NC0069841_Permit (Modification)_20070116

NPDES DOCUMENT SCANNING COVER SHEET
NPDES Permit:
NC0069841
Crooked Creek WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Technical Correction
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
January 16, 2007
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Michael F. Easley, Governor
oF\N A1F9
Ms. Christie L. Putnam, P.E.
Union County Public Works
400 North Church Street
Monroe, North Carolina 28112
Dear Ms. Putnam:
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Alan W. Klimek, P.E. Director
Division of Water Quality
January 16, 2007
Subject: NPDES Permit Modification
Permit Number NC0069841
Crooked Creek WWTP
Union County
The Division of Water Quality (DWQ) issued NPDES Permit NC0069841 to Union County Public Works
for the operation of Crooked Creek WWTP on May 20, 2005. On December 4, 2006, the DWQ received your
Permit Modification Letter requesting deletion of the Selenium limit and monitoring requirements. You supplied
test results, which reflected Selenium levels below 5ug/L from June 2005 to October 2006.
In accordance with our review, the Division is forwarding herewith a modification to the subject permit
and has removed the Selenium parameter from this modified effluent page. This new effluent page should be
inserted into your existing permit. This permit 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 take notice that this permit is not transferable. This permit does not affect the legal requirement to
obtain other permits which may be required by the Division of Water Quality or permits required by the Division of
Land Resources, Coastal Area Management Act or any other Federal or Local government permit that may be
required.
If you have any questions concerning this permit, please contact Bob Guerra at telephone number (919)
733-5083, extension 539.
Sincerely,
6,1--Alan W. Klimek, P.E.
cc: Central Files
Mooresville Regional Office / Surface Water Protection
NPDES Unit
North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 Phone [phone]
Internet: www.ncwaterquality.org Location: 512 N. Salisbury St. Raleigh, NC 27604 Fax [phone]
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A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
During the period beginning on the effective date of the permit and lasting until expiration, the Permittee is
authorized to discharge treated wastewater from outfall(s) 001. Such discharges shall be limited and monitored
by the Permittee as specified below:
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Flow
1.9 MGD
Continuous
Recording
I or E
BOD, 5-day, 20 °C2
(April 1- October 31)
5.0 mg/1
7.5 mg/1
3/Week
Composite
I,E
BOD, 5-day, 20 °C2
(November 1- March 31)
10.0 mg/I
15.0 mg/1
3/Week
Composite
I,E
Total Suspended Solids2
30.0 mg/1
45.0 mg/1
3/Week
Composite
I,E
NH3-N
(April 1- October 31)
2.0 mg/1
6.0 mg/L
3/Week
Composite
E
NH3-N
(November 1- March 31)
4.0 mg/1
12.0 mg/L
3/Week
Composite
E
Total Residual Chlorines
17 µg/L
28.0 µg/L
3/Week
Grab
E
Total Nitrogen
(NO2 + NO3 + TKN)
Monthly
Composite
E
Total Phosphorus
Monthly
Composite
E
Total Copper
Monthly
Composite
E
Chronic Toxicity!
Quarterly
Composite
E
pHs
3/Week
Grab
E
Dissolved Oxygen
3/Week
Grab
E,U, D
Fecal Coliform7
'200/100 m1
400/100 ml
3/Week
Grab
E,U, D
Temperature
Daily
Grab
E, U,D
~Conductivity
3/Week
Grab
U,D
Footnotes:
1. Sample Location: E - Effluent, I - Influent, U - Upstream 50 feet from the outfall, D - Downstream 1 mile below
discharge and at SR 1514. Upstream and Downstream samples shall be grab samples. In -stream samples shall be
collected three times per week during June, July, August, and September and once per week during the rest of the
calendar year. Instream monitoring is provisionally waived in light of the permittee's participation in the Yadkin -Pee
Dee River Basin Association. Instream monitoring will be immediately reinstated should the permittee end its
participation in the Association.
2. The monthly average effluent BOD5 and Total Suspended Residue concentrations shall not exceed 15% of the respective
influent value (85% removal).
3. TRC limit and monitoring requirement only apply if chlorine is used for disinfection.
4. Chronic Toxicity (Ceriodaphnia) P/F at 90%: February, May, August, and November (see Part I. A. (2.)).
5. The pH of the effluent shall not be less than 6.0 nor greater than 9.0 (on the standard units scale)
6. The daily average dissolved oxygen effluent concentration shall not be less than 6.0 mg/1.
7. Fecal Coliform shall be calculated using the geometric mean, according to the procedure detailed in Part II. Section A,
Paragraph 9b.
There shall be no discharge of floating solids or foam visible in other than trace amounts.

UNION COUNTY PUBLIC WORKS
Christie L. Putnam, P.E., Director
November 29, 2006
Toya Fields, Environmental Engineer
NCDENR — DWQ
NPDES Unit
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Em©ED-§[Ep
DEC 0 4 2006
DENR - WATER QUALITY
POINT SOURCE BRANCH
SUBJECT: Discontinuance of Monitoring Request - Effluent Selenium
Crooked Creek WWTP - NC0069841
Union County
Dear Ms. Fields:
Union County Public Works (UCPW) was issued NPDES Permit NC0085359 with an
effective date of July 1, 2005. Section A (1) of the Permit requires monthly monitoring
of Total Selenium. Footnote No. 4 allows the parameter to be deleted upon written
notification from your unit. Please accept this letter as a formal request to delete the
monitoring requirement for Total Selenium from our permit. UCPW feels that monthly
sample results dating back to June 2005 support this request.
UCPW had our contracted laboratory, Pace Analytical, analyze our effluent for selenium
18 times since June 2005. All results have been below the analytical method detection
level. Please find a recap of the monitoring results in the table below:
Crooked Creek Creek WWTP
Effluent Total Selenium Concentrations (ug/1)
DATE
CONCENTRATION (ug/l)
6-3-05
<5
7-1-05
<5
8-9-0-5
<5
9-6-05
<5
10-14-05
<5
11-2-05
<5
12-1-05
<5
1-6-06
<5
2-14-06
<5
3-16-06
<5
4-12-06
<5
5-9-06
<5
400 North Church St. • Monroe, North Carolina 28112-4804 • Phone: [phone] • Fax: [phone]

Crooked Creek WWTP
Effluent Total Selenium Concentrations (ug/I)
(continued)
DATE
CONCENTRATION (ug/I)
5-12-06
<5
6-8-06
<5
7-6-06
<5
8-8-06
<5
9-22-06
<5
10-27-06
<5
As can be seen from the monitoring results, selenium should not be a pollutant of
concern for the Crooked Creek facility. There are no known significant industrial users
discharging into the Crooked Creek WWTP and therefore no suspect contributors of
selenium. The facility consistently passes Chronic Toxicity testing.
UCPW appreciates your consideration of the request to remove the monitoring
requirement for selenium from our NPDES permit. If additional information is required
please do not hesitate to contact Mark Tye at [phone] or e-mail
ivi I YE(d)co union.nc.us
Respectfully,
hristie L. Put am, PE
Director of Public Works
CC: Mark Tye, UCPW
John Hahn, UCPW
Jim Struve, Hazen & Sawyer