NC0020443_WASTELOAD ALLOCATION_19910430

NPDES DOCUWENT SCAMMIM6 COVER SHEET
NPDES Permit: NC0020443
Columbia WWTP
Document Type: Permit Issuance
Wasteload Allocation ,
Authorization to Construct (AtC)
Permit Modification
Speculative Limits
201 Facilities Plan
Instream Assessment (67B)
Environmental Assessment (EA)
Permit
History
Document Date: April 30, 1991
This acpaxxment is printed on cease paper - ignore ang
content on the reverse lido

NPDES WASTE LOAD ALLOCATION
PERMIT NO.: NCO020443
PERMITTEE NAME: Town of Columbia / Town of Columbia W W`CP
Facility Status: Existing
Permit Status: Renewal
Major
Pipe No.: 001
Minor
Design Capacity: 0.150 MGD
Domestic (% of Flow): 100 %
Industrial (% of Flow): 0 %
Comments:
RECEIVING STREAM: Scupipernong River
Class: S C
Sub -Basin: 03-01-53
Reference USGS Quad:_ D 33 NE
(please attach)
County: T-ell
Regional Office: Washin ton Re 'onal Office
Previous Exp. Date: 11/30/91 Treatment Plant Class: H
Classification changes within three miles:
Requested by: Angela Y. Griffin Date: 3/25/91
Prepared by: i •`
Date: `J a q
Reviewed by: f Date: 2
-i,-o D J3.5
cz4\t L— -k�
Modeler
Date Rec.
#
39_6
3hukit
L (PI4.q
Drainage Area (mi` ) Avg. Streamflow (cfs):
7Q10 (cfs) ! id.t ( Winter 7Q10 (cfs) 30Q2 (cfs)
Toxicity Limits: IWC % Acute/Chronic
Instream Monitoring: !V D
Parameters
Upstream
Location
Downstream Location
Effluent
Characteristics
/10:. ` „"'''e
BOD5 (m )
30.0
NH3-N (mg/1)
D.O. (mg/1)
TSS (mg/1)
3 0. 0
F. Col. 000 ml)
PH (SU)
h
Comments:

A
r
FACT SHEET FOR WASTELOAD ALLOCATIONS
Facility Name:
NPDES No.:
Type of Waste:
Facility Status:
Permit Status:
Receiving Stream:
Stream Classification:
Subbasin:
County:
Regional Office:
Requestor:
Date of Request:
Topo Quad:
Request # 6149
Town of Columbia WWTP
NCO020443
Domestic 100%
Existing
Renewal
Scuppernong River
SC
03-01-53
Tyrrell Stream Characteristic: Tidal
Washington USGS #
AngelaGriffin Date:
3/25/91 Drainage Area:
D33NE Summer 7Q10: Tidal
Winter 7Q10:
Average Flow:
30Q2:
Wasteload Allocation Summary
Existing limits will protect water quality in the Scuppernong.River.
Special Schedule Requirements and additional comments from Reviewers:
Recommended by: /'/w� Date:
Reviewed by
Instream Assessment:
Regional Supervisor:
Permits & Engineering:
Date:
Date:
Date:
RETURN TO TECHNICAL SERVICES BY: MAY 15 1991

- 2 -
ExistingLimits:
CONVENTIONAL PARAMETERS
Monthly Ave.
Wasteflow (MGD):
0.150
BODS (mg/1):
30.0
NH3N (mg/1):
DO (mg/1):
TSS (mg/1):
30.0
Fecal Col. (/100 ml):
200.0
PH (SU):
6.8-8.5
Oil & Grease (mg/1):
TP (mg/1):
TN (mg/1):
Recommended Limits:
Monthly Ave.
Wasteflow (MGD):
0.150
BOD5 (mg/1):
30.0
NH3N (mg/1):
DO (mg/1):
TSS (mg/1):
30.0
Fecal Col. (/100 ml):
200.0
PH (SU):
6.8-8.5
Oil & Grease (mg/1):
TP (mg/1):
TN (mg/1):
Limits Changes Due To: Parameter(s) Affected
Instream Data
Ammonia Toxicity
Chlorine
Nutrient Sensitive Waters
HQW
New 7Q10 flow data
Special Modeling Studies
New facility information
Other
(explanation of any modifications to past modeling analysis
including new flows, rates, field data, interacting discharges).
(See page 3 for Miscellaneous and special conditions if apply)

- 3 -
MISCELLANEOUS INFORMATION & SPECIAL CONDITIONS
Miscellaneous information pertinent to the renewal or new permit for
this discharge. Include relationship to the Basinwide management plan.
INSTREAM MONITORING REQUIREMENTS:
Upstream: N Location:
Downstream: N Location:
Parameters:
Special Instream monitoring locations or monitoring frequencies:
SPECIAL INSTRUCTIONS OR CONDITIONS
Antidegredation statement:
All water quality parameters are effulent limited. For some parameters,
the available load capacity of the immediate receiving waters will be
utilized, and more stringent water quality based effluent limitations
may be established for dischargers downstream.
WASTELOAD SENT TO EPA?(Major) _N_ (Y or N)
(if yes, then attach schematic, toxics spreadsheet, copy of model, or
if not modeled, then old assumptions that were made, and description
of how fits into basinwide plan)
Additional Information attached? No (yes or no) If yes, explain
attachments.

WLA Notes
SRB
4/12/91
Town of Columbia WWTP
NC0020443
- The Town of Columbia has applied for a permit renewal for their
0.15 MGD facility. Over the last 12 months the facility has been
in compliance.
- The discharge is to the Scuppernong River, Class SC. 4.5 miles
downstream the classification changes to SB (Bull Bay of the
Albemarle Sound).
- Previous models assumed a fresh water flow of 20 cfs. This
flow is large enough to prevent ammonia toxicity at secondary
limits. No ammonia limit need be included in the permit. �=w� "' �•�.
- Ambient Station 02081166, 5 miles above Columbia on the
Scuppernong River, has recorded low summer DO. These low DO
values could not be the result of Columbia's discharge and
are most likely represent natural conditions in the
Scuppernong River.
- Existing limits will protect water quality in the Scuppernong
River.