20070211 Ver 1_Emails_20070412

Re: [Fwd: Williams Corner-DWQ approval]
Subject: Re: [Fwd: Williams Corner-DWQ approval]
From: Cyndi Karoly <[e-mail]>
Date: Thu, 12 Apr 2007 13:32:05 -0400
To: [e-mail]
CC: Ian McMillan <[e-mail]>, Cynthia F Van Der Wiele
<[e-mail]>, Amy Chapman <[e-mail]>, Lia Myott
<Li a. Myott@ncm ail. net>
Kevin - with the project being in a WS watershed, you'd need to submit a formal
application for approval anyway. Please be sure to include the info Ian referenced
below with respect to bottomless culverts with your application materials. If
bottomless culverts are demonstrated to be appropriate at the locations onsite, it
will make your application go more smoothly.
Ian McMillan wrote:
Kevin, please be advised your proposed bottomless culverts must include submittal
of a signed and sealed (by a Professional Engineer or Professional Geologist)
geotechnical investigation of subsurface soils which directly complies with the
*/ DIVISION OF HIGHWAYS - GUIDELINES FOR_/**/ DRAINAGE STUDIES AND HYDRAULIC
DESIGN /** /PREPARED BY A. L. HANKINS, JR., P.E./**/STATE HYDRAULICS ENGINEER -
1999/*, which states, "When a shallow (3-5 foot max. depth) non-erosive rock
foundation is found throughout the proposed site, the structure can be built on
footings without a bottom allowing retention of the natural channel bed. The
Geotechnical Unit must confirm the foundation acceptability prior to final
selection of the "bottomless" culvert." Our guidance for technical evaluation of
proposed bottomless culverts is Max Price at NCDOT telephone [phone].
Thanks, Ian McMillan
Cynthia,
Per the latest from the Corps on bottomless arch culverts, if our client wants
to span all stream crossings at the Williams Corner site, the only impact would
be retrofitting the pond dam at the pond, which would include impacting the
stream and wetlands adjacent to the dam, which we would be below the current
thresholds for GC 3402 in the Cape Fear Basin. We are in a WS-IV watershed, and
the only other notification trigger to DWQ would be if we proposed an impact to
the perennial streams shown on the USGS quad, which we are not. We would still
be providing stormwater management per the Phase II regulations through Chatham
County, but I want to confirm with you that we would not be required to notify
DWQ for this proposed scenario.
Thanks,
Kevin
*Kevin Yates*
*Sr. Environmental/Wetlands Scientist*
*THE JOHN R. McADAMS COMPANY, INC.*
2905 Meridian Parkway
Durham, NC 27713
919-361-5000 RTP, NC Office
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