20070776 Ver 2_More Info Received_20071109

t - O~o~ W AT ~9pG
O `c'
Michael F. Easley, Governor
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Coleen H. Sullins, Director
Division of Water Quality
November 9, 2007
CERTIFIED MAIL: RETURN RECEIPT REQUESTED
Waynesville Commons Retail Associates, LLC
Attn: David Scarnati
1765 Merriman Road
Akron, OH 44313
Subject Property: Waynesville Commons
DWQ EXP No. 07-0776v2
Haywood County
REQUEST FOR MORE INFORMATION (STORMWATER MANAGEMENT PLAN) -
EXPRESS REVIEW
Dear Mr. Scarnati:
On October 22, 2007 the Division of Water Quality (DWQ) issued a 401 Water Quality Certification to
impact 521inear feet of perennial stream for the purpose of constructing a commercial development
described in your application dated Apri125, 2007. In order to meet Condition 9 of the 401 Certification
for this project, a stormwater management plan was submitted to the Express Review Program of the
DWQ on November 6, 2007. The DWQ has determined that your application will require additional
information and clarification. Please provide the following information so that we may continue to
review your project and prevent denial of your application as required by 15A NCAC 2H .0506:
Additional Information Requested
1. General Information
a. The applicant must provide. his/her title as requested in Item 2 under Section I (General
Information) of the PCN Form.
b. On the page with summary of Pre- and Post-Construction design discharge data, please
explain how the Post-Construction totals of 151.41 ft3/s and 315.95 ft3/s were obtained
respectively for the 10-year and 100-year storms. The design discharges provided on that
page do not add up to the reported totals.
c. Please clarify if there are two Bioretention cells on this project as reported under Section 2.0
(Basis of Design) in the report. Reference is made to Bio-Basin A and Bio-Basin C, but only
information on Bioretention cell C is provided. If the Grassed Swale is referred to as Bio-
Basin A, please refer to each BMP by its appropriate name.
d. In order to obtain the required regulat©ry credits, each BMP must be designed such that, at a
minimum, it meets all the requirements in the North Carolina Division of Water Quality
Stormwater Best Management Practices Manual.
e. Please organize the site plan sheets and number your report when submitting any additional
information for easy reference, and to make it easy to follow.
401 Oversight I Express Review Permitting Unit
1650 Mail Service Center, Raleigh, North Carolina 27699-1650
2321 Crabtree Boulevard, Suite 250, Raleigh, North Carolina 271104
Phone: [phone] /FAX [phone]nternet: http://h2o.enr.state.nc.us/ncwetlands
No°° Carolina
~atcrra!!y
An Equal OpportunitylAffirmative Action Employer - 50% Recycled110% Post Consumer Paper

Waynesville Commons Stormwater Management Plan
Page 2 of 4
November 9, 2007
2. Runoff from Roof of Wal-Mart Building
a. Direct discharge of untreated stormwater runoff to the Creek is not acceptable. Please direct
the runoff from the roof of the Wal-Mart building to an appropriate BMP in order to achieve
the required treatment prior to discharging into the Richland Creek.
3. Extended Dry Detention Basin
a. On some pages in the report, such as the page with the chart for the Rip-Rap sizing and the
page with Table 3, Extended Dry Detention Basin has been referred to as Stormwater
Wetland. Please note that they are two different BMPs, have different design requirements,
and provide different treatment levels.
b. Please provide a different BMP for drainage districts SS and 7S. Please note that a stand-
alone Extended Dry Detention Basin does not meet the 85% TSS, 30% TN and 30% TP
treatment levels required for a site draining to Trout Waters per the Stormwater
Management Plan (SMP) Requirements for Applicants other than the North Carolina
Department of Transportation. Please refer to the following site for more information
http: //h2o. en r.state. nc. u s/ncwetlands/documents/SMPRequrementsforAppl icantsothe rthanN
CDOT.pdf
'y°f' 1a
4. Grassed Swale
a. If the Grassed Swale is referred to as Bio-Basin A, please use its appropriate name
throughout the report.
b. Please provide detail information on the grassed Swale, including all required items on the
Grassed Swale Supplement.
c. Much of the required information listed in the Required Items Checklist for the Grassed
Swale is not provided on plans (Sheet Nos. 1.0, 2.0, 3.8, L1-L3, and 3.8). These include
Swale dimensions, detail cross sections, grass species, recorded drainage easement and public
right of way (ROW), SHWT level(s), Freeboard levels, longitudinal slope, and maintenance
access.
5. Sand Filter A
a. Please explain how the storage volume of 222,048 ft3 was obtained for Sand Filter A as
indicated in Table 3 of the report.
b. Please note that the drainage area to the Sand Filter (approximately 7 acres) exceeds the
maximum allowable drainage area to a Sand Filter (Sacres) as stipulated in Chapter 11 of the
North Carolina Division of Water Quality Stormwater Best Management Practices Manual.
Please reduce the drainage area or choose another BMP.
c. Please note that the average head on the Sedimentation basin and sand filter (hA) cannot
exceed the maximum head on the Sedimentation basin and sand filter (h~~ilter)• Generally,
hA = 0.5 * hMaxFilter
d. The surface area provided for the sedimentation basin (96 ft2) is far less than the required
minimum surface area (1500 ftz per our calculations)
e. Please explain how you obtained the Time to drain the sand filter (t = 6.66 hours). Our
calculation shows that t = 16 hours.
£ Much of the required information listed in the Required Items Checklist is not provided on
plans (Sheet Nos. 3.3, 3.6, and 3.8). These include system dimensions for the sedimentation
basin, flow splitting device, recorded drainage easement and public right of way (ROW),
clearance from the surface of the sand filter to the bottom. of the roof of the underground
structure, SHWT level, and maintenance access.
6. Sand Filter B
a. Please address comments 5(c) - 5(f) under Sand Filter A as applicable to Sand Filter B.

Waynesville Commons Stormwater Management Plan
` Page 3 of 4
November 9, 2007
7. Bioretention C
a. Please explain why the total drainage area and impervious area for Drainage District 2S are
stated in Table 3 of the report as 177,527 ftZ and 126,498 ftZ respectively instead of 364,468
ftZ and 298,190 ft2 as in the HydroCAD SAMPLER Report.
b. Revise your project information table -item # 6 to read Drainage Area 1S + 2S. Additionally,
how do the impervious areas for 1 S and 2S from the HydroCAD SAMPLER Report add up to
378,427 ftZ?
c. Per the current version of the North Carolina Division of Water Quality Stormwater Best
Management Practices Manual, the ponding depth cannot exceed 12 inches. Please revise the
ponding depth of 24 inches provided.
d. On page 2 of BMP supplement, the Planting Plan seems to be inconsistent with the type of
cell proposed. A grass cell is proposed while the number of trees and shrubs are specified. If a
grass cell is proposed, it must specify the use of centipede sod.
e. Design Volume using the Simple Method for the total drainage area 384,343 ftZ, with 98.5%
imperviousness, and 1.0 inch of rainfall exceeds the volume given on the supplement sheet.
f. Calculate the surface area when the correct design volume has been computed, and a desired
ponding depth has been selected.
g. Calculations for sizing the underdrain pipes must be provided.
h. Please provide soil report(s) for both the planting soil and the insitu soil (based on actual field
investigation) that includes the information specified in item 4 of the Required Items
Checklist. In particular, for the insitu soil, description of soil layers to a depth lft below the
SHWT will be useful.
i. Infiltration rate of selected soil media (6 in/hr) is too high. Please select soil mix with lower
permeability (preferably 1-2 in/hr, since media depth of 2ft is too low) to achieve longer drain
time and to allow more contact time between the water and the soil media.
j. Calculation of drawdown times seems incorrect. Please explain how the stated values were
obtained.
k. Fertilizer Application Rate: Since the purpose of the Bioretention Cell is to reduce nutrients
in the watershed, DWQ will allow a,aper~;me only application of fertilizer for the initial
establishment of vegetation.
1. Much of the required information listed in the Required Items Checklist is not provided on
plans (2.0, 3.0, L1-L3) and/or plans are not at the correct scale. Also information provided on
sheet No. 3.8 is inadequate. Please provide detailed information on the pretreatment device
(all three types have been checked in the Required Items Checklist), recorded drainage
easement and public right of way (ROW), source of Nursery for the specified plants,
maintenance access, and boundaries of drainage easement.
Please respond within five (5) days of the date of this letter by sending two (2) copies of the above
information in writing. The Express Review Program .is~a process that requires all parties to participate in a
timely manner. `
This letter only addresses the application review and does not authorize any impacts to wetlands, waters
or protected buffers. Please be aware that any impacts requested within your application are not
authorized (at this time) by the DWQ.
Please contact Joseph Gyamfi or Lia Myott at 919-733-1786 if you have any questions regarding or
would like to set up a meeting to discuss this matter.
r~,,rF

Waynesville Commons Stormwater Management Plan
' Page 4 of 4
November 9, 2007
Sin ely,
Cyndi.Karoly, Supervisor
401 OversightlExpress Review Permitting Unit
CBK/jg
cc: Loretta Beckwith, USACE Asheville Regulatory Field Office
Kevin Barnett, DWQ Asheville Regional Office
File Copy
Central Files
Charles Christy, P.E., Wade Trim, Inc., Two.,Tgwn Square Blvd, Suite 245, Asheville, NC
28803
.., ,,
i~~ .-