NC0021121_permit modification_20080523

May 23, 2008
Don Brookshire
Town of Mount Airy
P.O. Box 70
Mount Airy, NC 27030-0070
Michael F. Easley, Governor
William G. Ross Jr.,
y
North Carolina Department of Environment and Natural Resources
Coleen H. Sullins, Director
Division of Water Quality
Subject: Monitoring for High Rock Reservoir (Permit - NC0021121)
Total Maximum Daily Load (TMDL) Study (chlorophyll a and turbidity)
Dear Mr. Brookshire:
The Division of Water Quality (DWQ), in partnership with the Yadkin Pee -Dee River Basin
Association (YPDRBA), has begun monitoring of the High Rock Reservoir watershed for the
purpose of chlorophyll a and turbidity TMDL development, as of April 2008. The monitoring
is scheduled to last for two years (April 1, 2008 - March 31, 2010).
Ms. Kathy Stecker, Supervisor, Modeling and TMDL Unit, discussed additional effluent
monitoring needs for NPDES dischargers at the YPDRBA meeting held October 5, 2007.
These increased nutrient and turbidity monitoring needs are not currently included in your
facility's permit effluent monitoring requirements. Members of YPDRBA have agreed to
perform the additional monitoring for the duration of the two-year study, in order to supply
sufficient data to perform a comprehensive TMDL for High Rock Lake. Although your permit
is not being reopened to include this additional monitoring, should the voluntary monitoring
falter, the Division will reconsider this decision to include the additional monitoring for the
time necessary.
The additional effluent monitoring requirements for your facility are:
Parameter Description
TKN as N (mg/L)
NO2+NO3 (mg/L)
Nitrogen, Total (as N)
(mg/L)
Turbidity (ntu)
Parameter
Code
00625
00630
00600
00076
North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 Phone [phone] Customer Service
Location: www.ncwaterquality.oro 512 N. Salisbury St. Raleigh, NC 27604 Fax [phone]
An Equal Opportunity/Affirmative Action Employer — 50% Recycled/10% Post Consumer Paper
Measurement
Frequency
Monthly
Monthly
Monthly
Weekly
Sample Type Sample
Location
Effluent
Effluent
Effluent
Composite
Composite
Composite
Grab
Effluent
N4°ehCarolina
dvatura/fy

Additional Monitoring for High Rock Lake
Page 2
Thank you for your cooperation and assistance with this monitoring effort. This data will be
invaluable to model development and improve model predictions. If you have any questions,
please contact Ms. Susan A. Wilson, ext. 510 (Supervisor, Western NPDES Program) or Ms.
Kathy Stecker , ext. 505.
Sincerely,
oleen H. Sullins
cc: Winston-Salem Regional Office / Steve Tedder
Central Files
NPDES Files
TMDL and Modeling Unit, Planning Section
Jennie Atkins, Environmental Sciences Section