NC0023884_Permit Modification_20080421

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
April 21, 2008
Ms. Sonja Basinger
Salisbury -Rowan Utilities
1 Water Street
Salisbury, NC 28144
Subject: NPDES Permit Modification
Permit Number NC0023884
Salisbury -Rowan WWTP
Rowan County
Dear Ms. Basinger:
Division personnel have reviewed and approved your application for minor modification of the subject
permit. Accordingly we are forwarding the attached modified permit pages. These pages should be
inserted into your permit and the old ones discarded.
This modification removes the effluent monitoring requirement for Selenium. The lifting of this
monitoring requirement was based upon the results of effluent sampling that indicated this element was
not present at levels such that it would be deemed a parameter of concern.
This modification is issued pursuant to the requirements of North Carolina General Statute 143-215.1
and the Memorandum of Agreement between North Carolina and the U.S. Environmental Protection
Agency dated May 9, 1994 (or as subsequently amended).
Please note that this permit is not transferable except after notice to the Division. The Division may
require modification or revocation and reissuance of the permit. This permit does not affect the legal
requirements to obtain other permits which may be required by the Division of Water Quality or permits
required by the Division of Land Resources, the Coastal Area Management Act or any other Federal or
Local governmental permit that may be required. If you have any questions concerning this permit,
please contact Bob Sledge at telephone number [phone], extension 547.
Sincerely,
44oleen H. Sullins
cc: Central Files
Mooresville Regional Office/Surface Water Protection Section
NPDES Unit
EPA Region 4
North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 Phone [phone]
Internet: www.ncwaterqualitv.org Location: 512 N. Salisbury St. Raleigh, NC 27604 Fax [phone]
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Permit NC0023884
A. (1) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (12.5 MGD)
During the period beginning on April 21, 2008 and lasting until expansion beyond 12.5 MGD, the
Permittee is authorized to discharge from Outfall 001. Such discharges shall be limited and monitored
by the Permittee as specified below:
PARAMETER
EFFLUENT LIMITATIONS =
MONITORING REQUIREMENTS
Monthly
-
Average. -
Weeklyf
Average
Daily,
Maximum
Measurement
g
_ <Frequency z
7
Sample Type
2,.
W ra';
Sample,Location
toL�'.,.
Flow
12.5 MGD6
Continuous
Recording
Influent or Effluent
BOD, 5 day, 20 °C
(April 1 to October 31) 5
15.0 mg/L
22.5 mg/L
Daily
Composite
Influent and Effluent
BOD, 5 day, 20 °C
(November 1 to March 31) 5
30.0 mg/L
45.0 mg/L
Daily
Composite
Influent and Effluent
Total Suspended Solids5
30.0 mg/L
45.0 mg/L
Daily
Composite
Influent and Effluent
NH3 as N
(April 1 to October 31)
6.0 mg/L
18.0 mg/I
Daily
Composite .
Effluent
NH3 as N
(November 1 to March 31)
12.0 mg/L
35.0 mg/I
Daily
Composite
Effluent
-
Dissolved Oxygen2
Daily
Grab
Effluent
Fecal Coliform
(geometric mean)
200/100 ml
400/100 ml
.
Daily
Grab
Effluent
Temperature
Daily
Grab
Effluent
pH
> 6.0 and < 9.0 standard units
Daily
Grab
Effluent
Total Residual Chlorine3
28pg/L
Daily :
Grab
Effluent
TotalNitrogenWeekly
(NO2 + NO3 + TKN)
Composite
Effluent
Total Phosphorus
Weekly
Composite
Effluent
Total Silver
Monthly
Composite
Effluent
Total Copper
Monthly
Composite
Effluent -
Total Zinc -
Monthly
Composite
Effluent
Effluent Pollutant Scan7
7
7
Effluent
Chronic Toxicity4
Quarterly
Composite
Effluent
Notes:
1. Combined effluent from the Grant Creek and Town Creek treatment trains, except that flow, BOD, and TSS shall be
sampled separately at the Town Creek treatment train and the Grant Creek treatment train. BOD and TSS removal
efficiency shall be calculated by mathematically aggregating the values for the Grant Creek and the Town Creek
treatment train. (Refer to A. (6.).) -
2. The daily average dissolved oxygen effluent concentration shall not be less than 5.0 mg/L.
3. Monitoring only applies if chlorine is added to the treatment system.
4. Chronic Toxicity limit (Ceriodaphnia) at 5.3 % with testing in March, June, September and December (see A. (4)).
5. The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed 15% of the respective
influent value (85% removal).
6. 7.5 MGD at Grant Creek treatment train. 5.0 MGD at Town Creek treatment train.
7. - Effluent pollutant scan must be done three times with seasonal variation before next permit application. See A. (8).
There shall be no discharge of floating solids or visible foam in other than trace amounts.

Permit NC0023884
A. (2) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (20 MGD)
During the period beginning after expansion beyond 1-2.5 MGD and lasting until expiration, the
Permittee is authorized to discharge from Outfall 001. Such discharges shall be limited and monitored
by the Permittee as specified below:
k. "..:,;,1",,,,,,-.
MToEts.
,EU
INS
A t x , 7tN.y
NITORINGREQUIREIVIETS
�t^Averages
Monthly.Weekly
Average
Daily.s
Maximum:
x Measurement
r .,_ �, ,
„ Frequency. 's
`-"� �'�'
Sam le Tye
pr :R p..._
„ � �, is �I
� Samn ple Locatio
Flow
20 MGD
Continuous
Recording
Effluent
BOD, 5 day, 20 °C
(April 1 to October 31) 5
5.0 mg/L
7.5 mg/L
Daily
Composite
Influent and Effluent
BOD, 5 day, 20 °C .
(November 1 to March 31) 5
10.0 mg/L
15.0 mg/L
Daily
Composite
Influent and Effluent
Total Suspended Solids5
30.0 mg/L
45.0 mg/L
Daily
Composite
Influent and Effluent
NH3 as N
(April 1 to October 31)
1.0 mg/L
3.0 mg/L
Daily
Composite
Effluent
NH3 as N
(November 1 to March 31)
2.0 mg/L
6.0 mg/L
Daily
Composite
Effluent
Dissolved Oxygen2
Daily
-Grab
Effluent
Fecal Coliform
(geometric mean)
200/100 ml
400/100 ml
Daily
Grab
Effluent
Temperature
Daily
Grab
Effluent
pH
> 6.0 and < 9.0 standard units
Daily
Grab
Effluent
Total Residual Chlorin e3
28 pg/L
Daily
Grab
Effluent
Total Nitrogen
(NO2+NO3+TKN)
Weekly
Composite
Effluent
'
Total Phosphorus
Weekly
Composite -
Effluent
Total Silver
Monthly
Composite
Effluent
Total Copper
Monthly
Composite
Effluent
Total Zinc
Monthly
Grab
Effluent
Effluent Pollutant Scan6
6
6
Effluent
Chronic Toxicity4
Quarterly
Composite
Effluent
Notes:
1. Sample locations: Effluent - Combined Effluent from Grant Creeks and Town Creek
2. The daily average dissolved oxygen effluent concentration shall not be less than 5.0 mg/L.
3. Monitoring only applies if chlorine is added to the treatment system for disinfection.
4. Chronic Toxicity limit (Ceriodaphnia) at 4 % with tests in March, June, September and December (see A. (5)).
5. The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed 15% of the respective
influent value (85% removal).
6. Effluent pollutant scan must be done three times with seasonal variation before next permit application. See A. (8).
There shall be no discharge of floating solids or visible foam in other than trace amounts.

February 22, 2008
Mr. Matt Matthews
NCDENR/ DWQ/ PSB Supervisor
1617 Mail Service Center
Raleigh, NC 27699-1617
Re: Salisbury -Rowan WWTP NPDES Permit NC0023884
Removal of Selenium Permit Requirement
Dear Mr. Matthews,
RECEIVED
FEB 2 6 2008
DENR - WATER OUALI1Y
POINT SOURCE BRANCH
Salisbury -Rowan Utilities (SRU) submits the following effluent selenium data for the
subject permit to demonstrate that selenium is not a pollutant of concern, and requests the removal
of the selenium requirement from our permit per Permit Condition A (1) Effluent Limitations and
Monitoring Requirements, footnote 8.
Date
ug/1
10/4/2006
<
10.0
11/1/2006
<
10.0
12/1/2006
<
10.0
1/2/2007
<
10.0
2/7/2007
<
10.0
3/7/2007
<
10.0
4/4/2007
<
10.0
5/16/2007
<
10.0
6/6/2007
<
10.0
7/10/2007
<
10.0
8/1/2007
<
10.0
9/4/2007
<
10.0
10/2/2007
<
10.0
11/6/2007
<
10.0
12/4/2007
<
10.0
1/2/2008
<
10.0
1 Water Street Telephone [phone]
Salisbury, NC 28144
Salisbury -Rowan Utilities Fax [phone]

Please contact me at [phone] if you require any additional information, and I
appreciate your assistance in this matter.
Sincerely,
Sonja Basinger
Environmental Services Manager
cc: Rob Krebs, Mooresville Regional Office
Mike Frick, Plant Operations Manager
1 Water Street Telephone [phone]
Salisbury, NC 28144
Salisbury -Rowan Utilities Fax [phone]