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NC0025496
Lincolnton WWTP
NPDES Permit:
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Correspondence
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Instream Assessment (67b)
Environmental Assessment (EA)
Permit
History
Document Date:
July 16, 1999
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State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
Kerr T. Stevens, Director
July 16, 1999
Mr. David E. Lowe. City Manager
City of Lincolnton
Post Office Box 617
Lincolnton, North Carolina 28095
Al;�
NCDENR
NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
Subject:
Dear Mr. Lowe:
Speculative Limits
Lincolnton WWTP
NC0025496
Lincoln County
The purpose of this letter is to provide speculative limitations for the proposed expansion of
the Lincolnton WWTP from 6.0 MGD to 9.0 MGD.
In light of current water quality concerns in the Catawba River Basin and more specifically in
the Lake Wylie Watershed, the Division is holding permitted load for expanding facilities at no more
than existing levels. Additionally, in order to provide continued protection of the 5.0 mg/L dissolved
oxygen standard, ammonia limitations will be installed when the permit is renewed in 2000.
Speculative effluent limitations for renewal at 6.0 MGD and expansion from 6.0 MGD to 9.0 MGD
are provided in the table below:
Flowrate
6.0 MOD
Renewal
9.0 MOD
Winter
BOD (mg/L)
30.0
20.0
NH3-N (mg/L)
7.5
5.0
TSS (mg/L)
30.0
30.0
Phenols (µg/L)
9.3
6.2
Fecal (#/100 ml)
200
200
pH (SU)
6.9
6.9
TRC (µg/L)
-
28
Under current Division policy, effluent residual chlorine limits and dechlorination facilities are
required for all new or expanding discharges proposing the use of chlorine for disinfection. Should an
alternate form of disinfection be employed, such as ultraviolet light. the chlorine limitation and
associated monitoring will be waived.
As the result of nutrient concerns in the Catawba River Basin, the City should plan on
designing a system upon expansion that is capable of removing total nitrogen to 6.0 mg/L and total
phosphorus to 1.0 mg/L. Although no effluent limitations for nitrogen and phosphorus are
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anticipated at this time, limits may be necessary at some point in the future should nutrient studies
indicate that nutrient enrichment is occurring.
Finally, the Division recently reviewed an Environmental Assessment for the proposed
expansion to 9.0 MGD. The only remaining outstanding comment relates to discharge alternatives.
The EA did not adequately address alternatives. Such an alternatives analysis must be completed
before the Division will consider any expansion of the City's discharge. In order to save the City
valuable time and money, it is strongly recommended that this engineering alternatives analysis be
included with the environmental assessment before project planning proceeds any further.
If you have any questions or comments regarding these speculative limitations, please do not
hesitate to contact Mark McIntire at telephone number (919) 733-5083, extension 553.
Sincerely
David A. Goodrich
NPDES Supervisor
Cc: Central Files
NPDES Permit File
Mooresville Regional Office, Water Quality
Planning Branch, Gloria Putnam
NCDENR/DIVISION OF WATER QUALITY
WATER QUALITY SECTION / N PDES UNIT
)ULY 13, 1999
MEMORANDUM
To: PERMIT/WASTELOAD ALLOCATION FILE
NC002 5496
FROM: MARK MCINTIRE
SUBJECT: SPECULATIVE EFFLUENT LIMITATIONS RATIONALE
CITY OF LINCOLNTON - NC0025496
LINCOLN COUNTY - 030835
The Division received a request for speculative effluent limitations from J. N. Pease
Associates on behalf of the City of Lincolnton on May 21, 1999. Speculative limits for
an expansion from 6.0 MGD to 9.0 MGD were requested. Additionally, the City has
anticipated a change in effluent limitations at 6.0 MGD upon renewal and requested
speculative renewal limits as well.
Because of the widespread occurrence of transitional waters in the Catawba River
Basin, management strategies have been recommended for oxygen -consuming
wastes as well as nutrients. A speculative limitations letter was sent to the City in
1992. Limits conveyed to the City in this letter follow:
Flowrate
6.0 MGD
Existing Renewal
9.0 MGD
BOD (mg/L)
_
30.0
30.0
20.0
NH3-N (mg/L)
-
7.5
5.0
TSS (mg/L)
30.0
30.0
30
Phenols (µg/L)
-
9.3
6.2
Fecal (#/ 100 ml)
200
200
200
pH (SU)
6-9
6-9
6-9
TRC (j.tg/L)
-
28
28
The basin plan recommends 15.0 mg/L BOD5 and 4.0 mg/L NH3-N limitations for new
or expanding discharges in Catawba watersheds draining to lakes. Lincolnton's
discharge is not considered in the area of influence of Lake Wylie, however oxygen -
consumption protection is necessary nonetheless.
Ammonia limits were never installed upon renewal at 6.0 MGD. The 7.5 mg/L
ammonia limit identified in the 1992 spec letter will be included in the spec letter
resulting from this memo. Oxygen -consumption limitations were established such
that no increase in permitted Toad would be realized. This strategy will be
maintained.