HomeMy WebLinkAboutNC0021881_Instream Assessment_19940422NPDES DOCUHENT SCANNING COVER SHEET
NC0021881
Lake Waccamaw WWTP
NPDES Permit:
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
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Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
April 22, 1994
This document is prizited on reuse paper - ignore any
content on the rezterse side
Note for Carla Sanderson
From: Carla Sanderson
Date: Fri, Apr 22, 1994 10:59 AM
Subject: RE: Lake Waccamaw WWTP exp.
To: Alan Clark
Page 1
Alan - sorry it has taken me so long to get back to you on this. (You're sounded g-
really covered alot of territory. It sounds like you explored not only natura beauty but rthe
significant landmarks as well. Sometime I will bring in pictures and show them to you.)
About the issue with Lake Waccamaw - the expansion in the order is not a permitted
expansion. The existing permitted flow is 0.4 MGD and they should not be exceeding that
because we have not seen a request for modification/expansion. For that matter we also did
not see a request for SOC. According to the SOC write-up an instream assessment was not
necessary. The additional flow will be after the Town takes care of current I/I problems and
other treatment inadequacies. So really (as the region puts it - I talked to Dave A.) the
wasteflow to the system will not change.
I thought we covered the issue of expansions and new facilities in 030756-030758 in Table
6.2 of the Lumber River Plan. The allowance of an expansion will involve no increase in
loading and therefore in some ca.cPs additional treatment will be necessary. Do you think this
will satisfy the US Fish & Wildlife's concerns? Or do they want to possibly request
enhanced treatment in the future for existing facilities
Page 1
Note for Carla Sanderson
From: Alan Clark
Date: Tue, Apr 12, 1994 2:58 PM
Subject: Lake Waccamaw WWTP exp.
To: Carla Sanderson
Sometime I'd love to talk to you about Puerto Rico. We saw El Yonque (the rain forest), the
town of Ponce and its famous black and red -striped firehouse, the caves and giant sinkhole
near Areciebo, and supposedly the oldest church in the new world in a small town near St.
German. We also went snorkling at Rincon and along the west shore south of Mayaguez,
went swimming at Boqueron, saw the phosphorescent bay (unfortunately under a full
moon), went to a street festival at La Paguera, visted the Cobo Rojo lighthouse and saw lots
of sights in between. I also drank a lot more rum than usual. What did you think of the
drivers down there?
But back to business. Do you know anything about the Lake Waccamaw WWTP being
under an SOC and expanding, and discharging into a stream with 7Q10 and 30Q2 of zero?
US Fish and Wildlife Service has suggested that we revise section 6.3.3 under the Subbasin
03-07-56 discussion to note that enhanced treatment for BOD and NH3 may be required as is
proposed for new facilities in the Waccamaw watershed.
)44
i
STAFF REPORT
FOR
TOWN OF LAKE WACCAMAW
SOC EMC NO. 93-08
COLUMBUS COUNTY
I. Discussion
i
NOV 1 0 1993
l�/�Y,�ft�:r'iL ts;is i+�aij t9: "7Ale.,
i'i.i;.•ii
The Town has submitted an application for an SOC to
address the problem of periodic sewer collection system
overflows. The SOC application requests an additional 100,000 gpd
flow volume. Additional information was requested from the Town
that specifically accounted for the 100,000 gpd additional flow
volume. This information resulted in lowering the flow request to
60,000 gpd. The Town operates a 0.40 MGD wastewater treatment
facility and holds NPDES Permit No. NC0021881. There is a
repeated history of sewer collection system overflows caused by
many conditions, including infiltration/inflow into the sewer
collection system. There have been no violations of permitted
monthly average flow volumes over the past year.
II. Additional Information
a. Current MP screen - The current MP screen is attached.
The Permittee's monitoring report file was checked for
DMR's generated from June 1992 thru May 1993. There
were cases of noncompliance due to fecal coliform
bacteria, ammonia nitrogen and some marginally low
dissolved oxygen readings. The high fecal counts may
have been caused by excessive flow volumes. The high
ammonia readings may have been attributed to sludge
accumulations within the polishing ponds producing
ammonia gas.
b. Funding source - The Town has indicated that local tax
revenues, utility system revenues, and other funds may
be used to finance the proposed sewer system
rehabilitation program.
c. Instream assessment - not required
d. Additional flows - The Town has requested an additional
60,000 gpd to add to the permitted 400,000 gpd. The SOC
is worded to allow additional flow volumes upon
removing a like amount of flow volume from I/I sources.
e. Facility improvements required by this Order - To
perform modifications for improved performance of
pumping scations and sewer collection system conduits.
The pumping station improvements should concern
reducing the frequency of pumping station overflows.
Three (3) miles of sewer collection system conduit will
be treated for infiltration/inflow. In addition, the
SOC compliance schedule contains milestone dates for
the construction of residual solids treatment/holding
facilities at the treatment plant.
f. Is facility monitored according to current NPDES Permit
or SOC? The facility will be monitored according to the
conditions specified within the NPDES permit.
g. Does toxicity need to be included? Toxicity is included
as a current requirement within the permit.
h. Does pretreatment need to be addressed? No, the current
waste stream is of domestic origin.
i. Facility type and design flow? The wastewater treatment
plant is an activated sludge extended aeration facility
with two polishing ponds and chlorine treatment
following the clarifier. The current permitted flow is
0.400 MGD. The design flow of this existing plant is
hot known but is assumed to be limited by the aeration
basin and clarifier. Exceeding the design flow may
result in solids washing into the polishing ponds from
the clarifier, but should have little effect on
effluent water quality for infrequent occurrences.
j. Is facility properly operated and maintained? No, the
facility is not properly operated. The plant does not
presently have a sludge treatment/holding unit. The
Town has a permit to land apply sludge, but has been
informed that unstabilized sludge can not be land
applied. The Town has been allowing solids to wash thru
the clarifier and accumulate within the polishing
ponds. This is not proper operational technique. The
Town has requested an Authorization to Construct sludge
treatment facilities and construction activities have
begun.
k.
Is NPDES Permit under adjudication? No
1. Are there special circumstances concerning issuance of
the SOC? The SOC is being requested to address frequent
sewer system over:lows relating to increased flow
within the sewer collection system from
infiltration/inflow. The Town will be required to
perform improvements/modifications to the sewer
collection system to achieve compliance with permit
requirements and reduce the frequency of sewer system
overflows.
m. The date to achieve permit compliance is
December 31, 1996, as listed on Attachments A and B of
the Special Order.
n. Are current NPDES parameters listed on the SOC
limits/monitoring page? Yes
o. Discuss downstream water quality impacts. The
collection system overflows into adjacent surface
waters can decrease oxygen levels to the extent of
causing fish kills and pose a health hazard to
swimmers. There are no water quality impacts predicted
to occur downstream of the wastewater plant discharge
point.
p. Explain mechanisms for arriving at interim limits and
compliance schedule. There are no interim limits
associated with the Special Order. The request for
additional flow volume and the compliance schedule was
submitted by the Town based on recommendations from
their consultant, McDavid and Associates, Incorporated.
Additional information was submitted by the Town
concerning specific flow volume allocations predicted
Ito occur during the SOC period. The completion of the
sewer system rehabilitation study, and a proposed
schedule for completing improvements to Pumping Station
11 and for treating excessive I/I in three miles of
sanitary sewers has been presented. The compliance
schedule, as submitted, is reasonable. The anticipated
additional flow volume is itemized below.
25,000 gpd - Annexation of Waccamaw Shores, Bella
Coola, and Shawnee Acres
16,000 gpd - Proposed build schedule based on a
historical average of 14 homes per year
19,000 gpd - Unspecified flow allocations
III. Recommendations
This report has been prepared based on a request by the
Town of Lake Waccamaw to enter into a Special Order by Consent
with the Commission for making sewer collection system
improvements necessary to eliminate overflow conditions. The Town
has submitted an application for Special Order by Consent and
related information which shows the necessity of sewer collection
system improvements. A request for an additional 60,000 gpd flow
volume has been made to account for sewer system expansions
during the SOC period. However, the Special Order is worded to
allow the 60,000 gpd additional flow upon removing a like amount
of flow volume caused by I/I with no additional permit limits
modifications. The average flow taken over the period of July
1992 thru June 1993 was 0.25 MGD which is well below the NPDES
permit limit if 0.40 MGD.
miwo+ rv\mAkiAli D. 3B 58
The Town has presented a general plan within this
application which concerns the performance of a sewer system
study, Pumping Station 11 improvements, and treating three miles
of sanitary sewers for excessive I/I. The application lists
several recent sewer overflows which were caused by electrical
problems in addition to I/I problems. The writer has made contact
with the Town's Administrator and it's consultant engineer to
address concerns over the frequency of overflows created by
electrical problems. Based on this conversation, adequate
safeguards are available at the problematic pumping stations
which include portable or fixed auxiliary power generators and
autodialing telemetry systems. The autodialers were installed at
the beginning of this year.
It is recommended that Special Order By Consent EMC WQ No.
93-08 be presented at public notice, and if no significant
adverse public comment is received, the Order be should executed.
ort epare =y
er Qua i y Regional Supervisor
JB:LAKEWAC3.893
cc: Steve Long
Wilmington Office Files
Central Files
Technical Support Branch
Oti S', M-3
Date
ritilb1/50( 1951.3
Date
North Carolina Division of Environmental Management
Water Quality Section/Rapid Assessment Group
September 25, 1992
MEMORANDUM
To: Coleen Sullins
Through: Carla Sanderson
From: Susan A. Wilson V(
Subject: Town of Lake Waccamaw
NPDES No. NC0021881
Columbus County
030756
Mike Williams of the Wilmington Regional Office has informed me that this facility is
currently monitoring for toxicity as required in an Administrative Letter. He requested that a
toxicity testing requirement be placed in the permit for Lake Waccamaw WWTP. The Technical
Support Branch agrees with this request and is recommending that a chronic bioassay test with a
pass/fail limit of 90% be included in this permit before going to public notice - see attached.
cc: Melissa Rosebrock
Mike Williams
racility Name LAKE (NA Cc47
Permit # n►G oo y t OS
Pipe #
CHRONIC TOXICITY PASS/FAIL PERMIT L
The effluent discharge shall at no time exhibit chronic toxicity using LIMIT (QRTRLY)
test procedures outlined in:
1.) The North Carolina Ce=Dia chronic effluent bioassay
Procedure - Revised *September 1989) or subsequent versions. procedure (North Carolina Chronic Bioassay
The effluent concentration at which there may be no observable inhibition of
is qo % (defined as treatment two in the North Carolina reproduction or si
n % (defined
usingatthis procedure document). The I ficant mortality
procedure to establish compliance with the permit holder shalle perform
performed SeP after thirty days from the effective date of thisPermit condition. The first test will be
Pr� '1''`� .Effluent samplingpermit during the months of
permitted final effluent discharge below all treatment for this testing Shall be performed at the NPDES
g processes.
All toxicity testing results required as part of this
MonitoringForm month in which it was permit conditionrwill entered on the Effluent Discharge
Additionay, DEM (MR
-1)
(original) s to be sent to the fo
llowing using the parameter code TGP3B.
g address: .
Attention: Environmental Sciences Branch
North Carolina Division of
Environmental Management
4401 Reedy Creek Road
Raleigh, N.C. 27607
Test data shall be complete and accurate and include all supporting chemical/ h
association with the toxicity tests, as well as all doseFiesponse data. Total residual chlorine of the effluent
sample must be measured and reported1? yslcal measurements performed in
if chlorine is employed for disinfection of the waste stream. toxicity
Should any single quarterly monitoring indicate a failure to meet specified limits, then monthlymonitoring
begin immediately until such time that a single test is passed. Upon passing, this monthly tesrequirement will
revert to quarterly in the months specified above. r'e9 will
Should any test data from this monitoring requirement or tests performed by the North Carolina Division of
Environmental Management indicate potential impacts to the receiving stream, this permit may be re -opened
modified to include alternate monitoring requirements or limits. and
NOTE: Failure to achieve test conditions as specified in the cited document, such as minim
survival and appropriate environmental controls, shall cons um rol organism
retesting(within 30 days of initial monitoring event). t±tut„ an invalid test and will require immediate
noncompliance with monitorin requirements.
Failure to submit suitable test results will �, pj�*�'te
g equire.*�nts.
7Q10 b . 0 cfs
Permitted Flow O. MGD
IWC Jco. o %
Basin & Sub -basin 030 56,
Receiving Stream _ uT Bo Ev-
County __Cal_ m8u5
QCL PIF Version 9/91
Recommended by:
Date �zs fq Z
c6s-71/4-