NC0086924_Permit (Modification)_20060626

�OF W A rFR Michael F.Easley,Governor
0 G William G.Ross Jr.,Secretary
rNorth Carolina Department of Environment and Natural Resources
Alan W.Klimek,P.E.Director
Division of Water Quality
June 26, 2006
Mr. W. Mack Carawan, Jr., County Administrator
Tyrrell County Water System
108 S. Water St.
Columbia, North Carolina 27925
Subject: NPDES Permit Modification
Permit No. NC0086924
Tyrrell County Reverse Osmosis WTP
Tyrrell County
Dear Mr. Carawan:
Division personnel have reviewed your request for revision of your permit and deletion
of limits for total cyanide, total arsenic, total beryllium, total cadmium, total lead, and total
silver. We have reviewed the discharge monitoring data for these parameters and have
conducted a reasonable potential analysis to determine whether there is potential to exceed
the instream water quality standards.
Accordingly, we are forwarding the attached NPDES discharge permit. This permit 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).
Effluent data from January 2004 through March 2006 was evaluated and used in a
reasonable potential analysis. Based on the results of our analysis, the data indicated that
none of the parameters show the potential to exceed the allowable concentrations for the
discharge from the WTP. Based on these results, the Division is recommending :
• The deletion of the effluent limitation and monitoring for total arsenic.
• The deletion of the effluent limitation and monitoring for total beryllium.
• The deletion of the effluent limitation and monitoring for total cadmium.
• The deletion of the effluent limitation and monitoring for total cyanide.
• The deletion of the effluent limitation and monitoring for total lead.
• The deletion of the effluent monitoring for total silver.
All other effluent limitations and monitoring requirements in the permit will remain the
same. Please place the attached effluent page in the permit and discard the old page.
I% Carolina
Naturally
North Carolina Division of Water Quality 1617 Mail Service Center Raleigh,NC 27699-1617 Phone[phone] Customer Service
Internet: www.ncwaterquality.org Location: 512 N.Salisbury St. Raleigh,NC 27604 Fax [phone]
An Equal Opportunity/Affirmative Action Employer—50%Recycled/10%Post Consumer Paper

Letter to Mr. Carawan
Page 2
If any parts, measurement frequencies or sampling requirements contained in this
permit 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
form 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 a demand is made, this permit shall be
final and binding.
Please take notice that this permit is not transferable. 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, Coastal Area
Management Act, or any other Federal or Local governmental permits may be required.
If you have any questions or need additional information, please contact Ms.
Jacquelyn Nowell at telephone number [phone], extension 512.
Sincerely,
v
�o an W. Klimek, P.E.
Attachments
cc: Washington Regional Office/Surface Water Protection
Washington Regional Office/DEH/Public Water Supply
Aquatic Toxicology Unit
Lynn Henry, Division of Marine Fisheries
Sara Ward, US Fish and Wildlife Service
1PDES Permit File I
Central Files

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 from outfall(s) serial number 001- Reverse Osmosis Reject
Water. Such discharges shall be limited and monitored by the Permittee as specified below:
EFFLUENT DISCHARGE LIMITATIONS Monitoring Requirements
CHARACTERISTICS
Measurement Sample
Monthly Daily Frequency Sample Type Location'
Average Maximum
Flow(MGD) 0.216 MGD Continuous Recording I or E
Total Dissolved Solids Monthly Grab E
Temperature Monthly Grab E&Instream
Dissolved Oxygen Monthly Grab E&Instream
Salinity Monthly Grab E&Instream
Conductivity Monthly Grab E&Instream
pH2 Monthly Grab E&Instream
NH3-N 2/Month Grab E
Total Aluminum Monthly Grab E
Total Chromium Monthly Grab E
Total Iron Monthly Grab E
Total Mercury 0.025 ug/L Monthly Grab E
Total Nickel 75 ug/L Monthly Grab E
Total Selenium 71 ug/L Monthly Grab E
Total Zinc Monthly Grab E
Total Copper Monthly Grab E
Chloride Monthly Grab E
TOC Monthly Grab E
Total Fluoride Monthly Grab E
Total Nitrogen _ Monthly Grab E
Total Phosphorus Monthly Grab E
Acute Toxicity3 _ Quarterly _ Grab E
NOTES:
1 Sample Locations: I - Influent; E-Effluent, Instream- see Part I, Special Condition A.(4). for locations
and frequencies.
2 The pH shall not be less than 6.8 standard units or greater than 8.5 standard units.
3 Acute Toxicity Monitoring (Mysid) 24hr P/F ® 90%, Quarterly; January, April, July, and October. See
Special Condition A(2). Quarterly toxicant monitoring should correspond with quarterly toxicity testing.
THERE SHALL BE NO DISCHARGE OF FLOATING SOLIDS OR VISIBLE FOAM IN OTHER THAN TRACE
AMOUNTS.
Tyrrell County Reverse Osmosis
NPDES Permit No. NC0086924

Tyrrell County Water System jmn
NC0086924 6/14/06
Bull Bay
030153
Facility requesting removal of limits for CN, As, Be, Cd,Pb,and Ag. Most recent permit
issued in November 2003 and the cover letter stated that if any metals are below
detection for 12 months, facility could request a reevaluation and determination of
reasonable potential. WTP discharges into SB waters. Stream has saltwater and its best
usage is for primary recreation.
Permitted limits are:
Arsenic 50 ug/1
Beryllium 0.117 ug/1
Cadmium 42 ug/1
Cyanide 1 ug/1
Lead 221 ug/1
Silver monitoring only
Did RPA on the parameters. Used data from January 2004 through March 2006.
All data for arsenic,beryllium,cadmium,cyanide,and lead were below detection from
January 2004 through March 2006. There was no reasonable potential to exceed the
allowable concentrations for those parameters. Silver data were below detection from
January 2005 through March 2006. Data values in the range of 6-8 ug/1 were reported in
February, March and December 2004. Because there was twelve consecutive months of
non detection will recommend removal of monitoring requirement.
Will recommend permit modification that limits and monitoring be dropped for Cyanide,
Arsenic, Beryllium,Cadmium,Lead, and Silver.
461"4D( Fly . PA‘51/41- 1114 Tom,s ¢t/- j}l& ?A
C u tDA- L1 — <0.0.,.
bI i i1

REASONABLE POTENTIAL ANALYSIS
8 14
Lead Silver
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 Mar-2006 < 10.0 5.0 Std Dev. 0.0000 1 Mar-2006 < 5 2.5 Std Dev. 1.3723
2 < 10.0 5.0 Mean 5.0000 2 < 5 2.5 Mean 2.9630
3 < 10.0 5.0 C.V. 0.0000 3 < 5 2.5 C.V. 0.4631
4 Dec-2005 < 10.0 5.0 n 27 4 Dec-2005 < 5 2.5 n 27
5 < 10.0 5.0 5 < 5 2.5
6 < 10.0 5.0 MuIt Factor= 1.0000 6 < 5 2.5 Mult Factor= 1.7900
7 < 10.0 5.0 Max.Value 5.0 ug/L 7 < 5 2.5 Max.Value 8.0 ug/L
8 < 10.0 5.0 Max.Pred Cw 5.0 ug/L 8 < 5 2.5 Max.Pred Cw 14.3 ug/L
9 '< 10.0 5.0 9 < 5 2.5
10 < 10.0 5.0 10 < 5 2.5
11 "''< 10.0 5.0 11 < 5 2.5
12 :< 10.0 5.0 12 < 5 2.5
13 < 10.0 5.0 13 < 5 2.5
14 ' < 10.0 5.0 14 < 5 2.5
15 < 10.0 5.0 15 < 5 2.5
16 Dec-2004 < 10.0 5.0 16 Dec-2004 8 8.0
17 < 10.0 5.0 17 Mar-2004 6 6.0
18 < 10.0 5.0 18 Feb-2004 6 6.0
19 < 10.0 5.0 19 < 5 2.5
20 < 10.0 5.0 20 < 5 2.5
21 < 10.0 5.0 21 < 5 2.5
22 < 10.0 5.0 22 < 5 2.5
23 < 10.0 5.0 23 < 5 2.5
24 < 10.0 5.0 24 < 5 2.5
25 < 10.0 5.0 25 < 5 2.5
26 < 10.0 5.0 26 < 5 2.5
27 .< 10.0 5.0 27 < 5 2.5
28 28
29 -., 29
30 30
3131
32 < 32
33 33
34 34
35 g 35
36 36
tyrrellcororpa,data
-3- 5/18/2006

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 from outfall(s) serial number 001- Reverse Osmosis Reject
Water. Such discharges shall be limited and monitored by the Permittee as specified below:
EFFLUENT DISCHARGE LIMITATIONS Monitoring Requirements
CHARACTERISTICS
Measurement Sample
Monthly Average Daily Maximum Frequency Sample Type Location'
Flow(MGD) 0.216 MGD Continuous Recording I or E
Total Dissolved Solids Monthly Grab E
Temperature Monthly Grab E&Instream
Dissolved Oxygen Monthly Grab E&Instream
Salinity Monthly Grab E&Instream
Conductivity Monthly Grab E&Instream
pH2 Monthly Grab E&Instream
NH3-N 2/Month Grab E
Total Aluminum `e? Monthly Grab E
Total Arsenic 50 ug/L Monthly Grab E
Total Beryllium 0.117 ug/L Monthly Grab E
Total Cadmium 42 ug/L Monthly Grab E
Total Chromium Monthly Grab E
Total Cyanide 1 ug/L Monthly Grab E
Total Iron Monthly Grab E
Total Lead 221 ug/L Monthly Grab E
Total Mercury 0.025 ug/L Monthly Grab E
Total Nickel 75 ug/L Monthly Grab E
Total Selenium 71 ug/L Monthly Grab E
Total Silver Monthly Grab E
Total Zinc Monthly Grab E
Total Copper Monthly Grab E
Chloride Monthly Grab E
TOC Monthly Grab E
Total Fluoride Monthly Grab E
Total Nitrogen Monthly Grab E
Total Phosphorus Monthly Grab E
Acute Toxicity3 Quarterly Grab E
NOTES:
1 Sample Locations: I - Influent; E - Effluent, Instream - see Part I, Special Condition A.(4). for locations
and frequencies.
2 The pH shall not be less than 6.8 standard units or greater than 8.5 standard units.
3 Acute Toxicity Monitoring (Mysid) 24hr P/F ® 90%, Quarterly; January, April, July, and October. See
Special Condition A(2). Quarterly toxicant monitoring should correspond with quarterly toxicity testing.
Upon sampling for 12 months, the permittee may request a review of reasonable potential for monitoring and effluent
limitations.
THERE SHALL BE NO DISCHARGE OF FLOATING SOLIDS OR VISIBLE FOAM IN OTHER THAN TRACE
AMOUNTS.
Tyrrell County Reverse Osmosis
NPDES Permit No. NC0086924

Tyrrell County Water System
108 S. Water St.
PO Box 449
Columbia, NC 27925
Phone: [phone]
Fax: [phone]
March 31,2006
Division of Water Quality
Mark McIntire
1617 Mail Service Center
Raleigh,NC 27699
Dear Mr. McIntire:
We would like to request to have 6 sampling parameters dropped. This is due to the fact
of not having any detectable limits from January 2005 to February 2006. The parameters
we would like to drop are:
Total Cyanide
Arsenic
Beryllium
Cadmium
Lead 92-cf
Silver
NPDES Permit#NC0086294—
Tyrrell County RIO Discharge
Thank You,
Pqathic
W. Mack Carawan Jr.
Tyrrell County Administrator
- 6 2006