NC0069841_Permit (Modification)_20110216

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
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
February 16, 2011
This document is printed on reuse paper - ignore any
content on the resrerse side

•
ern
CD NENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins Dee Freeman
Governor Director Secretary
February 16, 2011
Mr. Mark Tye
Union County Public Works
500 North Main Street, Suite 500
Monroe, NC 28112
Subject: Permit Monitoring Revision for Crooked Creek WWTP #2
NPDES Permit NC0069841
Union County
Dear Mr. Tye:
Division personnel have reviewed your request to remove the monitoring requirement for
Tetrachloroethylene from the Crooked Creek WWTP #2 permit. A review of the data collected from October
2009 through October 2010 demonstrates that the discharge from the facility shows no reasonable potential to
violate Water Quality Standards for this pollutant. As permitted by your permit the monitoring requirements and
limit for TCE have been removed.
We are forwarding you the new Section A. (1.) Effluent Limitations and Monitoring Requirements page.
You should replace your existing Effluent Limitations and Monitoring Requirements sheet with this revised page.
This permit correction 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
October 15, 2007 (or as subsequently amended).
If any parts, measurement frequencies or sampling requirements contained in this permit correction are
unacceptable to you, you have the right to an adjudicatory hearing upon written request within thirty (30) days
following receipt of this letter. This request must be. in the forth of a -written petition, conforming to Chapter
150B of the North Carolina General Statutes, and filed with the Office of Administrative Hearings (6714 Mail
Service Center, Raleigh, North Carolina 27699-6714). Unless such demand is made, this decision shall be final
and binding.
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
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
Location: 512 N. Salisbury St Raleigh. North Carolina 27604
Phone: [phone] FAX:[phone] Customer Service: 1-877-623-6748
Internet: www.ncwaterquality.org
- An Equal Opportunity 1 Affirmative Action Employer
One
NorthCarolina
`�Vatura!!y

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 Julie Grzyb at telephone number [phone].
Si.. ere ly,
ost&
leen . Sullins
Enclosure NC0069841 Modified page
cc: NPDES Unit
Central Files
Mooresville Regional Office/Surface Water Protection
e-copy:
Aquatic Toxicology
ESS, Carrie Ruhlman
EPA Region IV
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
Location: 512 N. Salisbury St. Raleigh, North Carolina 27604
Phone: [phone] FAX: [phone] Customer Service: 1-877-623-6748
Internefwwyv.ncwaterquality.O g
An Equal Opportunity 1 Affirmative Action Employer
NorthCarolina

Permit NC0069841
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
hwr1.
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:
EFFLUENT
CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Weekly
Average
Daily
Average
Measurement
Frequency
Sample
Type
Sample
Location'
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/1
15.0 mg/I
3/Week
Composite
I,E
Total Suspended Solids2
30.0 mg/1
45.0 mg/1
3/Week
Composite
I,E
NI-13-N
(April 1- October 31)
2.0 mg/1
6.0 mg/L
3/Week
Composite
E
NI-13-N
(November 1- March 31)
4.0 mg/1
12.0 mg/L
3/Week
Composite
E
Total Residual Chlorin&
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
Total Zinc
Monthly
Composite
E
Chronic Toxicity'
Quarterly
Composite
E
Effluent Pollutant Scans
Annually
Composite
E
pl-I
Between 6.0 to 9.0 standard units
3/Week
Grab
E
Dissolved Oxygen
3/Week
Grab
E,U, D
Fecal Coliform (geometric mean)
200/100 ml
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 1/4 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 Section A. (2.)).
5. Effluent Pollutant Scan annually for all parameters listed in Section A. (3.).
6. The daily average dissolved oxygen effluent concentration shall not be Tess than 6.0 mg/I.
There shall be no discharge of floating solids or foam visible in other than trace amounts.

REASONABLE POTENTIAL ANALYSIS
Crooked Creek WWTP #2
NC0069841
Time Period 0
Qw (MGD) 1.9
7Q1OS (cfs) 0
7Q10W (cfs) 0.2
30Q2 (cfs) 0.4
Avg. Stream Flow, QA (cfs) 13
Rec'ving Stream North Fork Crooked Creek
WWTP Class III
IWC(%)@7Q10S 100
@ 7Q10W 93.641
@ 30Q2 88.042
@ QA 18.47
Stream Class C
Outfall 001
Qw = 1.9 MGD
PARAMETER
TYPE
(1)
STANDARDS&
CRITERIA (2)
PQL
Units
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
NC WQS/
Chronic
Y2 FAV/
Acute
n
# Det.
Max Prod Cw
Allowable Cw
Tetrachloroethylene
C
3.3
ug/L
14
1
8.6
Acute:
Chronic:
N/A
18
North Carolina Human Health Standard 3.3 ug/L
Recommend monthly monitoring,_ after 12 months permittee
can request parameter be removed from permit if ND,
otherwise, the provisional limit of 18 ug/L will take effect.
Copper
NC
7
AL
7.3
ug/L
28
22
41.3
Acute:
Chronic:
7
7
Reasonable potential to exceed stds.
No limit as this is an action level parameter
Maintain monitoring.
* Legend:
C = Carcinogenic
NC = Non -carcinogenic
A = Aesthetic
** Freshwater Discharge
Sample recommendations:
Msg00
< No Data Entered >
Daily max limit
Msg01
MaxPredCw < Acute
Monitor 1/month
Msg02
MaxPredCw < Chronic
Monitor 1/week
Msg03
MaxPredCw « Acute
Monitor 2/month
Msg04
MaxPredCw « Chronic
Monitoring not necessary in permit
Msg05
MaxPredCw > Acute
No limit
Msg06
MaxPredCw > Chronic
No limit - assuming no tox (Action Level parameter)
Msg07
MaxPredCw» Acute
No limit (Action Level parameter)
Msg08
MaxPredCw» Chronic
Continue to monitor at 2/month
Msg09
No acute standard or 1/2 FAV
Mo. avg. limit (keep wk. avg. if existing)
Msg10
No chronic standard or criterion
Revise daily max. limit
roof eo t;reeK r<NH LUVy.xIS, rpa
2/11/2011

REASONABLE POTENTIAL ANALYSIS
Tetrachloroethylene
Beryllium
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
199
200
Date
Data
<
<
<
<
<
<
<
<
<
<
<
<
<
BDL=1/2DL
5.0 2.5
1.4 1.4
1.0 0.5
1.0 0.5
1.0 0.5
1.0 0.5
1.0 0.5
1.0 0.5
1.0 0.5
1.0 0.5
1.0 0.5
1.0 0.5
1.0 0.5
1.0 0.5
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
Max. Value
Max. Pred Cw
0.5690
0.7071
0.8047
14
3.4200
2.5 ug/L
8.6 ug/L
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
199
200
Date
Data
BDL=1/2DL
Results
Std Dev.
Mean
C.V.
n
Mult Factor =
Max. Value
Max. Pred Cw
NO DATA
NO DATA
NO DATA
0
N/A
0.0 ug/L
N/A ug/L
-1-
Crooked Creek RPA 2009.xls, data
2/11/2011

UNION COUNTY
DEPARTMENT OF PUBLIC WORKS
500 North Main Street, Suite 500, Monroe, NC 28112
Phone: [phone] • Fax: [phone]
December 13, 2010
Julie A. Grzyb, Environmental Engineer
NC DENR/Division of Water Quality/Surface Water Protection Section
NPDES Complex Permitting, Point Source Branch
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Request to Discontinue Effluent Monitoring for Tetrachloroethylene
Crooked Creek WWTP — NC0069841
Union County
Dear Ms. Grzyb:
The Division of Water Quality (DWQ) issued Union County Public Works (UCPW) NPDES
Permit NC0069841 with an effective date of October 1, 2009. Section A. (1) of the Permit
requires monthly monitoring of Tetrachloroethylene with a footnote (No. 4) allowing
UCPW to request that the parameter to be deleted from the Permit after twelve months of
sampling. Please accept this letter as a formal request to delete the monitoring
requirement for Tetrachloroethylene from our permit. UCPW feels that monitoring
dating back to October 2009 support this request.
UCPW had our contracted laboratory, Pace Analytical, analyze our effluent for
Tetrachloroethylene fourteen times since October 2009. All concentrations were w
below the 18 microgram limit set forth in the permit. Please find a recap of the
monitoring results in the table below:
Crooked Creek WWTP
Effluent Tetrachloroethylene
DATE
CONCENTRATION (ug/I)
10-22-09
<1.0
11-10-09
<1.0
12-15-09
<1.0
01-08-10
<1.0
02-12-10
<1.0
03-09-10
<1.0
04-06-10
<1.0

UNION COUNTY PUBLIC WORKS
05-11-10
<1.0
06-22-10
<1.0
07-27-10
<1.0
08-10-10
<1.0
09-07-10
1.4
9-21-10 (PP Scan)
<5.0
10-12-10
<1.0
All of the above samples were collected, preserved and analyzed in accordance with our
permit.
As can be seen from the monitoring results, Tetrachloroethylene is not 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
Tetrachloroethylene. The facility consistently passes Chronic Toxicity testing.
UCPW appreciates your consideration of the request to remove the monitoring
requirement for Tetrachloroethylene from our NPDES permit. If additional information is
required, please do not hesitate contact John Hahn at [phone] or email:
johnhahn©co.union.nc.us.
Respectfully,
Mark E Tye
Assistant Director of Public Works
CC: John Hahn, UCPW
12/13/2010