SW3190701_Add Info Request_20190731

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Director
Mitchell S. Latham, PE
16507-A Northcross Drive
Huntersville, NC 28078
NORTH CAROLINA
Environmental Quality
July 31, 2019
Subject: Request for Additional Information
Stormwater Permit No. SW3190701
Harwood Automotive
Cabarrus County
Dear Mr. Latham:
The Division of Energy, Mineral and Land Resources (DEMLR), received a Stormwater
Management Permit Application for the subject project on July 1, 2019. A review of that
information has determined that the application is not complete. The following information is
needed to continue the stormwater review:
Please correct the project type in Section II, 2. The definition of what constitutes a low
density project is more nuanced than the stormwater management report indicates. This
project has not been designed to maximize dispersed flow and minimize channelization
[15A NCAC 2H .1003(2)(b)] and therefore does not qualify as low density. More
information about low density projects can be found at the following link:
hgps://files.nc. gov/ncdeq/Energy%20Mineral%20and%2OLand%2OResources/Stormwate
rBMP%20Manual/E-1 %20Low%2ODensity%20FINAL.pdf
2. For this project, the applicant should be either the organization (Harwood Automotive,
Inc.), or the property owner (Wendy Harwood). If the organization will be the applicant,
the application must be signed by someone in the company that is at the level of vice
president or higher (Ms. Harwood is listed as a secretary). If the property owner will be
the applicant, Section III, La should be the property owner, not the company (Section III,
1). Ensure that all other sections of the application coincide with this one.
3. Please correct the stormwater management summary to coincide with Comment 1
(Section IV, 1).
4. Please include the total surface water area for this site (Section IV, 6). All surface waters
located on site, including the existing pond, must be accounted for in this area and
D EQ North Carolina Department of Environmental Quality I Division of Energy, Mineral and Land Resources
512 North Salisbury Street 1 1612 Mail Service Center I Raleigh, North Carolina 27699-1612
NORTH CAROLINA _
o.PaWnamofEnvironmental Qualify /� 919.707.9200

excluded from the percent impervious area calculation. Please also recalculate Section
IV, 7 and Section IV, 8 to reflect this.
5. For this project, only one drainage area column, the area draining to the SCM, is required
in this table (Section IV, 10).
6. Please complete a Supplement EZ form for the proposed SCM. The Supplement EZ form
can be found here: hgps:Hdeq.nc.gov/about/divisions/energy-mineral-land-
resources/energy-mineral-land-permit-guidance/stormwater-bmp-manual (Section V).
7. Please provide calculations showing that the inlet to the SCM is stable and riprap at the
outlet of the SCM is sized to prevent erosion during the peak flow from the 10-year
storm, in accordance with 15A NCAC 02H .1050(4) (Section VI, 7).
8. Please identify all surface waters on the plans (Section VI, 8, h).
9. Please delineate the wetlands on the plans or provide a note stating that no wetlands exist.
Provide documentation of the qualifications and identity of the individual who made this
determination (Section VI, 8, m).
10. Please show the drainage areas for the proposed SCM on the plans (Section VI, 8, o).
Please also clarify if the existing pond is currently providing any stormwater
management.
11. Please provide a map of the soil boring locations, soil boring logs, and a soils map
(Section VI, 9).
12. Sod is not an acceptable covering for the sand chamber. The entire surface area of the
sand chamber must contain sand (Sand Filter MDC 6).
13. The drawdown rate of the sand filter must be at least 2.0 inches per hour (Sand Filter
MDC 8). The stage -discharge data sheet shows the infiltration rate to be 1.75 inches per
hour (3.5 ft/day = 1.75 in/hr.) and the narrative indicates that the first inch of rainfall
takes 40 hours to drain. Since the filter is 18 inches deep, the infiltration rate is 0.45 in/hr.
(18 in/40hrs.). Please revise for consistency and compliance.
14. Provide pdfs of all revisions, 2 hardcopies of revised plan sheets, and 1 hardcopy of other
documents. Pdfs must be uploaded using the form at:
https://edocs.deq.nc.gov/Forms/SW Project —Submittal
While it is not required, it is recommended that:
- The offsite drainage areas be diverted around the proposed SCM since the applicant
cannot maintain control over property that they do not own. An increase in off -site BUA
can overwhelm the SCM and make it non -compliant.
- That the amount of pervious area that drains to the SCM be limited. Since a filtering
practice is proposed, limiting the pervious area will help reduce the fine particles that
enter the facility. Fine particles can cause the filter to become clogged which will
necessitate maintenance.

Please note that this request for additional information is in response to a preliminary review.
The requested information should be received by this Office prior to August 30, 2019, or
the application will be returned as incomplete. The return of a project will necessitate
resubmittal of all required items, including the application fee. Please reference the State
assigned project number SW3190701 on all correspondence.
If you need additional time to submit the information, please submit your request for a time
extension to the Division at the contact below. The request must indicate the date by which you
expect to submit the required information. The Division is allowed 90 days from the receipt of
a completed application to issue the permit.
The construction of any impervious surfaces, other than a construction entrance under an
approved Sedimentation Erosion Control Plan, is a violation of NCGS 143-215.1 and is subject
to enforcement action pursuant to NCGS 143-215.6A.
If you have any questions concerning this matter please feel free to contact me at
[e-mail] or [phone].
Sincerely,
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Jim Farkas
Environmental Engineer
Stormwater Program
cc: Mooresville Regional Office