ERDC TN-WRAP-05-2 June 2005 MAKING WATER -LEVEL MEASUREMENTS: Water levels in monitoring wells should be measured with an accuracy of±0.25 in., iFpossible. Measurements may be made manually or with automated equipment. The use of automated water -level recorders is recommended unless an uninterrupted schedule of Frequent site visits can be maintained. Automated recorders are also recommended in areas with highly variable or flashy hydrology. Whichever method is selected, it Should be used consistently throughout the duration of the monitoring study. .Manual Readings. Water -level measurements can be made easily with a steel measuring tape marked with chalk or a water-soluble marker. Another approach is to use an electric device that sounds or flashes when the sensor, attached to the end of a graduated tape, makes contact with the water. Measurement devices that displace large amounts of water (e.g., dowel rods) should not be used. Automated Readings. Automated recording devices record water levels with down -well transducers or capacitance -based sensors. An important consideration when purchasing automatic recording devices is the ability to compensate internally For variations in barometric pressure. These variations can be significant in wetland determinations. Automated equipment is more costly than hand measurement, but the devices can be used again in future studies. The credibility of monitoring results is enhanced with the high frequency of water -level readings that automated wells allow. Automated water -level recorders should be checked frequently for accuracy by comparison with manual readings. If automated readings are not within instrument specifications, the device Should be recalibratcd. Required Timing, Frequency, and Duration of Readings. Water -level measurements must be taken at least once each day, beginning 5-7 days before the first day of the growing season and continuing until the end of the growing season or until the minimum standard For wetland hydrology is met that year. I f automated recorders are used, readings four times per day are recommended (use the lowest reading each day). On sites subject to flooding or ponding, depth of surface water must be measured each day that water -table readings are made. Growing season beginning and ending dates shall be based on the median dates (i.e., 5 years in 10, or 50 percent probability) of'28 °F air temperatures in spring and fall as reported in WETS tables provided by the USDA-NRCS National Water and Climate Center. WE,rS tables are based on long- term temperature data collected at National Weather Service (N WS) cooperative weather stations throughout the United States and are available on the Internet at http_//www.wcc.nres.usda.2ovl climatelwetlands.html. For a particular project site, growing season information from the nearest available weather station should be used unless, due to elevation or other factors, a more distant weather station is considered to be more representative of conditions at the project site. Alternative local or regional procedures For determining growing season dates may be used at the District's discretion. 13CCause hydrologic conditions are naturally variable, many years of groundwater monitoring data may be needed to establish .what is typical for a given site. This is particularly true in the arid western United States where rainfall can be sparse, unpredictable, and highly localized. In general, ten or more years of water -table monitoring data may be needed to determine whether minimum standards For water -table depth, duration, and f-requency in wetlands are met. However, because long -.term monitoring is often impractical in a regulatory context, short-term studies may provide 11 ERDC TN-WRAP-05-2 June 2005 sufficient information if the normality of precipitation during the monitoring; period is considered. Determining "normal" rainfall is addressed in the following section. ANALYSIS AND INTERPRETATION OF MONITORING DATA Technical Standard for Wetland Hydrology. Wetland hydrology is considered to be present on an atypical or problem site if the following standard is met: The .site is inttndaled (flooded or ponde(l) at• the water table is S12 inches belo►i, the .soil , auface.for>_14 conseculive days during the grooving season at a tninimaun, frequency o1'5 years in 10 (?50% probability). An con?bination of inundation ot• shullotia ivater table is acceplable it? tneeting the 14-day tnini.inum requirement. Short-term monitoring data naav be used to address the frequency requiremew if the normality ofrainfall occurringpr-ktr to and during the monitoring period each year is considered The Corps Manual discusses wetland hydrology in general, but does not provide a wetland hydrology criterion suitable for use in interpreting; monitoring well data. The standard given above is based on recommendations by the National Academy of Sciences (National Research Council 1995). By requiring a water table within 12 in. of the surface, this standard ensures that saturation by free water or the capillary fringe occurs within the "rnaior portion ofthe root zone" described in the Manual. A 14-day minimum duration standard is assumed to apply nationwide unless Corps Districts have adopted a different standard at the local or regional level. The Corps Manual addresses the need for long-term data (10 or more years) in analyses of stream -gauge data but does not consider the use of short-term data in wetland determinations, nor does it address the frequency issue in relation to water -table monitoring. This Technical Standard allows the use of short-term monitoring; data to address the fi-equcncy requirement for wetland hydrology, if the normality of rainfall is considered. The depth to saturation depends both on the position ofthe water table and the height of the tension - saturated capillary fringe (National Research Council 1995). While its presence has an influcnee on both plant growth and soil features, the upper limit ofthe capillary fringe is difficult to mcasurc in the Feld and impractical as a basis for hydrologic monitoring. The Technical Standard for Wetland i-[ydrology is based on the depth of the water table because, in most cases, water -table depth can be monitored readily and consistently through the use ofshallow wells with either manual or automated data collection. Water -table measurements sliould not be corrected for a capiI lacy fringe unless other evidence, such as tensiometer readings, laboratory analysis of soi I water content, or evidence of soil anoxia, indicates that the height of the saturated capillary fringe is greater than a few inches. Determining Normal Precipitation. Short-term water -table monitoring data (i.e., <10 years) must be interpreted in relation to the amount of prccipitation that fell during and for at least 3 months prior to the monitoring period each year. This is done by comparing; the precipitation record for a given year with the normal range of precipitation based on long-term records collected at the nearest appropriate NWS cooperative weather station. The USDA-NRCS National Water and Climate Center calculates normal precipitation ranges for each month (defined as between the 30"' and 701h percentiles of monthly precipitation totals) for NWS stations tliroug llout the United States. The information is published in WE"I'S tables available on the Internet (littp://www.wcc.nres. usda.gov/ciimat_e/wetiands.litm]). 12 ERDC TN-WRAP-05-2 June 2005 Sprecher and Warnc (2000, Chapter 4) describe three methods for evaluating precipitation normality within a given year. The first method is taken from the NRCS Engineering Field !-Handbook (Natural Resources Conservation Service 1997) and involves the direct application of WETS tables in relation to monthly rainfall totals at the project site. At a minimum, this method shall be used to determine whether rainfall was normal immediately before and during a groundwater monitoring study. The analysis should locus on the period leading up to and during the time when water tables are usually high in that climatic region. In many parts of the country, this is at the beginning of the growing season, when precipitation is abundant and evapotranspiration is relatively low. The second method described by Sprecher and Warne (2000) evaluates daily precipitation data on the basis of 30-day rolling sums, and the third method combines the two procedures. if` daily precipitation data are available, the combined method is recommended. Tile evaluation of precipitation normality should include the three months prior to the startofthe growing season and extend throughout the entire monitoring period each year. For many wetlands, water tables in a given year may be affected by precipitation that occurred in previous years, especially if monitoring occurs after an extended period oi'drought or precipitation excess. A Iter a series of dry years, for example, it may take several years of normal or above -normal rainfall to recharge groundwater and return water tables to normal levels. 'Therefore, in evaluating wetland hydrology based on short-term monitoring, it is necessary to consider the normality of rainfall over a period of years prior to the groundwater study. Recent precipitation trends can be determined by comparing annual rainfall totals at the monitoring site with the normal range given in WETS tables for two or more years prior to the monitoring study, or by examining trends in drought indices, such as the Palmer Drought Severity Index (Sprecher and Warne 2000). This issue may not be important in soils with perched water tables that respond to the current year's rainfall and dry out seasonally. Interpreting Results. Iftcn or more years of water -table monitoring data are available for a site, the long-term record probably includes years of normal, below normal, and above normal precipitation and thus reflects the average hydrologic conditions on the site. Therefore, wetland hydrology can be evaluated directly by the following procedure: l . For each year, determine the maximum number of consecutive clays that the site was either inundated or the water table was :_I2 in. from the ground surface during the growing season. Wetland hydrology occurred in a given year if the number of consecutive days of inundation or shallow water tables was >_14 days. 2. The Technical Standard for Wetland Hydrology was met if wetland hydrology occurred in at least 50 percent of years (i.e., ?5 years in 10). This procedure may not be appropriate during extended periods of'drought or precipitation excess. Furthermore, in some regions with highly variable precipitation patterns (e.g., the and West) more than ten years of groundwater monitoring data may be needed to capture the typical hydrologic conditions on a site. 1f fewer than ten years of water -table data are available, then the normality of precipitation preceding and during the monitoring period must be considered. One option is to apply the procedures described in the section on "Determining Normal Precipitation" for each year that water tables were monitored. In addition, annual precipitation or drought severity indices should be 13 ERDC TN-WRAP-05-2 June 2005 evaluated for two or more years prior to the monitoring period on any site that lacks a perched water table. Wetland hydrology can then be evaluated by the following procedure: l . Select those years of monitoring data when precipitation was normal, or select an equal number ol'wetter-than-normal and drier -khan -normal years. 2. I f'wetland hydrology (i.e., any combination of inundation or water table <_ 12 in. from the surliice for >_14 consecutive days during the growing season) occurred in >50 percent of years (e.g., 3 years in 5). then the site most likely meets the Technical Standard for Wetland Hydrology. it is important to rci-rember that, even in normal rainfall years, many wetlands will lack wetland hydrology in some years due to annual differences in air temperatures (which affect evapotranspiration rates) and the daily distribution of rainfal I that are not considered in this analysis. This is particularly true of borderline wetlands that may have shallow water tables in only 50-60 percent of years. Therefore, this procedure may fail to identify some marginal wetlands. Another option, particularly for vcry short -duration monitoring studies (e.g., <3 years), is to evaluate water -table measurements in conjunction with groundwater modeling. 1-hint eta]. (2001 ) described one such approach, called the Threshold Wetland Simulation (TWS), which uses the DRAINMOD model. Actual water -table measurements in a given year are compared with those of a simulated, threshold wetland (i.e., one that meets wetland hydrology requirements in exactly 50 percent of years). The TWS approach requires detailed long-term precipitation and temperature data, soil characteristics, and considerable expertise with the DRAINMOD program. No method to determine wetland hydrology based on short-term water -table measurements is entirely reliable or free ofassumptions. Therefore, ultimate responsibility for the interpretation of water -table monitoring data rests with the appropriate Corps District. REPORTING OF RESULTS: Warne and Wakeley (2000) provided a comprehensive checklist of information that should be included in the report of a groundwater monitoring study. The report should also include a justification for any deviations from procedures given in this Technical Standard. The report should include a clear, graphical presentation of daily water -table levels at each well plotted over time and shown in relation to the soil surface and the 12-in. depth, the depth of the monitoring well, growing season starting and ending dates, local precipitation that year, and normal precipitation ranges based on WETS tables. Another useful feature is a diagram ofthe soil profile at the well location including depths and textUreS of eaelr rnajur horizon. An example graph with many of these featureS is shown in Figure 4 (Sprecher 2000). ACKNOWLEDGMENTS: The initial outline for this Technical Standard was developed at a workshop in Decatur, GA, in September 2003. Participants (in alphabetical order) were Mr. William Ainslie, U. S. Environmental Protection Agency (USEPA), Region 4; Mr. Bradley Cook, Minnesota State University, Mankato; Mr. Jason 1-1111, Tennessee Tech University (TTU); Ms. Julie Kelley, Geotechnical and Structures Laboratory (GSI1), U. S. Army Engineer Research and Development Center (ERDC); Dr. Barbara Kleiss. Environmental Laboratory (EL), ERDC; Dr. Vincent Neary, TTU; Mr. Chris Noble, EL-ERDC; Dr. Bruce Pruitt. Nutter and Associates, Inc.; Dr. Thomas Roberts, 'ITU, Mr. Paul Rodrigue, USDA Natural Resources Conservation Service (NRCS); 14 ERDCTN'N8R\P'05'2 June2OO5 lionkoring Well Reewd Columbus OH Area Wetland Site 1997 ra Twke daily level rewfts:_ son 000w*11"; Jan Feb Mar Apr May Jun M Aug Sep Oct Nov 0 Doc Gro%ving Season A. Example filled out 15 Figure 4. Example of graphical presentation of water -table monitoring data (Note that this example uses a deeper well than the 15 in. specified in this Technical Standard) Dr. 5Lcvcn Spruohcc D. S. /\nny En,gincor[US/\[) District, Detroit; and Dr. ]nnocs VVoks\ey, Ei- ERDC. The first dnahwas written by Do. Ncory and Wokc|oy and K1cnsrm. Hill and Noble. Technical reviewers inc)udcdHarry Bo',Jr,USA UDistrict, Anchorage; Mark Clark, MKCS;David D`&nnmrt, U. S. Forest Service (USFS); Jackie DcMoniigny. USFS; Michio| Ho|lcy, US/\B District, Anchorage; Wesley Miller, NRCS; ]nnney Miner, Illinois State Oco|og{uu| Survey; Joe Moore, NRCS; Dr. Chien-1-1.1 Ping, University of'Alaska, Fairbanks-, Ann PLiffer, USFS; and Ralph Rogers, |]SF_PA Region |O. A oubuonunniUcc of' the Y4uiionu| Technical Connmi1U:o For Hvdrio Soils (NTCUS) provided un independent peer review inaccordance with (}Olooof' Management and Budget guidelines. The authors are grutc[u| to fJTCHS rnunmbom Dn. Michael \/cnnssknxuod R. Wayne Skaggs, North Carolina Siuiu University; and Mr. 8d Qiuko, Mr. P. Mid)ot\ Whited, Ms. Lcno,c\/msi|os.and Mr.(l. Wade Hurt, NKCS_[6rtheir comments and suggestions. Thov/odkr/us supported by Huudquurium, U. S. /\rnny Corps of Engineers through the VVeUnndo Kcgu|o1nry Ayuiyiunuu Program (VVR/\P). POINTS OF CONTACT: For additional inhonnotion,contact Dr.]unnosS.VVokc|uy,U.8.Army Engineer Rxetorch and Dcvc}opnncn1 [cntcr (UK[)C). Vicksburg, MS, (601-634-]702, um dun�s Rc8v|o�or��� Figure 4. Example of graphical presentation of water -table monitoring data (Note that this example uses a deeper well than the 15 in. specified in this Technical Standard) Dr. 5Lcvcn Spruohcc D. S. /\nny En,gincor[US/\[) District, Detroit; and Dr. ]nnocs VVoks\ey, Ei- ERDC. The first dnahwas written by Do. Ncory and Wokc|oy and K1cnsrm. Hill and Noble. Technical reviewers inc)udcdHarry Bo',Jr,USA UDistrict, Anchorage; Mark Clark, MKCS;David D`&nnmrt, U. S. Forest Service (USFS); Jackie DcMoniigny. USFS; Michio| Ho|lcy, US/\B District, Anchorage; Wesley Miller, NRCS; ]nnney Miner, Illinois State Oco|og{uu| Survey; Joe Moore, NRCS; Dr. Chien-1-1.1 Ping, University of'Alaska, Fairbanks-, Ann PLiffer, USFS; and Ralph Rogers, |]SF_PA Region |O. A oubuonunniUcc of' the Y4uiionu| Technical Connmi1U:o For Hvdrio Soils (NTCUS) provided un independent peer review inaccordance with (}Olooof' Management and Budget guidelines. The authors are grutc[u| to fJTCHS rnunmbom Dn. Michael \/cnnssknxuod R. Wayne Skaggs, North Carolina Siuiu University; and Mr. 8d Qiuko, Mr. P. Mid)ot\ Whited, Ms. Lcno,c\/msi|os.and Mr.(l. Wade Hurt, NKCS_[6rtheir comments and suggestions. Thov/odkr/us supported by Huudquurium, U. S. /\rnny Corps of Engineers through the VVeUnndo Kcgu|o1nry Ayuiyiunuu Program (VVR/\P). POINTS OF CONTACT: For additional inhonnotion,contact Dr.]unnosS.VVokc|uy,U.8.Army Engineer Rxetorch and Dcvc}opnncn1 [cntcr (UK[)C). Vicksburg, MS, (601-634-]702, um dun�s Rc8v|o�or��� ERDC TN-WRAP-05-2 June 2005 Assistance Program, Mr. Bob Lazor (601-634-2935, Bob. L.La=oYa,ercic.rrsace.arm )l m il). This technical note should be cited as follows: U. S. Army Corps of I-Ingincers. (2005). "Technical Standard for Water -Table Monitoring of Potential Wetland Sites," TVRAP Technical Notes Colleclion (EIZDC TN- WRAP-05-2), U. S. Army Engineer Research and Development Center, Vicksburg. MS. REFERENCES Environmental Laboratory. (1987). "Corps of Engineers Wetlands Delineation Manual," Technical Report Y-87-1, U.S. Amoy Engineer Waterways Experiment Station, Vicksburg, MS. (Annotatedon-line version available at littp://el.erdC.Llsace.ariny.mil/elpubs/l)df/wiman87.pdD Hunt, W. F.. Ill. Skaggs,. R. W, Chescheir, G. M., and Amatya, D. M. (2001). "Examination of the Wetland Hydrologic Criterion and its Application in the Determination of' Wetland Hydrologic Status," Report No. 333, Water Resources. Research Institute ofthe University of'North Carolina, North Carolina State Univ., Raleigh. National Research Council. (1995). "Wetlands: Characteristics and Boundaries," National Academy Press, Washington, DC. Natural Resources Conservation Service. (1997). "Hydrology tools for wetland determination," Chapter 19. Engineering Meld handbook, Donald E. Woodward, ed., USDA-NRCS, Fort Worth, TX. (littp://www.iiifo.usda.uv/CED/ftp/CED/EFH-Cli 19.pdf) Sprecher, S. W. (2000). "Installing monitoring wells/piezometers in wetlands," WRAP Technical Notes Collection, ERDC TN-WRAP-00-02, U.S. Army Engineer Research and Development Center, Vicksburg, MS. (httpalel.erdc.usace,arm- .iy nil/elpubs/pdf/tmvrap00-2.pdf} Sprecher, S. W., and Warne, A. G. (2000). "Accessing and using meteorological data to evaluate wetland hydrology," Technical Report TR-WRAP-00- I, U.S. Army Engineer Research and Development Center, Vicksburg, MS. (htt ://cl.erdc.usace.arm .mil/el ubs/ df/wra 00-I/ wra 00-1, df) Warne, A. G., and Wakeley, 1. S. (2000). "Guidelines for conducting and reporting hydrologic assessments of potential wetland sites," [FRAP Technical Notes Collection, ERDC TN-WRAP-00-0I. U.S. Army Engineer Research and Development Center. Vicksburg. MS. (http:llel.erde.usace.anny.mil/ elVubs/pdf/tnwrap00-1.pdi) NOTE, The commis of !iris lechnical note are not to he used for advertising, pnblication, or promotional purposes. Citation of trade names does not cnrasiitute an of endorsenreni or approval of the use of such products. 16 .a ERDC TN-WRAP-05-2 June 2005 APPENDIX A. SOIL CHARACTERIZATION DATA FORM Soil Characterization Data Form Project Name Personnel Date Soil Pit ID Horizon Depths inches Texture Matrix Color (Munsell moist) Redoximor hic Features Induration (none, weak, stronqL Roots Color Abundance 'E Comments: 17 j.� ERDC TN-WRAP-05-2 June 2005 APPENDIX B. MONITORING WELL INSTALLATION DATA FORM Monitoring Well Installation Data Form Project Name Date of Installation Project Location Personnel Well Identification Code Attach map of project, showing well locations and significant topographic and hydrologic features. Characteristics of Instrument: Source of instrument/well stock Material of well stock Slot width Kind of well cap Installation: Was well installed by augering or driving? Kind of filter sand Depth to lowest screen slots Was bentonite wetted for expansion? Method of measuring water levels in instrument How was instrument checked for clogging after installation? Diameter of pipe Slot spacing Kind of well point/end plug Kind of bentonite Riser height above ground Instrument Diagrama Soil Characteristics Texture Matrix Color Redoximorphic Features Induration (none, weak, strong) Roots Color Abundance aShow depths (heights) of riser, well screen, sand pack, and bentonite in relation to soil horizons. 18 Q..4� A TFq S D `C June 30, 2009 Mr. Nuwan Wijesuriya, Mr. Steve Whitt Martin Marietta Materials, LLC P.O. Box 30013 Raleigh, NC 27622-0013 Michael F, Easley, Governor William G. Ross Jr., Secretary Nordi Carolina Department of Environment and Natural Resources Coieen ti Sullins, Director Division of Water Quality Subject: General Permit No. NCGO20000 Martin Marietta Selma Quarry, NCGO20735 Johnston County Dear Mr. Wijesuriya and Mr. Whitt: The Division of Water Quality's Stormwater Permitting Unit received a National Pollutant Discharge Elimination System (NPDES) permit application for Martin Marietta Materials, Inc., Selma Quarry, on September 15, 2008. In response to a DWQ request for additional information, we received additional. information from your site on April 20, 2009. I1n our last letter, we requested that an O&M Plan for your facility to be submitted to the Raleigh Regional Office before issuance of an NPDES permit. If you have further questions regarding your O&M plan we request that you to contact the Raleigh Regional Office.to address any wetland concerns for your facility in order to ensure a successful NPDES application review. , Although you have submitted some components of the O&M plan for review, we are still missing some of the requested components. Please submit the necessary components'of the O&M below that we had previously requested: y� Calculations to show the cone of influence �• Settling pond sizing information and calculations • Level -spreader -design and calculations • Description of measures to' prevent erosion and flooding • Annual Report • Restoration Plan (including an after -site plan for wetlands that for the life of the mirie are to be maintained by-Ievel-spreaders and dewatering). After review of your O&M plan we request that you address all the following points: Wetland 4: �. On page 2 of the OSM plan you state that groundwater flow in this area is typical of Piedmont where f OW direction is'torunlds streruus. You then state that wetland 4 will not be affected by the pit as water ivill flow front 1U(,use to if. These two statements are contrary, however you state that Wetland 4 will not be hydrologically affected by the development of the pit. After conversations with NCDENR DWR GroundwaLer hydrologist Nat Wilson, we do not br,.Iieve that this can be conclusively shown. Please show a monitoring plan for this wetland. Please'include: a. A monitoring plan that shows water table before mining is started near the wetland. kFo ` Carolina )WhIrn!!11 North Carolina Division of Water Quality 1617 Mail Service Censer Raleigh, NC 27699-1617 1'ltone (919) 807-6300 Customer Service internet: L4'1Sw.newaterguaiily.ore Location: 512 N. Salisbury St. Raleigh, NC' 27604 Fax (919) 807-6494 1-877-623-6748 An Equal OpportunitylAliimiative Action Employer-• 50% Recycled110% Post Consumer Paper :i 1 Mr. Steve Whitt & Mr. Nuwan Wijesuriya Martin Marietta Selma Quarry -� NCG020735 r July 2, 2009 b. Wells should be: i. 20-30' deep, ii. screened over 5' intervals iii. Monitoring relatively shallow groundwater. iv. These should be placed and monitored before the digging is begun. v. Monitored for the life of the well vi. Monitoring should be kept by the permittee. This data needs to be kept for the life of the permit. vii.. Monitoring needs to be summarized on a regular basis and sent to the Region. c. Please show from what areas the mine will be are discharging water. Stream 1, Wetland 1, Wetland 6:. You state in your submitted O&M plan that monitoring is not needed for wetlands 1& 6.You did not include cone of influence calculations. 1. Please include cone of influence calculations. 2. If cone of influence reaches wetlands 1&6, please submit a monitoring plan as per Wetland 4. . Wetland 2/Stream 3/Wetland 3: 1. As water is to be added to the.stream/wetland system. from dewatering, and as a proposed berm will diver water.from a wetland that currently feeds this system, please show how enough water will be put into wetland 3 that this wetland/stream system will still be: a.. Received at a non -erosive velocity and b. Yet still receiving enough water from the clarification pit to hydrate the wetlands. c. Please show calculations for this. 2. Please show on the large scale plans and in.the O&M plan: where the monitoring gauge will be placed in Wetland-2 and Wetland 3. Process Area: " Please show the discharge point(s) from the process area, especially as they pertain to wetland 6 and' stream 1. Constructed Wetland: Youstate in the O&M plan that you will create a constructed wetland. It appears to be Iocated in or near wetland 6. You cannot create a constructed wetland in wetlands or surface waters. Please address. X Level -spreaders: Concentrated Runoff into the buffer must be discharged in a diffuse manner. Please show that all t concentrated flow. into the buffer is done in a diffuse manner. 2. Please include plans and calculations for level -spreaders. A link to level-spreader'design , requirements can be found on the stormwater BMP manual webpage. ' If your level -•spreader designs require a bypass into the buffer, you will be required to have buffer authorization. Please contact Amy Chapman in the Division of Water Quality for requirements for buffer authorization. Please return a copy of filial correspondence regarding buffer authorization from Ms. Chapman. You may need a 401 permit modification if you will require a.buffer authorization. Please include a statement as to .whether. or not you will be required to have, one. 4. Please show where both sediment basins discharge on the large scale plans. onr` NthC7rolina �Natura!!� North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 Phone (919) 733-5093 Customer Service Internet: N v�newaterqual Morg Location: 512 N, Salisbury St.Raleigh, NC 27604 Fax (919) 733-9612 1-877-623-6748 An Equal Cpportunity/Affirmative Action Employer — 50% Recyded110% Post Consumer Paper Mr. Steve Whitt & Mr. Nuwan Wijesuriya :Iartii Marietta Selma Quarry - NCG020735 July 2, 2009 Large -Scale Plans: 2 1. Please show on the large-scale plans and in the O&M plan where the monitoring gauge will be placed in Wetland 2 and Wetland 3. 2. Please show the -discharge point(s) from the process area, especially as they pertain to Wetland 6 and Stream 1. 3. Please show where both sediment basins discharge on the large-scale plans. 4. You state in the O&M plan that you will create a constructed wetland. It appears to be located in or near Wetland 6. You cannot create a constructed wetland in delineated wetlands or streams. Please address. 5. Please label all wetlands, streams and BMPs on the large-scale map as per the O&M plan. 6. Please show approximate locations of ALL monitoring wells and gauges. 7. Stream 3 does not appear to be shown correctly on the large-scale plans. Please address. #. Please show the old borrow pit on. the large-scale plans and in the O&M plan. Other: 1. Please show vehicle maintenance areas of the site. 2. Please. show that you have applied for a flood -hazard permit and that your site plan does not need to be further modified to meet any local requirements. 3. Please show that you have applied and received, local stormwater approvals for water -supply watershed areas as your site is in a water -supply watershed. 4. If your site will include asphalt or ready -mix concrete industrial areas, please include information about those industrial practices including runoff, recycle systems, treatment systems, wash out areas and discharges. If your site will not contain these types of industrial activities, please include a statement to that effect. 5. On the.'&- M' plan prepared by Kimley-Born the stated project boundary is 503 acres. The other plans• state the project permitted boundary as 480 acres. Please resolve this discrepancy. 6.. You state that the site's final built out condition is based on 27.1 acres of developed area, however the full-scale plans provided show that stockpiles are 41.3 acres, processing area and haul roads account for 84.6 acres (gravel roads are considered to be impervious) and wastepiles account for 99.9 acres of impervious. Please resolve this'discrepancy.- 7. Please include a statement that there will.be non -erosive flow to all wetlands for stormwater. 8. Your large-scale map shows future closed -loop settling cells. If you will have an "other" type of recycle system you will need an Authorization to Construct. Please address. 9. All monitoring plans. should include: a. Wells should -be placed and monitored before the digging is begun. b. Show a plan that wells are to be monitored for the life of the well— 4�a1 c. Monitoring data should be kept by the permittee:.This data needs to be kept for the life of the permit. d., ' 'Moudtoring needs to be summarized on 'a regular basis and sent to the Region (on a schedule to be decided with the Region). 10. Please show all outfalls clearly marked on Iarge-scale plans. Please also include calculations to support stormwater outfall discharge rates. Please submit two copies if the above information to the Division for Review - one to nee at the Central Office (address below) and one to Danny Smith at the Raleigh Regional Office. The requested iatformzation Noi thCarolina North Carolina Division of Water Quality 1617 Mail Service Center . Raleigh, NC 27699-1617 Phone (919) 733-5083 Custonid Service loternct: www.ncwaterguill ijy.oM Location: 512 N. Salisbury St. Raleigh, NC 27604 . . Fax (919) 733-9612' 1-877-623-6748 An Equal 6ppMunitylAfBrmative Action Employer — 50% Recycled110%a Post Consumer Paper 7 Mr. Steve Whitt & Mr. Nuwan WijesuhyaN. Martin Marietta Selma Quarry NCG020735 July 2, 2009 should be received by this Office prior to July 31, 2009, or the application will be returned as incomplete. -If . you need additional time to submit the information, please mail, or fax your request for a time extension to the Division at the address and fax number at the bottom of this letter. The request must indicate the date- . by which you expect to submit the required information. If you would like to meet in person and discuss these changes we would'.welconie.that.'.I have, contacted you via email to indicate the dates I am available. If you have any questions concerning the NPDES permit approval process, please contact me at telephone number (919) 807-6379. If you would like to come into discuss any concerns, please contact me at the above number and we would be happy to meet with you. Sincerely, fifer e = Environmental Engineer cc: Raleigh Regional Office, Danny Smith, Lauren Witherspoon DWQ 401 Oversight/ Express Permitting Unit Home, AnnetffLucas; Amy Chapman NCDENR DWR, Nat Wilson Central Files Stormwatei Permitting Unit piles ` I�hCarolina ' )Vatarally Nnrth Carolina Division of Water Quality 1617 Mail Service Center -Raleigh, NC 27699-1617. Phone (9)9) 733-5093 . Customer Service Internet: www ncwater ualit .or Location: 5 t2 N. Salisbury St. Raleigh; NC 27604 Far (919) 733-9612 • 1-877-623-6749 . ' An Equal Opportunity/Affirmative Action Employer— 50% Recycled110% Post Consumer Paper , .' ; GROUND -WATER CONDITIONS IN THE VICINITY OF THE PROPOSED QUARRY SITE NEAR YATES MILL, TN WAKE COUNTY, NORTH CAROLINA PREPARED FOR MARTIN MARIETTA AGGREGATES RALEIGH, NORTH CAROLINA PREPARED BY TRIANGLE ENGINEERING AND SURVEYING, INC. 1625 NAVAHO DRIVE RALEIGH, NORTH CAROLINA GROUND -WATER CONDITIONS IN THE VICINITY OF THE PROPOSED QUARRY SITE NEAR YATES MILT. IN WAKE COUNTY, NORTH CAROLINA INTRODUCTION Purpose and_Scap a of the investigation The purpose of this investigation was to make a determination of the impart, on the local ground -water aquifer, caused by the development of a rock quarry near Raleigh, North Carolina. Near the quarry site are several single-family dwellings and a mobile -home park.. The residents have expressed concern that dewatertng operations at the quarry may cause excessive lowering of water levels in their wells. In response to this concern, Martin Marietta Aggregates requested Triangle Engineering and Surveying, Inc. to make an investigation of the ground -water conditions in vicinity of the quarry site and to determine, so far as reasonably possible, the amount of change that may be produced in ground -water levels at various distances from the proposed quarry pit. Descrigtion of the Area The area of investigation includes the 81-acre tract owned by Martin Marietta Aggregates. The tract lies on the east side of Lake Wheeler Road (SR 1371) near its intersection with SR 1379 at approximately 4 miles south of the City of Raleigh. The proposed pit area of the quarry lies on the south side of the creek leading from Yates Mill Pond in an east -west direction. The location of the tract is shown in figure 1. Underlying the entire tract is bedrock composed largely of hor.neblend gneiss. It is overlain by weathered rock and so.i-1 ranging in depth from one or two feet on the hill tops to a.i much as fifty f eut in the low flat areas. Ground -Water. The portion of the outer crust of the earth that contains ground -water may be regarded as an underground reservoor. The - underground reservoir in the Raleigh area consists of two contrast- ing types of materials, (1) the clayey and sandy soil and saprolite which underlies the surface to depths generally ranging from several tens of feet and (2) the underlying bedrock. In the soil. and saprolite, water occurs between the individual mineral grains, but in the underlying bedrock it occurs only in fractures. These fractures generally are riot evenly distributed, so that they may -2- 'MIT �1.� E 41 (�57 % ,f 'ram •-"�, -.! ^ f (/1, � � � \ , _.`� J - I,� �� �..;�� ll! v l i I . �a � Z- ��•r � :I•„` �� r � . \� (,_: anrn �>�Y`7• tier _ �,,"Y• �.- O j , �k, �.� � '��� i �", . � .tip ���, � �*� ~� •'.,� +� 7 i .f %-.!s'�.' / ` _� •cam h-yY . `.. it ,� 1 Ul 1 u J r.. 4 • be an inch or two or several feet apart. Many are interconnected sufficiently to allow ground -water to circulate through them. In many places fracture openings are only a fraction of an inch wide, = although there is a great variation in size of openings. The size and number of fractures appear to decrease with depth. As a result!, most ground --water occurs at a depth of less than 150 feet - much of it in the kipper 30 feet of bedrock. Therefore, the lower limit of the reservoir is a thick, indefinite zone; the top, however, is a definite though fluctuating surface known as the water table. Ground -water moves slowly through the soil and fractures in the rock, always under the influence of gravity. After percolating downward en masse through the soil and saprolite, ground --water is restricted in circulation to fractures in the bedrock. The water does not generally move to great depth, but instead is shunted almost laterally by "tight" or impermeable rocks to discharge points near the level of the perennial. streams. Thus, in areas such as the quarry site, the movement of ground -water from the recharge, or interstream, areas to the discharge, or stream, area follows, In general, a short, sinous path, with the water flowing locally through interconnecting fractures in the bedrock and through pare spaces in the overlying saprolite and soil. -3- The Water Table The water table, or upper surface of the underground reservoir, continuously changes its position. reflecting changes in ground -water storage. There is a constant discharge of ground -water by seepage into streams and by evaporation and transpiration by vegetation. The discharge causes a gradual lowering of the water table except during and immediately after periods of signigicant precipitation when recharge to the underground reservoir exceeds the discharge. As a result of these periods of precipitation, the water table rises. With a year of normal rainfall the recharge to Elie under- ground reservoir is approximately equal to the discharge from it, so that the water table at the end of the year is at approximately the same level as at the beginning of the year. In the Raleigh vicinity there is a noticeable change in the water table with the seasons. It generally begins to decline in April because of the increasing amount of evaporation and trans- piration by plants, which not only consume ground water but reduce the amount of precipitation that reaches the water table. Although interrupted by minor rises due to heavy rainfall, this decline generally continues through summer and autumn, in spite of the usual abundant rainfall of July and August. By November or December, when much of the vegetation is dormant and evaporation is low, more of the precipitation reaches the aquifer and becomes recharge, and the water table begins to rise until it reaches another high stage about March or April of the next year. -4 - i' Aside from the above considerations of climate , the depth of •"`�'`''' the water table in the Raleigh area depends chiefly on topography and on the transmitting characteristics of fractures in the rocks. The water table lies in the saprolite or overburden is most places, especially beneath the broad upland areas where the saprolite is thick. Although there is a great variation in the depth to the water table and in the thickness of the overburden, the water table generally lies several feet above the base of the saprolite. During droughts, when it may be several feet lower than during the wet seasons, the water table may be in the bedrock in some places. INVESTIGATION The first step in determining the ground --water conditions in an area is to research the available reports and records. This was done for the proposed quarry site. However, because of the sparse,population of that vicinity, there.are few well records available other than those published by the N.C. Department of Water Resources in 1968 in the report entitled,"Geology and Ground -Water Resources in the Raleigh Area, North Carolina". This report discusses, in general, the geology and occurance of ground- water in the various geologic and topographic conditions in the Raleigh area. --S- •• To obtain specific data at the proposed quarry site, Martin Marietta Aggregates drilled six wells on the tract as shown in figure 1. The wells were all 6-inches in diameter and were cased with steel casing and grouted with concrete. Logs of these wells are given in table 1. 'Attempts, were made to run aquifer tests using two of the wells for discharge points. However, insufficient sustained yields and running sand made it impossible to obtain a meaningful test even - though more than a full week was spent in the effort. The physical character of the bedrock in the quarry vicinity, and in general, makes it extremely difficult to determine its hydraulic properties. The size and degree of interconnection between the joints, bedding planes and fracture zones determine the aquifer's ability to transmit water to a pumping well and also determine the direction and distance from such a well or quarry pit that the effects of pumping can be detected. The occurence of the openings in the rock is quite heterogenous, and often there is no clue at the surface of their presence or character. Even with a test drilling program such as recently completed on the site, there is no quarantee that the true character of the water bearing rocks can be determined, IM. Inasmuch as the six test wells and attempted pumping tests did not produce any great amount of new data, we are now required to evaluate the hydraulic properties according to the general knowledge of the area and by applying specific information from other similar sites. In figure 2, a generalized section through a typical quarry wall is given. The section illustrates the occurrence of over- burden, bedrock, and the movement of water through the aquifer :towards the quarry pit. The most pertinent item to note.on•the drawing is the edge of the zone of influence at approximately 500 feet from the edge of the pit. This dimension was determined from a study made at the Stateville quarry where several wells were available to provide water level data from geologic conditions similar to those at the proposed site. Also at other quarries there are wells within 500 feet of the pits that have been producing water without problems for a number of years. At the proposed site, well number.3 was pumped for 9 hours with a drawdown of approximately 110 feet with no measurable effect on the water level in well number 2 at only 92 feet away. In summary, it is not anticipated that any significant lower- ing of water levels due to quarry dewatering will occur beyond approximately 500 feet from the edge of the pit in a year.of average precipitation.However, it must be recognized that an - 7 - anomalous extensive fracture system could be influenced at a greater distance by dewatering operations in the pit. These conclusions are based on a general knowledge of the geologic condition in the Raleigh area and experience in working with ground -water problems at quarries in similar geologic and topographic conditions. ME 101 cr 3 LJo G w Ic 3 m 2C 15 z z 10 2N rN -- I ` � f I VVI PRECiP!TCT1QN AT RGLE!GH ! Ox ,��?%',-•:,:•�;� I �i::,�- ,. �.ai 1953 j 1954 is55 { !956 k :957 Figure ? .--Craps shoeing relation of water -level r?uctuations in a dug well to precipir a -ion, xl for the period 1939-58. Well No. 1 Geology: 0-8' 8' 11'-I58' Well No. 2 Geology: fl--11' 11'-60' 60'-64 64 ' -120' Well No. 3 Geology: 0-7' 7-10' 10-120 TABLE 1 - WELL RECORDS Depth Casing Depth 158' 21' Red Sandy Clay Saprolite Bedrock F`TDepth 1N Lasing Depth 120' Overburden Bedrock Soft Micaceous Seams Bedrock Depth 120' Overburden Saprolite Bedrock Casing Depth ll' Static ^WL 21' Static 14L 21' Static WL j 13 ' �� TABLE 1 -- WELL RECORDS (Continued) Well No. - Depth~ Casing Death WL 4 158' 21' -'�tatic S' Geology: 0-9' Red Clay 9'-46' Bedrock i 46'-49' i Soft Seam 49'--100' Bedrock 100'-103' Soft Seam 103'-158' Bedrock Well No. Depth Casing gepCYi Static WL�� 5 158' 16' Geology: 0-7' Red and Brown Sandy Clay 7.'-35' Brown and Grey Saprolite 35'-158' Bedrock with Several Soft Seams Depth Casing _DepthStatic WL 6 30' Geology: 0-19" Overburden 19'--29' Saprolite 291- Bedrock NPDES Permit No. NCG020000 Vartin Marietta Materials STORM WATER POLLUTION PREVENTION PLAN (SPPP) Preparation Date: December 9, 2010 Revised: NIA Prepared For: Martin Marietta Materials, Ine. Selma Quarry Bear Farm Road Selma, NC Phone: 919-783-460 Fax: 910-510-4739 TABLE OF CONTENTS SECTION DESCRIPTION 1(a) Introduction Definition of a Stormwater Discharge Outfall Comingled Stormwater and Process Wastewater. 1(b) Site Narrative 1(c) Site Plan Details 1.(d) Significant Spills and Leaks l (c) Certification of Non-Stormwater Discharges 2 Erosion and Sediment Control, BMP's 3 Stormwater Management Plan. Materials Management Practices 3(a) BMP Identification 3(b) Maintenance and Visual Inspections 3(c) Secondary Containment Requirements and Records 4 Spill Prevention and Response Plan Pollutant Source Assessment 5 Good Housekeeping and Preventative Maintenance 6 Employee Training SPPP - Employee Training Record 7 Responsible Party Listing 8 Plan Amendment and Plan Review NPDES Permit No. NCG020000 PAGE 3 3 3 4 6 7 8 8 9 to 11 11 11 12 13 13 16 17 18 NPDES Permit No. NCG020000 (a). Introduction: Martin Marietta Materials, Inc. operates the Selma Quarry for the purpose of producing crushed aggregate for use in the construction industry. This quarry will operate on property that is located at the end of Bear Farm Road, Selma, NC. At this time this site has not been activated so no personnel or activities are on the property. This Storm Water Pollution Prevention Plan (SPPP) has been prepared in accordance with the conditions of NPDES Permit No. NCG020000, effective January 1, 2010 and valid through December 31, 2014. This permit allows the discharge of stormwater, mine dewatering wastewater, and process wastewater to the surface waters of North Carolina or to a separate storm sewer system conveying discharges to surface waters, from active and inactive mining sites. The SPPP has been prepared in accordance with good engineering practices and should be used in conjunction with other environmental permits, plans and practices. Definition of a Stormwater Discharge Outfall It is very important with the development of this plan and the oversight of Permit NCG020000 that there be a clear understanding of what constitutes a Stormwater discharge outfall. Permit NCG020000 defines a Stormwater Discharge Outfall as: "The point of departure of stonnwater from a discernible, confined, or discrete conveyance, including but not limited to, storm sewer pipes, drainage ditches, channels, spillways, or channelized collection areas, from which stormwater flows directly or indirectly into waters of the State of North Carolina." This definition is missing the fact that a discharge outfall can also be where the "point of departure" crosses your facility property line. In these cases the Stormwater flows into waters of the State of North Carolina at some point past our boundary. Using this definition it is clear that based on location and flow volume, many of our structural BMP's (basins, sediment traps, etc.) are located on the property in a manner that allows any overflow of treated stormwater to convert to sheet flow, dissipate or infiltrate before reaching the property boundary. The location of undisturbed/vegetated buffers and property boundary offsets are shown on the Mine Map and the Site Plan associated with this SPPP. In these cases the discharge of stormwater from these BMP's does not qualify as a Stormwater Discharge Outfall. The responsible parties listed in this SPPP should evaluate each structural BMP to determine if the Stormwater discharge from that location qualifies as an Outfall. CominIzled Stormwater and Process_ Wastewater Situations occur on our mine sites where stormwater comingles with process water. DWQ's position on this is very simple. All stormwater discharges that flow into wastewater and are comingled become wastewater. It is common for our vehicle maintenance area to flow to the pit. In these cases that water comingles with process wastewater and therefore there is no Vehicle Maintenance Stormwater Discharge. We should note that situation on the Site Plan as justification as to why no Vehicle Maintenance Stormwater Sample is collected. If stormwater from land disturbance areas comingle with process wastewater the same situation would apply. NPDES Permit No. NCG020000 l(b). Site Narrative This is a green field facility so the site is currently undisturbed property. This facility will produce crushed stone that will be quarried from an open pit. The material will be loaded in the pit by front-end Ioader and transported to the plant by large off -road haul trucks. The material will be processed by a series of crushers, screens and conveyors that segregates the material to large inventory piles. Customer, trucks will loaded by front-end loaders and they are weighed and ticketed before leaving the property. All of these processes take place outdoors. Any emissions (dust or particulate) created by these processes will be controlled by a water truck or by a wet suppression system employed in the plant. Waste materials associated with the production process will be minimal. Some rock fines are generated by the washing of stone and this material is captured in the closed loop water system. The material is dipped from this treatment system on a regular basis and disposed of on the property with the overburden or sold as a by-product. Other waste materials include the typical office trash, containers, wooden pallets, scrap metal, etc. that are handled by solid waste vendors. The Mine Permit for this facility does allow for the on -site disposal of certain mining refuse. This material would include land clearing debris, conveyor belts, wire cables, v-belts, air hoses and drill steel. By definition these materials are inert and do not Ieach out pollutants into the soil or groundwater. if this site has a mine refuse disposal area it will be shown on the Mine Permit - Mine Map and on the Site Plan associated with. this SPPP. Potential Pollutant Sources The types of pollutants likely to be present in the stormwater discharges will vary based on the drainage area. The typical pollutants reasonably expected to be present in runoff from the vehicle maintenance and fueling areas (On -Site Vehicle Maintenance Area Stormwater Outfall as defined in the permit) are settleable solids, suspended solids, and total petroleum hydrocarbons. Good housekeeping practices wilt keep these types of pollutants to a minimum. The types of pollutants reasonably expected to be present in runoff from the plant, stockpile area, earth -moving, and overburden storage area (Land Disturbance Stormwater Outfall as defined in the permit) are settleable solids and suspended solids. The types of pollutants reasonably expected to be present in pit activities and pit development activities (Mine Dewatering and Process Wastewater Outfall as defined in the permit) are settleable solids and suspended solids. This type of OutfalI may include areas that drain to the pit and this could potentially include all of the above types of activities, Inventory of Exposed Materials Storage practices employed at this facility will include both indoor and outdoor storage. Outdoor storage would consist of aggregate inventory piles, overburden waste piles, tires, various petroleum products, various large spare parts and equipment, various open -top scrap metal/solid waste containers, and the majority of the mobile fleet. Indoor storage would include the parts washer, paints, aerosols, tools, various small parts and equipment. These are primarily stored in the shop and associated storage areas. Some of the scrap metal/solid wast} _ containers may be stored in closed -top bins. A SPCC flan will be developed for this site once it is operational. A complete listing of all fuels and bulk oils stored on -site will be contained in the Spill Prevention, Control and Countermeasure Plan (SPCC Plan). 4 NPDES Permit No. NCG020000 All fuel and bulk oil tanks will be equipped with adequate secondary containment to contain a spill from the Iargest vessel stored within the structure plus sufficient freeboard. A Secondary Containment Dfainage Log, as required by the SPCC flan, will be maintained on -site to document containment drainage intervals. Any oil present on the water surface is to be removed prior to draining the structure by acceptable practices. A complete listing of the exposed materials at this facility is located on page 8 and 11. Other exposed areas that may be expected to contribute pollutants to stormwater runoff are inventory stockpiles, active stripping areas and berm expansion/earthmoving activities. The future location of each of these types of activities is denoted on the Site Plan, I NPDES Permit No. NCG020000 1(e). Site Plan Details I Site: Selma Quarry, Date: December 9, 2010 Instructions: Develop a map of your site including the site property boundary, topography, footprint of all buildings, structures, permanent paved areas, and parking lots. The information below describes additional elements required by NCG020000 . The following features must be designated and shown on the Site Plan: • All outfalls and storm water discharges with corresponding latitude and longitude • Drainage areas of each outfall and direction of flow in each'drainage area • Industrial activities occurring in each drainage area • Existing.$MPs (with design capacities) such as.- - Flow diversion structures - Retention/detention ponds - Vegetative swales r Sediment traps, riser basins, rock checks Drainage features and structures • 'Name of receiving waters (or if through a Municipal Separate Storm Sewer System) • General location map Distance legend or scale bar • Locations of all on -site and adjacent surface waters and wetlands • Locations of high -risk, waste -generating areas and activities common on industrial sites such as: Fueling stations Haul roads Vehicle/equipment washing and maintenance areas Area for unloading/loading materials Aboveground tanks for liquid storage Industrial waste management areas (landfills, waste piles, treatment plants, disposal areas) Outside storage areas for raw materials, by-products, and finished products Plant area Identify the pit as a "Area where blasting occurs" Include a general note on the map that "Painting, sanding welding and metal fabrication may take place anywhere in the plant and pit area." 6 NPDES Permit No. iNC0020000 1(d). Significant Spills _and _Leaks List any significant spills or leaks of pollutants that have occurred during the previous three (3) years and any corrective actions taken to mitigate spill impact. Use the form on this page to list these incidents. 1(d). LIST OF SIGNIFICANT SPILLS AND LEAKS Completed by: Steve Whiff Title: Director, Environmental Services Directions: Record below all significant spills and significant leaks of toxic or hazardous pollutants that have occurred at the facility in the previous three years and any corrective actions taken to mitigate spill impacts. Definitions: Significant spills include, but are not limited to, releases of oil or hazardous substances in excess of reportable quantities. North Carolina regulations define a reportable spill of oil as a discharge greater than 25 gallons, causes a sheen on surface water, or is 100 feet or less from a surface water body. Reportable quantities of hazardous substances can be found in Section 102 of CERCLA (Ref: 40 CFR 302.4). The SPPP Leader should consult with the environmental contact to determine if a spill of a hazardous material is defined as a significant spill, Date monthlda ear Spill Leak Description Response Procedure Preventive Measures Taken Type of Material Quantity Source, If Known Reason Amount of Material Recovered Material No Longer Exposed to Storm Water (TruelFalse) NPDES Pemr t No. NCO020000 1(e). Certification of Non-Stormwater DischarIzes My signature below certifies that I have evaluated all of the stormwater ouffalls at this facility for the presence of non-stormwater discharges. This certification requirement must be re -certified annually. The Clean Water Act provides that any person who knowingly makes any false material statement, representation, or certification in any application, record, report, plan, or other document filed or required to be maintained under this permit, or who knowingly falsifies, tampers with, or renders inaccurate any monitoring device or method required to be maintained under this permit shall, upon conviction, be punished by fine, imprisonment,' or both. Print Name & Xitle f Signature Date �L2 9 ho Annual Re -Certification Print Name & Title Signature Date Annual Re -Certification Print Name & Title Signature Date Annual Re -Certification Print Name & Title Signature Annual Re -Certification Print Name & Title Date Signature Date cI._-,S 2. Erosion and Sedimentation Control BMP's This facility shall implement the management practices and the erosion and sedimentation control measures that are included in the Mine Permit issued to this operation by the NC Division of Land Resources. A signed copy of the Mine Permit including the approved Mine Map and Reclamation Plan will be maintained on site at all times once the site is occupied and active. Until then this information will be maintained by the Environmental Services staff in the Raleigh Office. NPDrS Permit No. i-,CG420000 3, Material Management Practices Site: Selma Quarry Date: December 9, 2010 Instructions: Based on site material inventory, describe the management practices that control or minimize the exposure of significant materials exposed to stormwater, including structural and nonstructural measures. Description of Exposed Period of Quantity Location Method of Storage or Disposal Description of Materials Management Practices Significant Material Exposure Exposed (as indicated on the Site Plan). (e.g., pile, drum, tank) (e.g., pile covered, drum sealed) Units Crushed Stone Continuous Varies Plant Area Open stockpiles E&SC BMP's Overburden Continuous Varies Pit/Stripping area Open areas, berms E&SC BMP's, Sloping & Seeding Drippings Secondary containment, SPCC Plan, Fuels Fueling Containment Structure AST's only fueling procedure, sorbents Drippings Shop, containment Secondary containment, SPCC Plan, Lube Oils Lubing AST's only structure fueling procedure, sealed drums Corporate lead -acid battery recycling Batteries Limited Minimal Shop area Designated location program Organized storage areas, steel scrap Spare Parts & Periodic Varies Shop area, bone yard Outside/inside storage recycling, Corporate 212 Degrees Equipment Program Trash regularly picked up, placed in Trash Periodic Varies Shop, plant, scale Dumpster, trash drums containers, disposal, Corporate 212 Degrees Program NPDES Permit No. NCG020000 3(a). BMP EDENTIF'ICA ION Site: Selma Quarry Date: December 9, 2010 Describe the Best Management Practices (BMP's) that you have selected to include in your Stormwater Management Plan and the Spill Prevention and Response Plan. For each of the base BMPs, describe the activities involved in each. BMPs Brief Description of Activities Regular Housekeep Inspections; Follow policies regarding Fuels, Used Oil, drums, batteries, tires, Good Housekeeping recycling of steel and other materials; Follow SPCC Plan, Fueling Procedures & safety policies with respect to housekeeping; Corporate 212 Degrees Program; Employee Training. Preventive Maintenance Check for fuel, lube, hydraulic & radiator leaks in daily pre -shift inspections; Use Preventive Maintenance program to repair leaks as reported and conduct scheduled maintenance. Inspections Annual site compliance inspection and regular storm water inspections as required by permit. Housekeeping inspections as mentioned above_ Employee training. Spill Prevention Response Follow existing SPCC Plan including .Fueling Procedure,- maintaining sorbents; maintain ,fuel tanks,. AST; recycle Used Oil properly; keep parts washer inside. Employee training. Maintain'structures and vegetation in areas subject to erosion. Use water truck to wet shot piles, Sediment and Erosion Control stockpiles and roadways to prevent wind erosion. Maintain roadways. Maintain interior site drainage. Keep roadways clean. Maintain sump and stone filters. Work on keeping lids on trash drums and dumpsters closed. Employee training. Consider installing Management of Runoff check dams to trap sediment along haul roads. Recycle water in dust control, equipment washing, & wherever possible. Follow the DLR Mine Plan to insure that all runoff passes through an approved Erosion &Sediment Control structure. Additional BMPs (Activity -specific and Site- Maintain road, stockpile and plant dust controls. Proper recycling of fluids and solid wastes where specific) possible. Parts washer inside shop. =(b)- NPDES Permit No. NCG020000 Maintenance Erosion and sediment control Blrfp's must be cleaned out when sediment storage capacity is at 50% permitted volume. Filter stone on sediment traps, sediment basins, riser basins and rock,cheeks shall be removed and replaced when necessary. Pipes shall be kept free -flowing and accumulated debris shall be removed. Visual_ Inspections A Site Inspection Log has been developed and will be maintained on -site once activity begins. All stormwater structures should be inspected at least once every seven calendar days and within 24 hours after any storm event that results in a discharge. The log is to include at a minimum: the date and time of inspection, observations made, name of the person conducting the inspection, and any maintenance, repairs, or corrective actions taken. A rain gauge shall be kept on site and daily precipitation should be recorded. This record should be kept on site for a period of five (5) years. As required by Permit NTCG02000 semi-annual qualitative monitoring must be performed on each stormwater outfall. The specifies of this visual inspection are outlined in Part 1I1, Section D of Permit NCG020000. 3(c). Secondary Containment Requirements and Records Secondary containment is required for bulk storage of petroleum products in order to prevent leaks and spills from contaminating stormwater runoff. A summary of the tanks located and this facility and their content will be included in the Spill Prevention Control and Countermeasures Plan (SPCC Plan) kept on file at this facility when it is operational. This SPCC Plan will include the procedures and inspection forms for draining accumulated stormwater from the containment area. Records associated with this, should be kept on file for a period of five (5) years 4. Spill Prevention and Response Plan The specific location of all fuel and bulk oil tanks, along with surface flow drainage patterns will be shown in the SPCC Plan. In the event of a spill, response procedures to be followed are outlined in the SPCC Plan. A copy of this plan will be maintained on -site in a designated area. Spill prevention considerations include: leak detection devices, liquid level gauges, good housekeeping, routine maintenance and inspections, and waste minimization. An assessment of the potential pollution sources based on a materials inventory is included in.the Pollutant Sources Assessment Table located on Page 11 of this plan. Provided for each potential source is the name and signature of the facility personnel responsible for implementing that portion of the plan, NPDES Permit No. NCG020000 4. POLLUTANT SOURCE ASSESSMENT Site: Selma Quarry Date. December 9, 20t0 Component of the Spill Prevention and Response Plan Instructions: List all identified storm water pollutant sources from the materials inventory and describe existing management practices that address those sources. Designate the facility personnel res onsible for implementing the BMP's with their signature a knowledging their individual responsibilities., Storm Water Pollutant Sources Existing Management Practices Responsible Individual — Name/Si naturelDate 1. Crushed Stone Stockpiles Approved DLR Mine Plan; S&EC BMP's Not applicable at this time- site is undeveloped 2. Overburden Stripping Areas Approved DLR Mine Plan; S&EC BMP's Not applicable at this time- site is undeveloped 3. Fuels Secondary containment; SPCC Plan, fueling Net applicable at this time- site is undeveloped procedures Secondary containment; SPCC Plan, fueling 4. Lube Oils procedures, used oils recycled by approved Not applicable at this time- site is undeveloped vendor 5. Anti -freeze Inside storage; recycle by approved vendor Not applicable at this time- site is undeveloped 6. Outside storage of spare parts & equipment Designated area; scrap metal vendor Not applicable at this time- site is undeveloped 7, Batteries Recycled through vendor; designated storage Not applicable at this time- site is undeveloped area 8, Trash Trash receptors strategically located Not applicable at this time- site is undeveloped 9. Mobile Equipment Washing Internal Drainage Not applicable at this time- site is undeveloped NPDES Permit No. NCG020000 - }. Good Housekeeping Good housekeeping practices are designed to maintain a clean and orderly work environment. Poor housekeeping can result in excess waste being generated and increases the potential for stormwater contamination. The following are some simple procedures to be followed to promote good housekeeping: Improve operation and maintenance of industrial machinery and processes • Implement careful material storage practices • Provide trash receptors at appropriate locations • Schedule routine maintenance • Maintain well organized work areas • Inform employees about good housekeeping practices Martin Marietta has created the 212 Degrees Clean-up Improvement Program to assist sites in conducting regular scheduled housekeeping. Actions completed by the individuals conducting the work shall be recorded on a form. The forms are for internal or site use only and should only be kept as a record for the Plant Manager to use as a means to track or record what areas have been addressed and then disposed of appropriately Preventive Maintenance A preventive maintenance program is a necessary tool to deter problems before they occur, An effective program includes visual inspections and routine maintenance of the mobile fleet, plant equipment and stormwater management devices. Items to be inspected and routinely maintained are listed below: • Mobile equipment (i.e. pit trucks, loaders, etc.) • Plant equipment (crushers, screens, conveyors, etc.) • Fuel and bulk oil tanks (including all valves and fittings) • Containment structures a Erosion control structures and stormwater conveyance devices • Pit sump • Detention ponds Martin Marietta has incorporated an Asset Management System for tracking maintenance on all mobile and plant equipment. This is a web -based program that follows the manufacturer's recommendations for proper maintenance and repairs on mobile and process equipment. This system tracks hours of operation, repairs and maintenance. 'These records are maintained for the life of the asset (mobile or plant item) within the company. Martin Marietta also employs a pre -shift inspection program. This MSHA based requirement covers each workplace and documents if any imminent danger or hazards exist in the area. This visual inspection would note if there were any spills or leaks in the area. These forms are kept on site for one year. 6. Employee Training The goals of an effective training program are to teach plant personnel, at all levels of responsibility, the components and goals of the SPPP and to create awareness to stormwater pollution prevention concerns. Employees are to be informed of pollution prevention concerns such as: spill prevention and response procedures, preventative maintenance activities, potential sources of stormwater contamination, and materials :management practices. This information should be relayed to the plant personnel, at a minimum, annually during training sessions. Much of this information is already relayed to plant personnel by way of 13 NPDES Permit No. NCG020000 the existing SPCC Annual Training, MSHA Training, Tailgate Meetings and maintenance related training sessions. An outline of the required topics for the training can be found in the Employee Training Chart location on page 14 of this plan. The required Employee Training Record can be found on page 15 of this plan. 14 NPDES Permit No. -iv CG020000 Site: Selma Quarry 6. EMPLOYEE 'TRAINING Date: December 9, 201.0 Instructions: Describe the employee training program for your facility below. The program should, at a minimum, address spill prevention and response, good housekeeping, and materials management practices. Provide a schedule for the training program and list the employees who attend training sessions. Keep all records on file for five 5 ears. Brief Description of Training Schedule for Training Topics ProgramlMalerials (e.g., film, newsletter Training Person Responsible for course) (list dates Training Spill Prevention and Response Spill response procedures; sorbeni storage locations Annual SPCCTraining NIA — Site is undeveloped Good Housekeeping Stress importance to employees. Routine meetings NIA — Site is undeveloped Materials Management Practices Discuss BMP's of equipment, inventory, etc. Routine meetings NIA — Site is undeveloped Preventative Maintenance (Equipment) Shift inspections; scheduled repairs/maintenance Routine meetings NIA — Site is undeveloped Preventative Maintenance (E&SC BMP's) Inspection program; repair procedures Routine Meetings NIA --Site is undeveloped Used Oil Management Place all used oil in the used oil tank at the end Annual SPCC Training of each shift; proper recycling thru approved NIA -- SIte is undeveloped vendor Spent Solvent Management All solvents are recycled thru the parts washer Annual SPCC Training vendor; always cover containers. NIA — Site is undeveloped Spent Abrasives Minimize quantity and locate activity so that Routine Meetings NIA — Site is undeveloped BMP's contain any runoff Fueling Procedures Procedures as outlined in the SPCC Plan Annual SPCC Training NIA —Site is undeveloped Painting Procedures Storage, use and disposal practices Routine Meetings NIA —Site is undeveloped Used Battery Management Recycle through vendor, sales outlet Routine Meetings NIA — Site is undeveloped 15 NPDES Permit No, NCG020000 6. SPPP - EMPLOYEE 'TRAINING RECORD Facility:Selrna Quarry Date: December 9, 2010 Instructions: This training record needs to be completed each time SPPP related training takes place. The program should, at a minimum, annually address stoma water runoff, potential pollutants, surface water protection, spill response and cleanup, good housekeeping, preventative maintenance, erosion and sediment control BMP's, and materials management practices. Have employees who attend the training sign this form after training is complete. Suggested Training Topics Brief Description of Specific Training Conducted Training Date(s) • Surface/Storm Water Runoff + Preventative Maintenance • Spill Prevention and Response • Good Housekeeping • Materlal Management Practices Person Conducting Trainin.Uname and signature): Attendees (signature): Training Notes & Suggested Topics of Discussion: Pollution Prevention Team — Who is the leader and who are the members? Potential Pollution Sources — Identifies potential pollutant sources onsite (oil, sediment, soild waste)? Measures and Controls - What measures and controls are in place? How do they work? Site Evaluation/Inspection -- What is it? How is it done? What does it tell us? Copies of these completed Training Records shall be kept on fife at the facility for five (5) years. 16 NPDES Permit No. NCG020000 7. Responsible Party Listing Site: Selma Quarry Date: December 9, 2010 Each of the individuals listed below are responsible for the development, implementation, maintenance and revision of the SPPP. At this time this is an undeveloped piece of property. No activities are occurring on site that require development, implementation or training. As activity begins this plan will be modified and followed. Until the site is activated the following parties will be responsible for monitoring the site. Members: Steve Whitt Title: Director, Environmental Services Phone No.: 919-783-4630 Nuwan Wijesuriya Title: Environmental Engineer Phone No,: 919-783-4505 Ray Thatcher Title: Area Production Manager Phone No.: 910-796-7631 17 NPDES Permit No. NCG020000 $. Plan Amendment This plan shall be amended whenever there is a change in design, construction, operation, or maintenance that has a significant effect on the potential for the discharge of pollutants to i surface waters. Appropriate changes shall be made and a revision date should be' added to the front page. Plan Review The following certification needs to be reviewed by each Responsible Party identified on page 17 of this plan. My signature below certifies that I have reviewed and understand the Storm Water Pollution Prevention Plan (SPPP) and agree to perform, to the best of my ability, all requirements as described herein. The Clean Water Act provides that any person who knowingly makes any false material statement, representation, or certification in any application, record, report, plan, or other document filed or required to be maintained under this permit, or who knowingly falsifies, tampers with, or renders inaccurate any monitoring device or method required to be maintained under this permit shall, upon conviction, be punished by fine, imprisonment, or both. Print Name & ffitle Signature Date IZbahap Print Name & Title / l&( r✓y� �"� '9 iz I �'/a _ Nti Ciy „vF 2 Signature�_N Date / I�'�i� Print Name & Title Signature Print Name & Title Date Signature Date, 18 ii/Ao GROUND -WATER CONDITIONS IN THE VICINITY Or THE PROPOSED QUARRY SITE NEAR YATL'S MILL IN WAKE COUNTY, NORTH CAROLINA PREPARED FOR MARTEN MARIETI'A AGGREGATES RALEIGH, NORTH CAROLINA PREPARED BY TRIANGLE ENGINEERING AND SURVEYING, INC. 1625 NAVAHO DRIVE RALEIGH, NORTH CAROLINA GROUND -WATER CONDITIONS IN THE VICINITY OF THE PROPOSED QUARRY SITE NEAR YATES MILL IN WAKE COUNTY, NORTH CAROLINA INTRODUCTION Purpose and Scope of the Investigation The purpose of this investigation was to make a determination of the impact, on the local ground -water aquifer, caused by the development of a rock quarry near Raleigh, North Carolina. Near the quarry site are several single-family dwellings and a mobile -home park. The residents have expressed concern that dewatering operations at the quarry may cause excessive lowering of water levels in their wells, in response to this Concern, Martin Marietta Aggregates requested Triangle Engineering and Surveying, Tnc, to make an investigation of the ground -water conditions in vicinity of the quarry site and to determine, so far as reasonably possible, the amount of change that may be produced in ground -water levels at various distances from the proposed quarry pit. w Description of the Area The area of investigation includes the 81-acre tract owned by Martin Marietta Aggregates. The tract lies on the east side of Lake Wheeler Road (SR 1371) near its intersection with SR 1379 at approximately 4 miles south of the City of Raleigh. The proposed pit area of the quarry lies on the south side of the creek leading from Yates Mill Pond in an east --west direction. The location of the tract is shown in figure 1. Underlying the entire tract is bedrock composed largely of horneblend gneiss. It is overlain by weathered rock and soil ranging in depth from one or two feet on the hill tops to as much as f if ty f eet in the low f lat areas. Ground• -Water The portion of the outer crust of the earth that contains ground -water may be regarded as an underground reservior. .The underground reservoir in the Raleigh area consists of two contrast- ing types of materials, (1) the clayey and sandy soil and saprolite whieb underlies the surface to depths generally ranging from several tens of feet and (2) the underlying bedrock. In the soil and saprolite, water occurs between the individual mineral grains, but in the underlying bedrock it occurs only in fractures. These fractures generally are not evenly distributed, so that they may -2- 1.7 71 .77 i� be an inch or two or several feet apart. Many are interconnected sufficiently to allow ground -water to circulate through them. In many places fracture openings are only a fraction of an inch wide, although there is a great variation in size of openings. The size and number of fractures appear to decrease with depth. As a result; most ground -water occurs at a depth of less than 150 feet -- much of it is the upper 30 feet of bedrock. Therefore, the lower limit of the reservoir is a thick, indefinite zone; the top, however, is a definite though fluctuating surface known as the water table. Ground -water moves slowly through the soil and fractures in the rock, always under the influence of gravity. After percolating downward en masse through the soil and saprolite, ground -water is restricted in circulation to fractures in the bedrock. The water does not generally move to great depths but instead is shunted almost laterally by "tight" or impermeable rocks to discharge points near the level of the perennial. streams. Thus, in areas such as the quarry site, the movement of ground -water from the recharge, or interstream, areas to the discharge, or stream, area follows, in general, a short, sinous path, with the water flowing locally through interconnecting fractures in the bedrock and through pore spaces in the overlying saprolite and soil. -3- The water table, or upper surface of the underground reservoir, continuously changes its position, reflecting changes in ground --water storage. There is a constant discharge of ground -water by seepage into streams and by evaporation and transpiration by vegetation.. The discharge causes a gradual lowering of the water table except during and immediately after periods of signigicant precipitation when recharge to the underground reservoir exceeds the discharge. As a result of these periods of precipitation, the water table rises. With a year of normal rainfall the recharge to the under- ground reservoir is approximately equal to the discharge from it, so that the water table at the end of the year is at approximately the same level as at the beginning of the year. In the Raleigh vicinity there is a noticeable change in the water table with the seasons. It generally begins to decline in April 4ecause of the increasing amount of evaporation and trans- piration by plants, which not only consume ground water but reduce the amount of precipitation that reaches the water table. Although interrupted by minor rises due to heavy rainfall, this decline generally continues through summer and autumn, in spite of the usual abundant rainfall of July and August. By November or December, when much of the vegetation is dormant and evaporation is low, more of the precipitation reaches the aquifer and becomes recharge, and the water table begins to rise until it reaches another high stage about March or April of the next year. -4- A' Aside from the above considerations of climate, the depth, of the water table in the Raleigh area depends chiefly on topography and on the transmitting characteristics of fractures in the rocks. The water table lies in the saprolice or overburden in most places, especially beneath the broad upland areas where the saprolite is thick. Although there is a great variation in the depth to the water table and in the thickness of the overburden, the water table generally lies several feet above the base of the saprolite. During droughts, when it may be several feet lower than during the wet seasons, the water table may be in the bedrock in some places. INVESTIGATION The first step in determining the ground --water conditions in an area is to research the available reports and records. This was done for the proposed quarry site. However, because of the sparse.population of that vicinity, there are few well records available other than those published by the N.C. Department of Water Resources in 1968'in the report entitled,"Geology and Ground --Water Resources in the Raleigh Area, North Carolina". This report discusses, in general, the geology and occurance of ground- water in the.various geologic and topographic conditions in the Raleigh area. -57- To obtain specific data at the proposed quarry site, Martin Marietta Aggregates drilled six wells on the tract as shown in figure 1. The wells were all b-inches in diameter and were cased with steel casing; and grouted with concrete. Logs of these wells are given in table I. Attempts were made to run aquifer tests using two of the wells for discharge points. However, insufficient sustained yields and running sand made it impossible to obtain a meaningful test even - though more than a full week was spent in the effort. The physical character of the bedrock in the quarry vicinity, and in general, makes it extremely difficult to determine its hydraulic properties. The size and degree of interconnection between the joints, bedding planes and fracture zones determine the aquifers ability to transmit water to a pumping well and also determine the direction and distance from such a well or quarry pit that the effects of pumping can be detected. The occurence of the openings in the rock is quite heterogenous, and often there is no clue at the surface of their presence or character. Even wirb a test drilling program such as recently completed on the site, there is no quarantee that the true character of the water bearing rocks can be determined. Inasmuch as the six test wells and attempted pumping tests did not produce any great amount of new data, we are now required to evaluate the hydraulic properties according to the general knowledge of the area and by applying specific information from other similar sites. In figure 2, a generalized section through a typical quarry wall is given. The section illustrates the occurrence of over- burden, bedrock, and the movement of water through the aquifer towards the quarry pit. The most pertinent item to note.on the drawing is the edge of the zone of influence at approximately 500 feet from the edge of the pit. This dimension was determined from a study made at the Stateville quarry where several wells were available to provide water level data from geologic conditions similar to those at the proposed site. Also at other quarries there are wells within 500 feet of the pits that have been producing water without problems for a number of years. At the proposed site, well number 3 was pumped for 9 hours with a drawdown of approximately 110 feet with no measurable effect on the water level in well number 2 at only 92 feet away. In summary, it is not anticipated that any significant lower- ing of water levels due to quarry dewatering will occur beyond approximately 500 feet from the edge of the pit in a year,of average precipitation. However, it must be recognized that an -7 - anomalous extensive fracture system could he influenced at a greater distance by dewatering operations in the pit. These conclusions are based on a general, knowledge of the geologic condition in the Raleigh area and experience in working with ground -water problems at quarries in similar geologic and topographic conditions. tGAkfC)"I to . SEAS- . • X: r p 4 >0lo _ • C L01 2C ; 5 Z 10 0 CA CL t -T PRECiP:TaTlCN AT RALEIGH i955 9 94, 194D 1 194, 42 J'Z343 F� 11944 1 1945 1 1946 1 ; ' , i j 950 1951 1 1952 1 1953 1 s9541 ��6 :967 0 Iff94Y 1949 Figure I .--(-',-a-Dhs shoving relation of vater-levees. �'Iuctuat4or-s -n a duc, well to for the period 11339-58. Well No. 1 Gec .Logy : 0-8' 11'-1.58' Well No. 2 Geology: 0-11' 11'--60' 60' -64 ' 64 '-120' Well No. 3 Geology: 0-7' 7-10' 10-120 TABLE 1 - WELL RECORDS Depth 158' Red Sandy Clay Saprolite Bedrock Depth 120' -Casing Depth Static WL 21' ~21' Casing Depth 11' Overburden Bedrock Soft Micaceous Seams Bedrock Depth 120' Casing Depth 11' Static WL 21' Static WL 13' Overburden { Saprolite i Bedrock TABLE l - WELL RECORDS (Continued) Well No Depth Casing Depth 4 158' Geology: 0-9' Red Clay 9'-46' Bedrock 46'-49' Soft Seam 49'-100' Bedrock 100'-103' Soft Seam 1031 -158' Bedrock 5 Geology: 0-7' 7'-35' 35'-158' 21' Static WL 5' DeptE,�v Casing Depth � Static WL 158' 16' Red and Brown Sandy Clay Brown and Grey Saprolite Bedrock with Several Soft Seams Well No. Depth Casing Depth J M^� Static WL__�__ _ 6 30' Geology: 0-19" Overburden 19'-29' Saproli.te 291- Bedrock CARRY RIP-RAP OVER'MP OF PIPE CALF.P.MITRED To ER TORiN To SLOPE � ADJACENT LAND OWNER INFORMATION ADJACENT O O INFORMATION RIP-RAP(DUMPED IN PLACE)TO FORM r� ,r a 1 PARCEL ID OWNER NAME NC PIN NO, ACRE-AGE DB PG OWNER ADDRESS CHANNEL(SEE SCHEDULE) -- _ s.a.e.s soonnar 1f P LENGTI3 1'-0' I a,ft4. l -.1.-. tz^.ofNivvias 01 Ile SEE CHART BELOW - F Ir'°� m�f - ="57=��°=` PARCEL ID OWNER NAME NC PIN No. ACREAGE DB PG OWNER ADDRESS bj� a V' ' 1Nan.I.eve1 of sedirt■a,t - (Tdna1 Bacin Capacity) _ Clan 1 (((47,4))ye•t*Ib; p co c n n V-6' F - - 1 1 Vann Bernard&Wyrlema 169600-73-2842 0.81 17130364 100 Clearwater Drhe, Simthfield NC 27577 �- 4-FILTER WASHED STONE BED, when t level is reached sediment Depth +L� 1 FILTER NAaR1C OR EQUAL.t l 4Z 4 2 Tillery, Christopher& Heather 169600-73-3952 0.51 2111_Q234 104 Clearwater Drive, Simthfield, NC 27577fe CARRY t12 WAY UP PIPE EDGE. � ��r - vaxi 1 I Pixie. . Y I 3 Johnson, Marcia&Terrence 169600-73�929 0.51 1670 0567 108 Clearwater Drive, Simthfield, NC 27577 .�l� �tr��•t ,;,u. 4 Daniels, Carol G. 169600-74-4076 0.53 242f 0244 612 Powell Street, Smithfield, NC 27577 - r14,r:. l « t��'* C,�,;P,•P�P 5 Clay, Hal Robertson III& Cecil McNeil 169600-74-5142 0.56 1778_0809 116 Clearwater Drive, Smithfield, NC 27577 ."{fir IF t)4itrollr�>r sides of spillway TEMPORARY SEDIMENT BASIN DETAIL t ., .tr R ��,�'f V4 6 Johnson, Gregory & Elizabeth 169600-74�1 i9 0.55 25 _0 612 Powell Street, Smithfield, NC 27577 t b� R r t� •` • l4 A 7 Daniels, Carol G. 169600-74-6266 0.56 2552_0580 612 Powell Street, Smithfield, NC 27577 •)cif SEE SCIW.DULE FOR STONE SIZE&AREA IS® ~' 8 Johnson, Gregory& Elizabeth 169600-74-7321 0.58 2257 0003 612 Powell Street, Smithfield, NC 27577 ��, (cliff-Er PROTECTION) Pia al Rip-Rap 7441,11k4 1 9 Smith, Steven&Sherry 169600-74-8307 0.57 2326_0314 132 Clearwater Drive, Smithfield, NC 27577 ww '� 10 Gibson, Christopher&Tawanna 169600-74-8472 0.55 1779_0156 612 Powell Street, Smithfield, NC 27577 CULVERT MAX.FLOW ENERGY 5 R is ' SIZE SLOPE lei} DISSIPATER / a : 'l, 11 Johnson, Gregory & Elizabeth 169600-74-9457 0.53 2257 0019 612 Powell Street, Smithfield, NC 27577 (CMP) Class Li-idr thick �� a' 1.S 42" I"/a s4.6a « '101111111W S•�p„ 12 Huddleston, Kenneth & Donna 169600-84-0513 0.50 1806 0474 P.O. Box 463, Wilson, NC 27593 ` 28'Lx17.5'W �J'l- t 13 Wolfe Investments Inc. 169600-84-0588 0.51 1753 0678 2305 West US 70 Highway, Goldsboro, NC 27530-9549 - Culvert�ignmay be field modified oncetheMIN r 14 JI. ohnson, Gregory Elizabeth 169600-84-1t 5 t7.50 2175 0704 G12 Powell Strut, Smithfied, NC 27577 appropriate flaw is verified PERSPECTIVE VIEW 15 Daniels, Carol G. &Johnson, Gregory 169600-84-2741 0.50 2184 0110 612 Powell Street, Smithfield, NC 27577 PIPE OUTLET WITH RIP-RAP PRCI IECI'IOt3 16 Palma-Martinez, Ceasar Au gusto 169600-84-3707 0.51 2207 0750 160 Clearwater Drive, Smithfield, NC 27577 SECTION THROUGH TEMPORARY SEE0MAhIT BASIN 9 17 Daniels, Carol G. &Johnson, Gregory 169600-84-2741 0.52 2184 0110 612 Powell Street, Smithfield, NC 27577 - 18 Stevens, Oliver 169600-84-4859 0.53 2186_0134 168 Clearwater Drive, Smithfield, NC 27577 ` 19 Parrish, Doris&Thomas 169600-63-5819 14.85 3157 0812 112 Bridge Street, Smithfield, NC 27577 f if--ICI MID- --,r. 20 Roberts &Wellons, Inc. 260600-28-3235 750.90 0561_0113 P.O. Box 299, Smithfield, NC 27577 2441"Travel Surface Pitch mown to drain 21 Lucas, Robert&Victoria 260600-45-4517 56.97 2460_0321 ' 6095 Buffalo Road, Selma, NC 27576 A / interior of prepaay mono die 22 Lucas, Robert 26060t345-7011 50.40 1789 0029 6095 Buffalo Road, Selma, NC 27576 23 Lucas, Robert 260600-54-2320 76.16 . 1789_0029 6095 Buffalo Road, Selma, NC 27576 / 12'0" 12'-0" / s'o" Ditch t 28•Min. l p, y,yt;� 24 Creech, Gertrude 260600-63-6028 65.59 0745_0087 141 Clay Ridge Way, Holly Springs, NC 27540 !ram 21 2 Vaeies 25 Johns, Russell 260600-72-1327 7.52 2909_0203 5291 Buffalo Road, Selma, NC 27576 I grassed shoulder Grade Point shoulderI Existing • 26 Easom, Alma 260620-72-7092 21.94 0731 0078 118 Canterbury Road, Wilson, NC 27896 Existing l/z/� -1/4"/ ]la"/Ft /F 27 Rose, James Kirby EST&Thomas Franklin RMNDR 260620-91-0677 54.74 2911_0869 140 Old Plantation Ct. Winston-Salem, NC 27104 Glade �• ' 28 Thompson, Thomas 260620-80-0423 29.96 2975_0417 4775 Buffalo Rd., Selma, NC 27576 t-112"bituminous concrete surface course,type"e"or"f" 29 Thompson, Thomas 260502-79-6607 24.40 1511_0105 4775 Buffalo Rd., Selma, NC 27576 3"bituminous concrete binder course,type"b" 30 Roberts& Wellons, Inc. 260502-69-9086 60.00 1051_0202 P.O. Box 299, Smithfield, NC 27577 - Tack coat placed at rate of 0.05 galisq/yd. 31 Jams E Snakenberg,P.E,NCDOT-General Services Division Director 260502-59-9264 38.00 Not Available 1525 Mail Service Center, Raleigh, NC 27699-1525 8"aloe(crushed stone paving) Subgrade compacted to 95%AASHTO density 32 Hobbs, E.G. & Michael R. 260501-38-5359 95.50 Not Available 220 Glade St., Chapel Hill, NC 27516 Pitch crown m dial■ See ditch schedule for depth and width of ditch l T"° t I� of:� 33 Hinnant, Richard&Carolyn 260501-29-2529 43.21 3091_0580 4673 Hinnant Edgerton Rd. Selma, NC 27576 34 Bruton, Eugene&Sheila 260600-11-9019 3.43 1643_0410 105 Cobblestone Ct. Smithfield, NC 27577 i, ASPHALT ROADWAY WITH DITCH urtte■maSloped le Beach Sloped 35 Parrish, Thomas K. - 169600-63-3267 1.03 1109 0375 1834 Bear Farm Road Smithfield, NC 27577 re not to scale to Iaeier � to laicuor - "` Varies 36 Parrish,Doris J Like Estate& Parrish,Joseph E.Ill RMNDR 169600-63-8586 8.20 3167_0816 112 Bridge Street Smithfield, NC 27577 -ra 1 dL °'''E. 37 Parrish, Joseph E. III& Fairish,Allison J. 169600-63-4383 7.65 2309_0486 1836 Bear Farm Road Smithfield, NC 27577 38 Hales, S. Wallace& Glenda S. 169600-62-6695 12.20 1997_0360 9 Beach Front Road South, Wilmington, NC 28411 28 Thompson,Thomas 260620-80-0423 29.96 2975 0417 4775 Buffalo lid Selma,NC 27576 Table updated on 12-20-06 using information gathered from the Johnston County GIS website. 24'-0"Travel Surface(typ.) / 4775 Buffalo Rd 29 Thompson Thomas 260502-79 6607 24.40 1511 0105 Selma,NC 27576 Post Office Box 299 B'-0" l2'-0" 12+-0" 8'0" DITCH CH Top 30 Roberts&Wellons,Inc. 260502-69-9086 60 105l_0202 Smithfield,NC 27577 grassed / / / grime Pitch etowu to dreia 1 r0"DfftP�0 31 Department of Transportation 260502.59-9264 38 Not Available Not Available shoulder ishoulder ci �emeaar°rteape ern - ! Grade Point V ----�. Existing 20 Beech SlopedI 'I 2a Bench Sloped 32 Rah*,E-G.&Michael R. 260501-38-5359 95.5 Not Available �0 Glade S2. Existing _in.iv_ --u,i 1' -1/4"/1' -�"/I' Grade w Interior 3S rYP. mlmerior Chapel hill NC 275t6 Grade 1 1 l y �( 33 Hinnan,Richard&Carolyn 260501-29-2529 43.21 309 t_0580 467311inoant 2e7BeachSloped �E oe rv� ]STYP. 2oomaSiopee Etlgcttoand. // Selma,NC 27576 t ff Smithfield,NC 27577 2 1 lawn, 34 Brawn.Eugene&Sheila 250600 I 1-9019 3.43 r643_0410 105 Cobblestone CS- Su6grade compacted to 95%AASHTO density NOTE:crushed stone paving shall l be maintained by owner as requited / 357'`p z 8"min.crushed stone paving 24'ROADWAY(Crushed Stone) PIPE EXIT TO PLUNGE POOL not to scale NOTES: 1. Slopes will be tracked during construction to aid in the establishment ofvegefative cover. 2.An exposed areas will be stabilized immediately fallowing mnsbur2iun- PIPE TYPICAL BERM CROSS SECTION 1 5' FROM SUMP 5, NATURAL GROUND not to scale j 265'L x 75 W 1 PIPE OUTLET (INSIDE FROM TOPOF BANKS) PLUNGE POOL . . . ,....... NATURAL GRADE I 2:1 1I2 ' 2:1 n. _.A Vegetated 7toaiwm CO 3 �V 013,16,• NATURAL �.-•Diversion - GRADE 16111 `'-S1e°e Typical Cross Section )f Pit Clarification Pond with Plunge Pool ' not to scale Stable -f- - '�- ---. --, - unaisttul7ed` L . . calla _ _ _ \} . , . . . . • .'. vy c„mpaatea rat •. ...- .-. -•. r•.•.. • - Filter Fabric DIVERSION DITCH SCHEDULE NOTE: V-Ditch No. V-Ditch Size Length of Ditch Elevation Slope(%) Lining Temporary Ditch Liner I I / 1. NCDOT#5 stone is preferred. Pad to be 50 ft. L x T(Ft.t x D(Ft.Z (Ft.) Change(Ft.) • CROSS SECTION 1 / 4t 20 ft.W x 6 in.thick(min.). TD#1 6 x 1 349 2 0.6% Tall Fescue Not required g«I " e ,y* 2. Turning radius sufficient to accommodate large TD#2 6 x 1 564 10 1.8% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 Ibs/sq.ft. trucks• TD#3 6 x 1 600 4 0.7% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 Dbs/sq.ft Material Variable rt Min v Tom' \ �i"3tk permissible shear stress=1.45 lbs/sq.ft „, ,. 3. Must be maintained in a condition which will TD#4 6 x 1 350 3 0.9% Tall Fescue Straw wilh Net liner with a Backfill spin.8"thick / .41h!+'?s i J'O •>,sa. �Y�i prevent tracking or direct flow of mud onto streets. TD#5 9 x 1 370 1 0.3% Tall Fescue Not required ., -.. r r layer of gravel t+• . .t'�' 4,,... o g maymay- TD#6 9 x 1 558 1.5 0.3% Tall Fescue Not required " i ►►.y •�R Periodic topdressing be n r s • ✓ F ■i S s?Ss ■. s■' ■ -.'r x e-+",' r. .-'' ,...1„,,,..-` i r ;!aa. .', 4. This construction entrance will be installed at allpermissible shear stress=1.45 lbs/sq.ft. / ;� TD#7 6 x 1 485 4 0.8% Tall Fescue Straw with Net liner with a Filter Fabric r+. ti' r ►+S .+_ a •� ► ► • s } z i* :2 C - t / r� l � ��� �,��� entrance and exit points to the site. At this time the TD#8 6 x 1 561 6 1.1% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.it. i ■r •it ■•f • ■' ■ r r• ■ r'-P { +' a r a a•to r,!.r , 0: •'►a•'i + ���tt tt~y+ only entrance and exit shown on the site plan will be ID#9 9 x 1 520 1.5 0.3% Tall Fescue Not required i.� i! i..w,.� �t !': e P r� S ■ y P■ e- s %■ s s.�■ s s t, i .r+ra.4. as + ►♦��� ++s • •■.cos' ►`" I,ti.+Ir2+`ta Erbil ii �, paved as part of the initial project. TD#1 D 6 x 1 432 4 0.9% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft 6 a + w "..r �`h. P r,.' h a l'I a.�.,1 .rri �a1�a fit,,,� paS• ++� 1 }tat Isms i`:s*;- S AS,,, sss% 4� TD#11 6 x 1 430 2 0.5% Tall Fescue Not requited _ Level wreak.t o �> L 0-rha Ova15 ft.� �iiti .�l s ,1 TD#12 6 x 1 600 6 1.0% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. nya,fro.de " ' `+4.t. ��4;� 14; yy TD#13 9 x 1 504 1 0.2�a Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq-ft. The grade ma.rr wrnsae 4" Wire ,, Villi r%i' exceed 30 Cfs. s r„svx,anwe+a .,rnra 6u merit. stone Berl .ts`r .1 `j • ,,+.. r TD#14 6 x 1 368 1 0.3% Tall Fescue Not required - �' LEVEL SPREADER - TYPICAL tu"eahrm,me�rdu�..arae.�rarwu Extension of fabric and pit►iii'r ++`.i, l,�l� TD#15 9 x 1 406 1 0.2% Tall Fescue Not required ��� �, N TS wire into the trench `ir7 CONSTRUCTION ENTRANCE TO#16 6 x 1 367 2 0.5% Tall Fescue Not required Stone Size : NCDOT#5 TD#17 9 x 1 601 1 0.2% Tall Fescue Not required or#57 washed stone not to scale TO#18 6 x 1 274 1.5 0.5% Tall Fescue Not required SILT FENCE DETAIL TD#19 6 x 1 93 1 1.1% Tall Fescue Not required Level Spreader Design Notes - I TD#20 6 x 1 290 7 2.4% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft TD#21 6 x 1 165 2 1.2% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. TD#22 6 x 1 245 4 16% Tali Fescue Straw with Net liner with a permissible shear stress=1 45 lbs/sq.ft For all dischanre points located adjacent to the Ne use River Riparian Buffer: TD#23 6 x 1 172 2 1.2% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbslsq.ft Table 6-11p.Seeding for.Well-to-Poorly Drained Soils, w Maintenance SEEDBED PREPARATION NOTES: TD#24 6 x 1 464 2 0,4% Tall Fescue Design Flow Entrance Width Depth End Width Length [from North Carolina Erosion and Sediment Control Planning and Design Manual] � Not required 9P9 TD#25 9 x 1 886 14 1.$% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. 1 Erosion control Measures are to be installed accordingto ran. (cfs) {f0 (ft) (ft) (ft) ) p TD#26 6 x 1 542 7 1.3% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft 0-10 10 0-5 3 10 Seeding Mixture TD-- - benand spread with topsoil(ifnecessary), deep Total Tall Fescue Straw with Net liner with a permissible shear stress-1.451bs/ ft. _.. . n s Areas bestall be 4"- "rippedTall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. 2) seeded shall � sop sea 3" #27 x 1 284 5 1.8% Species Rate bs/ac,) seedbed prepared 6 deep. TD#28 6 x 1 297 12 4 0°/n TD#29 6 x 1 352 22 6.3% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 Ibslsq.ft. Tall Fescue 80 TD#30 6 x 1 694 5 0.7% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. Pensacola bahiagrass St) 3) Loose rocks,rods,and other obstructions shall be removed from the surface so as not to TD#31 6 x 1 890 9 1,0% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. Seneca lespedeza 30 interfere with the establishment and maintenance of vegetation. Surface for final seedbed Kobe lespedeza 10 preparation,at flnaltrades shown,shall be reasonably smooth and uniform. TD ilr32 9 x 1 542 1 0.2% Tall Fescue Not required TD#33 6 x 1 498 3 0.6% Tall Fescue Not required .f TD ilKi4 12 x 1 936 2 0.2% Tall Fescue Not required X 4) If no soil test is liken, provide fertilizer and lime according to seeding schedule. � - 1074sP• Seeding notes: TD#35 $ x 1 191 1 0.5% Tall Fescue Not required vs r "'� I ' ' 1.From Sept 1 -Mar.1,use unscarified sericea seed. TD#36 6 x 1 639 4 0.6% Tall Fescue Straw with Net liner with apermissible shear stress=1.45 lbs/sq.ft eP5) if soil testis take,provide fertilizer and lime according to the soil test report. Soil testing is•...,.., , .. ],„.,.,,......„, ,. 2.on poorly drained sites omit Seneca and increase Kobe to 30 lb/acre TD#37 6 x 1 96 4 4.2% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft 3.Where a neat appearance is desired,omit sericea and increase Kobe to 40 lb/acre. TD#38 6 x 1 238 10 4.2% Tail Fescue Straw with Net liner with a permissible shear stress=1.45 lbsfsq.R ' 6) Lime and fettllta shall be applied uniformly and mixed with the soil during seedbed TO#39 6 x 1 265 15 5.7% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. } Nurse Plants preparation. TD#40 6 x 1 210 18 8.6% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft- � � Between Apr. 15 and Aug. 15,add 10 lb/acre German millet or 15 lb/acre Sudangrass. TD#41 6 x 1 177 18 10.2% Bermuda Synthetic Mat liner with a permissible shear stress=2.00 lbs/sq.ft. las��- -" Prior to May I or after Aug, 15,add 25 lb/acre rye(gain). TD#42 6 x 1 215 21 9.8% Tall Fescue 7)Roughen surfaceaccording to Surface Roughening detail provided. Synthetic Mat liner with a permissible shear stress=2.00 lbs/sq.ft. TD#43 6 x 1 64 3 4.7% Tali Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. *is' ;s s _ TD#44 6 x 1 323 16 5.0% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. stair sp�nPi„a CIO sl.' Seeding Dates TD#45 6 x 1 500 10 2.0% Tall Fescue Straw with Net liner with a pemtissible shear stress=1.45 lbs/sq.ft. \ . .. .....att Best Possible TD#46 6 x 1 127 2 1.$% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. Early Spring: Feb. 15-Mar.20 Feb. 15-Apr.30 \'''4,.S.;:'4•',.::;:....: • Fall: Sept. 1 -Sep# 30 Sept.1 Oct.31TD#47 6 x i 32482.5% Tall Fescue StrawwithNetlinerwith a permissible shear stress=1.45 lbslsq.ft. TD#48 6 x 130D2fi8.79'oTallFescue5 ntheticMatlinerwitha I y permissible shear stress=2.DD rbslsq.ft. ,..,k--- 3' Soil Amendments TD#49 6 x 1 745 30 4.0% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 Ibs/sq.ft. Apply lime and fertilizer according to soil tests,or apply 3,000 lb/ac-5,000 lblac.ground TD 1150 6 x 1 114 1 0.9% Tall Fescue Not required croaviag slops agricultural limestone(use the lower rate on sandy soils)and 1,000 lb/ac. 10-10-10 fertilizer. - MIEBLaragi Mulch 1'tame SWIPE tat 05 t.raycr ar I outnne�t NOTES: Apply 4,000 lb/ac.grain straw or an equivalent cover of another suitable Washed Wimp - Rwegl,caw can be achieved with tracked machinery in area mulching material.Anchor mulch by tacking with asphalt,roving,or netting,or ,tpe aL .. Esr.woe voids sandy suds. bycrimpingwith a mulch anchoringtool.A disk with blades set nearlystraight .^ ..-.. . 4�+•u and u - Operate tracked machinery aP and down the slope to leak - t.9 lhicY SEDIMENT TRAP SCHEME • horizontal depressions m the raze SURFACE ROUGHENING DETAIL can be used as a mulch anchoring tool. �� - �- �pgorg�vecutslopeswithag rnrracerthan rnrq,xr 3:1. not to scale au-0ffirmm FILLER fA9N1C - use dsta gas say erodible material soft enough to be Maintenance - Immmedi Immediately seed and mulcb roughened arms to obtain optimum If growth is less than fully adequate,refertilize in the second year,according to soil tests orrix NAMd swarm arh Sediment Drainage Sediment Sedimen Trap Dimensions Weir Dimension seed germination�growth. or topdress with 500 lb/acre 10-10-10 fertilizer.Mow as needed when sericea is omittedege Trap No. Area(Ac.) Storage(Cu. Ft.) L(Ft.) �W(Ft.) H(Ft.) (Ft.) from the mixture.Reseed,fertilize,and mulch damaged areas immediately. ST A 0.25 450 28 14 4 4 ST B 0.50 900 40 20 4 4 • ST C 0.75 1350 48 24 4 4 Spillway peas STD 1.00 1470 56 28 4 4 _ . /< S4% Place material from excavation on ST E /e2, downhill side of flow. Use additional Taptt Rack Abutment ST F 1 50 22770000 68 31 4 6 fill to achieve specified height and width. :111 [anti Aran ./(Cf9\‘7,- ./ . ,�iQ�� 2'mill, slope F, ,t: ST G 1.75 3150 72 36 4 6 .•.. Spillways . ss sEem:, ......:::::.:-.--.11IIIIMII:: a...,.,.., 39 4. . • ST H 2 00 3600 78 6 " ID Filter abrfO f� +-� 2 HIGHWALL BARRIER SAFETY BENCH . .. `'\ H=-1' V Flow a ' NOTES: '° "°� ROCK DAM SCHEME sy a�� 111.._ 21 I Sediment MEAD dm basin win be located 1 � ' `3-1 away from than to prevent short circuits -* `s� -.- 3 `°'Whet Rock Dam Drainage Sediment Sedlient Trap Dimensions Weir Dimension Seed and mulch diversion channel artd dike - Three porous>Riea will be installed as _ immediately after construction.Choose appropriate • shown on tt" `d'Baffle No. Area AC. Sto a Cu. Ft. L(Ft. W(Ft.) H Ft. Martin Marietta Materials /� �- - sednaeat+avlll+temovMandns,medtn .Rock Dam 1 5.00 18000 122 61 6 12 RALEIGH, N.C. y V \\ .--- Varies seeding mixture from the seeding schedule. Basins will ba.p«tea steer every rainfall ( rag ( L ( ) (Ft. 3'min. 20'TO 100' original volume/hen sediment accumuhste l+ � ttli the d volume. ROCK DAM SEDIMENT BASIN observedMill - Repairs m d as` ''' °` N TS) DETAILS SHEET TEMPORARY DIVERSION DITCH See Rock File lame:Selma Details-S-9 47.dwg _1 REVISION SELMA QUARRY I Fia-o7 ceded details based on wrests far additional information e7'land Quality is a letter dared February 20,24107. Notes: C _ 1) Sediment traps(ST)are sized for the total drainage area with I clean out per year. PIT DIAGRAM JOHNSTON COUNTY, N.C. 3 NOT lttKALE Selma 'Permit No.: 51-46 2)Weir dimensions are minimum requirements from NCESCPDM(Table 6.60a) - ° Quarry: - 3)Erosion&sediment controls will be adjusted in the field as necessary to conform Go actual topography. p-�_ DWN BY: DATE: PAGE NO. N.Wijesurlya 8-27-09 6 - 2of2 -' 7 - CR_BY: S.Whitt SCALE: Not to scale - ate .-.7- - -- - II fr._'l-t i I ' • I+ : i ...QQQ - . :.I Tt- T' ,75-T+,�r1I :-5 , i' ,• TIS 1rI� 'I , 7 t t 1 I r , +..•,., .'.!'::/.... ".'!..:*i r .� t :...i.'..{. '.' 1 '� l '1. ., is l' . i 1 , t ',1, l rltf' a').'it ,i y� ��}f; CARRY RIP-RAP OVER TOP OF PIPE C.M P.MITRED TO CONFORM TO SLOPE .n 4m-� ADJACENT LAND OWNER INFORMATION ADJACENT LAND OWNER INFORMATION RIP-RAP(DUMPED IN PLACE)TO FORM 7°r of Hem C'°I paaP 01, y_ CHANNEL(SEE SCHEDULE) "�� .1."y t..Y e '."eu d PARCEL 113 OWNER NAME NC PIN NO. ACREAGE DE PG OWNER ADDRESS _ s,dintnu searx>Z,Zane ,tin. L T P-O• esa too..l -•-•r• lr min.orlucn0r ss l LENGTH 8' SEE CHART BELOW -IF'°°dent �� --""57 Mete PARCEL ID OWNER NAME NC PIN No. ACREAGE DB PG OWNER ADDRESS SediTa��, ' ^^ - (Total Basin Capacity? Max.level of sediment -r-d""" `-'" -'- r t itipwp .w �• `��&� >>M collected clean '^ `'�1°"` s 1 Vann, Bernard&W 169600 73-2842 0.81 1713_0364 100 Clearwater Drive Simthfield NC 27577 '� ru 0440)1) �+�j't�ti4"P1L1'ER WASHED STONE BE❑, when Po�level is reached Sediment Depth1M yla\�#,�S jFILTER FABRIC OR EQUAL. LL 2 Tillery, Christopher& Heather 169600-73-3952 p.51 2111_0234 104 Clearwater Oche, Simthf€eld, NC 27577+ '*� {� CARRY 1/2 WAY UP PiPE E❑GE. rs - R#`j *%!i.i „� Fah& Variva 3 Johnson, Marcia&Terrence 169600-73-4929 0.51 1670 0567 108 Clearwater Drive, Simthfield, NC 27577 •It% tli, I 4 Daniels, Carol G. 169600-74-4076 0.53 2426_0244 612 Powell Street, Smithfield, NC 27577 11.14... >r1 t�r'i +♦'�4r�4ftt=t,�f��` f�tT .' ��� 5 Clay, Hal Robertson III& Cecil McNeil 169600-74-5142 0.56 1778_0809 116 Clearwater Drive, Smithfield, NC 27577 r} R, =r,�,r uP sides"rsPd1 Y TEMPORARY SIDIMENTBASIN DETAIL 6 Johnson, Gregory & Elizabeth 169600-74-6119 0.55 2356_0822 612 Powell Street, Smithfield, NC 27577 t ; ���>rf � t / 7 Daniels, Carol G. 169600-74-6266 0.56 2552_0580 612 Powell Street, Smithfield, NC 27577 tvaries P ���� SEE SCHEDULE FOR 8 Johnson AREA , Gregory & Elizabeth 169600-74-7321 0.58 2257_0003 612 Powell Street, Smithfield, NC 27577 i �� (OUTLET STONE ROTECIION) Freeboard �,.#1 Rip-Rap 9 Smith, Steven& Sherry 169600-74-8307 0.57 2326_0314 132 Clearwater Drive, Smithfield, NC 27577 CULVERT ' ewwy �, (....,-.-FIK/I*4,4 �'�`°` 10 Gibson, Christopher&Tawanna 169600-74-8472 0.55 1779_0156 612 Powell Street, Smithfield, NC 27577 _ SIZE SLOPE MAX.FLOW ENERGY4 - B ° p '> h�(SIZE tom) DISSIPATERa % l.s 11 Johnson, Gregory & Elizabeth 169600-74-9457 0.53 2257_0019 612 Powell Street, Smithfield, NC 27577 42" 1% S4_t,q Class B-24"thick ��'�" a'�� 12 Huddleston, Kenneth& Donna 169600-84-0513 0.50 1806_0474 P.O. Box 463, Wilson, NC 27593 28'Lx 175'W r �;;, 'S'Max NOTE: �+ 13 Wolfe Investments Inc. 169600-84-0588 0.51 1 1753_0678 2305 West US 70 Highway, Goldsboro, NC 27530-9549 - Culvert design may be elatn°airted once the l i 14 Johnson, Gregory & Elizabeth 169600-84-1665 0.50 2175_0704 612 Powell Street, Smithfield, NC 27577 appropriate flow is verified. - PIPE OUTLET WITH RIP-RAP PROTECTION PERSPECTIVE VIEW 15 Daniels, Carol G. &Johnson, Gregory 169600-84-2741 0.50 2184_0110 612 Powell Street, Smithfield, NC 27577 SECTION THROUGH TEMPORARY SEDIMENT BASIN 16 Palma-Martinez, CeasarAugusto 169600-84-3707 0.51 2207_0750 160 Clearwater Drive, Smithfield, NC 27577 . 17 Daniels, Carol G. &Johnson, Gregory 169600434-2741 0.52 2184_0110 612 Powell Street, Smithfield, NC 27577 18 Stevens, Oliver _ 169600-84-4859 0.53 2186�_0134 168 Clearwater Drive, Smithfield, NC 27577 - 19 Parrish, Doris& Thomas 169600-63-5819 14.85 3 f570812 112 Bridge Street, Smithfield, NC 27577 _ �,dr,;, 20 Roberts &Wellons, Inc. 260600-28-3235 750.90 0551_0113 P.O. Box 299, Smithfield, NC 27577 24'-0"Travel Surface Pitch crown to drain 21 Lucas, Robert&Victoria 260600-45-4517 56.97 2460 0321 6095 Buffalo Road, Selma, NC 27576 - interiorofine sty 22 Lucas, Robert 260600-45-7011 60.00 1789_0029 6095 Buffalo Road, Selma, NC 27576 _ 23 Lucas, Robert 260600-54-2320 76.16 1789 0029 6095 Buffalo Road, Selma, NC 27576 gs 1z'-0" Iz'-0^ s'-0" Ditch II ztrMin. ( PmpoIylre 24 Creech, Gertrude 260600-63-6028 65.59 0745_0087 141 Clay Ridge Way, Holly Springs, NC 27540 - shoulder Gee mint shouldee 2 2 T Ya,ics 1' 25 Johns, Russell 260600-72-1327 7.52 2909_0203 5291 Buffalo Road, Selma, NC 27576 V--18ed26 Easom, Alma 260620-72-7092 21.94 0731_0078 118 Canterbury Road, Wilson, NC 27896 Existing l„1 Ft -I 4"lEt l/a"/Fi -1 Existing 27 Rose, James Kirby EST&Thomas Franklin RMNDR 260620-91-0677 54.74 2911_0869 140 Old Plantation Ct. Winston-Salem, NC 27104 ` Grade z:> ' 3> 28 Thompson, Thomas 260620-80-0423 _ 29.96 2975_0417 4775 Buffalo Rd., Selma, NC 27576 1-1/2"bituminous concrete surface course,type"e"or"P \ - 29 Thompson, Thomas 260502-79-6607 _ 24.40 1511_0105 4775 Buffalo Rd., Selma, NC 27576 3"bituminous concrete binder course,type"h" 30 Roberts &Wellons, Inc. 260502-69-9086 60.00 1051_0202 P.O. Box 299, Smithfield, NC 27577 Tack coat placed at rate ofp_OS gallsgl yd. 31 ,James E Snakenberg,RE,NCDOT General Services Division Director 260502-59-9264 38.00 Not Available 1525 Mail Service Center, Raleigh, NC 27699-1525 8"aloe(crushed stone paving) Snbgrade compacted to 95%AASIITO density 32 Hobbs, E.G. & Michael R. 260501-38-5359 95.50 Not Available 220 Glade St., Chapel Hill, NC 27516 See ditch schedule for depth and width of ditch I � P� 33 Hinnant, Richard&Carolyn 260501-29-2529 43.21 3091_0580 4673 Hinnant Edgerton Rd. Selma, NC 27576 - anes Pilch of the prop _erty 34 Burton, Eugene&Sheila 260600-11-9019 3.43 1643_0410 105 Cobblestone Ct. Smithfield, NC 27577 ASPHALT ROADWAY WiTH DITCH ImBench stnped la Benchslnpea - nottoscale to interior m1n 35 Parrish, Thomas K. 169600-63-3267 1.03 1109_0375 1834 Bear Farm Road Smithfield, NC 27577 "" `Vance 36 Parrish,Doris J Life Estate& Parrish,Joseph E.Ill RMNDR 169600-63-8586 8.20 3167_0816 112 Bridge Street Smithfield, NC 27577 I 'C y 37 Parrish, Joseph E. III& Parrish, Allison J. 169600-63-4383 7.65 2309_0486 1836 Bear Farm Road Smithfield, NC 27577 - 38 Hales, S. Wallace& Glenda S. 169600-62-6695 12.20 1997_0360 9 Beach Front Road South, Wilmington, NC 28411 28 Thompson,Thomas 260620-80-0423 29.96 2975 0417 4775 Buffalo Rd. Selma,NC 27576 24'-0"Travel Surface(typ.) Table updated on 12-20-06 using information gathered from the Johnston County GIS website. . / 29 Thompson,Thomas 260502-79-6607 24.40 1511 0105 4775 Buffalo Rd Selma,NC 27576 Post Office Box 8`0" 12'0" q,/' 12'-0" 8'-0" Top Width 30 Roberts&Wellons,Inc. 2605t12-69-9086 60 1051_0202 Smithfield,NC 27577 "I � i�rll-'I'I ' V ' Pitch crown to drain 1. grassedI f°Of to°'" 31 Department of Transportation 260502-59-9264 38 Not Available Not Available shoulder Grade Point shoulder e. �Nerior of the property 1 Existing r 32 Hobbs,E G.&Michael R 260501-38-5359 95.5 Not Available 220 Glade SL 1/4"/I' -ll4^!1' ter Bench Sloped 2a Bench slopes Existing -1/2"I I' -1/2 /I 1 Grade to Interior 35Ty tolatenor Chapel Hill NC275]6 33 Hinnant,Richard&Carolyn 260501-29-2529 43.21 3091 0580 NC 27576 Grade -3 I � 4673 Hinnant Edgerton Rd. 20'Bench Sloped 1 I neon v f 35 20'Bench Sloped '3 2 34 Burton,Eugene&Sheila 260600-1 1-90i9 3.43 1643_0410 105 Cobblestone Ct, Subgrade compacted to 95%AASHTO densityIn/ NOTE:crushed stone paving shall Smithfield NC 27577 be maintained by owner as required 11 IL_ ss rye. 8"min,crushed stone paving 2 L 24'ROADWAY(Crushed Stone) not to scale PIPE EXIT TO PLUNGE POOL NOTES: 1.Slopes will be hacked during coustructcon to aid in the establishment of vegetative cover. 2.All exposed areas will be stabilized immediately following construction. PIPE TYPICAL BERM CROSS SECTION 5' FROM SUMP S, NATURAL GROUND not scale 265'L x 75' i W 1 PIPE OUTLET (INSIDE FROM TOP OF BANKS) PLUNGE POOL Vegetated . . . . . i NATURAL GRADE 2:1 f 12' 2:l - --/ / 1Ya�eioo to ❑ivetsian. ,�� 3;y:_`: a 0srsle• NATURAL GRADE :; .. ��V . . , . . . . . . stabilized ... . l`Pe Typical Cross Section of Pit Clarification Pond with Plunge Pool Smble `• +•� •• 1 • • •• • � not to scale ' v.v . .'. .•.'. .'.' Compacted Fill • •--. ••• ••••. - • . - • V - . Filter Fabric DIVERSION DITCH SCHEDULE • • • - - - • -• - I+-••- 14" - NOTE: V-Ditch No. V-Ditch Size Length of Ditch , Slope(%) LiningTemporary r t. n9 Elevation Ditch Liner / I I 1_ NCDOT#5 stone is preferred. Pad to be 50 ft.L x T(Ft) x D(Ft.) (Ft) _Change(Ft) 20 ft.W x 6 in.thick min. . TD#1 6 x 1 349 2 0.6% Tall Fescue Not required CROSS SECTION k v) 5 2, Tltrnin radius sufficient to accommodate e °8" er tz3f S �$ TD#2 6 x 1 564 10 1.8/o Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. �`�,y ��,y � trucks. TD#3 6 x 1 600 4 0.7% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. 1 Variable „ Min v-Trench % ..ig+'' ,'" 3. Must be maintained in a condition which will -41: 7.1,. ', ,spermissible shear stress=1.45 lbs/sq.ft Backfill min.8"thick144114.401V41onto streets. Straw with Net finer with TO#4 6 x 1 350 3 0 9% Tall Fescue a O' prevent tracking or direct flow of mud ID#5 9 x 1 370 1 0.3% Tall Fescue Not required Lr ,a layer of gravel / �,c►`,►a± i � �" z fd:z ' ,r� " " ' . .r ",r'` "�r 4 r, 414'.!`' �+�,�' Periodic topdressing maybe 11ece 0.3% required ��1 �,� P grY TD#6 9 x 1 558 1.5 Tall Fescue Not '; r,,=` r', �r ,'� a �'•. "� -.S`,.-,44• ::t„ +[';".:' 4- This construction entrance will be installed at all TD#7 6 x 1 485 4 0.8% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 Ibs/s ft, q• il _e J• - "�' . . . as '-. a a „+a ,, r „}4 -2 Filter Fabric / ,<�+�Z�. �,l�: Rla,�r.�� entrance and exit points to the site. At this time the TD#8 6 x 1 561 6 1.1% Tall Fescue Straw with Net liner with a permissible shear stress=1,45 lbs/sq.ft. '_eT� �, +r! r �' .'4 . �i4- " ,?e. ."w -a:i;ai andyr „ e „ - ` f►.�,�►M.■t eittt tare " ''� / „t 1�Mel-.y ;y+Rrr+• +t4. •ha+; only entrance and exit shown on the site plan will be TD#9 9 x 1 520 1.5 0.3% Tall Fescue Not required Buried :..0 `'x:'„ �'�►itiVe�m�. i•s+'~^'� paved aspart of the initial project. TD#10 6 x 1 432 4 0.9% Tall Fescue Straw with Net liner with apermissible shear stress=1.45 lbs/sq.ft. ..� _.•' <...� ",6H•�yes?4.1 .1r4it`e•; ,: Prof q. 1 `a�i.ta�:'�.' I'!r,,t', it a?+I: TD#11 6 x 1 430 2 0.5% Tall Fescue Not require- Laud greader rapacity flay tam d 15 ft R. te`t +�r +i++:ii;�`fs TD#12 6 x 1 600 6 1.0% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. - '"�'""'i"°"`speak,mile. 8" " "'+':+':^' +t=r"ii• :' TD#13 9 x 1 504 1 02% Tall Fescue Straw with Net liner with a mama I0 '";+ t�+r1 :'� ,. permissible shear stress=1.45 lbs/sq.ft. - m ,."rr:r.t>,�,d..... 4" wire " '{!. ems• /' - spa�d..l;pw°la.p"rmedw�® 6 min. stone bed F +41 t■,�^ + i:' TO#14 6 x 1 368 1 0.3% Tall Fescue Not required °'""mcdo � " ''O' LEVEL SPREADER - TYPICAL "s'.7• -74, TO#15 9 x 1 406 1 0.2% Tall Fescue Not required - The maze disturbed ana Extension of fabric and r r.��� TD#16 6 x 1 367 2 0.5% Tall Fescue Not required he seeded matched a:misdate*o rrN TS wire into the trench t'ii CONSTRUCTION ENTRANCE r \ Stone Size :NCDOT#5 TO#17 9 x 1 601 1 0.2% Tall Fescue Not required or#57 washed stone not to scale TO#18 6 x 1 274 1.5 0.5% Tall Fescue Not required SILT FENCE DETAIL TO#19 6 x 1 93 1 1.1% Tall Fescue Not required .eve Spreader Design Notes TO#20 6 x 1 290 7 2.4% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. - - - 1 2%TO#21 6 x 1 165 2 Tall Fescue Straw with Net liner with a permissible shear stress=1-45 lbs/sq.ft. For all diachayre points located adjacent to tit® Meuse River Riparian Buffer: Straw with Net finer with shear stress 1.45 lbs/sq. Table 6 11p.Seeding for.Well-to-Poorly Drained Soils,Low Maintenance SEEDBED PREPARATION NOTES % all Fescue h a perm hear s - lbs/sq. ft. x 1 245 4 1 6 T Straw with Net liner with permissible tress--1 451 TD#23 6 x 7 172 2 1 2 T permissible TD#24 6 x 1 464 2 0.4% Tall Fescue Not - • (from North Carolina Erosion and Sediment Control Planning and Design Manual] - required Design Flow Entrance Width Depth End Width Length TD#25 9 x 1 886 14 1.6% Tali Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. (cfs) (ft) (ft) (ft) (ft) 1) Erosion control measures are to be installed according to plan_ TD#26 6 x 1 542 7 1.3% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbsisq.ft. 0-10 10 0.5 3 10 Seeding Mixture TD#27 6 x 1 284 5 1.8% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. rippedand spread with topsoil(ifnecessary),3„deep. Total 2) Areas to be seeded shall be r to so 10 _ TO#28 6 x 1 297 12 4.0% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. seedbed shall be 4"-6"d TO#29 6 x 1 352 22 6.3% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. Species Rate(lbs/ac.) l� �P• Tall Fescue 80 TA#30 6 x 1 694 5 0.7% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. Pensacola bahiagrass 50 3) Loose rocks,roots,and other obstructions shall be removed from the surface so as not to TD#31 6 x 1 890 9 1.0% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. Seneca lespedeza 30 interfere with the establishment and maintenance of vegetation. Surface for final seedbed Kobe lespedeza 10 preparation,at final grades shown,shall be reasonably smooth and uniform. TD#32 9 x 1 542 1 0.2% Tall Fescue Not required -�t TD#33 6 x 1 498 3 0.6% Tall Fescue Not required t y TO#34 12 x 1 936 2 0.2% Tall Fescue Not required tc 4) If no soil test is taken, provide fertilizer and lime according to seeding schedule. + VT4*- Seeding notes: TD#35 6 x 1 191 1 0.5% Tall Fescue Not required ""' l - _''" 1.From Sept. I-Max. 1,use unscarified sericea seed. TD#36 6 x 1 639 4 0.6% Tall Fescue Straw with Net liner with apermissible shear stress=1.45 ft. tip5) If soil testis taken,provide fertilizer and lime according to the soil test report. Soil testing is lbs/sq. „�°" �"e° 2.On poorly drained sites omit sericea and increase Kobe to 30 lb/acre. recommended. TO#37 6 x 1 96 4 4.2% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft 3.Where a neat appearance is desired,omit sericea and increase Kobe to 40 lb/acre. TO#38 6 x 1 238 10 4.2% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. 111 6) Lime and fertilizer shall be applied uniformly and mixed with the sod during seedbed TO#39 6 x 1 265 15 5.7% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. Nurse Plants preparation. TD#40 6 x 1 210 18 8.6% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. Between Apr. 15 and Aug. 15,add 10 lb/acre German millet or 15 lb/acre Sudangrass. y permissible shear stress=2.00 lbs/sq.ft. :',.'1.*"''''' TD#41 6 x 1 177 18 102% Bermuda Synthetic Mat liner with a ;, ;� Prior to May I or after Aug. 15,add 25 lb/acre rye(grain). TD#42 6 x 1 215 21 9.8% Tall Fescue 7)Roughen surfaces according to Surface Roughening detail provided. Synthetic Mat liner with a permissible shear stress=2.00 lbs/sq.ft. SNQVe t TD#43 6 x 1 64 3 4.7% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. TD#44 6 x 1 323 16 5.0% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq_ft. • Stair Stepping Cut sty Seeding\ . • - • pates TD#45 6 x 1 500 10 2.0% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. Best Feb.15e TD#46 6 x 1 127 2 1.6% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft Early Spring: Feb. -Mar.20 Feb.15 Ape 30 iiiiiii '0 Fall: Sept-1-Sept.30 Sept. 1 -Oct.31 TD#47 6 x 1 324 8 2.5% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft, TD#48 6 x 1 300 26 8.7% Tall Fescue Synthetic Mat liner with a permissible shear stress=2.00 lbs/sq.ft. �� E 3' Sell Amendments TD#49 i 6 x 1 745 30 4.0% Tall Fescue Straw with Net liner with a permissible shear stress=1.45 lbs/sq.ft. Apply lime and fertilizer according to sod tests,or apply 3,000 lb/ac-5,0001b/ac_ground TD#50 , 6 xi 1 114 1 0.9% Tall Fescue Not required Grooving slopes agricultural limestone(use the lower rate on sandy soils)and 1,000 lb/ac_ 10-10-10 fertilizer. nO/0le° Mulch r n000 SIMAit acne r Layered Abutment NOTES: Apply 4,000 lb/ac.grain straw or an equivalent cover of another suitable °5 Wa .sk..... I - Roughening can be achieved with tracked machinery in areas mulching material.Anchor mulch by tacking with asphalt,roving,or netting,or '41 - - TOP nF ...... W�Ft -„_ --Class l and U ltima with sandy soils.Operate true machinery up and down the slopeto leave by crimping with a mulch anchoring tool.A disk with blades set nearly straight - - - - ./, eta is midi SEDIMENT TRAP SCHEDULE horizontal depressions in the soil. SURFACE ROUGHENING DETAIL can be used as a mulch anchoring tool. L aa�At"u. - Stair-step grade or groove cut slopes with a gradient greater Mao p yt x 2'vral 3:1. gg not to scale ca onraxL F�TER FABI;lC - Use stair-steppin]dma y erodible material soft enough to be Maintenance C 8rd1iWE ripped with abul - -.- - Immediately seed and mulch roughened areasto obtain optimum If growth is less than fully adequate,refertilize in the second year,according to soil tests tommowCAW?) Sediment Drainage Sediment Sediment Trap Dimensions Weir Dimension • seed germination d or topdress with 500 lb/acre 10-10-10 fertilizer.Mow as needed when sericea is omitted CROSS SECTION • Trap No. Area(Ac.) Storage{Cu. Ft.) L(Ff.) W(Ft)) H(Ft.) (Ft.) ` from the mixture.Reseed,fertilize,and mulch damaged areas immediately. ST A 0.25 450 28 14 4 4 :a.e ST B 0.50 900 40 20 4 4. !a-, :: ST 0.75 1350 48 24 4 4 Place material from excavation on Spillway Details .. . Pt y r STD 1.00 1470 56 28 4 4_. . downhill side of flow. Use additional Top otRock Abutment $T E 1.25 2250 62 31 4 fi fill to achieve specified height and width Level,� ST F 1.50 2700 68 34 4 6 d, � 2'min. Slope F. �:;{ Spillway ST G 1.75 3150 72 36 4 6 _ ''' ST Fi 2.00 3600 78 39 4 6 10. Fillet abric • -?:/ HIGHWALL BARRIER SAFETY BENCH -NOW ry• NOTES: �� • 21 ROCK DAM SCHEDULE - Sediment inflow tithe basin will be located ..?„-/ away from the dam to prevent abort circuits 31toMende{ • SeedRock Dam Drainage Sediment Sediment Trap Dimensions Weir Dimension and mulch diversion channel and dike p° 1S banks will installed shown on me p`°`de1''BaffleDetail' No, Area(Ac.) Storage(Cu. Ft,) L(Ft.) W(Ft.) H (Ft,) (Ft.) Martin Marietta Materials immediately after construction.Choose appropriate Varies seeding mixture from the seeding schedule. - Basins will be impacted atter every rainfall 3'min. - Sediment will be,noved and t,awned to •4 4 - g 20'TO 100' original volume lien snit accu mulates Rock Dam 1 5.00 18000 122 1 61 6 12 RALEIGH, N.C. v to spprosimately bite design volume. . - Repairs will hepeehrmedas needed for any ROCK DAM SEDIMENT BASIN observed erosionr♦dlor rock displacement TEMPORARY DIVERSION DITCH - see Rock Dam&while for rock dam details (NTS) -- DETAILS SHEET y, File Name: Selena-Details-5-9-07.dwg oArr_ REVISION N SELMA QUARRY 1 a 1,7 Added details bawd on requests for main-Meal information by Land Quality • in a letter dated February 20,2007, 2 JOHNSTON COUNTY, N.C. . Notes: PIT DIAGRAM 3 1) Sediment traps(ST)are sued for the total drainage area with t clean-out per year. NOT,oSCALE Selma 'Permit No.: 5)-46 2)Weir dimensions are minimum requirements from NCESCPDM(Table 6.60a) 4 Quarry: 3)Erosion&sediment controls will be adjusted in the field as necessary to conform to actual topography. 5 DWN BY: DATE: PAGE NO. N.Wijesuriya 8-27-09 6 2 of 2 7 ' CK BY: S.Whitt SCALE: Not to scale , i / ° ®° i i 3 r 48 e a bg am ss a R a m SS a t'z a L61'z H H ldON M p z Q � 0 � J a-v W L_L a r U. w o brt +^ � 0 O O O O to CDm ka com N z z � � z SC ,d N m y } o F - UJjE d 00 z LL w / J to pz� d z w � �\ atW7 a 0 a J Q / // �mg z IL FCl) t` 0 Q -i d LL ���\ uj F O + O \ / w - .. + R F W t9 W U LL o m O 0 N O v + \\°c U (n G W I.-p U% _ ai a i a i• y a ink ; .x U' O Z F N \ a w Z J LU /O d / i -.- a s _�l i i i i i f i i°� • i i i i i i 0 QOC' 4 LL ff% / / i > i ./ a' a a i- i• i i i . a a a a a a a i i a i i a a \ \ a o 0 0 o m m � m m m m Z, z tY J ti ,g F 4 O F D m 0 0 y 'W^ R V J K d d Z U co) W U F p O a 0 0 0 o6 m m I R. ow' w + + ��1` LL oIL NJ G C d Z U w _ F C.,(v\ O NZ 4a Pit Limit I 9 r• 115;, ^O W Q O W h =r w N �e �03 a q oQ 00 h Permit Bormdary m 0 9 o z a G m V q m S m VI N ya V m $' 9 xa a $ y � V O ViQ 0 Z F O o to M dwF0 v rn! °° c M a b d � � o a � W d q aii a� C m ¢ w bo y > x d a F I a ' I ' I o M W I I N N W O z� �s L W a �Z aOsOtONO F CLaaa) ISW HAOEIV HOUVAaaa x 000150z'z al 009'so2:'2: al 000'zoz'z 31 oos`ooz'z a 000'661'z 91 009'461'2: 91 c� to cn al 0 O Cd rn Cd •C) b O^OU S�. a3 yO, 1- N i� V] O u °�z$� o J. y4O O T �+ O O VJ •cd V! O O N W5 •� 0 O *a cz Z —+ +O N "M U .00 u N 42 t04 • 1 'YI /�1,�� i �.i,r-.r .�::. ,. ,.. ., .�,. + ,. naJ �..+.+ _a .�.u.. .�r ,r. :�, +5 t.11i,.� f i ^ B' ® i Oee � p_p w U z 1'. z 0 Z 0 p � � Q 0 LU - LL W 0 _Z 0 C O O m m m O m m m z z z o N: CD O_ W�—��. NCD LL 7� z a O I \ m 0) All) in t, / w Q z $ w \ J R' i O O YD A \g O Q / x O N f V / i.. i U) \ �� .ff w fn / i i i f + F3 ": d, W \ f a x > • i i a i O O \\ d / i i > i ��> f i i p• \ o i IL W \\ W v.. of \ \\ \ 3 / \ _..-. CAW ;m '• � _ spy � •t'i n n I ��s 4 x, f 'z a 'G6i'z 3 NL�I O N KQ aOF t< oP ti Ox 0 > f i -i i > f > Q > > > Q' �. > im x> > > Yp i'- w J LLLLII CO > ti > i W > i f > i > r. (� > > > i > > 0 o w LPL > > > >> z J U O O Z) F w mxO �' > >; > >. > O F F to O m V UJ i > > > > > > ' Z to z y z w Q Q CO)i.,' l4. > >,> Owp m Z = U m U W w N •, > > i � Q F F F d m ' dx w uj J QJ � O O OF w y O Q Q i= Z U w to F p O a G z J W 3 ul w � F J a 3 F 0 0 CO Q Q _ w vJ F C O IL F O O LL LU LL � UQ' a O O o 0 o 0 to co to co to Z, z z z k r '' r 1 1! + a JO Pit Limit -s Qo� •' � h mE N v� � O O � C C Permit Boundary o °o z 20 0 a � E e 5g xe W U 9 �e 3 b � G z�r 0 0 C ko co wa H � o � M �Uw W Ida 'O Wd' t� d U N N 1 W O d h WWW W A r � w h U R�. 00 O O GNO 7SNI �AOgV NOLLVATI9 x 000'Soz'z o05's0z'z 000'zoz'z 000'66i'z oos'L6I'z con cz c� b y tr.yy cl t ^y V N «1 Sao 4a r7, O C;3 t 0 O A O t"y Con= O'+ V N rA AO cjz1 try Cd N 0 4a O M 'C7 N 04-1 O Cd Cd to Ts^ O �J to O O Vl -'Cj rrN^^ VI p U O (0 z ��0 0� N