NC0037834_Permit (Modification)_20050830

NPDES DOCU ENT !;CANNING COVER SHEET
NC0037834
Archie Elledge WWTP
NPDES Permit:
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
August 30, 2005
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Winston-Salem • Forsyth County
City/County Utilities
Water • Sewer • Solid Waste Disposal
Manson Meads Complex • 2799 Griffith Road • Winston-Salem, NC 27103 • Tel [phone] • Fax [phone]
August 30, 2005
Mr. Sergei Chernikov
North Carolina Department of Environment
and Natural Resources
NPDES Unit
1617 Mail Service Center
Raleigh, North Carolina 27102
Subject: NPDES Permit Modification
Permit NC0037834
Archie Elledge WWTP
Forsyth County
Dear Mr. Chernikov:
I have received Alan Klimek's letter of August 15, 2005 notifying us that DWQ has
declined our request for a permit modification that would extend the implementation date
for the Elledge Plant's effluent mercury limitation by an additional twelve months.
Winston-Salem will accept the limit effective August 1, 2005 with the understanding that
we can petition DWQ to have the limit removed from the permit if the monitoring data
we have developed since January 2005 continues to indicate that we have no potential to
exceed the water quality standard for mercury.
If current trends continue to show that the concentration of mercury in the plant's effluent
is substantially below the water quality standard we will probably ask to have the
limitation dropped from the permit in June of 2006. This will provide DWQ with data
from twenty-nine monitoring events and this should be adequate to make a valid RPA for
mercury.
Mr. Klimek's letter also indicates that DWQ will consider reducing the plant's
monitoring frequency for mercury to once per month if we demonstrate compliance with
the limitation during a six month period. Winston-Salem will ask for a reduction in
monitoring frequency to once per month effective March 1, 2006. This request will be
based on monitoring data collected during the period from August 1, 2005 through
January 31, 2006 provided no permit violations have occurred.
\.\
SEP - 6 2005
I. '1;

Sergei Chemikov
August 30, 2005
Page 2
Thank you for your assistance in this matter and please call me at 336-784-4700 if you
have any questions.
Sincerely:
Stanley B. Webb
Wastewater Operations Superintendent
CC: Ron Hargrove, Deputy Director
Jon Southern, Plant ORC
Frank Crump, Asst. Supt.
Steve Tedder, WSRO
Ref:L083005a

ATA
NCDENR
Mr. Stanley Webb
Wastewater Operations Superintendent
City of Winston-Salem
P.O. Box 2511
Winston-Salem, North Carolina 27102
Dear Mr. Webb:
Michael F. Easley
Govemor
William G. Ross, Jr., Secretary
North Carolina Department of Environment and Natural Resources
Alan W. Klimek, P.E., Director
Division of Water Quality
August 15, 2005
Subject: NPDES Permit Modification
Permit NC0037834
Archie Elledge WWTP
Forsyth County
The Division of Water Quality (Division) has reviewed your request to provide an additional
twelve months implementation period for the mercury limit. After carefully considering your
request, reviewing the city's data and consulting with EPA, the Division has made a decision
that your request cannot be granted at this time. The Division already provided the City of
Winston-Salem with a 12-month implementation period during which a substantial data set
was accumulated. This data set was used to conduct a statistical analysis of the effluent data
and the decision to implement the effluent limit was based on this analysis.
The mercury effluent limit might be deleted in the future, if Winston-Salem provides
updated effluent data that shows no reasonable potential to exceed the water quality standard
for mercury. The Division would consider reducing the mercury monitoring frequency from
2/month to monthly if the city demonstrates compliance with the mercury effluent limit during
a 6-month period.
If you have any questions concerning this permit modification, please contact Sergei
Chernikov at telephone number [phone], extension 594.
Sincerely,
/C/
Sn W. Klimek, P.E.
cc. Central Files
Winston-Salem Regional Ufiir_WWater Quality Section
Roosevelt Childress, EPA F=': )11 IV
NPDES Files
Aquatic Toxicology Unit
N. C. Division of'.'!a`
1617 Mail Service
Phone: [phone]
fax: [phone]
DENR Cust;n 1r Servic:: Ce

F NA-1- Michael F. Easley
QG Governor
r ©�� William G. Ross, Jr., Secretary
NCDENR North Carolina Department of Environment and Natural Resources
--I
Y Alan W. Klimek, P.E., Director
Division of Water Quality
August 15, 2005
Mr. Stanley Webb
Wastewater Operations Superintendent
City of Winston-Salem
P.O. Box 2511
Winston-Salem, North Carolina 27102
Subject: NPDES Permit Modification
Permit NC0037834
Archie Elledge WWTP
Forsyth County
Dear Mr. Webb:
The Division of Water Quality (Division) has reviewed your request to provide an additional
twelve months implementation period for the mercury limit. After carefully considering your
request, reviewing the city's data and consulting with EPA, the Division has made a decision
that your request cannot be granted at this time. The Division already provided the City of
Winston-Salem with a 12-month implementation period during which a substantial data set
was accumulated. This data set was used to conduct a statistical analysis of the effluent data
and the decision to implement the effluent limit was based on this analysis.
The mercury effluent limit might be deleted in the future, if Winston-Salem provides
updated effluent data that shows no reasonable potential to exceed the water quality standard
for mercury. The Division would consider reducing the mercury monitoring frequency from
2/month to monthly if the city demonstrates compliance with the mercury effluent limit during
a 6-month period.
If you have any questions concerning this permit modification, please contact Sergei
Chernikov at telephone number [phone], extension 594.
Sincerely,
t411-
an W. Klimek, P.E.
cc. Central Files
Winston-Salem Regional Office/Water Quality Section
Roosevelt Childress, EPA Region IV
NPDES Files
Aquatic Toxicology Unit
N. C. Division of Water Quality / NPDES Unit
1617 Mail Service Center, Raleigh, NC 27699-1617
Internet: h2o,enr.state.nc.us
Phone: [phone]
fax: [phone]
DENR Customer Service Center 1 800 623-7748

Winston-Salem • Forsyth County
' /County Utilities
v
ater • Sewer • Solid Waste Disposal
Manson Meads Complex • 2799 Griffith Road • Winston-Salem, NC 27103 • Tel [phone] • Fax [phone]
• OretWitttigIMMOIMIrSMAIVIN.7Ww.�A+w +Rb1!WP�4t%ireM''!�fl�il�,..• ,:.
July 29, 2005
Ms. Susan Wilson
North Carolina Department of Environment
and Natural Resources
NPDES Unit
1617 Mail Service Center
Raleigh, North Carolina 27102
Dear Ms. Wilson:
11111
1
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A U G 8 2005
DENR - WA'iEit (U.1LIIY
POi it SOW CI f3;i,;i;CH
Re: Request for Permit Modification
Archie Elledge WWTP (NC0037834)
City of Winston-Salem/Forsyth County
The City of Winston-Salem is requesting that the NPDES permit for our Archie Elledge
WWTP be modified to provide an additional twelve month implementation period for the
16 ng/1 effluent mercury limitation. We ask that the implementation date be extended to
August 1, 2006.
DWQ proposed a mercury limit for the plant when the NPDES permit was issued on June
28, 2004 because the Reasonable Potential Analysis (RPA) indicated that the WQS for
mercury may be exceeded. Winston-Salem objected to the limit because the RPA was
performed on a very small number of monitoring results.
An agreement was subsequently reached with DWQ that provided for a one year
implementation period to allow us to perform additional monitoring. DWQ would then
repeat the RPA using the larger database and the limit would be removed from the permit
if no potential to exceed the WQS existed.
I sent the additional monitoring results to Sergei Chernikov in a June 22, 2005 letter. I
asked him to repeat the RPA and requested that he exclude the highest and lowest values.
The highest value was suspect because it was three standard deviations above the mean of
the database. Subsequent statistical analysis using the outlier confirmation tests
recommended by EPA confirmed that the high value was an outlier and that the lowest
value was close to being so. I included detailed information in my letter to Sergei
regarding the statistical procedures I used to evaluate the data.

Ms. Susan Wilson
July 29, 2005
Page 2
Although the highest value in the database is an outlier and may not truly represent the
actual concentration of mercury on the day the sample was taken, DWQ has notified us
that all the data must be used to perform the RPA unless Winston-Salem can provide
proof that there was a problem with the way the sample was collected and subsequently
analyzed.
We cannot explain why the value is an outlier and there is no real way to prove that the
value represents the actual concentration of mercury in the plant's effluent on the day the
sample was taken. We also do not believe that the value is the result of a slug industrial
discharge because we have no industries that use mercury.
Winston-Salem's primary concern is that the RPA predicts the maximum expected
effluent concentration of mercury by multiplying the highest value in the database, in this
case a confirmed outlier that cannot be explained, by a multiplication factor that is based
on the sample size and the data's coefficient of variation. We are concerned that the
Maximum Predicted Effluent Concentration will be excessively high, not truly
representative and that we will receive a final limitation that may not be technically
justified.
Winston-Salem understands and appreciates the fact that DWQ must follow establish
policy regarding implementing permit limits for toxicants such as mercury. To do
otherwise exposes DWQ to third party lawsuits. Winston-Salem has no wish to see DWQ
exposed to unwarranted legal action any more than we wish to have that happen to us.
Winston-Salem believes that it can meet the proposed limit. Our reluctance to accept this
limit is based on a valid concern that having a limit for a "high profile" toxicant such as
mercury in the permit may bring unwarranted scrutiny by third party concerns such as the
Canoe Association. If we are to be exposed to the type of scrutiny from non -regulatory
entities looking for any reason to sue, we want to make absolutely sure that permit limits
responsible for that scrutiny are technically justified.
Winston-Salem believes that both our interests are protected if the current
implementation period is extended for an additional twelve months to allow additional
data to be developed. DWQ will have the same level of monitoring in place that you
would have if the limit were effective and DWQ has the right to open the permit and
implement the limit if conditions warrant such action. Winston-Salem will have the
opportunity to have the mercury limit removed if additional monitoring indicates that the
value of the outlier was a "fluke" and/or the monitoring results are well below the
proposed permit limit for an extended period of time.

Ms. Susan Wilson
July 29, 2005
Page 3
Winston-Salem asks that DWQ grant our request for a permit modification extending the
implementation date for the mercury limitation to August 1, 2006. Please call me at (336)
784-4700 if you have any questions or if you need additional information regarding this
matter.
149,i
Stanley B. Webb
Wastewater Operations Superintendent
Winston-Salem/Forsyth County Utility Commission
CC: Ron Hargrove, Deputy Director
Frank Crump, Asst. Supt.
Jon Southern, Plant ORC
Steve Tedder, WSRO
Ref L072805a