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HomeMy WebLinkAboutNC0024228_Meeting Notes_20060503NPDES DOCUMENT SCANNING► COVER SHEET NPDES Permit: NC0024228 High Point Westside WWTP Document Type: Permit Issuance Wasteload Allocation Authorization to Construct (AtC) Permit Modification Complete File - Historical Engineering Alternatives (EAA) Instream Assessment (67b) Speculative Limits Environmental Assessment (EA) Document Date: May 3, 2006 This document is printed csri reuse paper - ignore any content on the rezrerse side (4), ei4 bit;v7 A Zew 7/4 -Z�2£ s . Aim ,f, 3/Z(ra 4A‘,,/cec_f, 0)5) eo G g1/; .nr,//--d-- • l ""c 72� (1- C4)S� , ( -YI f c 1A-7,4 micvid-fe f/ .U[ Pc°I-15 im ,27 {-� lam. J/2 .--J-4&v:t 10'41;6- ./4"' 6tia4oL y ( /7,-7,4h wilt\ 74)66(a -4 litzt-7 4c41,te (,,stAr( 46 AI ctoi,/ t wE- 5 ��..� - 4c (111� 7L 5 / ±77-Par ") Aid I (r-b yze-sJ 14-671,t_tx_ 0.(Acrce.J. 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Co d..:?44. 4: fc.gu.,-,. m.40-0 4e-AINra .71; v 464cc.14 . egrtA-N nuc k.t- ll,t . woo l.G1t,ncrnc -eta- 1 1 1 1 1 Westside WWTP Expansion and Discharge Impacts to Rich Fork Creek Inn NORTH CAROI.I\A'S INTFRNATIONAL CITY City of High Point State Presentation May 3, 2006 dmp IIAZEN AND SAWYER Environmental Engineers & Scientists TETRATECH, INC. dip Presentation Overview History of Rich Fork Creek Presentation of Initial Modeling and Scoping Analysis City of High Point's Response Summary Westside Plant History Plant was Originally Constructed in 1930 Upgraded in 1959 Expansion and Upgraded Activated Sludge Facilities in 1986 Flow Equalizations Facilities 1992 Alum Phosphorus Removal Facilities 1998 UV and Sludge Facilities Upgraded in 1999 Multiple Process Upgrades 1 i t b 1 4760-002-01.ppt Westside Spills 2001 Total events: 8 Total Gallons: 19519 w+ Map Date: 05 APR 2006 Map By: Tim Ayers Legend • Spills U Repairs Outfal Is Corbett Country Club Ensley Creek Kennedy Kindergarten Kool Pool Rich Fork REPAIR u.. RE►AR R.{Y[.7.YMW. 1 e..1R t.) 24110At 1 [vuR,.,l 320GAL ARP►AMt: 1 Ev.1R (A) 11000A1. 1 E1..1 OA 3101AL 1 E.101116)r. 1700 GAL and lid 10 GAL 11 ev.a4.) fxoGA Ill 11603GA1 1: J11.1 4760.002 01.ppt Westside Spills 2002 Total events: 31 Total Gallons: 112872 Map Date: 05 APR 2006 Map By: Tim Ayers =T.=. Legend • Spills Outfalls Corbett Country Club Ensley Creek Kennedy Kindergarten Kool Pool Rich Fork 2 Erne1111. Er.nt �s(I 16561 GAL, -" 1 Event(.1 240 GAL 11 Event (q j 062 GAL 1 Ewe 7214 04 1Evert1.) Event 2202 GAL 1212 GAL A Evert(.) ETE GAL 2Event 0GA(.)� 720 GAL 1 Event (1) 100 GAL 1 EN. ).) 200E GAL 2 Ewm(.) 1411 1 Erre (.) E20 GAL 7 Evert (.) 7E GAL 2Erns p eGA\ 1 Evee (.) 1270E GAL 11 0 G .) 1 10GALLI 1 Ever (.)I� 2fOGAL 1 Ea GAL I1Event le Ira GAL ]100AL 1 GA 1H� .1 GAL 1Er.M(4) MO GAL 1 Ewe (.t 2E00 GAL 1 Y 1 1 1 1 I I 1 d 1 1 4760-002.01.ppt Westside Spills 2003 Total events: 27 Total Gallons: 149928 +1 Map Date: 05 APR 2006 Map By; Tim Ayers Legend • Spills r ) Repairs Outfalls Corbett Country Club Ensley Creek Kennedy Kindergarten Kool Pool Rich Fork fit 11 EvrA (.) Iswaw r21 Evont UI 73 GAL + Evaa(.) 120110AL REPAIR: Anchored and arou!walled REPAIR: MPle .d aR • Installed ocEl1q� aP4.: t W, Old Mad SEWRt(.) ISM OAL Evont(.J( awl r REPAIR f4 two MN and Instal .- .bd Replaced pip. REPAIR: Junction boa raised foot 1 Evan. (.l 1 1935 GAL 0 Ewnt (.) 3437 GAL E..IRml �G ( s. seA9Ev..0 (s) Maw 2313 GAL 2 Ens( (.) tpM GA 1, Event (a) 770 GAL , Even (a) 00 UAL 1 Ev.I(.1 05000 Westside Spills 2004 Total events: 27 Total Gallons: 436189 Map Date: 05 APR 2006 Map By: Tim Ayers Legend • Spills Repairs Duttalls Corbett Country Club Ensley Creek Kennedy Kindergarten Kool Pool Rich Fork I REPJUR: I R.plasb 2 1•I1r. 1 d.n. (.) 200000 GAL 0 EYMI 2.01 GAL 2 Ewn.(.)1 11400 AL REPAIR: R.yYc.010 fowl W pip. & added WI 1 1 IPS O (p 220 GAL f Even. (.) 240 GAL JI Ev.n.(.) 2N GAL MEIGAL)I MI GAL I I Emit p) H0 GAL • 0- 1 1 I I t I I 1 • Westside Spills 2005 TWA! esem> 27 fa:ul Gn.:cns 37�1ng Map Oaa 05 APR2006 Map By bin Ayers Legend • Spills Outfalls Repairs Corbett Country Club Ensley Creek Kennedy Kindergarten Kool Pool Rich Fork REPAIR. Boiled ring Yid Lid Impacts of Rural Areas OMER Agriculture ' Nonpoint Sources Impact DO Septic Systems ■ Increase in Private Subsurface System ' Municipal Service provides Uniform Controlled Development 1 rr moat SRI Economic Impacts — No Expansion Only Treatment Plant Option for • Western High Point and Guilford County • Northeastern Davidson County ■ Southeastern Forsyth County Recent Compliance Record - Westside Westside WWTP Violation Summary January 1996 - March 2006 2 Recent Compliance Record - Eastside Eastside WWTP Violation Summary July 1997 - February 2006 Compliance with ACA estside has met all the Conditions of the Consent Decree ee 3 IMO Water Quality Scoping Analysis for the High Point Westside Discharge to Rich Fork Creek TETRATECH, INC. Provide third party expert evaluation of assimilative capacity in Rich Fork Creek 4 Approach to Scoping ompile and review existing info ■ DWQ files ■ High Point data ■ Yadkin Pee -Dee RBA data Setup and review existing DWQ water quality model `' Stream reconnaissance Additional modeling analysis based on findings Location of High Point Westside discharge in the Rich Fork Creek Watershed 5 • Owl Monitoring Locations I HUC Boundary T DWQ Station u YPDRBA Stations Westside Monitoring Stations A/ Ricti Fork Creek , HUC Hydrography Frequency of Excursions of the DO Standard in Rich Fork Creek 60% 50% uJ 15 30% 10% 0% 10 Q5750000 C 05780000 0 05785000 E 05790000 —L— 1 r 1998 1999 2000 2001 2002 2003 2004 2005 6 Flows at USGS Abbotts Creek Gage downstream of Rich Fork Creek Cumulative Summer Flow (MG) 60,000 50,000 40,000 30,000 20.000 10,000 1998 1999 2000 2001 2002 2003 2004 2005 Dissolved Oxygen at YPDRBA Sites 14 13 12 4 3 2 Median ES 25%-75% Non-Ouilier Range Whets — Standard Upstrea m 05750000 3.9 mi 9 mi downstream downstream 05785000 05790000 Station 7 Dissolved Oxygen at YPDRBA and City of High Point Stations 14 13 12 10 9 8 rn E 7 s 5 4 3 2 tv�d ao ® 25%-75% j Non -Outlier Range Outliers — Standard What's happening here to cause rapid decrease in DO? 11 Q5750000 C1-P1 0-P3 05780000 0-P4 Q5785000 0HP5 05790000 Station Field Reconnaissance — January 2006 Rich Fork Creek at Chesnut Stove Rich Fork Creek at Lexington Avenue Rich Fork Creek at 20 Ft. Upstream of Discharge Rich Fork Creek at Highway 109 - Rich Fork Creek at May School Road Rich Fork Creek at Ball Road Rich Fork Creek at Kanoy Road Pa Creak at Ha 8 Just upstream of discharge Typical example of stream/floodplain relationship downstream of discharge (icture taken near Midwa Road 9 Three Anomalies Due to Sand Mining: Hwy 109 (1500 ft pool, about 0.3 mi downstream) all Road (500 ft pool, about 2.9 mi downstream) noy Road 500 ft pool, about 3.9 mi downstream) Aerial picture below at Ball Road illustrates change in stream width and configuration. 10 MI . .. MIR NM MI MI Comparing Upstream to Downstream at the Bali Road Bridge Crossing Comparison of substrate of unaltered versus sand -mined stream channel r,v1 11 Comparison of current DWQ model predictions to observed data for September 20, 2005 8 7 • Observed Data —Original DWQ Model —Standard 6 • — E 5 c • 4 3 m 0 2 • • • o Distance Downstream o1 WWTP (miles) Tetra Tech scoping model run incorporating pools and adjusting velocity, reaeration, BOD decay, and SOD 0 —Tetra Tech low flow run • Observed • • '. Ca '. 6 '. Distance (miles) 2,,At) `0),Y k0. \Y" 12 -With pools, SOD 0.25, BODult 10 mg/L -Restore pools, SOD 0.25, BODult 10 mg/L -Restore pools, SOD 0.25, BODult 5 mg/L • Observed Tetra Tech simulation of restoring channel in sand -mined area, plus BOD reduction 0 Distance (miles) Tetra Tech simulation of restoring channel in sand -mined area, plus 20% SOD reduction Dissolved Oxygen (mg/L) 7 6 5 4 3 2 1 • - Restore pools, SOD 0.20, BODult 5 mg/L - Restore pools, SOD 0.20, BODult 10 mg/L - Restore pools, SOD 0.25, BODult 10 mg/L • Observed • • 0 4;:s coc.3 A. O.• O. O. Distance (miles) 13 Mel Comparison of organic layer at Hwy 109 Pool (-1 in), Ball Road Pool (-1/4 in), and Kanoy Road Pool (-1/8 in) Recommended Next Steps Confirmation monitoring: SOD, flow/velocity, pilot reaeration Update QUAL2E and recheck scoping study conclusions Restore channel in mined areas Ambient monitoring to observe new DO profile Comprehensive monitoring to support model calibration/validation: complete oxygen balance, flow/velocity Calibrate and validate QUAL2E model with DWQ to support WLA application 1,1)6' etPd-3 fl 14 1 1 1 1 1 1 1 1 1 1 1 City of High Point's Response Westside Outfall Improvements • W.A. O.. AOC p. AAKI Wm. ...A. WWII IICA, •••••••“ .....1‘•••••••••••Eart •.• 6,...• Eh+. .. P....4 ,..••••••• •• C•••••••,... IN.•••• ••••••••.• ...• ••••• '••• .... • ' 1 '7,;::x: ::.....[::::::‘' -t ' L'''''''''''—'—"''' ..- •••• :,,,••,.,.......,,,--, ,-,,,..,---4---.,..-=.- 4 ..,..„ Legend Westalde_Outlaila - Country Club .... Kindergarten - Kool Pool ILAA PAO • 6.1Aes 2 . CITY OF HIGH POINT, NORTH CAROLINA ; • 1501.14.1111.140MILL ASSOCUM. WC dmp • YAK.. „,;„;••=7„, „ T" City Of High Point's Response estside Treatment Plant Expansion • Prepared to Implement BNR Facilities `a • New Preliminary Treatment New Filter Complex ■ Disinfection Facilities ■ Miscellaneous other Treatment Facilities illy Prepared to Implement Stream Restoration Restoration of Stream Reaches Identified by Model ' City will Contract with Third Party to Update 'Model ■ TetraTech will Update Model based on Field Reconnaissance 1 City of High Point's Request City requests Expansion to 10 mgd ■ Last Expansion for this Discharge Location "_ City requests Nutrient Limits for Design • Speculative Limits for TP and TN City requests Guidance on EA for Westside Summary The City's Commitment extends Beyond Upgrading and Expanding Treatment Facilities Collection System SOC Stream Restoration Biological Nutrient Removal Expansion of Westside WWTP will provide Controlled and Regulated Growth and Development Water Quality in Rich Fork Creek is Improved with this Approach to Expansion vIC(f A/Goa29Z S April 26, 2006 Re: City of High Point, N.C. Westside Wastewater Treatment Plant Expansion and Upgrade Mr. Steve Tedder Division of Water Quality Winston Salem Regional Office North Carolina Dept. of Environment & Natural Resources Dear Steve: We are enclosing support data for our meeting next week with the Permits and Engineering Section in Raleigh regarding the High Point Westside Treatment Plant Expansion and Upgrade. We provided you with information that we will be presenting to them including an incomplete Power Point show, history of the Westside Treatment Plant, information regarding impacts that are being created downstream of the Westside Plant within Rich Fork Creek, pictures of sand mining operations in Rich Fork Creek, collection system maps showing overflows that have taken place in the last five years along with associated rainfall data and an indication of when the particular intercept sewer contributing to the Westside Plant are scheduled to be replaced or upgraded. It is our desire when we meet with the Permits and Engineering Section in Raleigh that we request permission to proceed with an expansion of the Westside Wastewater Treatment Plant from its existing 6.2 mgd capacity to a 10 mgd capacity, with treatment to meet future limits for biological nutrient reduction. In addition to the Treatment Plant Expansion and Upgrade, we are proposing that certain improvements and restorations to the Rich Fork Creek be carried out downstream from the plant, specifically to those areas where sand mining has created deep pockets which adversely affect the velocity of the creek and allow for oxygen sags. I have also included a copy of a preliminary report prepared by Tetra -tech regarding the effect of this plant expansion upon the Deep River. In addition we are proceeding with a further study and model of Rich Fork Creek. A proposal for providing this study has been included in this information we are providing for you. The City has entered an SOC for the sewer system contributing to the Westside Plant. The City has complied with all Westside conditions of the American Canoe Association Settlement. After similar expansion and upgrade at the Eastside Plant, compliance has no longer been an issue. The City is prepared to commit an additional $35 million to this Westside Expansion and Upgrade in addition to hundreds of millions spent on infrastructure over the last 15 years. We appreciate your willingness to present this information to Paul Rawls, should you have questions, or need additional information, please let us know. Again, we appreciate your cooperation and look forward to a positive response to this request. With personal regards, I remain, Very truly yours, CITY OF HIGH POINT T_ Terry Houk , lic ervices Department Figure B-8 Yadkin -Pee Dee River Subbasin 03-07-07 • FORSYTH DAVIE AgwA NCDENR Planning Branch Basinwidc Planning Program-Unl March 21, 2003 Lexington vie B-1 Winston- Salem B.4 5 1 Kemersville ;4, cri 191 ea 192 B-3 Lak Thom -A Lex ; 169 t 165 e Q5906000 161A j /3-6 Q5930000.1 160 193 o B-2 F-2 F-1 188 Q5780000 213 A212 —21 Fork - - Hi4 Thomasville 'ALA SSB-1, A172 ‘4 SSB-2 147 DAVIDSON 0 164 5 Miles Trinity RANDOLPH High Point GUILFORD Legend Subbasin Boundary ID Ambient Monitoring Station j Benthic Station • Fish Community Station j Fish Tissue Station NPDES Discharges A Major Minor Use Support Rating Supporting AtImpaired Not Rated No Data .."/ V County Boundary Primary Roads Municipality Table B-14 DWQ Monitoring Locations, Bioclassifications and Notable Chemical Parameters (1998-2002) for Yadkin -Pee Dee River Subbasin 03-07-07 Site Stream County Road Bioclassification or Noted Parameter2 Benthic Macroinvertebrate Community Monitoring B-2 Abbotts Creek' Davidson SR 1755 Good -Fair B-3 Brushy Fork' Davidson SR 1810 Good B-4 Abbotts Creek Davidson SR 1243 Fair B-5 SSB-1 Rich Fork' Hunts Fork' Davidson Davidson SR 2005 SR 1787 Fair Not Rated Hamby Creek' Davidson SR 2025 Poor B-6 Hamby Creek Davidson SR 2017 Fair SSB-2 North Hamby Creek' Davidson SR 2031 Poor B-7 Leonard Creek' Davidson Leonard Cr Farm Good -Fair B-1 Swearing Creek' Davidson NC 47 Fair Fish Community Monitoring F-1 Abbotts Creek' Davidson SR 1800 Good -Fair F-2 Rich Fork' Davidson NC 109 Poor Ambient Monitoring Q5930000 Abbotts Creek Davidson SR 1243 Nutrients Fecal coliform Q5780000 Rich Fork Davidson SR 1800 Nutrients, Fecal coliform, Dissolved oxygen Q5906000 Hamby Creek Davidson SR 2790 Nutrients, Copper Yadkin -Pee Dee River Basin Association Monitoring Q5940000 Abbotts Creek Davidson I-85 Dissolved oxygen, Turbidity Q5750000 Rich Fork Davidson SR 1755 None Q5785000 Rich Fork Davidson SR 1787 Dissolved oxygen Q5790000 Q5135000 Rich Fork Swearing Creek Davidson SR 2123 SR 1272 Dissolved oxygen, Turbidity Davidson None Lakes Assessment -- Lake Thom-A-Lex Davidson 2 stations % DO saturation ' Historical data of this type are available for this waterbody; refer to Appendix II. Sites may vary. 2 Parameters are noted if in excess of state standards in more than 10 percent of samples collected within the assessment period (9/1996-8/2001). Section B: Chapter 7 - Yadkin -Pee Dee River Subbasin 03-07-07 182 agencies of water quality concerns regarding these waters and work with them to conduct further monitoring and to locate sources of water quality protection funding. In addition, Davidson County as well as High Point, Trinity and Thomasville are required to obtain an NPDES permit for municipal stormwater systems under the Phase II stormwater rules. Refer to page 37 of Section A, Chapter 2 for details. 7.3 Status and Recommendations for Newly Impaired Waters Rich Fork, North Hamby Creek, Swearing Creek, Lake Thom-A-Lex and a portion of Abbotts Creek are Impaired based on recent DWQ monitoring (1998-2001). This section outlines the potential causes and sources of impairment and provides recommendations for improving water quality. 7.3.1 Rich Fork (20.7 miles from source to Abbotts Creek) 1998 Recommendations Rich Fork was not rated in 1998, but problems associated with low dissolved oxygen were discussed in the basin plan. The plan stated that predictions from the model used to determine NPDES permit limits overestimated the ability of the stream to handle oxygen -consuming wastes. The plan recommended that no additional loading of oxygen -consuming wastes be permitted into Rich Fork. Status of Progress Biological surveys were conducted at two locations along Rich Fork in 2001 and water chemistry measurements were collected at four sites over the five-year assessment period. The biological community in Rich Fork is currently Impaired. Although the riparian vegetation was good at both biological monitoring locations, instream habitat was severely degraded. The stream bottom was almost completely filled with sediment and indicators of organic enrichment and toxicity were present. Water chemistry samples revealed significant problems with low dissolved oxygen concentrations. Turbidity is only slightly elevated, but nutrient concentrations are high. In addition, the geometric means of fecal coliform samples collected from one station between 1996 and 2001 and two stations between 1998 and 2001 in Rich Fork (254, 330 and 236 colonies/100m1) indicate that the stream may not be suitable for primary recreation. In addition, fecal coliform concentrations were greater than 400 colonies/100m1 in more than 20 percent of samples from each site. Rich Fork is not currently classified for primary recreation (Class B). However, the stream was historically placed on the 303(d) list for fecal coliform and a TMDL is currently being developed by DWQ. Over the most recent review period (2000-2001), High Point-Westside WWTP was in significant noncompliance for BOD and fecal coliform. Currently, the NPDES permit for the High Point- Westside WWTP contains a 2.0 mg/1 discharge limit for total phosphorus. The permit also outlines mass -based summer and winter discharge limits for total phosphorus which will be required beginning in 2004 as part of a point source nutrient reduction strategy for High Rock Lake. This strategy is outlined in Section A, Chapter 4, beginning on page 107. Section B: Chapter 7 — Yadkin -Pee Dee River Subbasin 03-07-07 185 2002 Recommendations DWQ will continue to monitor Rich Fork as strategies to reduce nutrient concentrations in High Rock Lake are implemented (refer to the discussion beginning on page 107 of Section A for details). DWQ will also continue to work with High Point-Westside WWTP to regain and maintain compliance with its NPDES permit. If dissolved oxygen problems downstream do not improve when the facility regains compliance, more modeling will likely be needed in order to further reduce sources of oxygen -consuming wastes. DWQ is currently developing a TMDL for fecal coliform in the Rich Fork watershed and will work with local agencies to implement it over the next five-year basinwide planning cycle. Although problems with point sources have been identified in Rich Fork, there are habitat degradation issues as well. Development in the headwaters of Rich Fork west of High Point continues to increase, and control of stormwater from construction sites and these new developed areas is imperative. Davidson County, Randolph County and the City of High Point are required to obtain NPDES permits for municipal stormwater systems under the Phase II stormwater rules. Refer to page 37 of Section A, Chapter 2 for details. 7.3.2 North Hamby Creek (5.8 miles from source to Hamby Creek) Current Status North Hamby Creek is the largest tributary to Hamby Creek in the Rich Fork watershed and is almost completely developed. Benthic macroinvertebrates received a Poor bioclassification in 2001 and the stream is rated Impaired. Data from 1987 and 1985 also indicated Poor conditions. Despite the developed watershed, instream habitat was available; however, there was little riparian vegetation. The water had a reddish tinge. There are no permitted point source discharges in the watershed. 2002 Recommendations Biologists report that flow and habitat are not likely to be limiting the benthic macroinvertebrate community of North Hamby Creek. Therefore, further investigation into the causes and sources of these water quality impacts is needed before recommendations to improve water quality can be made. Thomasville is required to obtain an NPDES permit for municipal stormwater systems under the Phase II stormwater rules. Refer to page 37 of Section A, Chapter 2 for details. 7.3.3 Swearing Creek (14.3 miles from source to High Rock Lake) Current Status The Swearing Creek watershed is primarily in agricultural land uses, but there is some development near Lexington. The stream has received Good -Fair or Fair bioclassifications over six collections at five locations since the 1980s. In 1996, the stream received a Good -Fair score. However, in 2001 the bioclassification declined to Fair. A decline in habitat over the five-year period was also observed. Because of the historical fluctuation in bioclassification, the stream was resampled in 2002. The benthic community again received a Fair bioclassification. Swearing Creek is currently rated Impaired. Severe habitat degradation was noted including sedimentation and bank erosion. Dissolved oxygen was slightly depressed, and turbidity was slightly elevated in water chemistry samples. There are no permitted point source discharges in the watershed. Section B: Chapter 7— Yadkin -Pee Dee River Subbasin 03-07-07 186 Lake Assessment Winston Lake Winston Lake (Figure 32) was most recently monitored during the summers of 2000 and 2001. Prior to 2000, this lake had been sampled five times (once in 1981 and 1990 and three times in 1999). The lake was dredged in 1986 due to sedimentation (accumulated sediment was estimated to range from two feet to almost 13 feet). WINSTON LAKE -n 0 Cre YAD077D F 0 1/2 mile Figure 32. Sampling site at Winston Lake, Forsyth County. In June 2000, turbidity was 40 NTU compared to the state water quality standard of 25 NTU. Total solids and suspended solids were also greater than during other sampling occasions. Field notes indicated that no rain had fallen within the watershed during the previous 48 hours. Subsequent turbidity samples were below the standard. It is possible that the elevated turbidity and solids measurements were due to algal activity. Nutrient concentrations in 1981 through 1999 fluctuated between low to elevated, indicating a large degree of variability. In 2000 and 2001, field notes described the water as appearing colored from algae. Analysis of a phytoplankton sample collected on August 2000 indicated a bloom of large colonial chrysophytes (golden -brown algae). As with most piedmont lakes, iron concentrations in the surface waters were occasionally elevated (in 1999 and 2000). Iron occurs naturally in the soils of the state; therefore, these concentrations are not considered to be problematic. All other parameters were within applicable state water quality standards. Winston Lake was determined to be mesotrophic in 1990 and eutrophic in 2001. Due to its shallow depth (mean of eight feet), the lake is vulnerable to increased nutrients and sediment inputs. Salem Lake Salem Lake is a water supply reservoir providing drinking water for the City of Winston-Salem and Forsyth County (Figure 33). This lake has a maximum depth of 36 feet (11 meters), well defined north and south arms and 14 miles of shoreline. The watershed includes portions of the Towns of Kernersville and Walkertown. Figure 33. Sampling sites at Salem Lake, Forsyth County. Salem Lake has been monitored since 1994, with the most recent samples taken in 2000 and 2001. Overall, the lake is showing some signs of nutrient over -enrichment, based on nutrient concentrations and NCTSI scores. Surface dissolved oxygen at Station YAD077B on June 12, 2000 was 3.4 mg/L, which was less than the state water quality standard of 4.0 mg/L for an instantaneous reading. A review of the data indicated that the sample was taken at 9:15 AM and that previous samples taken at the station that early also exhibited low dissolved oxygen compared to the other stations. In keeping with the moderate to elevated nutrient concentrations found over the years, chlorophyll a values for 2001 were in the moderate range (12 - 20 tig/L). Phytoplankton samples collected in 1999 NCDENR, Division of Water Quality Basinwide Assessment Report - Yadkin River Basin - June 2002 75 indicated that the lake contained a diverse assemblage of algae ranging from blue-green and green algae in the Kemers Mill Creek arm to diatoms near the dam. In September, 2000, the US Environmental Protection Agency investigated lead contaminated soil at a battery manufacturing plant in Walkertown and at an unnamed tributary to Lowery Creek (AP 2000). Lead levels of 320 pg/L were found in the creek. The NC DWQ's sampling during 2000 and 2001 found lead levels less than the water quality laboratory detection level of 10 pg/L. All other parameters were below state standards with the exception of manganese in 2000 at one station in July. Manganese concentrations above the state water quality standard of 200 pg/L for water supply sources are common in the state. The concentration of 340 pg/L did not present a potential problem for the drinking water intakes. Based on the calculated NCTSI score, Salem Lake was determined to be eutrophic in 1994. Data collected in 2001 were consistent with previous years resulting in a eutrophic rating. High Rock Lake • High Rock Lake is an impoundment of the Yadkin River (Figure 34). The maximum depth is 62 feet (19 meters). Because water from the lake is used to generate hydroelectric power, the reservoir's discharge rate remains fairly constant although the inflow varies. This variation causes considerable fluctuations in lake level and affects the hydraulic retention time. Residence times can range from as few as 3 days to as many as 50 days depending on inflow. The immediate drainage area includes several major urban areas of the Central Piedmont including the cities of Winston-Salem, Salisbury, Lexington, and High Point. The lake is classified WS-V from its headwaters to and including Crane and Swearing Creeks. From this point to 0.6 mile upstream of the dam, the lake is classified WS-IV and B. From a point 0.6 mile upstream of the dam to Badin Dam, the lake is classified WS-IV CA and B. The Abbotts Creek Arm of High Rock Lake is classified WS-V and B. Figure 34. Sampling sites at High Rock Lake, Davidson and Rowan counties. High Rock Lake was most recently monitored in 2000 and 2001. The lake has been monitored regularly since 1981. Concentrations of surface metals were within applicable state water quality standards with the exception of copper in July 1999 (11.0 pg/L), which was greater than the state water quality action level of 7.0 pg/L. Zinc in August 1997 (55 pg/L) was greater than the state water quality action level of 50 pg/L. These concentrations do not represent concentrations of concern based on a one-time exceedance. As has been seen during previous sampling efforts, Secchi depths were at or less than one meter in 2000 and 2001. Surface dissolved oxygen concentrations were also elevated at most of the sampling sites (range = 8.2 to 12.1 mg/L). Associated percent dissolved oxygen saturation ranged from 148% to 157%, which was greater than the state water quality standard of 110% for dissolved gases. Along with the elevated dissolved oxygen values, surface pH values were elevated suggesting increased algal productivity. As might be expected from the dissolved oxygen and pH levels, total phosphorus and total organic NCDENR, Division of Water Quality Basinwide Assessment Report - Yadkin River Basin - June 2002 76 nitrogen concentrations were also elevated in 2000, 2001 and previous years. These elevated nutrient concentrations continued to support increased algae productivity as evidenced by chlorophyll a values greater than the state water quality standard of 40 pg/L (range = 40 pg/L — 52 ig/L) in 2001. Blue-green algae species, commonly found in eutrophic waters and often associated with taste and odor problems, were present in 1994. They also dominated samples collected in July and August 1999. Based on the NCTSI scores for July and August, High Rock Lake was determined to be eutrophic. This lake has been consistently eutrophic since monitoring began in 1981. At High Rock Lake, symptoms of eutrophication (i.e., elevated pH values and dissolved oxygen, chlorophyll a, and nutrient concentrations, and algal blooms) have been documented since 1981. Decreased Secchi depths due to suspended sediments in the water column have also been common. The highly erodible soils of the stream and creek channels in this basin are subjected to sudden changes in water volume and force (flashing) due to stormwater discharge from urban areas within the watershed. These soils contribute to the red or brown colors observed in the river and streams following storm events. Transported sediment has reduced the depth of the upper end of the lake such that at low flow periods, the uppermost sampling site can no longer be reached by boat. In addition to reducing the clarity of the lake water, these sediments also contribute nutrients. Another source of nutrients to High Rock Lake is municipal wastewater treatment facilities. The NC DWQ has initiated a variety of actions to address over -enrichment in the High Rock Lake watershed and continues to monitor and reassess needed actions. Wastewater facilities are relocating discharges and improving their nutrient control processes. Nonpoint sources are being investigated. More information on these actions is available in the 1998 Yadkin - Pee Dee River Basinwide Water Quality Management Plan (NCDENR 1998). In addition to the Division's activities, Yadkin, Inc., the hydroelectric company that manages High Rock Lake has developed a Shoreline Management Plan to encourage responsible development around the reservoir. As a planning guide to future development, the Plan also identifies important natural resources and designates portions of the shoreline where these are found as "Conservation Zones". The Plan also contains a Shoreline Stewardship Policy, which contains specifications for private recreation facilities, subdivision access approval, multi -use facility permitting and industrial approval procedures. The plan was approved by the Federal Energy Regulatory Commission (FERC) in 2000. Lake Wright Lake Wright is located north of the Town of Landis in Rowan County. The town owns the lake, which is used as a back-up water supply during times of low flow. The watershed, which had consisted of areas of forest and row crops, was converted to a private golf course (Warrior Golf Club) in 1999. Grants Creek is the major inflow to Lake Wright (Figure 35). Access to Lake Wright is controlled and no recreation is allowed. Figure 35. Sampling site at Lake Wright, Rowan County. Lake Wright was most recently monitored in 1999. Previous monitoring took place in 1994 and indicated that the lake was very eutrophic. Sampling in 1999 seemed to continue to support that eutrophic evaluation, although a NCTSI score could not be calculated without a chlorophyll a reading. Secchi depths in 1999 ranged from 0.7 meter to 1.5 meters, consistent with previous readings. Surface dissolved oxygen and pH were elevated as was percent oxygen saturation. Field notes indicated that the color of the water was brownish -green. Photic zone algae samples NCDENR, Division of Water Quality Basinwide Assessment Report - Yadkin River Basin - June 2002 77 Westside WWTP The Westside WWTP was built in 1930 and "substantially modified" in 1959. It was one of the first activated sludge plants operating in North Carolina. The plant has been operating continuously since 1930 treating a combination of industrial and domestic wastewater prior to discharge to Rich Fork Creek. The Davidson County 201 Facilities Plan, initially completed in 1974, addressed the Westside WWTP. The Plan proposed rehabilitation, upgrading and expansion of the Westside WWTP at the current site. Willis Engineers completed design for the new facilities in 1983. Construction of the new facilities for the Westside Plant began in 1983. In order to construct the new facilities while keeping the existing plant in operation, construction occurred in two distinct phases. The first new facilities, including a new influent structure, primary clarifiers, aeration basin, final clarifiers, and effluent filters were completed in 1985. Following startup of the new facilities, most of the original treatment units were torn down and removed to make room for construction of the remaining new treatment units. Several of the original structures were modified and incorporated into the new facilities. All new facilities were completed in 1986. The Westside WWTP is a trickling filter / activated sludge treatment plant designed to treat an average daily wastewater flow of up to 6.2 MGD (million gallons per day). In 1990 construction of an additional influent screw pump and two -flow equalization basins was begun. Construction was completed in 1992. In 1997 construction of alum storage and pumping facility was begun for phosphorus precipitation in order to meet new effluent phosphorus limits. This system was placed in service in April 1998. In 1998 construction was begun on the new UV disinfection system. This system was placed in service in May of 1999. Chlorine use for disinfection was discontinued at this time. In June of 1996 a centrifuge was installed for sludge dewatering purposes. This unit is now being operated by a separate division but is still located at the Westside Plant. The most recent NPDES permit calls for a reduction in effluent phosphorus based on a mass loading (Ibs.), for summer and winter seasons. In June of 2005 Westside suspended acceptance of discharges from septage haulers. In April of 2006 Westside completed requirements for ending the consent decree with the (ACA) American Canoe Association. ) ) Recent Compliance Record - Westside Number of Violations 3760.002-01.ppt 30 25 20 - 15 - 10 5- 0 Westside WWTP Violation Summary January 1996 - March 2006 r1 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 Year 0 Total # of Violations Recent Compliance Record - Eastside 3760.002.01.ppt Number of Violations 80 70 60 50 40 30 20 10 0 Eastside WWTP Violation Summary July 1997 - February 2006 n 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 Year ❑ Total # of Violations WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 1 Introduction 1.1 BACKGROUND The City of High Point Westside Wastewater Treatment Plant (WWTP) discharges to Rich Fork Creek, which flows into Abbotts Creek before entering High Rock Lake (Figure 1). Data collected by the city and the North Carolina Division of Water Quality (DWQ) show that dissolved oxygen (DO) levels downstream of the facility frequently drop below the state water quality standard of 5 mg/L during the warm summer months. The city is interested in expanding its WWTP discharge with a higher quality of effluent. However, DWQ has indicated that the existing wasteload allocation modeling shows there is a lack of additional assimilative capacity downstream of the facility. Tetra Tech was hired by the city and its engineering consultant, Hazen & Sawyer, to provide third party expert services to evaluate existing data on assimilative capacity in Rich Fork Creek and examine whether more detailed modeling would help shed light on available assimilative capacity and discharge impacts. High-level modeling typically involves collection of significant amounts of field data to calibrate and validate models, which can be time and resource intensive. Prior to investing extensive city resources in such an endeavor, Tetra Tech recommended that a modeling scoping analysis and field reconnaissance be performed to assess the potential benefits of more detailed modeling. This report summarizes the findings of the scoping analysis and field reconnaissance and makes recommendations for next steps. Ei TETRA TECH. INC. 1 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 • Westside WWTP A/Rich Fork Creek Abbotts Creek ' High Rock Lake Lower Yadkin Hydrography County Boundaries 20 0 MONTGOMERY 20 40 Miles Figure 1. Location of the Westside WWTP and Rich Fork Creek TETRA TECH, INC. 2 • WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 1.2 OVERVIEW OF PROJECT APPROACH Tetra Tech's general approach to the scoping analysis was to examine the current modeling methods and assumptions used by DWQ for the Rich Fork discharge allocation in the context of actual monitoring data and receiving stream features. Tetra Tech analyzed the application to determine which parameters and processes seem to be most important in predicting the observed low DO concentrations, and whether there are plausible rates for key variables (velocity, reaeration, sediment oxygen demand, carbonaceous biochemical oxygen demand (CBOD) and nitrogenous biochemical oxygen demand (NBOD) decay, etc.) under which potentially positive outcomes would result from more detailed modeling. Reconnaissance of existing receiving stream features was conducted to help evaluate the appropriateness of existing model assumptions and the likelihood for model rates to change substantially if further detailed monitoring and modeling were performed. 1.2.1 Compilation and Review of Existing Information The first step in the scoping analysis was to compile existing data and information from DWQ, the City of High Point, and previous Tetra Tech studies. This review resulted in a better understanding of the relationship between the plant and water quality in Rich Fork Creek. Comparison of the original model to more recent monitoring data indicates that updates to the existing wasteload allocation model are needed with regard to plant effluent quality, hydraulic parameterization, and reaeration assumptions to obtain an accurate representation of impacts in Rich Fork Creek. 1.2.1.1 DWQ Files DWQ supplied Tetra Tech with copies of the model input files, project notes, and permit documents used for the wasteload allocation of Westside WWTP. A copy of the original Black & Veatch water quality report was also obtained for purposes of acquiring time of travel studies and cross sectional data. DWQ has collected monthly DO data on Rich Fork Creek at station Q5780000 (State Road 1800/Midway School Road). This data was combined with DO data from other sources to assess DO trends in Rich Fork Creek. Sediment oxygen demand (SOD) data was also obtained from DWQ for stations in the Yadkin River Basin (Dianne Reid, 2005). The SOD rates used in the original DWQ model are based on Black & Veatch instream measurements, which are within the range of SOD rates reported by the state for this basin. 1.2.1.2 High Point Data The City of High Point provided electronic DMR data for the Westside WWTP from January 1997 through November 2005. This data included daily measurements of effluent flow and measurements of pH, temperature, DO, ammonia, 5-day biochemical oxygen demand (BOD5), and total suspended solids (TSS) approximately five days per week. Measurements of nitrate plus nitrite, total Kheldahl nitrogen (TKN), total nitrogen (TN), and total phosphorus (TP) were collected approximately once per week. These data were used to set the discharge flow and pollutant concentrations in the QUAL2E model. Tetra Tech calculated average monthly BOD5 concentrations and discharge flowrates. From 1997 to 2005, the plant was compliant with the monthly average BOD5 limit 79 percent of months and the flowrate limit 98 percent of months. In the summer of 2005, staff at the Westside WWTP began collecting DO, temperature, and pH at eight locations in Rich Fork Creek three to five times per week. Simulated DO was compared to data collected at each of these stations to compare predicted concentrations throughout the length of Rich Fork Creek. STETRATSOI, INC. 3 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 1.2.1.3 Yadkin Pee -Dee River Basin Association Data The City of High Point Westside WWTP is a member of the Yadkin Pee -Dee River Basin Association (YPDRBA), which is a coalition of effluent dischargers who work together to collect instream water quality data in receiving streams. The association has compiled water quality data upstream of Westside WWTP and at two downstream locations since June 1998. Weekly observations include temperature, DO, pH, conductivity, and turbidity. Nutrient data are collected monthly. These data were used to set headwater conditions and assess DO trends at two downstream locations. 1.2.1.4 Tetra Tech Whole Effluent Toxicity Study The Owings Mills office of Tetra Tech was contracted by the Water Environment Research Foundation to test whether or not whole effluent toxicity (WET) tests are good indicators of overall stream health. Six dischargers were selected to participate in this study representing a range of influent and effluent conditions including industrial, municipal, effluent dominated and with/without a history of chronic toxicity. Dischargers make up 60 to 100 percent of the receiving streamflow under 7Q10 conditions. The Westside WWTP volunteered as one of the six dischargers assessed in the study. WET testing was performed with Ceriodaphnia dubia, Pimephales promelas, and Raphidocelis subcapitata. Bioassessments were taken for benthic macroinvertebrates, periphyton, and fish. Habitat assessments were taken at five sites along Rich Fork Creek. Preliminary data on biological impacts have been collected, but results have not yet been published. The RTP office of Tetra Tech has acquired the field data sheets and digital photos of Rich Fork Creek, which will serve as aids to qualitatively check model assumptions and assess restoration potential. 1.2.1.5 Streamflow Information US Geological Survey (USGS) does not maintain a streamflow gage on Rich Fork Creek. Flows were extrapolated from USGS gage 02121500 for Abbotts Creek (at Lexington), which Rich Fork Creek drains into further downstream of the gage. The drainage area at this gage is 174 square miles. The drainage area at YPDRBA station Q5750000 is 9.83 square miles (NCDWQ, 2004). Thus, a drainage area ratio of 0.056 was used to estimate flows on Rich Fork Creek upstream of the wastewater treatment. 1.2.2 Setup and Review of Existing DWQ Water Quality Model Tetra Tech set up a QUAL2E model for Rich Fork Creek and Westside WWTP using the DWQ version of the model. The DWQ model was outdated with respect to plant upgrades, which occurred after the original wasteload allocation. 1.2.3 Stream Reconnaissance Reconnaissance was performed by Tetra Tech at 11 sites along Rich Fork Creek and in the three major tributaries. The purpose of the trip was to gather information on channel structure, substrate composition, and source loads that may not have been accounted for in previous modeling. In particular, Tetra Tech focused on identifying potential reasons for the sharp drop in DO below the outfall that are not accounted for by current modeling assumptions. 1.2.4 Additional Modeling Analyses and Evaluation of Assimilative Capacity Tetra Tech reconfigured the existing QUAL2E model to better represent the stream system based on more recent water quality data and stream reconnaissance. Headwater quality and plant effluent quality measured on September 20, 2005 were used as model input, and DO data collected by the Westside TErw►rEa+,INc. 4 • WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 facility on the same day were used to confirm model accuracy. The updated model was then used to determine what changes would be required to bring the DO above the standard during low flow conditions. 1:::) TBTRATHCH.INC. 5 • WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 2 Review of Existing Water Quality Information 2.1 FLOW CONDITIONS FOR EVALUATING WATER QUALITY DATA Water quality on Rich Fork Creek is strongly correlated to streamflow. There is no USGS streamflow gage on Rich Fork Creek, so flows in nearby Abbotts Creek (Figure 2) were plotted to show the correlation between streamflow and excursions of the DO standard. Daily flows are shown in Figure 3, and cumulative summer flows are shown in Figure 4. Note that 2003 was a relatively high flow year, and that 2000 through 2002 and 2005 were estimated to be relatively low flow years. This will be referred to when discussing water quality observations. S TETRA TECH,INC. 7 WQ Scoping Analysis for the High Point Westside Discharge to Rich Pork Cr. March 2006 • Westside WWTP • USGS Gage 02121500 Rich Fork Creek Abbotts Creek /\./ Lower Yadkin Hydrography Figure 2. Location of the Abbotts Creek Gage (USGS 02121500) with Respect to Rich Fork Creek TETRA TECH, INC. 8 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 1 Jan- Jul- Jan- Jul- Jan- Jul- Jan- Jul- Jan- Jul- Jan- Jul- Jan- Jul- Jan- Jul- 98 98 99 99 00 00 01 01 02 02 03 03 04 04 05 05 Figure 3. Daily Flows at Abbotts Creek Gage (USGS 02121500) from January 1998 through October 2005 Figure 4. Cumulative Summer Flows (May through October) at Abbotts Creek Gage (USGS 02121500) TETRA TECH, INC. 9 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 2.2 INSTREAM WATER QUALITY DATA The City of High Point Westside WWTP is a member of YPDRBA, which is a coalition of dischargers who collect water quality data in receiving streams located in the river basin. Data for Rich Fork Creek are available from June 1998 to present. In addition, the Westside WWTP has monitored DO, temperature, and pH at two upstream locations and six downstream locations since July 2005. DWQ began collecting monthly DO samples in January 2000 at one location downstream of the plant. Tetra Tech has received this data through December 2004. Figure 5 shows the location of these monitoring stations along Rich Fork Creek. Site descriptions are listed in Table 1 and Table 2 along with data summaries by station. 2.2.1 Summary of Data Collected The largest database of water quality data for Rich Fork Creek is maintained by YPDRBA. Station Q5750000 is located upstream of the WWTP at State Road 1755. Two downstream stations are also monitored: Q5785000 at State Road 1787/Kanoy Road and Q5790000 at State Road 2123/Old Highway 29. Temperature, DO, pH, conductivity, and turbidity are analyzed weekly. Ammonia, nitrite plus nitrate, TKN, and TP are analyzed monthly. Table 1 and Figure 6 summarize the water quality data collected at these three sites. The Westside WWTP began collecting DO, temperature, and pH data at eight sites on Rich Fork Creek in July 2005, five days per week. Table 2 and Figure 7 summarize this data. DWQ provided Tetra Tech with monthly DO data collected from January 2000 through December 2004 at Q5780000 (State Road 1800/Midway Road). The minimum observed DO concentration at this location is 4.0 mg/L, the average is 7.9 mg/L, and the maximum is 13.5 mg/L. TETRA TECH. INC. 10 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 �J HUC Boundary DWQ Station ■ YPDRBA Stations * Westside Monitoring Stations A/ Rich Fork Creek A,� HUC Hydrography 6 0 6 Miles Figure 5. Water Quality Monitoring Stations in Rich Fork Creek Tt TETRA TECH. INC. 11 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Table 1. Summary of YPDRBA Data for Rich Fork Creek (1998 through 2005) Station Parameter Minimum Average Maximum Q5750000 - 1.3 miles upstream of the WWTP at State Road 1755 ! Lexington Avenue Temperature (°C) 1.0 17.9 25.9 DO (mg/L) 3.3 7.2 12.9 pH 6.6 7.4 8.3 Conductivity (µmhos/cm) 72 186 368 Turbidity (NTU) 3.4 21.1 241.0 Ammonia (mg-N/L) 0.01 0.1 0.9 Nitrate plus Nitrite (mg-N/L) 0.01 0.1 0.4 TKN (mg -NIL) 0.1 0.5 2.4 TP (mg-P/L) 0.01 0.1 0.6 Q5785000 - 3.9 miles downstream of the WWTP at State Road 1787 / Kanoy Road Temperature (°C) 1.5 18.8 27.9 DO (mg/L) 2.9 6.1 11.4 pH 6.5 7.3 8.4 Conductivity (µmhos/cm) 93 295 719 Turbidity (NTU) 2.0 22.0 400 Ammonia (mg -NIL) 0.01 0.2 1.6 Nitrate plus Nitrite (mg-N/L) 0.1 3.4 11.2 TKN (mg-N/L) 0.1 1.3 3.9 TP (mg-P/L) 0.01 0.5 2.3 Q5790000 - 9 miles downstream of the WWTP at State Road 2123 ! Old Highway 29 Temperature (°C) 1.0 18.5 26.1 DO (mg/L) 3.0 6.8 12.2 pH 6.7 7.4 8.3 Conductivity (mhos/cm) 88 253 470 Turbidity (NTU) 1.9 22.4 300 Ammonia (mg-N/L) 0.01 0.1 0.6 Nitrate plus Nitrite (mg-N/L) 0.1 1.8 8.0 TKN (mg-N/L) 0.1 0.9 1.9 TP (mg-P/L) 0.01 0.3 1.5 TETRA TECH, INC. 12 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 14 13 12 11 10 9 8 7 O 6 0 5 4 3 2 1 0 I Median 25%-75% T Non -Outlier Range o Outliers Q5750000 Q5785000 Station Q5790000 Standard Figure 6. Box Plots of Dissolved Oxygen Data Collected at YPDRBA Monitoring Sites TETRA TECH. INC. 13 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Table 2. Summary of Westside Instream Data for Rich Fork Creek (Summer 2005) Station Parameter Minimum Average Maximum Q5750000 - 1.3 miles upstream of the WWTP at State Road 1755/ Lexington Avenue Temperature (°C) 6.2 19.1 27.3 DO (mg/L) 5.5 7.5 11.1 pH 6.7 7.5 8.2 CHP1 - 20 feet upstream of the WWTP discharge Temperature (°C) 5.2 18.9 26.8 DO (mg/L) 4.0 7.1 10.9 pH 6.4 7.4 7.9 CHP3 - 0.3 miles downstream of the WWTP at Highway 109 Temperature (°C) 7.0 20.6 27.6 DO (mg/L) 4.5 7.1 10.9 pH 6.3 7.2 7.9 Q5780000 - 1.4 miles downstream of the V VVTP at State Road 1800 / Midway School Rd Temperature (°C) 7.4 20.7 29.1 DO (mg/L) 3.0 5.8 10.3 pH 6.5 7.2 7.8 CHP4 - 2.9 miles downstream of the WWTP at State Road 1790 ! Ball Rd Temperature (°C) 6.8 20.1 29.0 DO (mg/L) 2.8 5.7 10.4 pH 6.4 7.2 7.8 Q5785000 - 3.9 miles downstream of the WWTP at State Road 1787 / Kanoy Road Temperature (°C) 7.0 20.2 28.8 DO (mg/L) 2.6 5.7 10.5 pH 6.3 7.2 7.9 CHP5 - 6.6 miles downstream of the WWTP at Evans Rd Temperature (°C) 6.8 19.6 29.4 DO (mg/L) 3.4 6.1 10.7 pH 6.0 7.3 7.9 Q5790000 - 9 miles downstream of the WWTP at State Road 2123 ! Old Highway 29 Temperature (°C) 6.8 19.6 31.2 DO (mg/L) 2.8 6.0 10.6 pH 6.5 7.3 8.2 o TETRA TECH, INC. 14 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 14 13 12 11 10 9 8 i= 7 6 5 4 3 2 1 0 0 Median 25%-75% T Non -Outlier Range 0 Outliers Q5750000 CHP1 Standard CHP3 Q5780000 CHP4 Q5785000 CHPS Q5790000 Station Figure 7. Box Plots of Dissolved Oxygen Data Collected at Westside Monitoring Sites Both the YPDRBA and Westside data show a drop of approximately 1.5 mglL in DO downstream of the plant discharge. Tetra Tech plotted daily DO collected by the plant to see if that trend occurred on a daily basis, or if it was just a product of the means. TETRA TECH, INC. 15 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 On almost every day that Westside collected DO data, a drop of 1 to 2 mg/L of DO is observed within three miles of the plant discharge. On high flow and/or low temperature days, the standard of 5 mg/L is still met. Figure 8 shows the DO on three sampling days with varying flow and temperature conditions. August 10th, 2005 had an estimated flow rate of 24 cfs and an average water temperature of 23.7 °C (high flow, high temperature). DO decreases by 1.3 mg/L, but does not drop below the standard. The flow rate on September 20th, 2005 was approximately 0.5 cfs, and the average water temperature was 22.7 °C (low flow, high temperature). The DO drops by 1.6 mg/L and does not meet the standard. October 19th, 2005 had a flow rate of approximately 1 cfs and a water temperature of 16.8 °C (low flow, low temperature). The DO dropped by 1.9 mg/L, but the standard was still met. These data confirm that the critical conditions for this creek are low flow coupled with high temperature. 7 6 L 5 D) E 4 0 3 2 1 0 —A-10/19/05 (low flow, low temp) -8/10/05 (high flow, high temp) i 9/20/05 (low flow, high temp) Standard 0.0 2.0 4.0 6.0 Distance from WWTP (miles) 8.0 10.0 Figure 8. Observed Dissolved Oxygen Concentrations on Three Dates Representing Various Flow and Temperature Conditions TETRA TECH, INC. 16 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 2.2.2 Summary of Relevant Information Tetra Tech combined the DO data from YPDRBA, Westside WWTP, and DWQ into one database to assess DO trends in Rich Fork Creek. The Westside data were also used to compare simulated DO concentrations to observations at multiple locations in the creek. The majority of the DO data has been collected at four locations: Q5750000, Q5780000, Q5785000, and Q5790000. Data from these stations (June 1998 through December 2005) were plotted by month to identify seasonal trends (Figure 9). Excursions of the DO standard (5 mg/L) only occurred during the summer months (May through October). • Q5750000 • Q5780000 Q5785000 Q5790000 — Standard 14 13- 12 11 10 a 9 E 8 a 7 6 5 4 3 2 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Month Figure 9. DO Concentrations at Four Primary Stations in Rich Fork Creek, by Month TETMTECH.INC. 17 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 24. Algal Growth in Pooled Area at Site 3 Pooled area formed by old road abutment. Figure 25. Rich Fork Creek at Site 3, Facing Downstream Banks show signs of erosion but not severe. Banks are well vegetated. A sand bar was forming on left side of channel downstream of the old abutment. nTETRA TECH, INC. A-23 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 26. Sand Bar Formation at Site 3, Facing Downstream Figure 27. Rich Fork Creek at Site 3, Facing Upstream Sand bar formation on the right bank; deposition on top of the left bank. TETRA TECH, INC. A-24 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 28. Rich Fork Creek at Site 3, Facing Downstream Well vegetated banks. Sand bar formation on left. a TETRATECH, INC. A-25 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 5 Site 4: Rich Fork Creek Twenty Feet Upstream of WWTP Discharge The following general observations were noted at Site 4: • This site corresponds to the Westside monitoring station CHP1 which is 20 feet upstream of the WWTP discharge. • CHP1 is sampled from a sampling bridge when water is accessible. • Width of water on this day was approximately 30 feet; depth was %2 to 1 foot. • Substrate is primarily sand and course sand. Substrate sample had top 8 inches of brown course sand similar to upstream. However, deeper 4 inches of sand was gray. A second sample from an adjacent bank had 12 inches of brown sand underlain by gray sand. No accumulations of organic material. • Steep banks with some vegetation. Banks not eroding significantly; erosion does not appear to be the source of sediment in the stream. • Banks are silty but channel substrate is not (similar to Site 3 at Lexington Avenue.) • Saw mussel shells in the stream. • Began to notice fallen trees in the channel when looking upstream. Trees were leaning and falling in because of channel movement in the sandy substrate. • Near full canopy at leaf out. • Can smell plant effluent. Effluent has a light green color and mixes in fairly quickly with streamflow on this day. Substrate taken from mixing zone is similar to that seen upstream of the discharge. Figure 29 through Figure 43 illustrate these observations. 1::::) TETRA TECH. INC. A-27 WQ Scoping Analysis for the Nigh Point Westside Discharge to Rich Fork Cr. March 2006 Figure 29. Westside Sampling Bridge at Site 4 Water quality samples are taken from the downstream,left corner of bridge when water is present. Figure 30. Facing Opposite Bank from Sampling Bridge at Site 4 Green tint in pooled areas — approximately 2 ft deep. TETRA TECH, INC. A-28 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 31. Rich Fork Creek Facing Upstream at Site 4 Banks are vegetated with trees, but groundcover and shrubs limited. Sand bars forming. Deposition on top of left bank. OTETRA TECH, INC. A-29 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 32. Facing Downstream at Site 4 Large sand bar forming on right bank. Sandy substrate. Well vegetated floodplain.. Figure 33. Insertion of Shovel at Site 4 Shovel easily pushed through two feet of unconsolidated substrate. TETRATECH. INC. A-30 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 34. Deposition of Silts on Left Bank Fines evident on banks, but not in stream. Figure 35. Facing Downstream from CHP1 Sampling Bridge Sampling of Westside WWTP Effluent as part of the Westside instream monitoring program. ILL I TETRA TECH, INC. A-31 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 36. View of Channel Substrate Upstream of the Plant Discharge Three distinct layers seen in substrate: top 4 inches is course brown sand, middle 4 inches is Tight brown sand, and deepest four inches is gray sand. No organic material present. Figure 37. Shovel Sample Taken from Adjacent Bank Material taken from bank has more silt and clay than instream sample. Top foot extracted has brown color; gray material present below. riTETRA TECH, INC. A-32 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 38. Sandy Substrate at Site 4 Figure 39. Westside WWTP Effluent Discharge Effluent has green tint compared to streamflow. nTETRATECH. INC. A-33 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 40. Rich Fork Creek Below Effluent Discharge See effluent discharge moving downstream. Not yet completely mixed. Figure 41. View of Effluent Discharge Mixed with Streamflow on Bank Opposite Discharge riTETRA TECH, INC. A-34 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 42. Sand Bar Formation on Right Bank Downstream of Effluent Discharge Substrate sample appeared the same as CHP1: brown sand on top underlain by gray sand. No organic accumulation on substrate. Leaf litter present in stream to the right of field technician. Figure 43. Rich Fork Creek Downstream of WWTP Discharge, Facing Downstream Floodplain well vegetated. Sand bars prevalent; sediment deposition on banks. g TETRA TECH, INC. A-35 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 6 Site 5: Rich Fork Creek at Highway 109 The following general observations were noted at Site 5: • The Highway 109 bridge is the sampling site for Westside instream station CHP3. This site is approximately 0.3 miles downstream of the WWTP discharge. • This site was visited twice. The downstream section was visited during the middle of the day. The upstream section was visited in the early evening after finding sand mining equipment at other locations on Rich Fork Creek. • There is an ongoing construction project at this site for road and bridge widening. • Initial site visit, downstream of Highway 109 bridge: o Water is green, pooled, and flat. Slow moving. Water is approximately 50 feet wide on day of reconnaissance and 3 to 5 feet deep (depth guessed because bottom could not be seen). Banks are approximately 8 ft higher than water surface. o Can still smell plant effluent. No DO problems detected here in the summer of 2005 from Westside instream monitoring, but that may be due to high DO concentration in WWTP effluent. o Substrate had approximately one inch of organic material underlain by gray, cohesive sand. Substrate composition is completely different compared to other sites upstream of the plant. • Second site visit, upstream of Highway 109 bridge: o Walked upstream behind road construction project. Saw crane with dipping bucket, recent tire tracks, scrape marks in stream. Instream mining has formed a pool approximately 1500 feet long with an estimated depth of 3 to 5 feet. o Was not able to sample substrate with shovel, but organic layer was visible from stream bank. o Field technicians noted that though it seems likely that the organic layer would be removed during excavation along with the sand, this layer was easily washed off during substrate sampling at other sites. Therefore, it is expected that much of the organic material is suspended during dredging and is re -deposited on the pool bottom. Accumulations of organic material are likely due to low velocities in pooled areas as well as washoff during sand removal. Figure 44 through Figure 56 illustrate these observations. (7) TETRA TECH. INC. A-37 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 44. Sample of Substrate Taken at Site 5 Layer of brown organic material underlain by gray cohesive sand. Completely different substrate compared to other sites. Due to pool depth and limited access to thalweg, this sample was taken at the toe of the right bank and may not represent substrate along the pool bottom. ei TETRATECH, INC. A-38 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 45. Sample of Substrate Taken at Site 5 Note consistency of organic material pulling away on top left of sample. Finger smudge on right side of sample. Figure 46. Rich Fork Creek at Site 5, Facing Downstream Water is estimated as 3 to 5 feet deep and approximately 50 feet wide. Water has green tint. Banks are well vegetated, but entrenched. TETRA TECH. INC. A-39 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 47. Rich Fork Creek from Highway 109 Pool, Facing Upstream Water has murky tint. Figure 48. Sand Mining Equipment Located Upstream of Highway 109 Bridge Crane parked in front of creek. Has same type of dipping bucket found on Ball Road crane. TETRA TECH, INC. A-40 WQ Scoping Analysis for the High Point Westside Discharge to Rich Pork Cr. March 2006 Figure 49. Tire Tracks Behind Sand Mining Crane Due to precipitation prior to field evaluation, tracks indicate that crane was recently in use. Figure 50. Residual Sand Pile at Mining Site Adjacent to Rich Fork Creek El TETRA TECH. INC. A-41 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 51. Recently Mined Section of Rich Fork Creek Above Highway 109 Scrape marks evident on opposite bank from sand dipping operation. Figure 52. Rich Fork Creek at Sand Mining Operation, Facing Upstream Excavated material pulled up left side of channel. s TETRA TECH, INC. A-42 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 53. Sand Mining Operation Adjacent to Rich Fork Creek, Facing Upstream Disturbed area extends back to tree line. Recent tire tracks evident. Figure 54. Sand Mining Operation Adjacent to Rich Fork Creek, Facing Downstream Looking downstream toward bridge construction at Highway 109. Water pump with truck filling apparatus. TETRATECH,INC. A-43 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 55. Excavated Bank on Rich Fork Creek, Facing Upstream Figure 56. Recent Tire Tracks at Sand Mining Operation Adjacent to Rich Fork Creek Track patterns indicate use of machinery to load dredged sand into trucks for transport. o TETRA TECH, INC. A-44 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 7 Site 6: Rich Fork Creek at Midway School Road The following general observations were made at Site 6: • Site 6 corresponds to YPDRBA site Q5780000 and is also sampled routinely by the Westside WWTP. This site is located approximately 1.4 miles downstream of the Westside facility. • Stream geometry has recovered compared to pooled reach at Highway 109. • Substrate is sandy. Algae evident on fixed woody material. • Substrate sample has brown sand underlain by gray sand. No accumulation of organic material. • Water is approximately 45 feet wide and 1 to 2 feet deep. • Banks are steep but vegetated (approximately 3 feet high). Stream has access to a broad floodplain. • Mussel shells present in stream. • Fewer fallen trees in channel. Pools present. • Canopy cover approximately 75 to 100 percent during leaf out. Figure 57 through Figure 60 illustrate these observations. Figure 57. Wetland Floodplain Adjacent to Rich Fork Creek at Site 6 TETAATECH,INC. A-45 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 58. Rich Fork Creek at Site 6, Facing Upstream Water is 1 to 2 feet deep with green color. Banks are well vegetated. Broad floodplain. Figure 59. Rich Fork Creek at Site 6, Facing Downstream Water is shallower than in upstream direction. (-3 TETRA TECH, INC. A-46 • WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 60. View of Floodplain at Site 6 Water is deeper along sides of channel due to sediment deposition along centerline. TETRA TECH, INC. A-47 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 8 Site 7: Rich Fork Creek at Ball Road The following general observations were made at Site 7: • This site corresponds to the Westside instream monitoring site CHP4 and is approximately 2.9 miles downstream of the plant discharge. • Upstream of the Ball Road bridge, water is shallow and fast moving. Notice green color in deeper waters. Lots of mussel shells. Water is approximately 4 inches deep in the center and deeper on the sides. Deep pool on right side facing bridge (greater than 4 feet). Frank Skee says large sand deposit in center of channel is from recent storm and field technician sank when walking to get estimate of pool depth. Can still smell plant effluent. • Substrate sample upstream of bridge is course sand only. • Substrate sample downstream of bridge has a couple of inches of organic material underlain by gray sand. Adjacent banks have the same sand, but top half is brown. Other than the color change, the sand is the same. • Field technician noticed bubbles when he lifted the shovel. Bubbles are also evident in undisturbed areas of the pool. Frank Skee says bubbles are prevalent in summer months. • Water is 75 to 100 feet wide downstream of the bridge. Very deep, dark green water. Visibility approximately 2.5 feet; water depth approximately 5 feet. Depths at this site were estimated using a weighted rope. • Completely different channel geometry upstream and downstream of the bridge. Substrate changes from brown sand to gray sand covered by organic material. Channel width increases three fold. Depth increases from 1 to 5 feet. • Downstream of the bridge water is much deeper and wider. Old crane with dipping bucket parked next to stream. Appears that historic instream sand mining caused the change in channel shape downstream of the bridge. • Feasible restoration site in sand -mined pool. Figure 61 through Figure 71 illustrate these observations. lib TETRAT@CH.INC. A-49 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 61. Approaching Rich Fork Creek from Ball Road Bridge, Looking at the Main Channel from the Right Bank (Flow is from Left to Right in the Figure) See color change of deep side pool compared to shallow stream channel. Broad floodplain. Well vegetated banks. Figure 62. Standing on Ball Road Bridge, Facing Upstream See sandy, mobile substrate. Water is shallow and fast moving, approximately 30 feet wide and to 1 foot deep. Substrate sample was course brown sand throughout. OTETRA TECH, INC. A-50 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 63. Sand Dipping Crane Located Downstream of Ball Road Bridge Next to Rich Fork Creek Water on downstream side is three times as wide and five times as deep compared to upstream reach. Figure 64. Sand Dipping Bucket Attached to Crane - TETRA TECH, INC. A-51 WQ Scoping Analysis for the High Point Wesiside Discharge to Rich Fork Cr. March 2006 Figure 65. Substrate Sample Taken from Ball Road Pool Substrate is course gray sand covered by 1 to 2 inches of organic material. Figure 66. Sample from Adjacent Bank Here there is at least 1 foot of brown sand above the gray sand. In the channel, only gray sand is present. TETRA TECH, INC. A-52 WQ Scoping Analysis for the High Point Westside Discharge 10 Rich Fork Cr. March 2006 Figure 67. View of Rich Fork Creek at Ball Road Pool, Facing Upstream Toward Bridge Figure 68. Channel Substrate in Ball Road Pool o TETRATECN,INC. A-53 • WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 69. Review of Rich Fork Creek Facing Upstream from Ball Road Bridge Figure 70. Edge of Sandbar and Pool on Upstream Side of Bridge It's possible that some dipping occurred on this side of the bridge to form this pool. 1 1 TETRA TECH, INC. A-54 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 71. Review of Downstream Section of Rich Fork Creek Water is much wider and deeper downstream of crossing. Bubbles were observed rising to surface (figure fails to clearly show bubbles in lower left quadrant of photo). nTETRATECH,INCA-55 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 9 Site 8: Rich Fork Creek at Kanoy Road The following general observations were made at Site 8: • Site 8 corresponds to YPDRBA site Q5785000 and is also sampled routinely by the Westside WWTP. This site is located approximately 3.9 miles downstream of the Westside facility. • Stream not easily accessible upstream of the bridge. • Looking a few hundred feet upstream of the bridge, the stream is fairly narrow and sinuous. The banks are approximately 1 foot above the water surface, well vegetated, with mature trees. • Just upstream of the bridge the stream is wide and deep. Even more so downstream of the bridge. On the downstream side, the water surface was approximately 150 feet wide and 5 feet deep (depth estimated as the bottom could not be seen). Banks are approximately 2 to 3 feet higher than the water surface. Rooted plants present in pooled areas. • Substrate sample from downstream section is about 6 inches of brown sand underlain by 6 inches of gray sand. Not as much accumulation of organic material on the top layer. The organic material is mixed in with sand over a depth of approximately 'Y4 inch. • Saw live mussels in downstream section. • Feasible restoration of sand -mined pool. Figure 72 through Figure 75 illustrate these observations. Figure 72. Substrate Sample at Site 8, Sample 1 Substrate sample shows approximately 6 inches of brown sand underlain by gray sand. Some organic material on top, though not clearly illustrated in the photo. TE TRA TECH. INC. A-57 .en.., WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 73. Substrate Sample at Site 8, Sample 2 This photo does not show a vertical profile. The field technician skimmed the surface to view the organic material and determine if it looked similar to that seen at the other pools. At this site the organic material covers the top Vs inch and is mixed with brown sand, as shown in the center sample. The left sample is gray sand from a vertical profile in the stream. The right sample is gray organic matter taken from a bar in the stream and appears to be decaying leaf litter. TETRA TECH, INC. A-58 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 74. Rich Fork Creek Facing Upstream at Kanoy Road Pool Water is approximately 150 feet wide and 5 feet deep in this pool. Wide, flat field on opposite bank looks similar to Ball Road and Highway 109 mining operation sites. Figure 75. Rich Fork Creek Facing Downstream From Kanoy Road Pool It appears that the stream is reestablishing a more natural geometry. The depositional bar forming on the right side of the channel is beginning to restrict flow to the left side only. TETRA TECH. INC. A-59 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 10 Site 9: Rich Fork Creek at Evans Road The following general observations were made at Site 9: • Evans Road at Rich Fork Creek corresponds to the Westside instream monitoring site CHP5 and is approximately 6.6 miles downstream of the WWTP. This site is downstream of the first major tributary (Hunts Fork Creek) which has entered the system since Kennedy Mill Creek joined Rich Fork Creek just upstream of Highway 109. • The channel at Evans Road is more similar to the upstream sites compared to the pools. The water is approximately 20 to 30 feet wide and 1 to 2 feet deep. The sandy substrate is visible from the bridge. Waters in deeper areas have a green color and are approximately 3 feet deep. Lots of woody debris in the channel downstream of Evans Road. Water is moving, but is fairly deep. • Banks are 2 to 4 feet above water surface with some vegetation. Noticeable sand bar deposition. • Substrate sample is comprised of brown sand with a layer of organic material on top (less than 1/8 inch). • Upstream of the bridge, shovel sample has more gray sand, but less of the accumulated organic material. Water moves faster on the upstream side. • Good condition riparian buffer. Figure 76 and Figure 77 illustrate these observations. Figure 76. Rich Fork Creek at Evans Road, Facing Upstream Broad floodplain, well vegetated banks. Water has green color in deeper areas. Sand bar was forming along the left side of channel. TETRATECH, INC. A-61 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 77. Rich Fork Creek at Evans Road, Facing Downstream Well vegetated banks. Water is pooled behind woody debris. a TETRA TECH, INC. A-62 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 11 Site 10: Rich Fork Creek at Old Highway 29 The following general observations were made at Site 10: • Site 10 corresponds to YPDRBA monitoring site Q5790000 which is approximately 9 miles downstream of the WWTP. This site is also monitored by the Westside facility for general water quality parameters. • Water at this site was approximately 50 feet wide and 3 to 4 feet deep on the day of reconnaissance. Bottom width of channel is approximately 80 feet. Large sand bars forming. Entrenched banks (3 to 4 feet above water surface) with vegetation. Water has green color. • First substrate sample had 1/8 inch accumulation of organic material followed by 2 inches of brown sand underlain by gray sand. • Lots of mussel shells present. • Second substrate sample had no accumulation of organic material and was comprised of 6 inches of brown sand underlain by 6 inches gray sand. • Bubbles were noted rising to surface. Figure 78 and Figure 79 illustrate these observations. Figure 78. Rich Fork Creek at Site 10, Facing Upstream Broad, well vegetated floodplain. Water is approximately 50 feet wide and 3 to 4 feet deep. Th TE TRA TECH, INC. A-63 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 79. Rich Fork Creek at Site 10, Facing Downstream Stream is much wider just downstream of the bridge, but no evidence of historic sand mining. 1 1 TETRA TECH, INC. A-64 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 12 Site 11: Payne Creek at Hanes Road The following general observations were made at Site 11: • Payne Creek joins Rich Fork Creek between Site 3 and 4. • Field technicians visited Payne Creek just upstream of its confluence with Rich Fork Creek. • Payne Creek drains a significant fraction of the urban area in this watershed based on the 1992 NLCD land use coverage as discussed in the main report. • Channel geometry and substrate look similar to sites on Rich Fork Creek above the WWTP and sand mining operations. • Water is approximately 10 to 12 feet wide and %2 to 1 feet deep upstream of bridge and 12 to 15 feet wide and 8 inches to 1 foot deep on downstream end. • Vegetation and litter are present on the top and sides of the banks. • Large sandbar forming downstream of the bridge. • The right side of the channel downstream of bridge has been stabilized with grass and large rocks. • Substrate sample has brown sand underlain by light gray sand — not dark gray as on Rich Fork Creek. No accumulation of organic material. Substrate does have some fine silts, but they are not as cohesive or as dominant as in Rich Fork Creek. Figure 80 and Figure 81 illustrate these observations. mraarec►+,tNc. A-65 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 80. Payne Creek at Site 10, Facing Upstream Well vegetated banks with a broad floodplain. This stream is in much better shape than expected given the large portion of urban area in headwaters. Figure 81. Payne Creek at Site 10, Facing Downstream Large sand bar forming on left bank. Right bank required stabilization to protect adjacent fence. TETRATECH, INC. A-66 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 200E 13 Site 12: Kennedy Mill Creek at Burton Road The following general observations were made at Site 12: • This site is on Kennedy Mill Creek just upstream of its confluence with Rich Fork Creek. This creek drains a large portion of urban area according to the 1992 NLCD land use coverage as discussed in the main report. • Channel bottom is sand and course sand with some gravel. Water is approximately 10 to 15 feet wide and to 1 foot deep. • Substrate sample is comprised of brown sand with some gray streaks. One of three samples had 6 inches of brown sand underlain by 6 inches of gray sand. No accumulation of organic material. • Broad, well vegetated floodplain. Figure 82 and Figure 83 illustrate these observations. Figure 82. Kennedy Mill Creek at Site 12, Facing Upstream This creek has well vegetated banks and an accessible floodplain. Expected to see some degradation given the amount of impervious surface in the upstream areas, but stream appears stable. TETRA TECH, INC. A-67 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 83. Kennedy Mill Creek at Site 12, Facing Downstream Stream has well vegetated banks and access to floodplain. Sand bars forming. TETRA TECH, INC. A-68 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 14 Site 13: Hunts Fork Creek at Stone Road The following general observations were made at Site 13: • This site is on Hunts Fork Creek just upstream of the confluence with Rich Fork Creek. This creek drains a large portion of urban area according to the 1992 NLCD land use coverage as discussed in the main report. • Heavy sediment deposition in stream. One of the four box culverts under the road is almost completely filled in with sand. • Large sand bars are spaced in an alternating pattern down the channel and are reestablishing sinuosity. No significant stream bank erosion at this site. Banks are well vegetated. Water is approximately 20 feet wide and''V2 foot deep. • There is a large wetland area on the left side of the channel which is separated from the channel by a berm. May have historically been straightened with dirt placed on left bank. • Substrate sample has brown sand underlain by a mixed layer underlain by a gray layer. Color change does not have the sharp contrast seen at the Rich Fork sites and no accumulation of organic material. Figure 84 illustrates some of these observations. Figure 84. Hunts Fork Creek at Site 13, Facing Downstream Formation of alternating sand bars in stream is reestablishing sinuosity. Floodplain is well vegetated. FE) TETRA TECII, INC. A-69 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 1 Phase 1 - Confirm Impacts of Pools The objective of the first phase of monitoring is to verify the time of travel and sediment oxygen demand (SOD) rates assumed in Tetra Tech's low flow version of the QUAL2E model as well as to observe DO trends along the lengths of each of the three sand -mined pools. 1.1 MONITORING OBJECTIVES • Obtain flow and velocity measurements to verify the QUAL-2E hydraulic components and provide a basis for predicting stream reach velocities in Rich Fork Creek in both the pooled areas and the unaltered sections of the channel during low flow. • Continue to monitor general water quality parameters at the eight Westside instream monitoring sites. • Sample water quality in the three pools to measure DO concentrations in the slower moving sections of the creek. • Collect measurements of SOD from upstream of the wastewater treatment plant and downstream of the plant in both the pooled and unaltered sections of the channel to accurately represent the spatial variability of the demand. 1.2 SAMPLING COMPONENTS Three primary monitoring components are required to meet the objectives of the monitoring plan: 1) time of travel study, 2) general water quality characterization, and 3) sediment oxygen demand measurements. 1.2.1 Time of Travel Study A time of travel study is needed to differentiate the residence times of each pool from the unaltered sections of the channel. Streamflow and dye studies will be performed to verify stream velocities and travel times used in the low flow version of the QUAL2E model. Distribution of dye concentrations will help calculate longitudinal dispersion, and peak -to -peak time will support velocity estimates. The time of travel study should be conducted during summer low flow as close to or at 7Q10 critical conditions. The timing of these studies will require that no significant rainfall events (> 0.5 inch) have occurred in the previous seven days and that the creek has reached steady state flows during the sampling period. Streamflow should be measured on the same days as dye studies are performed. Additional cross section measurements should also be taken to update the previous sections and to ensure accurate representation of sand mine pool versus natural stream channel reaches. The initial dye injection point will be at the WWTP discharge location. Dye concentrations should be monitored upstream and downstream of each pond. This will allow time of travel estimates through each pond as well as through the connecting reaches. 1.2.2 General Water Quality Characterization In addition to the instream sampling collected by the Westside plant, general water quality parameters (temperature, pH, conductivity, DO) should be measured during critical conditions at the upper, middle, and downstream sections of each pond. Sampling events should correspond to days of Westside instream sampling so that a complete DO profile is collected downstream of the plant. At least two sampling s TETRA TECH, INC. B-3 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 events during critical conditions are recommended to capture representative profiles. Sampling will be performed using handheld instruments and all pertinent data will be recorded in a field log. This sampling will be used to characterize the overall water quality in the ponds compared to the rest of the system. 1.2.3 Sediment Oxygen Demand Measurements SOD is an important parameter in the Rich Fork Creek model, but there is uncertainty in how to represent SOD throughout the downstream reach. Based on visual inspection of channel substrate in January 2006, it is expected that SOD rates may vary with the amount of organic material layering the substrate surface along the length of the study reach. Because the low -flow version of the scoping model is so sensitive to the SOD rate (a 20 percent reduction is predicted to result in compliance with the DO standard during critical conditions), it is imperative that this parameter be defined as accurately as possible. SOD should be measured upstream of the wastewater treatment plant, near the middle of each pool, in the unaltered sections of the channel between the three pools, and downstream of the last pool. 1.3 MONITORING SCHEDULE The preliminary field studies will ideally be carried out during the summer of 2006. The time of travel study and collection of water quality data in the pools should be conducted during steady state flow conditions near the 7Q10. The SOD testing apparatus may require water deeper than available in the unaltered sections during low flow conditions and there must also be sufficient levels of DO available in the water column. Therefore, SOD measurements should be taken at the lowest flows and highest temperatures possible without interfering with the operation of the equipment. For purposes of this study, no appreciable rainfall (> 0.5 inches) shall have occurred in the seven days prior to the sampling events. Rainfall events which occur during the sampling events will be considered on a case by case basis to determine whether they will interfere with the objectives of the study. EZ, TETRATECH.INC. B-4 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 2 Support QUAL2E Model Recalibration After the three pools have been restored and the plant has upgraded its facility to consistently discharge high quality effluent, a full scale study will be needed to gather the information required to properly calibrate and validate a wasteload allocation model reflective of the changed conditions. It is important that the system reach equilibrium with the new flow regime and waste loads before monitoring begins. Tetra Tech suggests that bank stability and substrate composition be monitored periodically at several locations to determine if the system has reached equilibrium. Once stability is reached, it will be appropriate to gather data for the wasteload allocation model. 2.1 MONITORING OBJECTIVES • Obtain physical measurements to refine QUAL2E model input assumptions that represent Rich Fork Creek channel width and depth under low flow conditions. • Obtain flow and velocity measurements to calibrate QUAL2E hydraulic components. • Continue to monitor general water quality parameters at the Westside instream monitoring sites. • Collect general water quality data at the restored sites to assess impacts of restoration and provide additional calibration data. • Collect data to simulate full oxygen balance with QUAL2E. • Collect field samples for lab analysis to characterize parameters associated with assimilative capacity and initial modeling conditions at key locations. 2.2 SAMPLING COMPONENTS Four primary monitoring components are required to meet the objectives of the full scale study: 1) hydraulic studies, 2) general water quality characterization, 3) DO balance analysis, and 4) detailed water quality analysis. 2.2.1 Hydraulic Studies Hydraulic studies are required to estimate the velocity of Rich Fork Creek throughout the study area during low flow conditions. Physical channel measurements will be performed at transects throughout the study area to determine the physical channel dimensions. Measurements should be made during low flow conditions with water surface elevations recorded as well. Additionally, two dye studies will be performed to characterize the flow/velocity relationships and prediction of travel times. One study should be conducted near 7Q10 flow; the second should be conducted during average flow conditions. Distribution of dye concentrations will assist in the estimation of longitudinal dispersion; peak -to -peak time will support velocity estimates. Dye concentrations should be monitored at the upstream and downstream end of each pool so that travel times through the pools and each unaltered section can be accurately simulated. The timing of these studies will require that no significant rainfall events (> 0.5 inches) have occurred in the previous seven days and that the creek has reached steady state flows during the sampling period. S TETRATECH,INC. B-5 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 2.2.2 General Water Quality Characterization In addition to the sampling sites already monitored by the Westside WWTP, field sampling for general water quality parameters should be performed in the middle of each restored segment. These sites should be added to the Westside sampling protocol for at least one summer to accurately calibrate the wasteload allocation model and to assess the impacts of the channel restoration. 2.2.3 DO Balance Analysis The QUAL2E model requires estimates of reaeration rates, BOD decay rates, nutrient kinetics, algal kinetics, and SOD by reach. Each of these components should be measured during low flow, warm temperature conditions (when feasible) after the system has achieved equilibrium with the restored channel. 2.2.4 Detailed Water Quality Characterization (Intensive Survey) Detailed intensive surveys are required to gain a more complete understanding of the water quality in Rich Fork Creek during critical conditions. These surveys combine field observations with the collection of water samples for analysis of parameters such as ammonia and biological oxygen demand to characterize the complete cycle of oxygen demanding wastes. As with the hydraulic studies, timing will require that no significant rainfall events (> 0.5 inches) have occurred in the previous seven days and the creek has reached steady state flows during the sampling period. Two separate events should be sampled for the purposes of calibrating and validating the wasteload allocation model. Detailed water quality studies should be conducted on Rich Fork Creek just upstream of the WWTP discharge, at the three YPDRBA sites, and on the WWTP effluent. The intensive surveys will consist of field measurements as well as the collection of water quality samples for lab analysis (parameters to be agreed upon with DWQ prior to sampling). In addition, one long-term sequential sample of DO midway between the wastewater treatment plant and Hamby Creek will be used to characterize the diurnal fluctuation of DO and pH downstream of the WWTP. 2.2.5 Monitoring Schedule The full scale monitoring study for Rich Fork Creek should occur after the channel has been restored, the plant has been upgraded, and the system is in equilibrium with the new flow regime. When feasible, all studies should occur during summer low flow conditions with the exception of the second dye study which should occur during average flow conditions (or at a significantly different flow level from the critical flow). Two intensive water quality sampling surveys will be performed to collect data for the calibration and validation stages of the model development. The QUAL2E model predicts water quality under steady-state conditions. The monitoring events specified in this plan are designed to capture instream water quality to aid in the calibration of the model during baseflow conditions. For purposes of this study, no .appreciable rainfall (> 0.5 inches) shall have occurred in the seven days prior to the sampling events. Rainfall events which occur during the sampling events will be considered on a case by case basis to determine whether they will interfere with the objectives of the study. S TETRA TECH, INC. B-6 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 The frequency of excursions at each of the four primary stations was estimated for each year from 1998 through 2005 (Figure 10). Data were not collected at Q5780000 prior to the year 2000, so the number of excursions at this station in 1998 and 1999 could not be estimated. No excursions were observed in 2003 at any station. Excursions were typically highest at station Q5785000 3.9 miles downstream of Westside WWTP) and lowest at Q5750000 (upstream of Westside WWTP). Frequency of Excursions 60% 50% 40% 30% 20% 10% 0% • Q5750000 ❑ Q5780000 0 Q5785000 ❑ Q579000(3 • 1998 1999 2000 2001 2002 2003 2004 2005 Figure 10. Frequency of Excursions of the DO Standard (5 mglL) In 2003, the flow at Abbotts Creek did not drop below 58 cfs, and no excursions were observed that year. In 2004 the minimum flow was 16 cfs, and excursions occurred Tess than 10 percent of the time at the two downstream monitoring locations where excursions were observed. The year 2001 had greater than 10 percent excursions at each of the four monitoring stations; this year also had the lowest cumulative flow volume from 1998 to 2005. Year 2005 had the highest frequency of excursions at the downstream stations. A leaky sewer main at Chesnut Street discharged an unknown amount of raw sewage into the stream during the summer of 2005 (Skee, 2006). TETRA TECH, INC. 18 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 2.3 PLANT EFFLUENT QUALITY DATA To further understand potential influences on the instream DO concentrations and patterns, Tetra Tech analyzed the High Point effluent and nonpoint source loads. Scoping analysis of the point source is provided below, and scoping of nonpoint sources is summarized in Section 2.4. The City of High Point Westside WWTP provided Tetra Tech with effluent quality data from January 1997 to November 2005. Figure 11 shows the daily BOD5 concentrations discharged from the plant. There is no daily maximum BOD5 concentration limit for the Westside facility. BOD5 at 20C (mg/L 80 70 Average Daily Effluent Concentration 60 -- 50 40 30 20 10 0 OA 0� 00 O°� O°� 00 O^ O� Oq' O� O� Off` O) 0 t P� O\^O ONO +�\^O O�O t) O�O ^'�(O t) '�flO Co\�O ps4 O rO\IO ,yh\�O c,\ �\� \ti \ti cam\ �l\ No\ c\ti )\ \,%\ ,A\ 4 NN\ Figure 11. Daily BOD5 Concentrations Discharged from the Westside WWTP Tetra Tech calculated the average monthly BOD5 concentrations for comparison to the monthly average permit limit of 5 mg/L from April 1 to October 31 and 10 mg/L from November 1 to March 31. Figure 12 shows the average monthly reported values compared to the permitted concentrations. The Westside plant was compliant with the BOD5 limit 79 percent of the months reported. ♦Tt TETRA TECH, INC. 19 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Average Monthly Discharge Concentration —Average Monthly Limit 16 14 12 =i 10 8 O 6 co 4 2 0 Jan-97 Feb-98 Mar-99 Apr-00 May-01 Jun-02 JuI-03 Sep-04 Oct-05 r A A Figure 12. Monthly Average BOD5 Concentrations from the Westside WWTP The permitted monthly average flowrate is 6.2 MGD. Figure 13 compares the monthly average of daily reported flows to the permit limit. Since 1997, the plant was compliant with the flowrate limit 98 percent of the months reported. —Average Monthly Discharge Flowrate —Average Monthly Limit 2 1 0 Jan-97 Feb-98 Mar-99 Apr-00 May-01 Jun-02 JuI-03 Sep-04 Oct-05 Figure 13. Monthly Average Discharge Flowrate from the Westside WWTP OTETRA TECH. INC. 20 WQ Scoping Analysis for the High Point Wesiside Discharge to Rich Fork Cr. March 2006 2.4 DIGITAL ORTHOPHOTOS AND MRLC LAND USE DATA In order to assess upland sources of pollutant loading to Rich Fork Creek, Tetra Tech downloaded 1998 digital orthophotos from DOT and the 1992 National Land Cover Data (NLCD) land use cover from the Basins website. The orthophotos show several mobile home parks within one-half mile of the creek. The majority of the riparian buffer is either forested or agricultural fields. Much of the eastern third of the watershed is in urban development. Figure 14 shows the NLCD land use coverage (30-m resolution). The watershed boundary is the 14-digit hydrologic unit acquired from Basinpro. Note that the areas draining to Jimmys Creek and Hamby Creek do not drain to the simulated segments of Rich Fork Creek. Comparison of the orthophotos to the land use coverage show that the NLCD generally depicts the extent of urban development accurately through at least 1998. Table 3 summarizes the land cover data for the Rich Fork Creek watershed. * Westside WWTP Streams NL D Barren or Mining Transitional Agriculture - Cropland Agriculture - Pasture Forest Upland Shrub Land Grass Land 1.11 Water Wetlands Low Intensity Residential Other Grasses (parks, lawns, etc.) High Intensity Residential High Intensity Commercial/Industrial 3 0 3 6 Miles Figure 14. 1992 NLCD Land Use Coverage for the Rich Fork Creek Watershed ICI TETRA TECH, INC. 21 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Table 3. NLCD 1992 Land Cover in Rich Fork Creek Watershed Land Use Area (ac) Percent Open Water 88.5 0.2% Low Intensity Residential (1/3 ac) 6,061.1 14.3% High Intensity Residential (1/8 ac, townhouses, etc) 1,847.7 4.3% Commercial/Industrial/Transportation 3,624.6 8.5% Bare Rock/Sand/Clay 56.9 0.1% Quarries/Strip Mines/Gravel Pits 172.8 0.4% Transitional - 0.0% Deciduous Forest - Fair 16,340.9 38.5% Evergreen Forest - Fair 2,387.9 5.6% Mixed Forest - Fair 2,779.0 6.5% Pasture/Hay - Fair 4,485.0 10.6% Row Crops, straight, good 3,814.3 9.0% Other Grasses/Urban/Recreation, >50% grass 303.1 0.7% Woody Wetlands - Poor Forest 492.4 1.2% Emergent Herbaceous Wetlands - Inundated Forest 21.3 0.1% Total 42, 475.6 100.0% 2.5 ANECDOTAL INFORMATION Tetra Tech gathered anecdotal information concerning Rich Fork Creek from the Westside WWTP, DWQ, and the Tetra Tech Owings Mills office to include all information available to date conceming the overall health of Rich Fork Creek. 2.5.1 Westside WWTP Correspondence According to staff at the Westside WWTP, instream DO concentrations are not well correlated to plant effluent quality and have not responded significantly to plant upgrades. The plant manager (Bill Frazier) states that historic agriculture has burdened the stream with sediment and damaged instream habitat. During the recent fecal coliform TMDL for Rich Fork Creek, the plant utilized DNA tracing to identify the sources of the fecal coliform load. The plant states that the majority of the fecal coliform loading is not from human sources, and that what is human is not originating from the treatment plant or its collection system, but rather from septic systems and package treatment plants. TETRA TECH, INC. 22 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 2.5.2 DWQ Modeling Files Tetra Tech examined the modeling report, modeling notes, and permitting files of DWQ for additional information concerning low DO in Rich Fork Creek. In August 1986, DWQ cited poor quality effluent as the source of DO excursions and noted that large accumulations of sludge and sediment occurred downstream of the plant. Several correspondence letters question the estimation of the 7Q10 for Rich Fork Creek above the plant. DWQ noted several days were there was zero flow upstream of the discharge. The allocation report stated that two fish kills occurred downstream of the plant in 1983 due to toxic substances. 2.5.3 Black & Veatch Field Reconnaissance The Black & Veatch report lists findings from a field reconnaissance which took place during the summer of 1986 between the WWTP discharge and Evans Road (approximately 6.5 miles downstream of the plant). The report notes sludge deposits visible from the Highway 109 Bridge to the confluence with Hamby Creek. Deposits were typically covered by 'A to %2 inch of clean sand during the summer visit. During October and November field visits, sludge was covered by approximately 2 inches of clean sand. It was their assessment that the sludge deposits were slowly disappearing following the plant upgrades of September 1986. It is more likely that higher flows in the fall carried a greater sediment load, which was later deposited on the sludge. Black & Veatch attributed the large number of trees in the stream to undercut banks no longer able to support the trees. 2.5.4 Summary of Notes from Different Parties Regarding Conditions Affecting Quality The anecdotal information gathered on Rich Fork Creek confirms that DO concentrations are low during the warm summer months during low flow conditions and that the stream is already exceeding its assimilative capacity. Sludge accumulations were noted downstream of the plant, though it is unknown whether the resulting SOD has diminished over the last 20 years following the plant upgrade in 1986. 2.6 TETRA TECH WHOLE EFFLUENT TOXICITY STUDIES The Owings Mills office of Tetra Tech conducted habitat assessments and bioassessments of Ceriodaphnia dubia, Pimephales promelas, and Raphidocelis subcapitata in the 250 meters up and downstream of the Westside WWTP. Results of the study have not been finalized, but Tetra Tech RTP was able to obtain the field data sheets and several digital photos of the stream. The field data sheets indicate that the stream habitat is poor upstream and downstream of the plant. Generalities are listed below that reflect conditions along the 500-meter reach studied: 1) Bed material is comprised primarily of sand. 2) Low percentage of stable substrate (less than 30 percent). 3) No submerged vegetation in ponds; bottom completely covered by mud, clay, or sand. 4) Shallow pools more prevalent than deep pools. 5) Low channel sinuosity. 6) Heavy deposits of fine material with increased bar development. 7) Moderate to high levels of bank erosion. 8) Larger particles surrounded by more than 75 percent fine sediment. TURA TECH. INC. 23 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 9) Not all velocity / depth regimes present. 10) Low frequency of riffles; poor riffle habitat. The field data sheets indicate little change in habitat functionality above and below the WWTP discharge. The digital photos up and downstream of the plant are similar as well (Figure 15 through Figure 21). Figure 15. Rich Fork Creek 250 Meters Upstream of the WWTP Plant, Facing Downstream TE NIA TECH, INC. 24 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 16. Rich Fork Creek 150 Meters Upstream of WWTP Plant, Facing Downstream Figure 17. Rich Fork Creek 5 Meters Upstream of WWTP, Facing Upstream ICI TETRATECH, INC. 25 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 18. Rich Fork Creek 5 Meters Upstream of WWTP, Facing Downstream Figure 19. Rich Fork Creek 10 Meters Downstream of WWTP, Facing Downstream STETRA TECH. INC. 26 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 20. Rich Fork Creek 180 Meters Downstream of WWTP, Facing Upstream Figure 21. Rich Fork Creek 270 Meters Downstream of WWTP, Facing Upstream (j] TETRA TECH, INC. 27 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 3 Review of Existing Water Quality Model 3.1 SUMMARY OF MODELING INFORMATION COMPILED FROM NCDWQ Tetra Tech visited the office of DWQ to obtain modeling reports, modeling notes, and electronic modeling files. Some of the information went back 20 years and was very helpful in understanding the water quality issues in Rich Fork Creek. The various sources of information are described below. 3.1.1 Black & Veatch Report Black & Veatch (1987) completed a water quality study and QUAL2E model of Rich Fork Creek and the Westside WWTP for the City of High Point, Davidson County, and the North Carolina Department of Natural Resources. The study cited problems with odor downstream of the plant as well as fish kills and noticeable sludge deposits. Black & Veatch modeled Rich Fork Creek with 13 reaches based on results of several studies described briefly below. Black & Veatch collected water quality samples at 10 locations along Rich Fork Creek on July 9 and August 27, 1986 to obtain two independent data sets for purposes of model calibration and validation. A flow determination study was performed on July 10, 1986 at several of the water quality monitoring stations by measuring velocities with a Pigmy meter at 2-foot intervals across the stream and multiplying by the corresponding cross sectional area. On July 10th, the headwater flows were estimated to be 0.25 cfs and a loss of 2.5 cfs was measured over 8.5 miles. Model runs have tributary flows set to zero and incremental losses defined over the length of the creek. A time of travel study was conducted from July 14 through July 20, 1986. Rhodamine dye was injected at the point of discharge of the WWTP, and concentrations were measured at six stations with a fluorometer. The time of passage of the maximum concentration from station to station was recorded to estimate the time of travel. Travel velocities ranged from 0.08 to 0.24 feet per second with an overall travel velocity of 0.1 feet per second. A diurnal study was performed on September 18, 1986. DO, pH, temperature, and specific conductivity were measured four times during the day at each of the 10 water quality stations. Data did not indicate that algae contributed significantly to the DO balance, though field notes indicate that September 18 was an overcast day. Twelve cross sections were taken along Rich Fork Creek. Though water depths were recorded, the dates were not, so there is no way to verify whether or not the cross sections were taken during the same period as the flow determination and time of travel studies. Tetra Tech evaluated USGS streamflows at Northern Potts Creek at Linwood (a tributary to High Rock Lake; USGS gage 02121180) to compare flows during the hydraulic and water quality studies. The Abbotts Creek gage went online in 1988, so flows were not available from this gage. Flows on Northern Potts Creek were similar during the flow determination (1 cfs) and time of travel study (average 0.97 cfs). During the water quality study (August 27, 1986), flows in Northern Potts Creek were approximately 2 cfs. Thus, flow conditions in a nearby creek were approximately twice as high during the water quality study compared to the flow studies. For the model calibration run (August 27, 1986), Black & Veatch had to increase headwater flows measured on July 10 from 0.25 cfs to 1.6 cfs and Kennedy Mill Creek flows from zero to 0.5 cfs. A six -fold increase in headwater flow was required to simulate observed water quality. Though the headwater flows were likely higher in August compared to July, Black & Veatch probably overestimated headwater flow for this calibration run. To calibrate the hydraulic parameters that define velocity, depth, and width based on flow, Black & Veatch used the assumed headwater flow of 1.6 cfs with the time of travel data collected when flows were TETRATHCN, INC. 29 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 closer to 0.25 cfs. Simulated flow and travel time matched observations well during the calibration run, even though the headwater flows were six times higher than observed during the flow determination and time of travel study. Travel times for the validation run were not shown, though water quality graphs for the validation graph were shown. Because flows in nearby Northern Potts Creek were fairly stable in July, the predicted travel times in the validation run should have been consistent with those determined from July 14th through July 20`h. Given the discrepancy in headwater flows and the apparent absence of the validation data, it is not likely that the hydraulic parameters were calibrated well. Plant effluent characteristics were based on data collected in the late 1980s. The ratio of ultimate CBOD to BOD5 was assumed to be 2 and the ammonia concentration was 7.3 mg/L. The reaeration option chosen for the simulation was Thackston and Krenkel (QUAL2E option 5). The Tsivoglou and Wallace method was also considered. During the calibration run (August 27th), DO concentrations are simulated to within 0.7 mg/L at the seven monitoring stations. During the validation run (July 9th), predicted DO concentrations are within 4.5 mg/L of observed. Poor agreement during validation indicates that the model does not accurately represent the system during low flow. SOD measurements were taken upstream of the WWTP and at Midway Road. During calibration of DO, Black & Veatch varied the SOD rates from 0.10 to 0.25 g/ft/d in accordance with measured values and inability of the lower reaches to recover DO at rates expected from reaeration. The Black & Veatch modeling indicated that the monthly average allocation limits for BOD5 should be reduced from 12 mg/L to 5 mg/L, and ammonia limits should be reduced from 5 mg/L to 2 mg/L. These are the current permit limits as of January 2006. 3.1.2 NCDWQ Modifications to Black & Veatch Modeling In late 1988, NC Department of Environmental Management (NCDEM, now DWQ) examined the validity of the Black & Veatch QUAL2E model for Rich Fork Creek and identified several problems with the model (DEM, 1989). 1) The version of QUAL2E used by Black & Veatch was outdated and did not include simulation of organic nitrogen. 2) The flow measurements, time of travel study, cross section measurements, and water quality studies were all performed on different dates. 3) The long-term BOD test was run for 30 days. Oxygen consumption was still occurring rapidly at the end of the test, so ultimate BOD was not determined. 4) The ratio of CBOD to BOD5 was underestimated based on long-term BOD data collected by DEM in August 1988. 5) The BOD decay rate of 0.5/day seemed high. The DEM bottle rate determined during the August 1988 study was 0.02/day. DEM estimated a decay rate of 0.05/day instream using the Bosco equation. However, the most recent electronic files from DWQ show a BOD decay rate of 0.1/day in both the calibration and waste load allocation models. 6) The ammonia oxidation rate (0.4/day) was high compared to literature values (0.05 to 0.3/day). 7) The SOD rates ranged from 0.3 to 3.7 g/m2/d, which were somewhat high compared to other values measured in North Carolina at that time (1 to 2 g/m2/d). DEM modified the QUAL2E model by reducing the number of reaches from 13 to 8 and averaging the hydraulic parameters from the Black & Veatch model to estimate velocity, depth, and width based on flow. Reaches 1 through 4 were grouped together and reaches 5 through 8 were grouped together based on change in average slope. DWQ modeling notes indicate that the average slope in the upper four TETRA TECH, INC. 30 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 reaches is 7.5 feet per mile, and in the lower four reaches the average slope is 3.3 feet per mile. Table 4 summarizes the DEM hydraulic parameters. Table 4. DEM Hydraulic Parameters for Rich Fork Creek Reach Velocity Coefficient on Flow Velocity Exponent on Flow Depth Coefficient on Flow Depth Exponent on Flow Width Coefficient on Flow Width Exponent on Flow 1-4 0.10 0.5 0.5 0.8 20 0.1 5-8 0.04 0.5 0.4 0.4 31 0.1 Reaction rates and reaeration options were also set for each group (Table 5). Table 5. Reaction Rates Used in the DEM QUAL2E Model for Rich Fork Creek Reaction Rate (1/day) Reaches 1 - 4 Reaches 5 - 8 Organic Nitrogen Hydrolysis 0.1 0.05 Organic Nitrogen Settling 0.1 0.1 Ammonia Oxidation 0.2 0.2 Benthic Source of Ammonia 0.0 0.0 Nitrite Oxidation 0.5 0.5 BOD Decay 0.1 0.1 BOD Settling 0.0 0.0 Reaeration Option Churchill Owens and Gibbs Simulated SOD rates vary beyond the two reach groups. In reaches 1 through 6, the SOD rate is 0.1 g/ftz/d, in reach 7 the SOD rate is 0.2 g/ft2/d, and in reach 8, the SOD rate is 0.25 g/ft&/d. These values were not changed from the original Black & Veatch model. Black & Veatch indicated that higher SOD rates were expected in the lower reaches due to an increase in sludge deposits corresponding to pooled areas with low velocities. DEM used the Monte Carlo simulation option to perform a sensitivity analysis for the prediction of DO. DEM found that the velocity and depth equations, SOD rates, and the initial temperatures were the most influential factors determining DO concentrations at the sag point. They recommended additional monitoring studies to determine appropriate parameters for this system. For the allocation run, the 7Q10 flows for Rich Fork Creek (0.67 cfs), Kennedy Mill Creek (0.1 cfs), and Hunts Fork Creek (0.19 cfs) (DEM, 1989) were used along with treatment plant permit limits (6.2 MGD, 5 mg/L BOD5, and 2 mg/L ammonia). Incremental flows were assumed to be 0.073 cfs per mile. A calibration run was set up, though the date is not specified in the file or the DEM report. For this run, the headwater flow is 0.25 cfs, and there is no additional flow from Kennedy Mill Creek, Hunts Fork Creek, or incremental sources. C TETRA TECH, INC. 31 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 3.2 TETRA TECH MODEL EVALUATION ANALYSES First, Tetra Tech ran the current DWQ model with a headwater flow of 0.25 cfs to determine if velocity, depth, and width were consistent with the time of travel and cross section data collected by Black & Veatch. In general, velocity was overpredicted (Figure 22), and depth was underpredicted (Figure 23). Note that depths were recorded during cross section measurements and exact dates and flow conditions are unknown. ■ Simulated Velocity with DWQ Model ❑ Time of Travel Study Measured Velocity Velocity (feet per second) 0.30 0.25 0.20 0.15 0.10 0.05 0.00 1 2 3 4 5 6 7 8 QUAL2E Reach Figure 22. Comparison of Simulated and Observed Instream Velocity When Headwater Flow is 0.25 cfs Th TETRA TECH, INC. 32 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 3.50 3.00 2.50 - 2.00 m 1.50 1.00 0.50 0.00 • Simulated Depth with the DWQ Model 0 Average Measured Depth 1 2 3 4 5 6 7 8 QUAL2E Reach Figure 23. Comparison of Simulated and Measured Depth When Headwater Flow is 0.25 cfs Because the two reaeration options chosen by DWQ rely on velocity and depth for their calculation, Tetra Tech compared the predicted reaeration rates (at 20 °C) using the DWQ simulated velocity and depth and the average measured velocity and depth observed by Black & Veatch. DWQ assigned the Churchill method for reaches 1 through 4 and the Owens and Gibbs method for reaches 5 through 8. The EPA Rates, Constants, and Kinetics guide (USEPA, 1985) states that the Churchill method is applicable at depths greater than two feet and velocities greater than 1.5 ft/s (Figure 24). Thus, during low flow conditions, this method is not suitable for Rich Fork Creek. The Owens and Gibbs method is recommended for depths less than two feet across all reasonable velocities. Tetra Tech calculated the reaeration rates using observed widths and velocities with the Owens and Gibbs method. With the exception of reach 1 and 3, the DWQ estimates of reaeration appear high. fct TETRA TECH. INC. 33 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 ■ DWQ Simulated Reaeration 0 Reaeration Calculated with Observed Data 4.5 .. 4.0 3.5 U N 3.0 as 2.5 ce 2.0 - 0 1.5 :rs 6. 1.0 ea ce 0.5 0.0 2 3 4 5 6 7 8 QUAL2E Reach Figure 24. Comparison of Reaeration Rates Using DWQ Simulated Velocity and Depth and Black & Veatch Observed Velocity and Depth Tetra Tech ran the original DWQ model with data collected on 9/20/2005 to verify that the simulated reaeration was too high and that simulated DO would be higher than observed. Plant effluent and headwater quality were modified to reflect actual conditions for that day. No rates were changed for this run. TETRA TECH, INC. 34 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 September 20, 2005 was chosen as the model run day to test the DWQ version of the QUAL2E model based on availability of data and near steady-state conditions observed in a nearby creek (Abbotts Creek). The headwater flow was assumed 0.55 cfs based on the ratio of drainage area at Rich Fork Creek above the WWTP to Abbotts Creek at the USGS gage (0.056). DO concentrations were available at eight locations in Rich Fork Creek from the Westside WWTP files, and nutrient data to characterize plant effluent quality were available the day prior. Headwater BOD data were not available, so the DWQ model calibration input value of 0.75 mg/L BODult was left unchanged. Table 6 summarizes the headwater and WWTP inputs. Table 6. Headwater and Westside WWTP Model Inputs for September 20, 2005 Model Input Headwater Westside WWTP Flow (cfs) 0.55 5.1 Temperature (°F) 71.4 77 DO (mg/L) 6.4 6.8 Ammonia (mg-N/L) 0.01 0.04 TKN (mg-N/L) 0.29 1.42 NO3 plus NO2 (mg-N/L) 0.02 14.7 Organic N (mg-N/L) 0.28 1.38 BOD5 (mg/L) No instream measurement. Use BODult = 0.75 mg/L as in original DWQ model. <2 BODuIt (mg/L) 10 Nutrient data for Westside WWTP are from September 19, 2005. T ETIIA TECH, INC. 35 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 25 compares the DWQ simulation to observed data. The DWQ model overestimates DO throughout the creek due to poorly calibrated hydraulic parameters and an overestimation of reaeration. The model predicts that the DO standard is met throughout the length of the creek, but the observed data show that the standard was not met over at least 8.5 miles. Observed • Data —Original DWQ Model —Standard a Dissolved Oxygen (mg/L) > > N W A CTt Cn V C ♦ ♦ ♦ ♦ V illt 111 it tlli III IIIIIIIIIIIIIII 111 II IIIIIIIIIIIIIII IIIIIIIIIII 11111 IIIIIEIIIII 111 111fIlliilIIIi 1l N 6 ^ co N co ^ Co ^ Co ^ Co N Co N Co ^ Co ^ Co N Distance Downstream of WWTP (miles) Figure 25. Comparison of DWQ QUAL2E Model to Observed Data fr't, TETRA TECH, INC. 36 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 4 Stream Reconnaissance January 20, 2006, Tetra Tech visited 11 sites on Rich Fork Creek and one site on each of the three major tributaries (Figure 26). Four sites were upstream of the wastewater treatment plant and seven sites were downstream. The purpose of the trip was to gather general information on channel structure, substrate composition, and source loads that may not have been accounted for in the original DWQ model and to identify potential reasons for the 1 to 2 mg/L drop in DO downstream of the plant. The water quality analyst for the plant, Frank Skee, accompanied two Tetra Tech associates for the majority of the site visits. The weather was clear and unseasonably warm for this time of year. Flow at the plant upstream of the discharge was estimated to be 30 cfs based on fraction of flow discharged from the plant and a Manning's equation estimate. Application of the drainage area ratio to gaged flows on Abbotts Creek yields an estimate of 6 cfs. The following general observations were made: • Substrate composition became finer in the downstream direction. • Historic and active sand dipping operations have formed three large pools that appear stagnant during low flows. The Highway 109 pool is approximately 1,500 feet in length; the Ball Road and Kanoy Road pools are approximately 500 feet in length. On January 20, 2006, the water widths at each pool ranged from 50 to 100 feet and the depths appeared to be 4 feet or greater. The storage capacity of the pools increases travel time through these segments allowing for increased settling and accumulation of organic material. • Accumulations of organic material were seen in each of the three pools. The depth of material in each pool decreased further downstream of the plant. • With the exception of the three pools, the channel is fairly stable and has access to a broad, well vegetated floodplain. Observed water width during the field reconnaissance was 30 to 40 feet and the depth was 1 to 2 feet. • Most of the adjacent lands were forest, pasture, and low density residential lots. No row crops were seen from the car. Cattle access was not evident at any of the sites visited. • The tributaries that drain the urban areas from the eastern portion of the watershed are well connected with their floodplains. Substrate is similar to that seen in the sites upstream of the wastewater treatment plant on Rich Fork Creek. No accumulations of organic material were seen. • Heavy sediment deposition and large sand bars were seen at all sites. Figure 27 through Figure 33 show examples of these observations. A complete set of photos and field notes are included in Appendix A. TETRA TECH, MC. 37 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 • Field Reconnaissance Sites Streams HUC Boundary Rich Fork Creek at High Point Road Rich Fork Creek at Chesnut Street Rich Fork Creek at Lexington Avenue Rich Fork Creek at 20 Ft. Upstream of Discharge Rich Fork Creek at Highway 109 Rich Fork Creek at Midway School Road Rich Fork Creek at Ball Road Rich Fork Creek at Kanoy Road Rich Fork Creek at Evans Road Rich Fork Creek at Old Highway 29 3 0 3 6 Miles s Road urton Road tone Road Figure 26. Sites Visited During January 2006 Field Reconnaissance S TETRA TECH, INC. 38 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 27. Example of Floodplain Along Unmined Section of Rich Fork Creek, Near Midway Road Figure 28. Example of Sediment Deposition in Rich Fork Creek (nl TUNA TECH, INC. 39 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 29. Comparison of Substrate Composition in Unaltered and Sand Dipped Portions of the Channel, Respectively Figure 30. Comparison of Organic Layer at Highway 109 Pool (- 1 inch), Ball Road Pool (-1/4 inch), and Kanoy Road Pool (-1/8 inch), Respectively ICI TETRATECH,INC. 40 WO Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 31. Sand Dipping Crane at Active Mining Site Upstream of Highway 109 [m] T[TfA TCCH, INC. 41 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 32. 1998 Orthophoto Showing Change in Channel Width Upstream and Downstream of Ball Road Bridge Figure 33. Comparison of Stream Channel Upstream and Downstream of Ball Road Bridge, Respectively TETRA TECH, INC. 42 e: WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 5 Additional Modeling Analysis and Evaluation of Assimilative Capacity Tetra Tech created a model run to simulate the channel and pools as seen during field reconnaissance and to incorporate more recent data concerning BOD decay, headwater quality, and plant effluent quality. Data to calibrate hydraulic equations were not available. The velocity was fixed such that the residence time observed during the Black & Veatch time of travel study was replicated at low flow (6.5 days). Velocity, depth, and width were fixed for the pools and channel as summarized in Table 7. Table 7. Fixed Velocities, Widths, and Depths for the Pools and Unaltered Channels of Rich Fork Creek e 1 1etacit(p) D L epttt 3611 h())` Pool 0.02 4 85 Unaltered Channel 0.12 2 28 Review of the original DWQ model showed that the reaeration options were overestimating reaeration in most of the simulated reaches and were not consistent with guidelines provided by EPA concerning the applicability of reaeration methods based on velocity and depth constraints (Section 3.2). Therefore, Tetra Tech updated the reaeration options for this run and assigned QUAL2E option 4 (Owens method) to the unaltered segments and QUAL2E option 3 (O'Connor and Dobbins) to the pooled segments. Based on a long-term BOD study performed by DWQ in 1996, Tetra Tech updated the ratio of BOD ultimate to BOD5 to 5. The BOD bottle decay rate during this test was 0.03/day. Tetra Tech applied the Bosco equation (USEPA, 1985) to estimate instream decay rates. The SOD rates were also changed. The original model had lower SOD rates in the first six miles downstream of the plant, followed by a 2 to 2.5 fold increase in the lower four miles. Tetra Tech set the SOD to a constant rate of 0.25 g/ft2/d which is at the upper end of the range observed in the Yadkin Basin (Reid, 2005). SOD rates were left constant because of observed organic material and the fact that no recent SOD monitoring data were available to spatially vary the load. TETRA TECH, INC. 43 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 September 20, 2005 was used as the simulation day because of low flow conditions and quantity of water quality observations. Table 6 in Section 3.2 lists the headwater and effluent quality assumptions. Figure 34 compares the observed DO concentrations to the low flow simulation set up by Tetra Tech. The curve fits well in the upper five miles but tends to overestimate DO in the lower five miles. This may be due to incorrect hydraulic functions or poorly estimated SOD rates. Neither of these parameters can be improved without a detailed field monitoring study. Dissolved Oxygen (mg/L) 4 3 0 Tetra Tech low flow run • Observed • III1 I lIl IlII111III II111111T 11IIIIIiIIi II�If Ill11 iii 111II!li�I��I �11I11IlIII1 IIII IIIIIii Co �o 116 . ro \ 0 ' ro ^ co ^ 6 ^ io ^ 6 +� 0, 4. \. ^. �,. �. nl. De N. <0. <j. 6. ca. .`. A. tb. (b. cy cb• No. Distance (miles) Figure 34. Comparison of Tetra Tech Low Flow Simulation to Observed Dissolved Oxygen on September 20, 2005 S TETRA TECH, INC. 44 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 After Tetra Tech developed a reasonable model that included the three pools, several scenarios were run to determine what changes would be required to bring the DO above the standard during low flow conditions. Figure 35 shows the effect of restoring the pools to their natural channel with and without a reduction in ultimate BOD concentration from the plant. On September 20, 2005 the ultimate BOD concentration is assumed to be 10 mg/L based on daily reported effluent data for BOD5 and a ratio of BOD ultimate to BOD5 of 5. The reduced scenario assumes a 50 percent reduction in BOD ultimate concentration to 5 mg/L. Restoring the ponds without altering the plant effluent quality only moved the location of the DO sag. After approximately four miles downstream from the plant, the simulated curves converge at the sag concentration of 4.6 mg/L. Reducing the ultimate BOD load from the plant by one- half results in a DO sag of 4.7 mg/L. Dissolved Oxygen (mg/L) 4 3 —With pools, SOD 0.25, BODult 10 mg/L Restore pools, SOD 0.25, BODult 10 mg/L Restore pools, SOD 0.25, BODult 5 mg/L ♦ Observed • 0 rIII 11 1 11111 11111 lll111 lllllll 1I111 IIII II 1 IIIIIIIIII t Il ril 111111Il lI III111111111111111111ll N Co N Co N. Co Co Co Go h. Co h. 4o t• CO N. Co h. c). A. ^. 1.* na. na. �. y. h. CO. �. .,. .`. �.• cb• 03. off• Distance (miles) Figure 35. Impacts of Channel Restoration and WWTP BOD Load Reduction on Simulated 9 p Dissolved Oxygen Concentrations in Rich Fork Creek Th TETRATECH. INC. 45 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 36 shows the impacts of reducing the SOD rate by 20 percent with and without a reduction in the ultimate BOD load. The standard of 5 mg/L DO is met when the SOD rate is reduced to 0.2/d with and without the reduction in BOD Toad. Dissolved Oxygen (mg/L) 5 4 3 2 1 0 Restore pools, SOD 0.20, BODult 5 mg/L —Restore pools, SOD 0.20, BODult 10 mg/L —Restore pools, SOD 0.25, BODult 10 mg/L • Observed • i r� Ii 11 I I I I 111 ill i i i it 1 ii iii ill 11 l i i ii l l l l l i� i iii iil 1 Iir ii ii iii ii ili 1 i lip i ii i i i iii i iiii ii ON 06 ".. �6 'v r ,. Co ^b^ vb bi brO h^ ho 6 Oo 1• A. O^ 06 0. Oo ^s. Distance (miles) Figure 36. Impacts of SOD and BOD Load Reduction on Simulated Dissolved Oxygen Concentrations in Rich Fork Creek I� I TETRA TECH, INC. 46 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Under the simulated low flow condition, the SOD rate appears to be the most important factor in improving DO conditions in Rich Fork Creek besides restoring the stream channel configuration. Tetra Tech evaluated plant effluent BOD loads to determine if process disturbances, such as a high runoff event, would result in reduced effluent quality that may lead to a build up of oxygen demanding wastes in the stream. Figure 37 shows the monthly BOD5 load compared to the maximum permitted load based on a permitted flow rate of 6.2 MGD and BOD5 concentrations of 5 mg/L in the summer months and 10 mg/L in the winter months. The monthly BOD5 loads discharged by the plant are within the maximum permit limits 93 percent of the time. 700 600 500 - 400 p 300 m 200 100 —Average Monthly Load —Monthly Permitted Load 0 Jan-97 Feb-98 Mar-99 Apr-00 May-01 Jun-02 JuI-03 Sep-04 Oct-05 Figure 37. Comparison of Monthly BOD5 Load to Permitted Monthly Load A 20 percent reduction in the SOD rate results in DO concentrations above the standard even during critical conditions. It is feasible that a 20 percent reduction could be achieved because: 1) the assumed existing SOD rate is at the high end of the range observed in the Yadkin Basin, 2) the altered hydrology of the pools appears to cause an accumulation of organic material, and 3) improvements in plant effluent quality will reduce the amount of organic material available for decomposition. Because the low flow simulation has fixed velocities and cross sections, it is not possible to simulate other flow conditions. Hydraulic studies and cross section measurements will be required to obtain the parameters necessary to simulate a range of flows with an updated QUAL2E model. TL IRA TECH, INC. 47 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 6 Overall Conclusions and Recommendations The scoping analysis performed by Tetra Tech identifies several factors that will likely influence future permitting and wasteload allocations for the High Point Westside facility's discharge to Rich Fork Creek. 6.1 POTENTIAL FOR INCREASED WASTE FLOWS FROM WESTSIDE WWTP Tetra Tech's evaluation of the current model used for High Point's wasteload allocation revealed several areas where model setup and calibration could be improved to better represent assimilative capacity in Rich Fork Creek. A field reconnaissance of Rich Fork Creek in January 2006 revealed altered hydrology due to instream sand mining at three locations. The resulting pools are accumulating noticeable deposits of organic material and may be increasing the overall sediment oxygen demand in the creek. Tetra Tech's low flow version of the QUAL2E model for Rich Fork Creek indicates that SOD is driving DO below the standard during low flow, high temperature conditions. The modeling indicates that a 20 percent reduction in SOD would likely improve conditions such that the DO standard is met. Because the assumed SOD rate is at the high end of the range observed in other streams in the Yadkin Basin, a 20 percent reduction seems feasible if the pools are removed and the effluent quality is further improved. Under current conditions, it is not likely that DWQ will grant permission to Westside WWTP for increased waste flows, even with improved effluent quality. Observed data and the Tetra Tech low flow model indicate that the assimilative capacity of the creek is currently exceeded. However, stream channel restoration to remove the pools coupled with improvements in plant effluent quality could result in reduced SOD rates and DO concentrations above the standard even during critical conditions. If this occurs, assimilative capacity for High Point's discharge would be restored. 6.2 RECOMMENDED NEXT STEPS In light of the scoping analysis findings, Tetra Tech suggests the following steps be taken to determine if plant improvements and stream restoration will effectively increase the assimilative capacity of the creek. 1) Meet with DWQ to review the scoping analysis results and to confirm the recommended path forward. Tetra Tech proposes that two separate field studies be conducted to gather data concerning travel times, kinetic parameters, and additional DO monitoring. These studies are discussed in more detail in Appendix B. The first study should be conducted prior to altering the stream system so that the low flow version of the model can be validated with field parameters. This study will focus on the parameters carrying the greatest uncertainty such as the time of travel through the pools and the SOD rates in and out of the pools. The second study should occur after the plant improvements and stream restoration are complete and the stream channel and substrate composition have reached equilibrium. Because the ensuing model may be used to determine the wasteload allocation of the plant, a complete field study including time of travel, cross section measurements, and all dissolved oxygen balance parameters should be performed. The remaining steps outline how monitoring and modeling could proceed to accomplish the city's objectives. 2) Conduct Phase 1 of monitoring to confirm the hydraulic assumptions of the low flow version of the QUAL2E model and determine the impacts of the pools on DO: a. Perform a time of travel study during low flow conditions to confirm the travel time through the pools and the unaltered sections of the channel. b. Collect SOD measurements upstream of the plant, downstream of the plant in each pool, and downstream of the plant in the unaltered sections between the pools. S TETRA TECH.INC. 49 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 c. In addition to the current Westside general water quality monitoring locations, monitor the upstream, downstream, and middle sections of each pool. 3) Update the low flow version of the QUAL2E model with field observed values for residence time and SOD rates to validate or refine the scoping analysis conclusions. 4) Hold a meeting with DWQ to review the monitoring and updated modeling results, and to get a regulatory opinion on restoring the stream channel to improve assimilative capacity. 5) Work with regulatory agencies to obtain necessary permits for stream restoration and with landowners to obtain conservation easements to prevent further sand mining along Rich Fork Creek. Restore the three pools at Highway 109, Ball Road, and Kanoy Road. 6) After the pools are restored, periodically monitor the thickness of organic material deposited on the substrate downstream of the discharge to determine if the system has regained equilibrium under the restored flow regime. 7) After plant upgrades are complete and stream equilibrium is confirmed, conduct Phase 2 of monitoring which should include updated time of travel estimates during low and average flow conditions, cross section measurements at several locations, instream SOD measurements upstream of the plant and at two or three locations downstream of the plant, parameters describing the oxygen balance including reaeration estimates, nutrient transformations, and algal kinetics, and long-term BOD estimates for the headwater, plant effluent, and selected downstream locations. Continue monitoring general water quality at all Westside stations as well as the restored segments. 8) Update the QUAL2E model for Rich Fork Creek to reflect channel restoration, plant upgrades, and field study results. Reassess assimilative capacity of the stream based on model simulation and observed data, and provide the model and results to DWQ for use in determining future wasteload allocations. In addition, the City of High Point should continue to identify and repair malfunctions of the sewer collection system to reduce overall loading to the stream. STOMATO:H. 04C. 50 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 1 Introduction Tetra Tech staff conducted a field evaluation of Rich Fork Creek in January 2006 to determine if any additional physical factors, particularly those not already represented in the QUAL2E model, may be contributing to the dissolved oxygen (DO) problems in the creek. Fourteen sites were visited, as shown in Figure 1. Three were located on tributaries just upstream of their confluence with Rich Fork Creek. Four sites were upstream of the Westside wastewater treatment plant, and seven sites were downstream. • Field Reconnaissance Sites Streams HUC Boundary Rich Fork Creek at High Point Road Rich Fork Creek at Chesnut Street Rich Fork Creek at Lexington Avenue Rich Fork Creek at 20 Ft. Upstream of Discharge Rich Fork Creek at Highway 109 Rich Fork Creek at Midway School Road Rich Fork Creek at Ball Road Rich Fork Creek at Kanoy Road Rich Fork Creek at Evans Road Rich Fork Creek at Old Highway 29 3 0 3 6 Miles Figure 1. Sites Visited During January 2006 Field Reconnaissance I I TETRA TECH, INC. A-3 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 At each site, observations of stream morphology were recorded, including the potential for streambank erosion, floodplain access, and substrate composition. Approximations of water width and depth were also noted. A narrow shovel with a one -foot long blade was used to extract substrate profiles beneath the water surface and from adjacent banks. The following general observations were made concerning the fourteen sites visited: • Substrate composition became finer in the downstream direction. • Historic and active sand dipping operations have formed three large pools that appear stagnant during low flows. The Highway 109 pool is approximately 1500 feet in length; the Ball Road and Kanoy Road pools are approximately 500 feet in length. On January 20, 2006, the water widths at each pool ranged from 50 to 100 feet and the depths appeared to be 4 feet or greater. The storage capacity of the pools increases travel time through these segments allowing for increased settling and accumulation of organic material. • Accumulations of organic material were seen in the substrate profiles taken from each pool. The depth of material in each pool decreased with distance downstream from the plant. • With the exception of the three pools, no major physical degradation was observed in any of the stream channels — likely due to the connection of the channel to broad, well vegetated floodplains. Above Hunts Fork Creek, the observed water widths were approximately 30 to 40 feet and the depths were 1 to 2 feet. Below Hunts Fork Creek, the water widths were approximately 40 to 50 feet and the depths were 2 to 3 feet • Most of the adjacent lands were forest, pasture, and low density residential lots. No row crops were seen from the car. Cattle access was not evident at any of the sites visited. • The tributaries that drain the urban areas from the eastern portion of the watershed are well connected with their floodplains. Substrate is similar to that seen in the sites upstream of the wastewater treatment plant on Rich Fork Creek. No accumulations of organic material were seen. • Heavy sediment deposition and large sand bars were seen at all sites. The following sections of this Appendix present the digital photos and field notes taken at each site. As a matter of convention, descriptions of "left" and "right" are based on a downstream facing view. ID TW►TEC,. MC. A-4 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 2 Site 1: Rich Fork Creek at High Point Road The following general observations were made at Site 1: • Water was approximately 4 feet wide and 4 inches deep. Good riffle movement. Algae growing on rocks. Water was clear. Banks are slightly entrenched but well vegetated and appear stable. • Substrate comprised of bedrock, cobbles, gravel, and sand. • Substrate sample showed mix of sand and gravel, no color changes, no accumulation of organic material. • Bottom plants growing in sand. Green algae abundant on larger substrate, indicating that high flows rarely mobilize the streambed substrate. • No pools, but consistently spaced riffles. • Adjacent cleared areas are grassed. • No significant sand bars or channel erosion. • Presence of Ephemeroptera species (mayflies) and Trichoptera species (caddisflies) under larger rocks in the streambed. Many of these species are sensitive to water quality and habitat degradation, so their presence indicates good habitat and water quality. • The observed reach has only limited restoration potential, but riparian planting would be feasible if elevated water temperatures are deemed a problem. • An adjacent landowner stated that fields are present upstream of this site, but he had no knowledge of their use as pasture or of the presence of cattle in the stream. He has worked adjacent to the stream for one year and had not seen high flows, although the he noted that the stream had essentially dried up during the 2005 summer. Figure 2 through Figure 13 illustrate these observations. Specific notes follow each photo. S TETRATECH,MC. A-5 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 2. Substrate at Site 1 Course sand and gravel substrate. Well vegetated banks. nTETRA TECH. INC. A-6 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 3. Rich Fork Creek at Site 1, Facing Upstream See large cobble, well vegetated banks. Access to floodplain. Regularly spaced riffles. Pri TETRATECH, INC. A-7 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 4. Substrate sample at Site 1 Substrate composition over approximately 1 foot of depth: course sand, gravel, no change in color, no organic layer on surface. Figure 5. Filamentous Algal Growth on Ei TETRA TECH, INC. Rocks in Stream at Site 1 A-8 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 6. Algal Growth on Rocks at Site 1 Figure 7. Algal Growth on Rocks at Site 1 OTETRATECH, INC. A-9 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 8. Algal Growth in Stream Picture clarity failed to show algal growth on substrate. (i) TETRA TECH. INC. A-10 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 9. Rich Fork Creek at Site 1, Facing Downstream Good access to floodplain, vegetated banks with grass and small brush. Few trees and canopy vegetation provide limited shading, thereby allowing for sunlight to elevate water temperatures. ci TETRA TECH, INC. A-11 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 10. Rich Fork Creek Floodplain at Site 1 Access to floodplain, well vegetated banks with grass and small brush. Few trees and not much shading. Ill l TETRA TECH, INC. A-12 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 11. Ephemeroptera species at Site 1 Figure 12. Ephemeroptera Species at Site 1 Top left specimen had gills on underside. Both specimens had three tails. g TETRA TECH, INC. A-13 WQ Scoping Analysis for t/ie High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 13. Trichoptera and Ephemeroptera species at Site 1 Picture fails to clearly show specimens seen on underside of rock. 1 1 TETRA TECH, INC. ` A-14 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 3 Site 2: Rich Fork Creek at Chestnut Street The following general observations were recorded at Site 2: • Sandy substrate. A few large boulders have algal growth. • Thalweg is approximately 1 foot deep. • Small gravel and sand deposition bars. Banks entrenched with some vegetation. • Pool upstream is 2 to 3 feet deep. • Water is approximately 16 feet wide. Banks are approximately 7 to 8 feet high. Steep with some grass and tree roots. • Instream erosion does not appear to be the significant source of sediment in the stream. • Substrate sample comprised of sand on top 6 inches underlain by course sand on bottom 6 inches. No change in color; no accumulation of organic material. • Sandy substrate moving constantly under observed flow conditions.. • Saw no evidence of organic material or sludge at this site, though a leaky sewer pipe at Chestnut Street allowed raw sewage into the stream during the summer of 2005 for weeks to months before being detected (Frank Skee, 1/20/06). • Trees on banks would provide approximately 75 percent cover during leaf out. • During drive from Site 1 to Site 2, field team saw no cattle in fields or row crop agriculture, only grass and pasture. Figure 14 through Figure 20 illustrate these observations. STETRATECKINC. A-15 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 14. Rich Fork Creek Facing Upstream at Site 2 See entrenched banks with good vegetation. Sand bar forming on left side. Figure 15. Movement of Sandy Substrate at Site 2 Sandy substrate constantly moving. See sand ripples. a TETRATECH. INC. A-16 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 16. View of Sand Bar at Site 2 Sand bar comprised of course and fine grained sand. Stream banks entrenched with some vegetation. Figure 17. Entrenched Banks at Site 2 Banks are approximately 8 feet high. Elongated sandbar. Vegetated banks. Though this site does not have easy access to floodplain, banks do not appear to be eroding significantly. riTETRA TECKINC. A-17 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 18. Algal Growth on Rocks in Stream on Right Side of Channel Picture fails to clearly show the algal growth. Figure 19. Substrate Sample Extracted from Site 2 Deeper 6 inches (left side of shovel scoop in the figure) has course brown sand. Top 6 inches has finer sand. Little color change. No accumulation of organic material. I I TETRA TECH,INC. ^_1 O WQ Scoping Analysis for• the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 20. Algal Growth on Woody Debris at Site 2 Algae growing on fixed limb. nTETRA TECN, INC. A-19 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 4 Site 3: Rich Fork Creek at Lexington Avenue The following general observations were made at Site 3: • This site corresponds to YPDRBA site Q5750000 and is approximately 1.3 miles upstream of the WWTP. The Westside WWTP also samples general water quality at this site on a routine basis. • Sand bars are present. Eroded banks are steep but vegetated. Water is green and murky in the pooled area formed behind old bridge abutment. This color was not evident at the other two sites, but no pools were present there either. • Substrate sample shows 6 inches of brown sand underlain by gray sand. No organic layer present. • Algae present. Attached plants growing on old bridge abutment. • Water is about 18 feet wide and Y2 to 1 foot deep on this day. More algae present here than at the two upstream sites. Pool formed by abutment was approximately 3 feet deep. • Noticeable sediment deposition on banks. • Canopy cover would be approximately 50 percent during leaf out. • Banks were approximately 5 feet high. Figure 21 through Figure 28 illustrate these observations. Figure 21. Sand Bar Formation at Site 3 TETRATECI1,INC. A-21 WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006 Figure 22. Rich Fork Creek Facing Downstream at Old Bridge Abutment Green murky water in pooled area. Deposition on left bank. Figure 23. Substrate Sample at Site 3 Substrate sample has fine brown sand on top 6 inches underlain by course gray sand. Ei TETRATECM, INC. A-22 ralt RAIN FALL !MONTHLY AVG. IN INCHES 2001 2002 2003 2004 2005 2006 JAN 0.34 JAN 0.44 JAN 0.12 JAN 0.15 JAN 0.29 JAN 0.18 FEB 0.35 FEB 0.55 FEB 0.4 FEB 0.25 FEB 0.56 FEB 0.23 MAR 0.43 MAR 0.27 MAR 0.49 MAR 0.2 MAR 0.72 MAR 0.2 APR 0.42 APR 0.15 APR 0.53 APR 0.33 APR 0.21 APR MAY 0.41 MAY 0.21 MAY 0.39 MAY 0.13 MAY 0.24 JUNE 0.44 JUNE 0.32 JUNE 0.4 JUNE 0.29 JUNE 0.26 JULY 0.47 JULY 0.42 JULY 0.49 JULY 0.45 JULY 0.57 AUG 0.35 AUG 0.42 AUG 0.58 AUG 0.4 AUG 0.46 SEPT 0.47 SEPT 0.47 SEPT 0.94 SEPT 0.91 SEPT 0.1 OCT 0.29 OCT 0.58 OCT 0.17 OCT 0.16 OCT 0.62 NOV 0.21 NOV 0.68 NOV 0.27 NOV 0.37 NOV 0.46 DEC 0.34 DEC 0.6 DEC 0.31 DEC 0.5 DEC 0.32 YEARLY AVG.IN INCHES 2001 2002 2003 2M p, Mi. 4.52 5.11 5.09 3.96 4.81 0.61 Westside Spills 2001 Total events: 8 Total Gallons: 19519 Map Date: 05 APR 2006 Map By. Tim Ayers 1,500 750 0 1,500 Feet -- REPAIR: Replace Line Legend O Spills ORepairs Outfalls Corbett Country Club Ensley Creek Kennedy IUndergarten Kool Pool Rich Fork REPAIR Replace 3 Manholes j 1Event (s) j 1800 GA` 1 1 Event (e) 50GAL REPAIR: Regan ring and 6d 1 Event (s) 314GAL 1 Evert(e) 1200 GAL r 1 Event (s) 1500 GAL — 1 Event (s) 11860 GAL Westside Spills 2002 Total events: 31 Total Gallons: 112872 Map Date: 05 APR 2006 Map By: Tim Ayers 1,500 750 0 1,500 Feet Legend Outfalls Spills Corbett Country Club Ensley Creek Kennedy IGndergarten Kool Pool Rich Fork 2 Event (s) 40785 GAL 1 Event (s) 250 GAL ,L,... II1 Event (s) 100 GAL • 2000 GAL) 8Event ( 78 GALs) 1 Event (s) 930 GAL 1 Event(s) 8400 GAL 1 Event (s) 76 GAL 2 Eveia (s) 290 GAL 1 Event (s) 210 GAL . 1 Event (s) 100 GAL Westside Spills 2003 Total events: 27 Total Gallons: 149928 Map Date: 05 APR 2006 Map By: Tim Ayers 1,500 750 0 1,500 Feet Legend C7 Spills Outfalls Repairs Corbett Country Club Ensley Creek Kennedy Kindergarten Kool Pool Rich Fork I REPAIR: Old One repaired I bet eenjunction end pled 1 Event(s) 2340 GA. 1 Event (s) 2340 GAL REPAIR: Anchored end betldJled scored MH REPAIR: Junction bat raised 21eet REPAIR: Fix two MH and indall loddrg Od 1 Event (s) 980 GA. 1 Event(s) 273 GA. .14 Event (s) �3637 GA. • 1 Event (s) �GAL 3 Event (s) 2313 GAL 1 2 Event (s) 24906 GAL \1 GAL Event (s)I 1 I 1 Event (s) 1200 GAL Westside Spills 2004 Total events: 27 Total Gallons: 436189 Map Date: 05 APR 2006 Map By: Tim Ayers 1,600 800 0 1.600 Feet Legend a spills Outfalls Repairs Corbett Country Club Ensley Creek Kennedy Kindergarten Kool Pool Rich Fork • REPAIR: I Repaired men pipe 4 Event (s) 3651 GAL 1 Event(e) 234 GAL I1 Event(e) �� I 296 GAL z 1 Event (s) 318 GAL Westside Spills 2005 Total events: 18 Total Gallons: 34322 Map Date: 05 APR 2006 Map By. Tim Ayers 1,600 800 0 1,600 Feet Legend 0i Spills Outfalls Repairs Corbett Country Club Ensley Creek Kennedy Kindergarten Kool Pool Rich Fork "SS)1 Event (s) 276 GAL 0 TETRA TECH, INC. 3200 Chapel Hill - Nelson Highway Cape Fear Building - Suite 105 P.O. Box 14409 Research Triangle Park, NC 27709 Telephone: (919) 485-8278 Telefax: (919) 485-8280 MEMORANDUM To: Terry Houk, City of High Point Alan Stone, Hazen & Sawyer From: Trevor Clements Date: 4/4/06 Subject: Budget Planning for Rich Fork Creek Monitoring, Restoration, and Modeling Work The following budget numbers are provided to guide the City of High Point in its budget planning for the monitoring, stream restoration, and modeling work proposed for Rich Fork Creek in support of the High Point Westside cooperative NPDES permitting process with NCDWQ. Budget estimates for Steps 1 - 4 (Phase 1 Validation Monitoring and Reporting) are based on detailed research and planning. The remaining estimates are approximations based on preliminary planning. Steps 1 - 4. Phase 1— Validation Monitoring and Reporting A. Planning and reconnaissance $8,000 B. Flow and Time -of -Travel $32,000 -- cross -sections -- manual flow measurement -- dye study through 3 pools and portion of creek -- D.O. profiles through pools C. Sediment Oxygen Demand Study $30,000 -- 1 upstream, 3 pools, 1 between pools, 1 downstream (insitu measurements, 3 reps per D. Reaeration Study (optional but recommended) $10,000 -- through 1 pool and 1 downstream reach E. Documentation and presentation of monitoring results $12,000 (assumes 1 meeting with City and DWQ) G. Project management/contract administration $3,000 H. Contingency to cover unforeseen events $5,000 ID TETRA TECH. INC. TOTAL including reaeration study $100,000 TOTAL without reaeration study $90,000 1 O Budget Planning for Rich Fork Creek Monitoring, Restoration, and Modeling Work 4/4/06 Step 5. Stream Restoration Restoration of three pools Estimated: -- Planning $600,000 - -- Design $750,000 -- Permitting -- Construction Oversight (Does not include cost of obtaining any necessary easements) Step 6. Phase 2 — Monitoring to Support Model RecalibrationNalidation A. Recalibration monitoring (low flow condition) . -- Planning -- Detailed cross -sections and flow -velocity studies -- Complete oxygen dynamics survey (total community primary production & respiration, water column P&R, SOD and community substrate oxygen demand, reaeration, long-term BOD) -- Supplemental water chemistry -- Documentation of monitoring results B. Validation monitoring (moderate flow condition) -- Range of cost reflects level of validation that will be required by DWQ: from limited to flow -velocity and water chemistry, to additional reaeration or other oxygen dynamics survey. Estimated: $150,000 - $200,000 Estimated: $75,000 - $125,000 Step 7. Model Recalibration and Reporting -- Model set-up Estimated: -- Calibration $60,000 - -- Validation $85,000 -- Documentation -- Presentation of modeling results/transfer of modeling files and DWQ staff orientation Please call if you have any questions or wish to discuss anything in more detail. Ej TETRATECN, INC. 2