20070468 Ver 1_Emails_20070418 (2)

Red Oak Dortchess Park - 401 Certification
Subject: Red Oak Dortchess Park - 401 Certification
From: "David Rector" <[e-mail]>
Date: Wed, 18 Apr 2007 11:54:29 -0400
To: <[e-mail]>
CC: "Richard Callahan" <[e-mail]>, <[e-mail]>
Oops!! Here are the "correct" spreadsheets for Red Oak.
Annette:
Good morning. Thanks for talking with us regarding the proposed storm water
management plan for the above referenced project yesterday afternoon. Per your
suggestion, we have looked at the potential installation of bioretention areas in
order to provide additional water quality measures for impervious areas (parking,
restroom building, and tennis courts) at the park. Although we do have some available
area to provide bioretention for the restroom and tennis courts, we do not have
sufficient area for the parking lot. In order to provide bioretention for this area,
we would need to redesign the project and risk pushing the development further
eastward towards the existing wetlands that we are trying to preserve. After some
further inhouse discussions with our staff and consultants, we still do not
understand why the State would require additional best management practices for a
park and recreation project that is exempt from local or county stormwater detention
and water quality requirements. Since we are discharging into an existing roadway
ditch and not into an established buffer, why do we need to diffuse flow? Since our
proposed pond is not within a drainageway, why is a buffer or forested buffer strip
required? Attached are the completed pre and post TN/TP loading and BMP Removal
spreadsheet(s) for your review. As you will see, we are well under the nutrient
loading goals established by the State for the Tar-Pamlico River Basin.
In light of this .information, is DWQ still going to require additional stormwater
BMP's in order to issue a 401 Certification for this park and recreation project?
Please advise.
Respectfully.
David P. Rector, PE
Site Solutions
2320 West Morehead Street
Charlotte, NC 28208
Direct: 704.943.3188
Phone: [phone]
Fax: [phone]
http://www.sitesolutianspa.com/
«redoak denrcalcsht.xls »
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Tar-Pamlico StormwaterRule 15A NCAC 28.0258
Last Modified 4/18/2007
Piedmont of the Tar-Pamlico River Basin:
Includes Oxford, Henderson, Rocky Mount and Tarboro as well as Franklin, Nash and Edgecome Counties
Total Nitrogen and Total Phosphorus Loading Calculation Worksheet (Automated)
Project Name: Ilillsborough River Ft aPk (G~IrI Far°k)
Date: 4/=t/2tlll7
By: 13ar~id t'. Reerix•, Pl Checked By:
Directions (same for pre-development and post-development tables):
> Enter the acres of each type of land cover in the green boxes. The spreadsheet will calculate all of the values in light blue.
> Compare total areas of development in pre- and post- tables for consistency (bottom of column (2)), and also for consistency with
the site plans. If all of these values are not the same, there is an error that must be corrected.
> Unless drainage onto the development from offsite is diverted around or through the site, offsite catchment area draining in must
be included in the acreage values and treated.
Pre-development:

T'tpc of Land C'o~'cr' r\rea S.t'f. Formula : ~ivet•age I~AIC L,olu[trn Average laA1C :: troluri-n
(acretil 0.46+& 31 of T'V:ii} /1. 2 3 « -1 of I'P.:: 1. ~ :*:. ~ (r
Transportation impervious! 0.46 2.60 0.00 0.19 0.00
Roof mpervioos 0.46 1.95 0.00 0.11 0.00
>~Iapaged p{'YYIOU' _
~{' ~`~
0.46
1.42
11.01
0.28
2.17
!' (laivnllandsca~tedl
managed I>er~iaus
0.46
4.23
0.00
1.23
0.00
c~ o I rrrd !
(1?% )
1\lanaged lrers'iAUs
0.46
2.04
0.00
0.62
0.00
('Pasture) ',
bVoodecl perms=ious ,. ' _' 0.46 0.94 3.12 0.14 0.47
TN' IKoadrri~ `~':1oading
kraetion Impervious 41) ~-' 0.00 14.13 2.64
T;v Ekp Cvet'#' TP tsp. Coeff
Totat Area of betelopment = ~
~~ 24.07 ~ ~
(Ib/ac/t-r1,_ 0.59 ~
4lblaclyt).:: 0.11
Post-development:
'' (11 L! f21 ' ,11.31 1~1 151..: ' C6? 471'
T~pe,oi Lend Coyer 'area S.m. Formula .~vcr;tbe E\F;C', Column: 'Average!El\IC' ! Column
!arres 046#.831 ot'TIY. rn /L Z *I3 ~: .:of CY :' 1, 2 .: 3!!*.6
Tt•ansporfation inipervioi3s ._- - 1.01 2.60 4.13 0.19 0.30
Raofirnpervious ~).'!~ 1.01 1.95 0.05 0.11 0.00
Managed 1>er•Fious I ~.~fi 1.01 1.42 27.09 0.28 5.34
\1'ooded pertious ~.t,! 1.01 0.95 3.47 0.14 0.51

!Fractionlmpersious (I) -',
0.07 T1V Loading
~
34.73 TP L4admg
~
6.16
:..'.1416/vrj :~ (Ib/yr)
TN bzp C'oef€ !T`P It ~[~_ Coeff:
Tots! .Areaof Dese opment= 24.07 ~~
(tbJact~~r 1::: 1.44 ~ ~
(lbr~ctyr).:.: 0.26
Note: The nutrient loading goals are 4.0 Ib/ac/yr for TN and 0.4 lb/ac/yr for TP. If the post-development nutrient
loading is below these levels, then no BMP is necessary. Otherwise, the next worksheet calculates
post-development TN and TP loadings after BMPs are installed.