NC0033111_Minor Modification Notice_20070205

OQ W AT$ Michael F. Easley
QrdGovernor
„Din, NCDENR William G. Ross,Jr., Secretary
> North Carolina Department of Environment and Natural Resources
-c Alan W. Klimek, P.E., Director
Division of Water Quality
February 5, 2007
Mr. Arthur L. Hough, Operating Manager
Carolina Water Systems, Inc.
575 Broad Creek Road
New Burn, North Carolina 28560
Subject: Minor Modification of
NPDES Permit NC0033111
Fairfield Harbor Subdivision WWTP
Craven County
Dear Mr. Hough:
The Division of Water Quality (the Division) has reviewed and approved your request to modify the
subject permit. We understand you have installed ultraviolet (UV) disinfection to replace your chlorine-
contact system.
Accordingly, we hereby forward permit change pages reflecting your need to monitor chlorine only if
you use chlorine as backup or in the event of UV system failure. Please insert these change pages into
your existing permit and discard the old pages.
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 Joe Corporon at telephone number
[phone], extension 594.
Sincerely,
Acif V
Alan W. Klimek, P.E.
cc: Central Files
Washington Regional Office/Water Quality Section
NPDES Program
N.C. Division of Water Quality/NPDES Unit Phone: [phone]
1617 Mail Service Center,Raleigh,NC 27699-1617 fax:[phone]
Internet:h2o.enr.state.nc.us DENR Customer Service Center: 1 800 623-7748

Permit NC0033111
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
Beginning on the effective date of this permit and lasting until expansion above 0.6 MGD,the Permittee is
authorized to discharge treated domestic wastewater through Outfall 001. Such discharges shall be limited and
monitored by the Permittee as specified below:
EFFLUENT LIMITATIONS MONITORING REQUIREMENTS
PARAMETER _
Monthly Weekly Daily Measurement Sample Sample
Average Average Maximum Frequency Type Location'
Flow 0.600 MGD Continuous Recording E
BOD5 ,20°C 30 mg/L 45 mg/L 3/Week Composite E
Total Suspended Residue(TSR) 30 mg/L 45 mg/L 3/Week Composite E
NH3 as N 3/Week Composite E
Total Residual Chlorine(TRC)2 28 µg/L 3/Week Grab E
Fecal Coliform 3 200/ 100 ml 400/ 100 ml 3/Week Grab E
pH 4 3/Week Grab E
Temperature _ Daily Grab E
No Effluent Limit (mg/L) Weekly Composite E
Total Nitrogen (TN) No Effluent Limit (lbs/month) Monthly Calculated E
(NO2-N+NO3-N+TKN)5 Monitor and Report Monthly Calculated
E
11,263 lbs/year (Annual Mass Loading)6 Annually Calculated
TKN(mg/L) Monitor and Report Weekly Composite E
NO2-N+NO3-N(mg/L) Monitor and Report Weekly Composite E
TN(mg/L) Monitor and Report Weekly Composite E
Total Monthly Flow(MG) Monitor and Report Monthly Calculated E
Total Phosphorus(TP) 2.0 mg/L(quarterly average) Weekly 7 Composite E
Footnotes:
1. E=effluent
2. Facility is allowed 18 month from the effective date of the permit to comply with the Total Residual Chlorine(TRC)
limit.This time period is allowed in order for the facility to budget and design/construct the dechlorination and/or
alternative disinfection systems—The Permittee shall monitor for TRC only if chlorine is used to disinfect. 1
3. Calculate Fecal Coliform using the geometric mean(see procedure Part II. Section A,Paragraph 9b)
4. pH of wastewater shall not fall below 6.8 nor exceed 8.5 standard units.
5. See Special Condition A.(3), TOTAL NITROGEN MONITORING.
6. Annual Mass Loading limit for total nitrogen shall become effective with the calendar year beginning on January 1,
2003 unless provisionally waived(See Special Condition A.(4), Annual Limits for Total Nitrogen.)
7. Permittee shall report total phosphorus as a quarterly average of composite samples collected weekly during
the calendar quarters January-March,April-June,July-September,October-December.
Units:
MGD= million gallons per day
BOD= biochemical oxygen demand
mg/L= milligrams per liter
lbs/Month= pounds per month
lbs/year= pounds per year 1
Effluent shall contain no floating solids or foam visible in other than trace amounts.

Permit NC0033111
A. (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
Beginning after approved expansion above 0.6 MGD, the Permittee is authorized to discharge up to 1.0
MGD of treated domestic wastewater through Outfall 001 until the expiration date of this permit. Such
discharges shall be limited and monitored by the Permittee as specified below:
EFFLUENT LIMITATIONS MONITORING REQUIREMENTS1
PARAMETER _
Monthly Weekly Daily Measurement Sample Sample
Average Average Maximum Frequency Type Location'
Flow 1.0 MGD Continuous Recording E
BOD5,20°C (Apr 1 —Oct 31) 5.0 mg/L 7.5 mg/L 3/Week Composite E
BOD5,20°C (Nov 1 —Mar 31) 10.0 mg/L 15.5 mg/L 3/Week Composite E
Total Suspended Residue(TSR) 30.0 mg/L 45.0 mg/L 3/Week Composite E
Fecal Coliform 2 200/ 100 ml 400/ 100 ml 3/Week Composite E
NH3 as N(April 1-October 31) 1.0 mg/L 5.0 mg/L 3/Week Composite E i
NH3 as N(Nov. 1 —March 31) 2.0 mg/L 10.0 mg/L 3/Week Composite E
Total Residual Chlorine(TRC)3 28 µg/L 3/Week Grab E
pH 4 3/Week Grab E
Dissolved Oxygen 5 3/Week Grab E
Acute Toxicity 6 Quarterly Composite E
Temperature Daily Grab E
No Effluent Limit (mg/L) Weekly Composite E
—
Total Nitrogen (TN) No Effluent Limit (lbs/month) Monthly Calculated E
(NO2-N+NO3-N+TKN)7 Monitor and Report Monthly Calculated E
11,263 lbs/yr(Annual Mass Loading)8 Annually Calculated E
TKN(mg/L) Monitor and Report Weekly Composite E
NO2-N+NO3-N(mg/L) Monitor and Report Weekly Composite E
TN(mg/L) Monitor and Report Weekly Composite E
Total Monthly Flow(MG) Monitor and Report Monthly Calculated E
Total Phosphorus 1.0 mg/L(monthly average) Weekly Composite E I
Temperature Weekly Instantaneous 9 D1 D2D3 D4
Dissolved Oxygen Weekly Instantaneous 9 D1 D2D3 D4
Salinity Weekly Instantaneous 9 D1 D2D3 D4
PH 10 Seasonal 11 Instantaneous 9 D, D2 D3 D4
TKN Seasonal 11 Composite 12 D1 D2D3 D4
NH3 Seasonal 11 Composite 12 D1 D2D3 D4
NO2+NO3 Seasonal 11 Composite 12 D1 D2D3 D4
TN Seasonal 11 Composite 12 D1,D2,D3,D4
TP Seasonal 11 Composite 12 Di, D2,D3,D4
Chlorophyll-a Seasonal 11 Composite 12 D1. D2,D3,D4
Fecal Coliform 13 Seasonal 11 Grab Di, D,,D3.D4
(See next page for Table Footnotes and Units)

Permit NC0033 111
A. (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS -- Continued
Table Footnotes:
1 Facility Sample Locations:
E = Effluent
Instream
s eam Sampling Loc
ations g (see attached map, Monitoring
P Points):
D1 = offshore of Outfall 001 piping within the Neuse River
D2 = in the channel at the Northwest Creek Channel Marker No. 1
D3 = in the channel at the Upper Broad Creek Channel Marker No.2
D4 = in the channel at the Upper Broad Creek Channel Marker No.3
at a point 300 feet from the marker
For Instream Monitoring Report requirements,See Special Condition A(5).
2 Calculate Fecal Coliform using the geometric mean(see procedure Part IL Section A, Paragraph 9b)
3 Total Residual Chlorine(TRC)—The Permittee shall monitor for TRC only if chlorine is used to disinfect.
4 pH of wastewater shall not fall below 6.8 nor exceed 8.5 standard units.
5 DO- Daily average effluent concentration of dissolved oxygen(DO)shall not fall below 6.0 mg/L.
6 Acute Toxicity—during the months of March,June,September,and December,a 24-hour static test(Pimephales
promelas)at 90%. See Special Condition A.(7)ACUTE TOXICITY PASS/FAIL LIMIT
7 Special Condition A.(3),TOTAL NITROGEN MONITORING.
8 Annual Mass Loading limit for total nitrogen shall become effective with the calendar year beginning on January 1,
2003 unless it is provisionally waived(See Special Condition A. (4),Annual Limits for Total Nitrogen.)
9 Instream pH -- Permittee shall make instantaneous measurements from grab samples collected at discrete depth
intervals of one(1)foot throughout the water column.
10 Instream pH to be taken concurrently with instream chlorophyll-a sampling only.
11 Seasonal Sampling — the Permittee shall collect instream samples two times per month (2/month) during the
summer months of June,July,August,and September only.
12 Instream sample shall be collected via a spatial composite through the photic zone defined as twice the Secchi
depth.
13 Fecal conform instream sample shall be a grab sample collected approximately six (6) inches below the
water surface.
Units:
BOD= biochemical oxygen demand
MGD= million gallons per day;
NH3= ammonia
TSR= total suspended residue
ml= milliliters
mg/L= milligrams per liter
µg/L= micrograms per liter
lbs/Month= pounds per month
lbs/year= pounds per year
Effluent shall contain no floating solids or foam visible in other than trace amounts.