20010093 Ver 1_More Info Letter_20020719 (2)

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Michael F. Easley, Governor
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Gregory J. Thorpe, Ph.D.
Acting Director
Division of Water Quality
July 19, 2002 u
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CERTIFIED MAIL: 7001 1940 0000 4636 0506 ~ ' ,~ ~ r ~ }
RETURN RECEIPT REQUESTED ~~} ~' ~ ~' '~''~?~ ~n:.:'
New Hanover County Engineering Dept. ~Y~T~~ztaS Gf~00P 9
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Mr. Wyatt Blanchard -~ - .
414 Chestnut Street
Wilmington, NC 28401
SUBJECT: PROJECT ON HOLD FOR
ADDITIONAL INFORMATION
New Hanover County
Middle Sound Sewer Project
PROJECT # 010093
New Hanover County
Dear Mr. Blanchard:
Thank you for your letter dated June 10, 2002. Subsequent to consideration/review of your
letter, plans, and Preconstruction Notification Request (401 Certification request), this office wishes
to address both the items noted in your correspondence and several additional concerns.
In the June 10, 20021etter, James Craig states that he sees no purpose for the installation of
the anti-seep collars for the Middle Sound sewer project that are required under the general conditions
of GC# 3374. He states that the sewer main nor the stone bedding will divert basins or attempt to
drain isolated wetlands located upland of the project. He also states that it would be hydraulically
impossible for the sewer main's stone bedding to drain or alter any "waters" of the State or wetlands
due to the pipe being installed in saturated soils.
General Water Quality Certification 3374 condition number 16 is a requirement for the
installation ofanti-seepage collars. The purpose of anti-seepage devices is to stem the wetland
drainage effect that has been observed by DWQ staff, subsequent to the installation of sewer lines.
That is, gravity sewer lines are .installed at a slope, on a gravel bed and as such enables sewer line to
behave like aFrench-drain, thereby removing wetland hydrology. (Please note: it is the expectation
of DWQ staff that anti-seepage device requirements are relatively inexpensive as compared to the
requirement for wetland delineation well outside the utility line right-of--way footprint, and prevents
extensive, long-term hydrologic monitoring of adjacent wetlands.) The conditions set under these
General Certifications have been approved by federal agencies (Corps of Engineers and EPA) as well
as the Environmental Management Commission (EMC) and if you feel that you cannot or do not want
to meet with these conditions, New Hanover County may apply for a variance.
The June 10, 2002, letter also requested a "general exemption" for condition number 16
(anti-seep collar requirement) during the review of all future projects where the site condition as
described in your letter exists for New Hanover County. This office cannot issue "general
exemptions" to 401 Water Quality Certifications Conditions for future projects. Each project is
reviewed on a case-by-case basis and the option of applying for a variance is applicable for each
project.
Ex127 Cardinal Drive t., Wilmington, NC 28405-3845 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer
~ICl7ENlt

Page Two
Mr. Wyatt Blanchard
July 19, 2002
The second item addressed by Mr. Craig concerns the requirement of General Certification #
3374 (condition #4) that states that the construction corridor for the utility line shall not be installed
parallel to and closer than 10 feet (3 meters) to a stream and 25 feet in waters classified as high
quality waters (HQVd). Utility lines shall not cross a stream channel at other than anear-
perpendicular direction (i.e., stream channel crossings shall not be at an angle of less than 75 degrees
or more than 105 degrees to the stream bank). Streams typically meander and move around thereby
enabling stream infrastructure/maintenance problems to chronically occur, and installations of sewer
lines adjacent to the stream cause difficulties with respect.to turbidity impacts, settleable solids, and
thermal pollution issues to the stream. As such, a 10-foot set back from the stream is the minimum
authorized under the 401 Certification and the respective stream classifications for AIWW/Howe
Creek are SA-ORW and for Pages Creek is SA. The classification SA is HQW as defined by 15A
NCAC 2B.0101(e)(5). As such, a 25 feet from the stream is the minimum distance allowed for the
utility lines on this project. A copy of the regulation is attached.
In addition, 15A NCAC 2H .0219 (i) (2) _(G) {v), (vi),-and (xii) states thefollowing: All
sewers shall .be_designed based upon_at the .following minimum_standards which include; 1) minimum
separation from Waters Classified as WS-II, WS-III, B, SA, ORW, HQW or SB (from normal high
water (or tide elevation)] at 50 feet. Any_other stream, lake-or impoundment must be at least 10 feet.
Furthermore, ferrous sewer pipe with joints equivalent to water main standards, shall be used where
these minimum separations cannot be maintained. (Note: minimum separation shall however, not be
less than 25 feet from a private well or 50 feet from a public water supply well).
Please indicate whether the Middle Sound Sewer Collection System~cvill be able to comply
with the above mentioned minimum standards. You explained in the June 10, 20021etter that the
meanders of the stream channels, existing structures, constntction depth and easement concerns
require the encroachments of the utility line within 10 feet of a stream and non-perpendicular stream
crossings. It is recommended that you provide specific information that depicts how you have .
minimized the stream impacts and avoided the streamside area. You should also provide the amount
of linear stream footage impacts that will occur during the construction phase of the project and
provide suggestions/proposals for stream restoration/mitigation due to the impacts that are beyond
that typically approved through the use of the General Certification
Please respond within three weeks of the date of this letter if you are going to comply with
the conditions of the General Certification # 3374 or if you are planning to apply for a variance.
Please send a copy of this letter to Cyndi Karoly, c/o 401 Wetlands Unit, 2321 Crabtree Blvd.,
Raleigh, NC 27604-2260. Her phone number is [phone]. If we do not hear from you within
three weeks, we will assume that you no longer want to pursue this project and we will consider the
project as withdrawn and your application will be returned. If you have any questions, please feel
free to call me at (9.10) 395-3900.
Sincerely,

Rick Shiver
Water Quality Regional Supervisor
Attachment:
cc: Cyndi Karoly -Wetlands Group
Danny Smith -Wetland Group
Angie Pennock - US Army Corps of Engineers
Dave Weaver -.Assistant County Manager
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