NC0081621_More Information Requested_20180504

Water Resources
Environmental Quality
June 4, 2018
Certified Mail # 7016 2140 0000 4371 0745
Return Receipt Request
Mr. Charles A. Willis, P.E.
Willis Engineers
10700 Sikes Place
Charlotte, NC 28277
Subject: Request for Additional Information
NPDES Application NCO081621
Muddy Creek WWTP
Dear Mr. Willis:
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
LINDA CULPEPPER
Interim Director
The Division received two permit applications for the Muddy Creek WWTP. One for renewal of the existing
facility and the other one is for a new permit for the future facility. It appears that both facilities will serve
the Town of Midland residents. After reviewing your permit applications and the Engineering Alternative
Analysis (EAA), both applications will be considered as one (a renewal/expansion). The permit for both
facilities would include three flow tiers; the current 0. 15, 0.3 and if the expansion is approved, an additional
tier of 1.0 MGD will be added as the ultimate capacity.
To enable us to complete our review in accordance with N.C.G.S. 143-215.1 and 15A NCAC 2H.0105,
please provide additional or revised information to address the following comments:
EAA:
1. What is the current and projected population within the service area by the year 2040 (data from
NC Census)? Based on the projected population, please estimate the projected flow in accordance
with the EAA Guideline Document. The EAA Guidance Document is attached for your reference
and please see page 3 of 8 on how to determine Municipal Flow Projections.
2. Please provide an acceptance or rejection letter from Rocky River WWTP in regard to alternative
A- Connection to existing Wastewater Treatment Facility in your EAA.
3. The EAA states that the ultimate capacity of the proposed facility is 1.5 MGD (page 7) - please
confirm the ultimate capacity will be 1 MGD as discussed over the phone with Julie Grzyb. In
addition, please confirm that the existing facility will be taken off-line after the new facility
becomes operational. Note that the Municipal Flow Projection must justify the ultimate capacity
being requested.
4. Both applications give the same longitude and latitude for the Outfall location. Is this correct (i.e.
will the new plant discharge through the existing outfall)? Will the outfall have to be resized? If
the new facility will not discharge through the existing Outfall, please explain and provide details
on the proposed location.
State of North Carolina I Environmental Quality
1611 Mail Service Center I Raleigh, North Carolina 27699-1611
919-707-9000

Permit Application:
5. Your speculative limits request dated back on November 2, 2015 had an updated USGS summer
7Q10 value but missing the updated winter 7Q10 value. Please provide the updated USGS winter
7Q10 value for the receiving stream.
BioWin Results:
In the results and discussion section of the BioWin, it is obvious that the facility without the tertiary
filtration will not meet the speculative limit of 5 mg/L for BOD5, which is different than the conclusion
drawn in the EAA. Based on the BioWin results; with tertiary treatment the effluent BOD5 is 4.8 mg/L vs
5.3 mg/L without tertiary treatment; therefore, any proposed facility should have tertiary treatment in order
to meet the speculative limits for BODS. Please review this conclusion and reassess plant costs with tertiary
treatment if needed to meet a BOD5 limitation of 5 mg/L. Provide an explanation on your conclusion if
tertiary treatment is not added.
If no response is received August 1, 2018 [per 15A NCAC 211.0107(b)], the project will be deactivated and
withdrawn from our review process and the documents will be recycled. If you have any questions, please
contact me at 919-807-6396 or email at [e-mail].
Sincerely,
Qais Banihani, Environmental Engineer
NPDES Complex Unit
Division of Water Resources/NCDENR
cc: Mr. John W. Ritchie, Wastewater Operations Manager, WSACC
Mr. Timothy R. Kiser, P.E., Engineering Director, WSACC
Mr. T. Mark Fowler, Facilities Director, WSACC
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