NC0046728_Correspondence_20050125

NPDES DOCIMENT SCANNING COVER !MEET
NPDES Permit:
NC0046728
Mooresville / Rocky River WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
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Correspondence
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Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Permit
History
Document Date:
January 25, 2005
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Michael F. Easley, Govemor
State of North Carolina
William G. Ross, Jr., Secretary.
Department of Environment and Natural Resources
Alan W. Klimek, P.E., Director
Division of Water Quality
January 25, 2005
Mr. Wilce Martin
Utilities Director
P.O. Box 878
Mooresville, North Carolina 28115
Subject: NPDES Permit NC0046728
Rocky River WWTP
Iredell County
Dear Mr. Martin:
The Division received the comments on the final permit that you submitted on December 12, 2004. In
response to your questions/concerns about the final permit:
➢ We understand that there are no industries discharging pesticides into the collection system. Our
intent is that the monitoring requirement will help determine whether pesticides continue to be a
pollutant of concern for your facility.
➢ The limits for endrin, heptachlor, and beta-BHC are based on water quality criteria. We
understand that they are below BAT for measuring pesticides. If all of your monitoring results
show readings that are below the method detection level, we would interpret that as showing
there is no potential for an exceedance of water quality standards, and therefore the limit would
be removed. Conversely, any reading above the method detection level would also be far above
the permit limit, and that could be considered evidence that the pollutant is a parameter of
concern.
> In your comments you proposed that the Town be allowed to submit six months of data for re-
evaluation of the permit requirements. Currently the permit requires monthly sampling;
therefore six months of data would only yield six data points. That would not be enough data
upon which to base a decision. At a minimum we would need 8-12 data points. During a recent
telephone conversation you indicated that the Town would voluntarily perform bi-weekly
monitoring in order to collect more data, which would be acceptable. Or, alternately, you could
submit data for re-evaluation after 12 monthly samples.
If you have any questions or need additional information, please contact Toya Fields, telephone number
[phone], extension 551.
Sincerely,
.v
LeT6ya D. Fields
NPDES Western Permitting Unit
cc: NPDES file
Mooresville Regional Office, Water Quality Section
North Carolina Division of Water Quality
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
[phone]
FAX [phone]
On the Internet at http://h2o.enr.state.nc.us/

TOWN OF
MOORESVILLE
Utilities Department
Ms. Toya Fields
NCDENR/NPDES
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: NPDES Permit # NC0046728
Dear Ms. Fields:
Wilce Martin
Utilities Director
Town of Mooresville
P. O. Box 878
Mooresville, NC 28115
[phone]
Fax [phone]
Mobile [phone]
12/22/04
We have reviewed our discharge permit issued on December 15, 2004 which has an
effective date of January 01, 2005. After our review we have questions regarding the
pesticides added to the permit that were not listed on the draft. We understand the need to
monitor these constituents but we have concerns about the proposed schedule. Following
is a list of our concerns.
(1) We do not have any industry that is discharging pesticides into the Town wastewater
system.
(2) The proposed limits are well below BAT "Best Available Technology" currently available
to measure pesticides.
(3) If we measure Endrin using BAT, results would be reported as parts per billion, lowest
detection levels we have found are 0.06 parts per billion. The proposed limit for Endrin is 2
parts per trillion otherwise stated as 0.000002 parts per billion. We could not achieve this
level unless it is understood that BAT would give us a less than or zero reading.
What we propose is beginning January 2005 we will sample our receiving stream, effluent
and significant industrial users for a period of six months based on BAT and at that time
evaluate the data and contact your office again to discuss the pesticide issues.
We look forward to your response to the three items above and to our proposal. Should you
require additional information or have any suggestions please contact me at 704-663-7282.
Thanks for all your support in these matters.