HomeMy WebLinkAboutNC0064726_SPECULATIVE LIMITS_20040405NPDES DOCUWEMT SCANNIMO COVER $MEET
NPDES Permit:
NC0064726
East Bend Industrial Park WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Speculative Limits
Instream Assessment (67b)
Environmental Assessment (EA)
Permit
History
Document Date:
Aril 5, 2004
This aocumeat is priatea on reuse paper - ignore any
content on the reverse side
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11
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' �hcrnW'Y'
April 5, 2004
Mayor William G. Hardy
Town of East Bend
P.O. Box 189
East Bend, North Carolina 27018
Michael F. Easley, Governor
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
Subject: Speculative Limits for East Bend WWTP
NPDES Permit NCO064726
Town of East Bend
Yadkin County
Dear Mayor Hardy:
This letter serves to transmit speculative effluent limits for a proposed WWTP
discharging to two potential points on an unnamed tributary (UT) to Logan Creek
(alternatives 1 and 2), and two potential points discharging to an unnamed tributary to
the Yadkin River (alternatives 3 and 4). Your consultant requested speculative limits for
permitted wastewater flows of 0.12 MGD.
We have reviewed the request and provide the following response. The
speculative limits presented here are based on our understanding of the proposal and of
present environmental conditions. The Division of Water Quality (DWQ) cannot
guarantee that it will issue the Town an NPDES permit to expand its discharge of treated
wastewater into waters of the State. Nor can we guarantee that the effluent limitations
and other requirements included in any permit will be exactly as presented here. Final
decisions on these matters will be made only after the Division evaluates a formal permit
application for the Town's discharge and notices the proposal for public comment.
Environmental Assessments of New Projects and Expansions
Any entity proposing to construct new or expanded wastewater treatment facilities
using public funds or public (state) lands must first prepare an environmental
assessment (EA) when wastewater expansions equal or exceed 0.5 MGD. The expansion
phase to 0.12 MGD appears to be below this threshold and an EA may not be required.
Please contact the Division's State Environmental Policy Act (SEPA) coordinator,
currently Alex Marks, at (919) 733 - 5083, ext. 555 to ensure that this is the case. DWQ
will not accept a permit application for a project requiring an environmental assessment
until the Division has approved the EA and sent a Finding of No Significant Impact
(FONSI) to the state Clearinghouse for review and comment.
Engineering Alternatives Analysis (EAA)
In accordance with the North Carolina General Statutes, the most practicable
wastewater treatment and disposal alternative with the least adverse impact on the
environment is required to be implemented with any expansion. Therefore, as a
component of all NPDES permit applications for new or expanding flow, a detailed
engineering alternatives analysis (FAA) must be prepared. The EAA must justify
— requested flows and provide an analysis of potential wastewater treatment alternatives.
North Carolina Division of Water Quality — (919) 733-7015
1617 Mail Service Center '^ FAX (919) 733-0719
Raleigh, North Carolina 27699-1617 On the Internet at http://h2o.enr.state.nc.us/
Mr. Hardy
Page 2
Alternatives to a surface water discharge, such as a spray/drip irrigation, wastewater
reuse, or inflow/infiltration reduction, are considered to be environmentally preferable.
A copy of the EAA requirements is attached to this letter. Permit applications for new or
expanding flow will be returned as incomplete if all EAA requirements are not adequately
addressed. You may also wish to refer to the NPDES Unit website for more information
regarding requests for expansion, http://h2o.enr.state.ne.us/NPDES/. j
Speculative Effluent Limits
We have reviewed information provided by your consultant and existing environmental
conditions at the potential discharge points and determined that the proposed
alternatives 1,2, and 3 are not viable due to the zero -flow nature of the receiving
streams. We have included one additional alternative (Alternative # 5) in our analysis.
Alternative # 5 is shown on the attached map, and it is located approximately 1000 ft.
downstream of the alternative 2, after the confluence with a tributary. You should
discuss the feasibility of this alternative with your consultant.
Based on the available information, tentative limits for the proposed discharge of 0.12
MGD flow to the UT to the Logan Creek (State Alternative) and to the UT to the Yadkin
River (Alternative 4) are outlined below. Also refer to Table 1 and Table 2 for an outline
of the speculative limits.
Alternative # 5
Flow Limits. The flow will be limited to 0.12 MGD as requested by the Town's
consultant. Detailed justification for this level of flow must be provided.
BOD5. The limits for BODS are based on minimum treatment levels required by federal
regulations (30 mg/L monthly average). A water quality model was also used to ensure
that this value would protect the instream dissolved oxygen standard of 5.0 mg/L.
NH3-N. The 2.1/5.4 mg/L (summer/winter) limits were developed to protect aquatic life
against ammonia toxicity in the receiving stream at the low flow.
TSS. The limits for total suspended solids are based on minimum treatment levels
required by federal regulations (30 mg/L monthly average).
Fecal Coliform, pH. The limits for fecal coliform bacteria and pH are derived to protect
water quality in the receiving stream and will likely remain the same as in the previous
permit.
Total Residual Chlorine (TRC). To protect the receiving stream from high concentration
of chlorine, a TRC limit of 28 fig/L would be required at this site.
Dissolved OxvEen (D.O.) The 5.0 mg/L effluent limit was based on the EPA -approved
water quality model to protect aquatic life in the receiving stream against oxygen
deficiency and to ensure protection of the D.O. water quality standard.
Alternative # 4
Flow Limits. The flow will be limited to 0.12 MGD as requested by the "rown's
consultant. Detailed justification for this level of flow must be provided.
BODF,. The 6.7 mg/L limit was developed to protect aquatic life in the receiving stream
at the -low flow. A water quality model was also used to -ensure that this value would
protect the instream dissolved oxygen standard of 5.0 mg/L.
Mr. l-lardy
i Page 3
NH3-N. The 1.2/2.7 mg/L (summer/winter) limits were developed to protect aquatic life
against ammonia toxicity in the receiving stream at the low flow.
TSS. The limits for total suspended solids are based on minimum treatment levels
required by federal regulations (30 mg/L monthly average).
Fecal Coliform, pH. The limits for fecal coliform bacteria and pH are derived to protect
water quality in the receiving stream and will likely remain the same as in the previous
permit.
Total Residual Chlorine (TRC). To protect the receiving stream from high concentrations
of chlorine, a TRC limit of 21 pg/L would be required at this site.
Dissolved Oxvaen (D.O.) The 5.0 mg/L effluent limit was based on the EPA -approved
water quality model to protect aquatic life in the receiving stream against oxygen
deficiency and to ensure protection of the D.O. water quality standard.
If you have any additional questions about these limits, feel free to contact Sergei
Chernikov at (919) 733-5083, extension 594.
Sincerely,
� �
&�
,,y David A. Goodrich, Supervisor
NPDES Unit
Water Quality Section
cc: Winston-Salem Regional Office/ WQS
Central Files
NPDES Unit Files
Gregory K. Meshaw, P.E.
Municipal Engineering Services Co. PA
P.O. Box 97
Garner, NC 27529
Mr. Hardy
Page 4
Table 1. Speculative Limits for the Alternative #5
Parameter
Monthly
Average
Weekly
Average
Daily
Maximum
BOD5 (summer)
30.0 m
/L
45.0 m
/L
BOD5 (winter)
30.0 m
/L
45.0 m
/L
NF13-N (summer)
2.1 m
/L
6.3 m
/L
NF13-N (winter)
5.4 m
/L
16.2 m
/L
TSS
30.0 m
/L
45.0 m
/L
Fecal coliform
200 #/ 100 mL
400 #/ 100 mL
PH
6-9
DO*
Total residual
chlorine
28 pg/L
* DO of the effluent has to be maintained at the level > 5.0 mg/L.
Table 2. Speculative Limits for the Alternative #4
Parameter
Monthly
Average
Weekly
Average
Daily
Maximum
BOD5 (summer)
6.7 m
/L
10.1 m
/L
BOD5 (winter)
6.7 m
/L
10.1 m
/L
NH3-N (summer)
1.2 m
/L
3.6 m
/L
NH3-N (winter)
2.7 m
/L
8.1 m
/L
TSS
30.0 m
/L
45.0 m
/L
Fecal coliform
200 #/ 100 mL
400 #/ 100 mL
PH
6-9
DO*
Total residual
chlorine
21 µg/L
* DO of the effluent has to be maintained at the level > 5.0 mg/L.
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Facility
M '
Proposed Discharge SOUTH To
Logan Creek
Location
Alt #1 Latitude: 36' 12' 32" N Longotude:
80° 31' 13" W
_ 'r
Alt#2 Latitude: 36 12' 08" N lon `tude
80° 3V 11" \V
not to scale
Flow Request 0.120 MGD Reoeivrtt2 SieBn:
UI' of the Yadkin River
Stre Class: C Sate Grid/ LISGS quad:
C 16 NE / East Bend, N.C.
North
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Sub -Banc 03-07-02 Drai+4�e Basin:
ax
Yadkin - PDee
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