HomeMy WebLinkAboutNC0050342_permit modification_20090807ATA
NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins Dee Freeman
Governor Director Secretary
August 7, 2009
Mr. David K. Saunders P.E.
Director of Utilities
City of Winston-Salem
P.O. Box 2511
Winston-Salem, North Carolina 27102
Subject:
Dear Mr. Saunders,
Permit Modification
NPDES Permit NC0050342
Muddy Creek WWTP
Forsyth County
On July 24, 2009, the Division of Water Quality issued NPDES Permit No. NC0050342 to the City of Winston-
Salem. However, EPA requested the Division to change the mercury limits to meet the requirement of the 40 CFR Part 122.45
(d)(2). Therefore, the Division made a correction to the Effluent page. The Division also updated Toxicity test requirements
on the Effluent page. Please insert the enclosed corrected effluent sheet and discard the old sheet. This permit modification
becomes effective on the effective date of the permit.
All other terms and conditions in the original permit remain unchanged and in full effect. These modifications are
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 December 6, 1983.
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
demand is made, this decision shall be final and binding.
Sincerely,
Coleen H. Sullins
cc: US EPA, Marshall Hyatt (e-copy)
WSRO-Surface Water Protection
NPDES File
Central Files
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
Location: 512 N. Salisbury St. Raleigh, North Carolina 27604
Phone: 919-807-63001 FAX: 919-807-6492 \ Customer Service: 1-877-623-6748
Internet www.ncwaterquality.org
An Equal Opportunity : Affirmative Action Employer
NorthCarolina
Naturally
Permit NC0050342
A. (1) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS [001]
During the period beginning on the effective date of the permit 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:
PARAMETER
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Weekly
Average
Daily `
Maximum
Measurement
Frequency
Sample
Type
Sample Locations
Flow
21 MGD
Continuous
Recording
Influent or Effluent
CBOD, 5-Day, 200C2
25.0 mg/L
40.0 mg/L
Daily
Composite
Influent & Effluent
CBOD, 5-Day, 20°C
Variable3
Grab
U & D
Total Suspended Solids2
30.0 mg/L
45.0 mg/L
Daily
Composite
Influent & Effluent
NH3 N
(April 1 — October 31)
14.0 mg/L
35.0 mg/L
Daily
Composite
Effluent
NH3-N
(November 1— March 31)
Daily
Composite
Effluent
NH3-N
Variable3
Grab
U & D
Dissolved Oxygen.'
Daily Average > 5.0 mg/L
Daily
Grab
Effluent
Dissolved Oxygen
Variable3
Grab
U & D
Fecal Coliform
(geometric mean)
200/100 mL
400/100 mL
Daily
Grab
Effluent
Fecal Coliform
(geometric mean)
Variable3
Grab
U & D
Total Residual Chlorines
28 pg/L Daily Average
Daily
Grab
Effluent
Total Nitrogen
{NO2+NO3+TKN}
Weekly
Composite
Effluent
Total Phosphorus
Weekly
Composite
Effluent
Temperature, 0C
Daily
Grab
Effluent
Temperature, °C
Variable3
Grab
U & D
Conductivity
Daily
Grab
Effluent
Conductivity
Variable3
Grab
U & D
Chronic Toxicity6
Quarterly
Composite
Effluent
pH
> 6.0 and < 9.0 standard units
Daily
Grab
Effluent
Total Mercury
0.2162 pg/L
0.2162 pg/L
2/Month
Grab
Effluent
Annual Pollutant Scan
Annually ,
See A. (5)
Effluent
Notes:
1. The effluent composite sampling location is established at the parshall flume immediately below the chlorine
injection point.
2. The monthly average effluent CBOD5 and Total Suspended Solids concentrations shall not exceed 15% of their
respective influent values (85% removal).
3. U: upstream at Idols Dam. D: downstream 0.26 miles below U.S. Highway 64. Instream sampling requirements
are provisionally waived in light of the permittee's participation in the Yadkin -Pee Dee River Basin Association.
Should participation in the Association cease, all instream sampling requirements are immediately reinstated.
Should instream sampling be reinstated, grab samples shall be collected 3/week during the months of June, July,
August, and September and weekly during the remainder of the year.
4. Effluent samples shall be taken prior to entering the 5 mile outfall line.
5. Facility shall report all effluent TRC values reported by a NC certified laboratory including field certified.
However, effluent values below 50 µg /L will be treated as zero for compliance purposes.
6. Chronic Toxicity (Ceriodaphnia) P/F @ 5.5%; January, April, July, October [see A. (3)].
There shall be no discharge of floating solids or foam visible in other than trace amounts.