NC0074268_instream assessment_19940811

DMSION OF ENVIRONMENTAL MANAGEMENT
August 11, 1994
MEMORANDUM
TO: Rex Gleason
FROM: Jacquelyn M. Nowell/\
THRU: Don S
Ruth Swanek 2(.5
Carla Sanderson
SUBJECT: Instream Assessments for the City of Gastonia Wastewater Treatment Plants
Catawba Creek WWTP - NC0020192 - (SOC # 93-017)
Long Creek WWTP - NC0020184 - (SOC # 93-015)
Crowders Creek WWTP - NC0074268 - (SOC # 93-016)
Gaston County
Summary
The Technical Support Branch has reviewed the request for instream assessments
for the City of Gastonia's WWTPs . The City is requesting Special Orders of Consent
(SOCs) for all facilities for whole effluent toxicity problems and noncompliance with limits
for metals and other toxics. In addition, each facility is requesting an increase in wasteflow
during the life of the SOC, however this flow will be 100% domestic and there will be no
increase in allocated BOD. Based on this, the wasteflow at the Gastonia plants may be
increased in the following amounts:
SOC Flow (MGD)
Catawba Creek WWTP 1.973
Long Creek WWTP 0.817
Crowders Creek WWTP 1.371
Existing design flows and instream waste concentrations of the three plants are as
follows:
Design Qw IWC
Catawba Creek WWTP 9 MGD 90%
Long Creek WWTP 8 MGD 80.5%
Crowders Creek WWTP 6 MGD 42%
The Catawba Creek plant has consistently experienced toxicity problems since the
implementation of toxicity testing, however the Long Creek and Crowders Creek plants
have just recently started to have problems. Increased pollutants from industries tying on
to the plants are evidently where the toxicity problems are originating but additional time is
needed to correct the situation. MRO staff have indicated that the request for chronic
toxicity monitoring - full range testing has already been reviewed and approved by the
Environmental Sciences Branch, and Technical Support will concur with their
recommendation.

Memo to Rex Gleason
page 2
Discussion
Gastonia has also requested monthly average limits for the metals instead of daily
maximum limits that have been assigned in the NPDES permit. The City has also
requested SOC limits for several metals however the staff of the Mooresville Regional
Office (MRO) does not think that SOC limits for all the requested metals are warranted.
The MRO recommended daily maximum limits for the Gastonia WWTPs are as follows:
Catawba Creek
Cyanide 27
Nickel 205
Cadmium 12
Long Creek
10
210
8
Crowders Creek
nr
nr
12
The Instream Assessment Unit has reviewed 1994 effluent data from all three
facilities and has determined that the following metals limits could be recommended in the
SOCs for the Gastonia facilities. The Division can offer Gastonia the option of limits
permitted in weekly averages and higher daily maximum limits. The daily maximum limit
could be established to provide protection from acute toxic effects.
Compliance with the weekly average limit is determined by the average of the daily
samples for that week. For the purposes of this calculation, samples listed at less than
analytical detection will be assumed to be zero. The penmittee may choose to collect 5
samples for the week and base the number of analyses run on the outcome of the first
sample. If the first sample is in compliance with the weekly average limit, then no more
analyses need be run for that week. However, if the first sample is above the weekly
average, then more samples should be analyzed and the permittee must comply with both
the weekly average and daily maximum limits. If this option is implemented, the
recommended metals limits for each of the plants would be as follows:
Catawba Creek WWTP
Long Creek WWTP
Cyanide
Nickel
Cadmium
Cyanide
Nickel
Cadmium
Crowders Creek WWTP
Cadmium
Recommendation
Weekly Avg.
5.5 µg/1(WQ)
97 µg/1 (WQ)
2.2 µg/1(WQ)
Weekly Avg.
6.2 µg/1(WQ)
109 µg/1(WQ)
2.5 µg/l (WQ)
Weekly Avg.
4.8 µg/1 (WQ)
Daily Maximum
22 µg/1
388 µg/1
5.5 µgf1
Daily Maximum
251.41
436 µg/1
6.2 µg/l
Daily Maximum
12 µg/1
After review of the effluent data for all the facilities and discussion with MRO staff,
the Instream Assessment Unit recommends the following monitoring requirements for the
SOCs for the Gastonia plants. The exceedance of allowable concentrations for parameters

Memo to Rex Gleason
page 3
is not normally recommended, in those cases we suggest that effluent monitoring only for
that substance is placed in the SOC. Our recommendations for the Gastonia SOCs are as
follows:
Catawba Creek WWTP
Long Creek WWTP
SOC requirement
Cyanide monitor
Nickel monitor
C dmium _ monitor
SOC requirement
Cyanide monitor
Nickel monitor
Cadmium monitor
Crowders Creek WWTP
SOC requirement
Cadmium monitor
If there any questions concerning these recommendations, please contact me.
cc: Kent Wiggins
Dave Goodrich
Central Files
WLA File

DIVISION OF ENVIRONMENTAL MANAGEMENT
June 2, 1994
Memorandum To: Ruth Swanek
From: D. Rex Gleason
Prepared By: Kim H. Colson-j�
Subject: City of Gastonia
Crowders Creek WWTP
SOC # 93-016
NPDES Permit No. NC0074268
Gaston County, NC
This Office request that the Instream Assessment Unit
conduct an instream assessment for the subject facility's
request for interim effluent limits for Nickel, Cyanide,
Cadmium, Chromium, and Lead (request enclosed). The
facility has also requested that daily maximum limits for
these parameters be changed to a monthly average.
This Office does not recommend any interim limits for
Nickel, Cyanide, Chromium or Lead. Since the facility has
only reported 1 violation for Nickel, 1 violation for Lead,
and no violations for Chromium in the past year, interim
limitations do not appear to be needed. Cyanide is no
longer limited in the recently renewed NPDES Permit.
This Office would most likely recommend a maximum
interim limit for Cadmium of 12 ug/1 (daily maximum).
Please evaluate the facility's proposed interim limits
and this Office's suggested interim limits with regard to
potential instream affects. Also advise on other possible
alternatives to monthly average limits, such as weekly
average / daily maximum limits. If you have any questions
concerning this matter, please advise.
Attachment
cc: Jeff Bouchelle, Facility Assessment Unit

TOXICANT ANALYSIS
Facility Name
Gastonia-Crowders Creek
NPDES #
NC0074268
Qw (MGD)
6
7Q 1Os (cfs)
13.3
Crowders Creek
IWC (%)
,.._.._.._.._.._.._.._.._.._.._.._..41.15
Rec'ving Stream
Stream Class
C
FINAL RESULTS
Cadmium
Max. Pred Cw
41.6
Allowable Cw
4.9
Nickel
Max. Pred Cw
930
Allowable Cw
213.8
Cyanide
Max. Pred Cw
17.1
Allowable Cw
12.2
Chromiu m
Max. Pred Cw
84
Allowable Cw
.121.5
Lead
Max.. Pred Cw
478.4
Allowable Cw
60.8
0
Max. Pred Cw
0
Allowable Cw
0.0
0
Max. Pred Cw
0
Allowable Cw
0.0
0
Max. Pred Cw
0
Allowable Cw
0.0
0
Max. Pred Cw
0
Allowable Cw,
0.0
0
Max. Pred Cw
0
Allowable Cw
0.0
0
Max. Pred Cw
0
Allowable Cw
0.0
0
Max. Pred Cw
0
Allowable Cw
0.0
6/25/94
PAGE'

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Instream Assessment Request for Gastonia WWTPs
- Crowders Creek WWTP- NC0074268 SOC No. 93-016
- Catawba Creek WWTP - NC0020192 SOC No. 93-017
- Long Creek WWTTP - NC0020184 SOC No. 93-015
The City of Gastonia is requesting SOCs for all their treatment plants for toxicity and
metals.
Telecon w/ Kim Colson
All Gastonia plants are failing toxicity. Catawba creek started failing in the late 80's,
starting passing and then started consistently failling again. Town submitted THE for
Catawba Creek, and are in the process of finalizing TREs for Long Creek and Crowders
Creek facilities. All the language for chronic monitoring and test ranges have been
reviewed by Aquatic Toxicity. Gastonia wants monthly averages for all the metals.
Gastonia knows that the problems are from pollutants coming into the plants from the
industries that are tying on. Crowders plant can ease the problem through source
reduction. Long Creek plant wants to wait until they expand and relocate to SF Catawba
River to start working an toxicity problems. Catawba will be using lime precipitation and
new industrial waste surveys and headworks analysis.
The City requested SOC limits for several metals and MRO reviewed the requests and made
recommendations of their own. The tables below show the limits requested from Gastonia
and the MRO, plus data from January to April, 1994 for the treatment plants
1/2 FAV Values
Cn Cr Ni Cd Pb Hg
22 984 789 5 33.8 2.4
Crowders Creek WWTP
Cn Cr Ni Cd Pb
Existing Limits m o n. 120 211 4.8 60
Town Requested -data not included-
MRO Recommended 12
Max. value reported 9 35 300 16 104
Max. value predicted 17 8 4 930 4 2 478
# Obs. for analysis 2 7 2 6 26 2 5 2 6
Below Detection 2 3 3 7 10
Catawba Creek WWTP
Cn Cr Ni Cd Pb
Existing Limits 5.5 55 97 2.2 28
Town Requested 12.4 55 212 5 2 8
MRO Recommended 2 7 - 2 0 5 12 -
Max. value reported 7 2 2 5 230 17 113
Max. value predicted 410 57.5 552 42.5 520
# Obs. for analysis 21 21 21 21 21
Below Detection 9 4 - 3 5

Instream Assessment Request for Gastonia WWTPs
page 2
Long Creek WWTP
Cn
Existing Limits 6.2
Town Requested 18
MRO Recommended 10
Max. value reported 40
Max. value predicted 232
# Obs. for analysis 15
Below Detection 9
Cr Ni Cd Pb Hg
62 109 2.5 31 0.02
62 142 8.4 31 0.36
210 8 - -
56 210 14 85 0.3
140 441 67 408 0.51
16 19 16 18 23
2 1 6 7 21
7/5/94
Talked w/ Kim Colson and related recommendations for the SOCs. Said that he'd call back
after talking w/ Rex.
7/26/94
Kim Colson called with MRO recommendations:
Catawba Creek- can't meet the limitsrecommended by TSB
Cyanide
Nickel
Cadmium
Weekly Avg.
5.5 µg/1(WQ)
97 µg/1(WQ)
2.2 µg/1(WQ)
Daily Maximum
22 µg/1
388 µg/1
5.5 µg/1
MRO wants to keep daily maximum values. Doesn't want the Town to spend all their
efforts sampling effluent to try to meet weekly avg limit. Would rather have Gastonia
sample influent and collection systems to track down the source of the cyanide in the
discharge. Based on recent samples, Kim doesn't think that Catawba Creek could meet the
Cd limits recommended by TSB. MRO recommends following Daily Max. limits for the
Catawba Plant:
CN 27 nil
Ni 205 µg/1
Cd 12 µg/1
The SOC will be effective through Dec. 1995. Gastonia has submitted ATC for addition of
lime precipitation at the Catawba plant that will precipitate out a lot of metals. The toxicity
problems are probably being caused by concentrations of Ni, Zn, Cu and Cd.
Dechlorination has also been added that will help some with the toxicity problem, but
chlorine is not the major source of the tox problem.
Crowders Creek - MRO recommends that the daily max. limit of 12 ug/1 for Cadmium
be given for this facility. TSB had recommended Wk avg of 4.8 µgf1 and Da. Max. limit of
12 µg/1.
Long Creek - MRO recommends daily max. limits:
Cn 10 µg/1
Cd 8 µg/1
Ni 210 µg/1

Instream Assessment Request for Gastonia WWTPs
page 3
Kim thought that since MRO recommended da. max. values for some parameters like Ni
were less than TSB recommended limits, that it was okay. However, for Cd, the TSB
recommended limits could not be met by the plants during the SOC and that some leeway
needed to be given.
Told him that I would probably still include the wk avg./da. max limits in the instream
assessment letter but that our officewould probably go along with whatever
recommendations the MRO wanted to give for the SOC limits.
7/28/94
After review of Carla's comments on the first draft of the instream assessment, I'm
recommending effluent monitoring for the parameters where the MRO recommendation
exceeds the allowable concentration. In the cases where the MRO recommendation is
lower than the calculated daily maximum limit, we will concur with their lower limit for the
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Page 1
Note for Jackie Nowell
From: Randy Kepler
Date: Mon, Feb 28, 1994 11:31 AM
Subject: RE: Gastonia-Crowders Creek
J
To: Jackie Nowell
I don't think it is in the regs but i have done several like this. For chlorine, Charles A. has
said that with other facilities, DEM has required the facility to use a new test called the DPD
colormetric method (blanks at 50 µg/1, test number 4500-G-Cl). This if done correctly will
detect to 1014/1. Charles said Bill Edwards in the lab gave this to him. I had asked to see if
you guys have changed policy or anything like that. I'll keep the C12 level the same and tell
them what i said above... Thanks. R
From: Jackie Nowell on Mon, Feb 28, 1994 11:24 AM
Subject: RE: Gastonia Crowders Creek
To: Randy Kepler
Our response in the past has been that if your limit is lower than detection level, a reading of
less than detection, in this case, less than 100 ug/1 will be considered in compliance.
Therefore, no need to increase the limit, if they can record less than 100 ug/1. I'm checking
the regs to see what the exact statement is.
From: Randy Kepler on Mon, Feb 28, 1994 11:10 AM
Subject: Gastonia-Crowders Creek
To: Jackie Nowell
03-08-37, NC0074268. They have commented on the draft but it is only one concern. They
don't like to chlorine limit of 1914/1. They dislike it because of their measurement and
control systems are not capable to measure down to that level. Can only go to 10014/1. They
request their chlorine level be raised to 100 µg/1 weekly average combined with 100 µg/1
daily maximum. They say these limits " represent the current best technology control loop
detection levels for chlorine control. Could you send me back some form of response for
this request. A mail message should be sufficient.
Thanks, Randy K.