NC0031879_Correspondence_19890610

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State of North Carolina
Department of Natural Resources and Community Development
Division of 1:nvironr cil:ill Mdna.enleir.
512 North Salisbury Street • Raleigh, North Carolina 27611
James G. Martin, Governor R. Paul Wilms
William W. Cobey, Jr., Secretary June 10, 19$9 Director
Mr. John T. Marlar, Chief
Facilities Performance Branch
Water Management Division
U.S. Environmental Protection Agency
Region IV
345 Courtland St.
Atlanta, Ga. 30365
Subject: City of Marion-Corpening Creek WWTP
NPDES Permit No. NC0031879, McDowell County
City of Hickory -Northeast WWTP
NPDES Permit No. NC0020401, Catawba County
Town of Henderson-Nutbush Creek
NPDES Permit No. NC0020559, Vance County
Dear Mr. Marlar:
I am writing in response to the letters received from EPA regarding your
concern over possible ammonia toxicity and subsequent NH3-N limits for the
subject facilities. As you are aware, and as was indicated in a recent let-
ter from Trevor Clements to Sally Turner (copy attached), North Carolina
requires whole -effluent toxicity testing for all major NPDES facilities as
well as all other NPDES discharges of complex wastewater. Each of the three
facilities in question is required to perform effluent monitoring for both
whole -effluent toxicity and ammonia. As such, I believe the current subject
draft permits contain adequate provisions for maintaining the water quality
standards within the receiving waters.
The Division of Environmental Management (DEM) currently has a suffi-
cient database on these three discharges to indicate that ammonia toxicity
does not pose a threat to the receiving waters. Effluent ammonia concentra-
tions and whole effluent toxicity test results are summarized in Tables 1 &
2, respectively. A brief capsulation on each facility follows:
- The City of Marion-Corpening Creek WWTP has been in compliance with
their whole -effluent toxicity limit for the past year. In addition, their.
NH3-N concentrations have averaged less than 1 mg/1 and we would not expect
an instream problem.
P.O. Box 27687, Raleigh, North Carolina 27611-7687 Telephone [phone]
An Equal opportunity Affirmative Action Employer

- The City of Hickory -Northeast WWTP discharges into Lake Hickory (one
of the Catawba Chain Lakes). The effluent limits were based on minimum
:instantaneous release from the Lake Rhodhiss Dam upstream and are conserva-
tive since they do not take into account the actual volume of water and dis-
persion that occurs within the lake. We do not expect the facility to
impose an ammonia toxicity threat to Lake Hickory. Also, the City has been
in compliance with their toxicity limit for the past year.
- The Town of Henderson has exhibited a toxicity problem and is cur-
rently under a Judicial Order by Consent to address the situation. The Town
cannot accept additional complex waste under conditions of the Order. Their
effluent ammonia nitrogen concentrations consistently average less than 1
mg/1 and have not: been considered the cause of the problem.
The Division is aware of the potential problems that can be caused in
receiving streams by ammonia toxicity. The development of a NH3-N toxicity
wasteload allocation procedure is on our program agenda for this year.
If you have any additional questions or comments on this matter, please
contact Trevor Clements or myself at [phone].
Sincerely,
Steve W. Tedder, Chief
Wat.f:.r Q ''ty Section:
Attachments
cc: Trevor Clements
Dennis Ramsey
Ken Eagleson
Arthur Mouberry
Forrest Westall
Rex Gleason
Bill Kreutzberger
Central Files
WLA =File

' Table 1. Comparison of Effluent Ammonia Nitrogen Concentrations (mg/1)
for Marion, Henderson, and Hickory
Marion Henderson • Hickory
Summer Average 0.12 5.05 1.04
Minimum <0.10 0.30 • 0.07
Maximum 4.58 15.00 5.74
Winter Average 0.70 13.00 0.95
Minimum <0.10 1.60 0.07
Maximum 8.80 23.00 9.10

Table 2. Whole -Effluent Toxicity Testing Information and Results
Facility:
Marion Henderson Hickory -NE
Required By: Admin. Letter Admin. Letter NPDES Permit
Acute/Chronic: Chronic Acute Chronic
Target/Limit: Target Target Limit
Frequency: Quarterly P/F Monthly Quarterly P/F
IWC: 74% 97% 11%
Begin Date: November 1988 January 1988. July 1987
Tox Test Date:
7/87 - NR
8/87 - - PASS
9/87 - -
10/87 - -
11/87 - -
12/87 - FAIL
1/88 - 28.3 -
2/88 - 71.0 FAIL
3/88 1.9 NR
4/88 FAIL 98.5 -
5/88 NR 79.0 PASS
6/88 PASS 92.0 -
7/88 PASS 92.0 -
8/88 PASS 79.4 PASS
9/88 PASS 97.7.1 -
10/88 - -
11/88 PASS 20.0 PASS
12/88 - 83.7 -
1/89 - 94.2 -
2/89 PASS 15.0 PASS
3/89 - NONE