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HomeMy WebLinkAbout20240358 Ver 1_DWR Responses Letter Binder1_20240519www.MogMit.com M M I -Charlotte (704) 576-1111 MMI - Raleigh (919) 556-8845 17 May 2024 MOGENSEN MITIGATION INC. Maria Schutte NC Division of Water Resources 401 & Buffer Permitting Branch 1617 Mail Service Center Raleigh NC 27699-1617 ENVIRONMENTAL CONSULTING DVM MOGENSEN MITIGATION, INC Subject: Responses to DWR Comments on Oakboro West Stanly WWTP Expansion, DWR # 20240358 Dear Ms. Schutte, Mogensen Mitigation, Inc. (MMI) and Wooten Engineering offer the following responses to your comment letter dated April 29, 2024 regarding the Oakboro West Stanly WWTP Expansion project, DWR # 20240358. 1. Send NEPA final approval letter from State Clearinghouse or schedule for when approval is expected. Response: The PER/EA for the current project design (as submitted in the PCN application) was submitted to USDA Rural Development for review in February 2024. USDA issued an EA acceptance form on March 7, 2024. The first notice of availability (NOA) for public review was published on May 7, 2024, and a second NOA will be published on or about May 14. After the second 14-day public review period USDA will consider any comments received and then issue a final environmental approval for the project. Approval is expected on or about June 7, 2024. See attachments: (1) USDA EA acceptance form; (2) USDA NOA for public review. 2. Need justification for open trench crossings vs directional boring. "all reasonable avoidance and minimization efforts" WRC letter reports rare mussels in creeks downstream; DWR believes trenchless install is warranted to protect stream habitat. Response: The four proposed stream crossings that could possibly support mussels (intermittent or perennial streams) are all along roadsides (Figures attached). Two of these crossings, S-4 and S-8, will be installed directly under the culvert within the maintained road shoulder and will not disturb the stream channel beyond the culvert outlet. Stream S-8 is the only stream in which NC-WRC has reports of rare mussels downstream. Crossings S-12 (Horse Branch) and S-15 (Long Creek tributary) will involve trenching across the stream, but the disturbance will be kept as close as possible to the culvert outlet (16 lin.ft of stream impact at S-12 and 28 lin.ft of stream impact at S-15). Pipe installation by HDD rather than by open trench at S-12 and S-15 would cost approximately $1,389,000 as opposed to $54,000 for open trenching at these two crossings. The drilling length required is approximately 400 to 520 feet at each crossing (due to required pipe depth and allowable bending radius) and would also require more forest disturbance beyond the mowed roadside for the starting and ending pits. The potential stream habitat protection benefit of using HDD at these crossings is slight and may not be worth the additional cost and forest disturbance. 3A. Any utility construction corridor that is parallel to a stream or open water shall not be closer than 10 feet to the top of bank or ordinary high-water mark." If this requirement cannot be met in a specific Environmental Field Studies ■ Wetland & Stream Delineation ■ 404-401 Permits ■ Mitigation Plans & Banking MOGENSEN MITIGATION INC. location, please identify that location and provide details of why the project cannot be modified to meet this condition. Response: There are four force main segments that are roughly parallel to intermittent or perennial streams: S-8, S-12 (Horse Creek), S-15, and Long Creek. The stream crossing angles at S-8 and S-15 are determined by the existing road rights -of -way, which are not perpendicular to the streams. S-8 is the only one where the construction corridor is within 10 feet of the stream top -of -bank for a short segment (approximately 40 feet along the right bank) immediately downstream of the crossing. At S-15, the force main diverges away from the stream immediately after the crossing. To make these crossings closer to perpendicular, the construction corridor would need to be shifted farther beyond the maintained roadside and would impact more forest. The small potential reduction in stream impact at these two crossings is probably not worth the increased forest clearing and construction costs. The force main segments parallel to S-12 and Long Creek are 100 feet or more from their respective streams. 3B. Provide detailed construction sequence that includes measures taken to protect long term stream stability and downstream water quality. Response: The planned construction sequence for stream crossings is as follows, subject to modifications based on the contractor's discretion: 1) Install silt fence; 2) Clear vegetation in construction areas; 3) Install cofferdams above and below the in -stream work area; 4) Temporary piping or pumps will carry normal stream flow through the cofferdams; 5) Excavate trench for pipe installation after dewatering; 6) Pump any water that accumulates in the trench into a silt basin or silt bag before discharging the water; 7) Install the force main in the trench and backfill with excavated bed material; 8) Place riprap where needed in the upper part of the backfill to re-establish the pre -construction stream bed grade; 9) Re -seed all disturbed soil areas beyond the creek bed and plant native live stakes at 3 to 4 foot spacing along the creek banks. Note: The open -trench stream crossings are adjacent to culvert outlets where riprap is already present for channel stabilization. 4. DWR does not recommend rip -rap be placed in stream channels. It may be used for bank stabilization, but in many cases, coir fiber matting and plants would allow the streams to return to near normal. Please explain Response: All four intermittent or perennial stream crossings (S-4, S-8, S-12, S-15) are along the downstream sides of road crossings where riprap has been used for decades to minimize plunge pool erosion at the road culvert outlets. Replacing the riprap after force main installation will have negligible adverse effect on stream habitat. Streams in this region often contain natural riprap-size boulders and cobbles. 5. Utility lines shall cross the stream channel at a near -perpendicular direction (i.e., between 75 degrees and 104 degrees to stream bank)." Please explain/verify crossings are between 75 degrees and 105 degrees to the stream bank and provide justification if not. Area 2, sheet 1; Area 3, sheet 2. Area 15, sheet 12 - Verify if width of stream is entire area in blue or well within the angled FM turns? Response: Crossing S-2 is approximately 20 degrees from perpendicular and crossing S-3 is approximately 30 degrees from perpendicular, but both are ephemeral channels that are important for their hydrologic contributions but provide negligible aquatic habitat at the force main crossing sites. These off -road crossing angles are determined by property lines and field edges. Crossing S-15 is approximately 50 degrees from perpendicular; this angle is determined by the existing roadway as explained above in the NM www.Mogmit.com Page 12 MOGENSEN MITIGATION, INC MOGENSEN MITIGATION INC. response to comment 3A. The blue and green areas shown in the S-15 figure are riparian buffer impacts; the red outlined area is the stream impact. 6. Horse Branch Creek - stream impact SI (AREA 12 plan sheet 9 of 13) is 25 feet wide. The Division has significant concerns regarding open cut installation methods in large stream systems. It is staff's experience that open cut installation methods within large streams are extremely difficult to construct and maintain in a manner that ensures compliance with water quality standards. Please provide specific construction details, including proposed dewatering methodology, expectation of encountering rock and methodology for removal of rock, expected construction timeline, and additional measures proposed to ensure water quality protection during construction. Response: See response to item 3B above for construction sequence. See attached plan and cross-section figures showing the proposed dewatering method at crossings S-12 and S-15. 7. The Effluent Cutfall Plan Sheets (AREA 16) are confusing. What is the existing arrangement vs. the proposed changes? What is the "smooth foundation" under the filter fabric? Is the outfall pipe buried under this and then the rip -rap on top? What is the placement of the discharge pipe in relation to typical water level? Why is rip -rap on stream -bed? Please explain and provide more detailed profile sheet(s). Response: The new effluent discharge pipe will be installed in a trench alongside the existing discharge pipe extending down the riverbank, and the existing pipe will be removed after the new line is activated. The backfilled soil in the trench on top of the new pipe will create the "smooth foundation" on top of which the filter fabric and riprap will be placed to stabilize the riverbank. The lower end of the pipe will have a duck -bill check valve (similar to the existing discharge) placed at the same invert elevation as the existing discharge, but it will be set back a few feet in a notch excavated into the riverbank and stabilized with additional filter fabric and riprap. The existing discharge is submerged during normal and high river flows, but is exposed during low flow periods when the water spills vertically into the river; the new design will eliminate this vertical spill. The riprap at the outlet will provide a dissipator pad from the discharge to the river bed for erosion control as required by DEQ Land Quality Section. 8. Standard 401 Certification requirements state, "Construction corridors in wetlands and/or across stream channels shall be minimized to the maximum extent practicable and shall not exceed 40 feet wide." Please confirm there are no areas that will exceed 40' of disturbance (temporary or permanent). Response: The longest stream impact is S-15 which affects 28 linear feet of stream. All other crossings affect less than 20 linear feet of stream. 9. Standard 401 Certification regulation states, "Permanent maintained access corridors in wetlands and across stream channels shall be restricted to the minimum width practicable and shall not exceed 30 feet wide." Permanent easements are different than permanent, maintained corridors. Do you intend to have permanent, maintained corridors wider than 30 feet? If so, justify. Response: The permanent maintained (mowed) force main access corridors do not exceed 30 feet wide at stream crossings. To the extent practicable they have been routed along roadsides and field edges to minimize impacts to riparian forests. NMwww.Mogmit.com Page 13 MOGENSEN MITIGATION, INC MOGENSEN MITIGATION INC. HDD OW Cot I Crossing Name I HHH I Length (ft HDDCastM I C TOWCoI Lem st I fin} Cffosskg Cast In Temp. Creek C(LS) Total Coat Horse Branch Creek I 525 $1,600.00 M,500.00 I 25 $251)M $3D,0OD.0D $X250.00 I Long CreekTributary I 401 I $1,500.00 I $601,500.00 I 10 I M.00 $15,000.00 $17,500.00 Grand Total $1,363,000. Grand Total M750.00 Cost comparison of Horizontal Directional Drilling versus open trench installation at stream crossings. AMwww.Mogmit.com Page 14 MOGENSEN MITIGATION, INC O m L CL 7r.9 �C� 1..0 W eta zo Z Ln d 110 W O LU J s-I J CC w � Ln fJ Q = � z cq C) W [C Q 5l } 1 k iII i � W I r 5y 1 i 1 x � � y k Soo � I i I I f t I I � J I � � I I � V' 415 ZIPS I Nz IIILL c IIZ LU C-� ;,j I r -j LL I�IZ LL ,- q ph rV N M 00 LD ao w 0 o L� w �w LLI uLrIp ¢ W00 m Tt _ Tt N o w f•- �w D �z Q u, ❑� w H ri W F-ILO < � ao cn❑w 11 <0 U') CLz17) ' yr--qCD to � U w o w H d u-s z J LL w H —ow r- moo . C) LLI Lm LL. Q "z 0 Z w � aC u? O tu mf w � ` wm D } r} 'r w w w W w Z Lj Z Z 'off CL a cn +r 0 r 1 w> O U / 0. 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LU = CL {..� Lh D Z CC J Z Z rn < LU W Vn o �J = Q i Sl] Lfi �n O PROPOSED 30" � DIP DISCHARGE DIFFUSER CHECK VALVE CLASS 'R' RI PRA P Discharge notched into riverbank SIDE FRONT UTF LL DIFFUSER CHECK VALVE OC FILTER FABRIC TO Y BE KEYED INTO TOP OF SLOPEf� 18" OF CLASS c-? r "I" RIP -RAP 7.2m t NON, 5MOOTf I FOUNDATION p UNDER FILTER FABRIC �,' 4QL Rocky River bank stabilization with filter fabric and riprap placed over outfall pipe. ROY COOPER Governor ELIZABETH S. BISER Secretary RICHARD E. ROGERS, JR. Director faro NORTH CAROLINA Environmental Quality April 29, 2024 D W R # 20240358 Stanly County Stanly County Utilities Attn: Mr. Duane S. Wingo, Utilities Director 1000 North First St., Suite 12 Albemarle, NC 28001 Delivered via email to: dwingoW@stanlycountync.gov Subject: REQUEST FOR ADDITIONAL INFORMATION Oakboro West Stanly WWTP Expansion Project Dear Mr. Wingo: On February 27, 2024, with fee received on March 6, 2024, the Division of Water Resources (Division) received your application requesting a 401 Individual Water Quality Certification from the Division for the subject project. The Division has determined that your application is incomplete and cannot be processed. The application is on -hold until all of the following information is received: 1. The PCN states this project requires NEPA permitting. In accordance with 15A NCAC 01C .0107 please provide a final approval from the State Clearinghouse or provide a schedule for when the document is expected. 2. Trenchless boring is used throughout the state in various projects to minimize stream impact / potential WQ issues from trenches. In this project it is only proposed at the railroad crossing. Was it considered for other stream crossings? Further justification is needed to adequately document that all reasonable avoidance and minimization efforts have been taken. Note: Given the attached comments from NCWRC regarding the presence of the Carolina Creekshell and Eastern Creekshell in Stony Run Creek and its unnamed tributary, the Division believes that trenchless methods of installation are warranted to protect these species and their habitat. 3. A few plan sheets show the limit of disturbance up to the top of streambank. Standard 401 Certification requirement states, "Any utility construction corridor that is parallel to a stream or open water shall not be closer than 10 feet to the top of bank or ordinary high-water mark." If this requirement cannot be met in a specific location, please identify that location and provide details of why the project cannot be modified to meet this condition. Please also submit a North Carolina Deparhnent of Environmental Quality I Division of Water Resources 512 North Salisbury Street 1 1611 Mail Service Center I Raleigh, North Carolina 27699-1611 Noa�1�1 919.707.9000 oepanmem or enviro memai auaZ Oakboro West Stanly WWTP Expansion - Project DWR# 20240358 Request for Additional Information Page 2 of 3 detailed construction sequence that includes additional measures that will be taken to protect long term stream stability and to protect downstream water quality standards. 4. Most plan sheets state that rip -rap will be emplaced in the stream bed/channel to stabilize after pipe is installed and trench backfilled. DWR does not recommend rip -rap be emplaced in stream channels. It may be used for bank stabilization, but in many cases, coir fiber matting and plants would allow the streams to return to near normal. Please explain. Standard 401 Certification requirement states, "Where there are temporary or permanent impacts from stream crossings, utility lines shall cross the stream channel at a near -perpendicular direction (i.e., between 75 degrees and 104 degrees to stream bank)." Please explain/verify crossings are between 75 degrees and 105 degrees to the stream bank and provide justification if not. Plan sheets at closer scale for details of crossings would be beneficial, please submit if available. • AREA 2 on Plan Sheet 1 of 13 • AREA 3 on Plan Sheet 2 of 13 AREA 15 on Plan Sheet 12 of 13 (Verify if width of stream is entire area in blue or well within the angled FM turns?) Horse Branch Creek — stream impact S1 (AREA 12 plan sheet 9 of 13) is 25 feet wide. The Division has significant concerns regarding open cut installation methods in large stream systems. It is staff's experience that open cut installation methods within large streams are extremely difficult to construct and maintain in a manner that ensures compliance with water quality standards. Please provide specific construction details, including proposed dewatering methodology, expectation of encountering rock and methodology for removal of rock, expected construction timeline, and additional measures proposed to ensure water quality protection during construction. The Effluent Outfall Plan Sheets (AREA 16) are confusing. What is the existing arrangement vs. the proposed changes? What is the "smooth foundation" under the filter fabric? Is the outfall pipe buried under this and then the rip -rap on top? What is the placement of the discharge pipe in relation to typical water level? Why is rip -rap on stream -bed? Please explain and provide more detailed profile sheet(s). Standard 401 Certification requirements state, "Construction corridors in wetlands and/or across stream channels shall be minimized to the maximum extent practicable and shall not exceed 40 feet wide." Please confirm there are no areas that will exceed 40' of disturbance (temporary or permanent). Standard 401 Certification regulation states, "Permanent maintained access corridors in wetlands and across stream channels shall be restricted to the minimum width practicable and shall not exceed 30 feet wide." Permanent easements are different than permanent, maintained corridors. Do you intend to have permanent, maintained corridors wider than 30 feet? If so, justify. Pursuant to Title 15A NCAC 02H .0502(e), the applicant shall furnish all of the above requested information for the proper consideration of the application. Please respond in writing within 30 calendar days of receipt of this letter by sending one (1) copy of all of the above requested information to the 401 & Buffer Permitting Branch, 1617 Mail Service Center, Raleigh, NC 27699-1617 OR by D E Q��!/ North Carolina Department of Environmental Quality I Division of Rater Resources v 512 North Salisbury Street 1 1611 Mail Service Center I Raleigh, North Carolina 27699-1611 NORTH CAROLINA 919.707.9000 Department of Environmental Duallry Oakboro West Stanly WWTP Expansion - Project DWR# 20240358 Request for Additional Information Page 3 of 3 submitting all of the above requested information through this link: https://edocs.deg.nc.gov/Forms/Supplemental-Information-Form (note the DWR# requested on the link is referenced above). If all of the requested information is not received within 30 calendar days of receipt of this letter, the Division will be unable to approve the application and it will be denied as incomplete. The denial of this project will necessitate reapplication to the Division for approval, including a complete application package and the appropriate fee. Please be aware that you have no authorization under the Section 401 of the Clean Water Act for this activity and any work done within waters of the state may be a violation of North Carolina General Statutes and Administrative Code. Please contact Maria Schutte at 704-235-2184 or.Maria.Schutte@deg.nc.gov if you have any questions or concerns. Sincerely, CA DocuSigned by: �w H P44ft F161FB69A2D84A3... Andrew H. Pitner, P.G., Regional Supervisor Water Quality Regional Operations Section Division of Water Resources, NCDEQ Attachment: NCWRC Comments Electronic cc: Gerald Pottern, Morgensen Mitigation, Inc. Krystynka Stygar, USACE Charlotte Regulatory Field Office DWR 401 & Buffer Permitting Branch file Filename: 20240358 Oakboro West Stanly WWTP Expansion Project — Stanly - addinfo.docx D E Q�� North Carolina Department of Environmental Quality I Division of Water Resources 512 North Salisbury Street 1 1611 Mail Service Center I Raleigh, North Carolina 27699-1611 NORTH CAROLINA 919.7�7.96�� nePenmem of environmental ouar� Baker, Caroline D From: Munzer, Olivia Sent: Tuesday, April 16, 2024 4:08 PM To: gerald@mogmit.com Cc: Stygar, KRYSTYNKA B CIV USARMY CESAW (USA); Pitner, Andrew Subject: NCWRC Comments - Stanly County Oakboro Wastewater Expansion - DWR no.. 20240358 Attachments: NC Native Plant Alternatives_October2018.pdf Good afternoon, We have records of the state endangered Carolina creekshell (Villosa vaughaniana) and state significantly rare eastern creekshell (V. delumbis) in Stony Run. We are requesting surveys for mussels at locations where the project will cross Stony Creek and its unnamed tributary. Prior to construction, surveys for state -listed mussel surveys should be conducted within the instream work area and 50 meters above and 100 meters below the work area. Any protected species surveys should be conducted by biologists with both state and federal endangered species permits. If state -protected species are found in the project area, the mussels should be relocated to suitable habitat above the project area. Also immediately contact Brena Jones, the Central Aquatic Wildlife Diversity Research Coordinator, at 919-707-0369 or brena.jones@ncwildlife.org if protected mussel species are found during surveys. Also, the state endangered and federal proposed tricolored bat (Perimyotis subflavus) is known to occur in Stanly County. We recommend any tree clearing activities should occur outside the "active season" (April 1—November 14) for the tricolored bat. Conducting tree clearing activities during the winter avoids impacting bats roosting in trees, particularly during the maternity season (June —July). Tricolored bats are known to roost in culverts and in bridges, including in the winter in the Piedmont of North Carolina. Therefore, any existing culverts greater than 3 feet wide or bridges adjacent to or within the project area should be surveyed for bats within 15 days of construction. Surveys should be conducted in accordance with the National White -nose Syndrome Decontamination Protocol and the NCWRC Culvert Survey Protocol. Please use native plants for seeding disturbed areas. Avoid using invasive and/or non-native species such as Bermudagrass, redtop, tall fescue, and lespedeza. A list of alternatives to non-native species has been attached. Alternatively, use a grain, such as oats, wheat, or rye for temporary cover and native seed mixes for permeant seeding. We recommend planting native, wildflower seed mixes that will create pollinator habitat within the project boundary. Lastly, erosion control matting made of plastic mesh or twine should not be used within the project area because it can injure or kill wildlife. Please let me know if you have questions. Thankyou, Olivia Olivia Munzer Western Piedmont Habitat Conservation Coordinator NC Wildlife Resources Commission Rogers Depot 1718NCHwy 56W Creedmoor, NC 27522 Office: 919-707-4056 (note new number) Cell: 336-269-0074 olivia.munzer@ncwildlife.or>; www.ncwildlife.org 13 MIJ. Email correspondence to and from this sender is subject to the N.C. Public Records Law and may be disclosed to third parties.