20100400 Ver 1_More Info Received_20100628

FW: Extended Day School Sewer USACE Action ID: 201000858 Page 1 of 1
FW: Extended Day School Sewer USACE Action ID: 201000858
Homewood, Sue
Sent: Monday, June 28, 2010 9:27 AM
To: Dennison, Laurie; Strickland, Bev
Attachments: revised S1 (1 MB) ; Dav Co Sewer PCN revised p7.pdf (23 KB) ; Dav Co Sewer PCN revised p3.pdf (18 KB) ; Dav Co Sewer
PCN revised p5.pdf (21 KB)
For File 10-0400
I've asked them to resend the one called "revised Si" because I can't open it.
Sue Homewood
NC DENR Winston-Salem Regional Office
Division of Water Quality
585 Waughtown Street
Winston-Salem, NC 27107
Voice: [phone]
FAX: [phone]
E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law and may be
disclosed to third parties.
From: Phil May [mailto:[e-mail]]
Sent: Sunday, June 27, 2010 10:46 PM
To: Homewood, Sue
Cc: [e-mail]; 'Ben Palmer'
Subject: Extended Day School Sewer USACE Action ID: 201000858
Sue,
As we discussed last week, Davidson County is willing to eliminate one of the low-water ford crossings for maintenance
vehicles. The revised plan sheet shows this crossing (S1) as a typical sewer crossing (temporary disturbance). The
remaining two ford crossings (S2 and S3) would be installed to allow the maintenance crews to access half of the run
between the pump station and US 64. The following information is attached for your review:
- Revised PCN Form pages 3, 5, and 7. Pages 3 & 7 mentioned all three crossings in the text. Page 5 revises the impact
numbers slightly (permanent impact only).
- Revised plan sheet showing S1 as a standard sewer crossing (temporary impacts only).
The temporary crossing detail is already in the existing plan set submitted with the permit.
John - Please let us know if there is any need to modify the issued 404 permit or if you need any additional information.
Let me know if you have any questions or need additional information - I will be intermittently available by cell until
Thursday as I am in the mountains of Kentucky with marginal cell coverage. Checking email mornings and evenings if
you need anything else to issue the 401 Certification.
Thanks
Phil
Phil May
CAROLINA ECOSYSTEMS, INC.
[phone]
https://mail.nc.gov/owa/?ae=Item&t=IPM.Note&id=RgAAAAAAOgPoLNIPQZ06vHVR... 6/28/2010
B. Project Information and Prior Project History
1. Property Identification
1 a. Property identification no. (tax PIN or parcel ID): See table appended to this form
1 b. Site coordinates (in decimal degrees): Latitude: Table Longitude: - Table
(DD.DDDDDD) (-DD.DDDDDD)
1 c. Property size: 5.5 acres (easement) acres
2. Surface Waters
2a. Name of nearest body of water (stream, river, etc.) to Pounder Fork
proposed project:
2b. Water Quality Classification of nearest receiving water: WS-V, B
2c. River basin: Yadkin
3. Project Description
3a. Describe the existing conditions on the site and the general land use in the vicinity of the project at the time of this
application:
The proposed gravity sewer passes through primarily forest and agricultural areas with some residential and commercial
land. The proposed forcemain runs along existing NCDOT roadsides through primarily agricultural and residential areas
with some adjacent forest land.
3b. List the total estimated acreage of all existing wetlands on the property:
0.03 acres delineated along project corridor
3c. List the total estimated linear feet of all existing streams (intermittent and perennial) on the property:
118 linear feet of perennial stream within proposed easements
3d. Explain the purpose of the proposed project:
The proposed gravity sewer, pump station, and force main are being provided to connect the Extended Day School in
Lexington, North Carolina to the existing City of Lexington municipal sewer system. The school's current wastewater
facility has exceeded limits for ammonia nitrogen and fecal coliform. Due to these issues, the Extended Day School
system was included in the attached Special Order by Consent from the NCDWQ. Plans for sewer system improvements
to address the issues are due by June 30, 2010. This project meets these requirements.
3e. Describe the overall project in detail, including the type of equipment to be used:
The Extended Day School wastewater will be transported to the Lexington sewer system via approximately 6000 linear
feet of 8-inch gravity sewer to a 200 gallon-per-minute pump station adjacent to Pounder Fork. The pump station will
transfer sewage along 12000 feet of forcemain to an existing City gravity sewer adjacent to Abbotts Creek (Figure 1).
Sewer line construction will occur within a 40-foot construction easement and be accomplished using standard
construction equipment and techniques. Clearing and grubbing will occur along with implementation of the NCDENR
approved sediment and erosion control plan. A trench will be excavated and the lines installed and backfilled. The
construction area will be graded to pre-construction contours and seeded. Stream crossings will be constructed in the dry
using a bypass pipe or coffer dam. The crossing locations will be stabilized using natural material or rip-rap over filter
fabric below the stream bed elevation. A 15-foot low water ford crossing will be maintained at two of the three stream
crossings to allow access for inspection and maintenance of the line. These crossings will be constructed as shown in
the attached plans.
Page 3 of 11
PCN Form - Version 1.3 December 10, 2008 Version
C. Proposed Impacts Inventory
1. Impacts Summary
1 a. Which sections were completed below for your project (check all that apply):
® Wetlands ® Streams - tributaries ? Buffers
? Open Waters ? Pond Construction
2. Wetland Impacts
If there are wetland impacts proposed on the site, then complete this question for each wetland area impacted.
2a. 2b. 2c. 2d. 2e. 2f.
Wetland impact Type of jurisdiction
number - Type of impact Type of wetland Forested (Corps - 404, 10 Area of impact
Permanent (P) or (if known) DWO - non-404, other) (acres)
Temporary (T)

W1 ? P ®T Clearing,
excavation,
Headwater forest
El
? No
® Corps
? DWO
<0.01
backfill

W2 ®P ? T Maintained
Headwater forest ® Yes ® Corps
<0.01
clearing ? No ? DWO
W3 ? P ? T ? Yes ? Corps
? No ? DWO
W4 ? P ? T ? Yes ? Corps
? No ? DWO
W5 ? P ? T ? Yes ? Corps
? No ? DWO
W6 ? P ? T ? Yes ? Corps
? No ? DWO
2g. Total wetland impacts 0.01
2h. Comments: One small wetland within construction corridor (W-1 0.006 ac), with small maintenance corridor impact (W-2
0.003 ac). See Figure 6 for details.
3. Stream Impacts
If there are perennial or intermittent stream impacts (including temporary impacts) proposed on the site, then complete this
question for all stream sites impacted.
3a. 3b. 3c. 3d. 3e. 3f. 3g.
Stream impact Type of impact Stream name Perennial Type of jurisdiction Average Impact
number - (PER) or (Corps - 404, 10 stream length
Permanent (P) or intermittent DWO - non-404, width (linear
Temporary (T) (INT)? other) (feet) feet)
S1 ? P ®T Excavation, UT Pounder Fork ® PER ® Corps g 36
backfill ? INT ? DWO
S2 ®P ®T Excavation,
backfill Pounder Fork ® PER
? INT ® Corps
? DWO g 41 (15)
S3 ®P ®T Excavation,
backfill Pounder Fork ® PER
? INT ® Corps
? DWO 10 41 (15)
S4 ?P?T ?PER ?Corps
? INT ? DWO
S5 ?P?T ?PER ?Corps
? INT ? DWO
S6 ?P?T ?PER ?Corps
? INT ? DWO
3h. Total stream and tributary impacts 118(30)
3i. Comments: Temporary open-cut stream crossings due to significant amount of bedrock in the stream channels (see cover
letter). Permanent impacts of 15 linear feet at S2 and S3 from low water ford crossings (permanent impacts in parentheses).
Page 5 of 11
PCN Form - Version 1.3 December 10, 2008 Version
D. Impact Justification and Mitigation
1. Avoidance and Minimization
1 a. Specifically describe measures taken to avoid or minimize the proposed impacts in designing project.
As seen in Figure 4, multiple avoidance and minimization techniques have been implemented for the gravity sewer section.
The forcemain has been designed within previously disturbed roadside right-of-way, and the pump station will be located
entirely in uplands. The gravity sewer corridor was initially located using early input on environmental issues and avoiding
areas with potential wetlands to the greatest extent possible. The gravity sewer line was designed to avoid the larger wetland
area at W1/W2 while minimizing property encroachment. Based on NCDWQ Winston-Salem Regional office correspondence,
the sewer line is located at least 50 feet from the stream banks even though steep slopes along some sections require deeper
trenching. The crossing of UT to Pounder Fork is located upstream of the confluence with Pounder Fork in order to avoid
encroaching on the 50-foot setback and cutting through a large ridge between the streams. The two crossings of Pounder
Fork near the pump station are designed to avoid impacting a pond, dam, and outfall located in an outer bend of the creek
where future encroachment of the stream may occur. This also allowed the sewer to remain 50 feet from stream banks, which
would not be possible if the line crossed below the dam and pond. All stream crossings are proposed at near perpendicular
angles to minimize impacts. Reducing the footage of forcemain and using another section of gravity sewer and a crossing of
Abbotts Creek was considered for economic reasons, but not implemented due to the additional stream crossings and steeper
downstream topography that would have required the line to be within 50 feet of the stream.
1 b. Specifically describe measures taken to avoid or minimize the proposed impacts through construction techniques.
Construction impacts will be minimized by using a maximum 40-foot construction corridor and limiting maintainenance corridor
mowing to a maximum of 15 feet. As discussed above, the 15-foot maintenance corridor crossings S2 and S3 will be
stabilized per the attached ford crossing detail to prevent future erosion and bank degradation from access to the line.
Erosion control measures will be implemented and maintained throughout the construction to avoid sedimentation of surface
waters. Wetland areas temporarily disturbed will be seeded with a wetland seed mix (no fescue) and allowed to naturally
regenerate into forested wetlands. Stream crossings will be stabilized with natural stream bed materials (if
appropriate/available) or rip rap over geotextile fabric. Directional drilling or boring was evaluated for this project but the
presence of a significant amount of bedrock along the stream channels made this impractical, except at the Abbotts Creek
forcemain crossing. If drilling were proposed and bedrock encountered (which is likely based on field observations - see
attached photos and Figure 4), the construction would have to stop and disturbed areas remain open while new equipment is
mobilized to the site and updated plans and approvals sought. Drilling through rock would take highly specialized and
expensive equipment if possible at all, and greatly increase the amount of time needed to construct the stream crossings. This
would increase the amount of time the riparian areas are disturbed and increase the possibility of environmental impacts
occuring due to large rain events etc. The most practical method for accomplishing these crossings will be to quickly and
efficiently use open-cut techniques and stabilize the construction corridor.
2. Compensatory Mitigation for Impacts to Waters of the U.S. or Waters of the State
2a. Does the project require Compensatory Mitigation for ? Yes ® No
impacts to Waters of the U.S. or Waters of the State?
2b. If yes, mitigation is required by (check all that apply): ? DWQ ? Corps
? Mitigation bank
2c. If yes, which mitigation option will be used for this
El Payment to in lieu fee program
project?
? Permittee Responsible Mitigation
3. Complete if Using a Mitigation Bank
3a. Name of Mitigation Bank:
3b. Credits Purchased (attach receipt and letter) Type Quantity
Page 7 of 11
PCN Form - Version 1.3 December 10, 2008 Version