HomeMy WebLinkAboutNC0064726_SPECULATIVE LIMITS_19990716NPDES DOCUWEMT SCANNINO 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
r
0,§Peculative Limits
Instream Assessment (67b)
Environmental Assessment (EA)
Permit
History
Document Date:
July 16, 1999
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State of North Carolina
i - Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
Kerr T. Stevens, Director
Mayor William G. Hardy
Town of East Bend
P.O. Box 189
East Bend, NC 27018
Dear Mayor Hardy:
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NCDENR
NORTH CAROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
16 July, 1999
Subject: Speculative Limits
UT to Logan Creek, Sites I & 2
Town of East Bend
Yadkin County
This letter serves to transmit speculative effluent limits for a proposed W WTP discharging to two
potential points on an unnamed tributary (UT) to Logan Creek. This plant would discharge 200,000 GPD
of treated domestic wastewater to the UT to Logan Creek in the Yadkin River Basin in Yadkin County.
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 discharge 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 receives and evaluates a
formal permit application for the Town's proposed discharge and provides the public an opportunity to
comment on a proposed permit.
Water Quality Issues in the High Rock Lake Watershed
The Division has significant concerns about the level of nutrients entering the High Rock Lake
watershed. The high rate of nutrient loading to High Rock Lake, as well as high levels of in -lake
nutrients, have caused excessive algal growth. The nutrient enrichment problem in the watershed has
been well researched and is well documented. The proposed discharge to the UT to Logan Creek would
add to the current nutrients entering the High Rock Lake watershed. DWQ is concerned that additional
loading to the system, especially during low flow periods, could cause water quality to decline and
threaten the designated uses of High Rock Lake.
DIVISION OF WATER QUALITY • NPDES UNIT • NC DENR
PO BOX 29535. 1617 MAIL SERVICE CENTER • RALEIGH NC 27699-1617
Telephone 919-733-5083 FAX N 733-9919
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In order to ensure that water quality conditions do not worsen, DWQ intends to proceed with the
development of a nutrient management strategy for the High Rock Lake watershed during the next
basinwide planning cycle. The process may include all or part of the watershed. The long-term solution
to nutrient enrichment in this watershed may require a comprehensive approach to nutrient reduction
affecting both new and existing dischargers. DWQ has recommended that all dischargers in the
watershed make progress toward decreasing end -of -pipe phosphorus loads. Further, DWQ strongly
advises potential new dischargers to provide for biological nutrient removal in the design of their
W WTP systems. Failure to adequately plan for this eventuality may cause lengthy project delays
and increased costs to the Town of East Bend.
Environmental Assessments of New Proiects and Expansions
Please be aware that you will have to evaluate this project for environmental impacts before
applying for a NPDES permit. Due to the size and placement of the potential discharge, an
Environmental Assessment (EA) must be prepared.
Anyone proposing to construct new or expanded waste treatment facilities using public funds or
public (state) lands must first prepare an environmental assessment (EA) when wastewater Flows
(1) equal or exceed 0.5 MGD or (2) exceed one-third of the 7Q 10 flow of the receiving stream.
Both of the proposed sites meet the second condition of exceeding one-third of the 7Q10 flow of
the receiving stream. DWQ cannot accept a NPDES 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.
The Environmental Assessment should contain a clear justification for the new or expanded flow. It
should also provide a comprehensive analysis of potential alternatives to the discharge, including a
thorough evaluation of non -discharge alternatives. Non -discharge alternatives, such as spray irrigation,
are considered to be environmentally preferable to a surface water discharge. The following items
should be thoroughly investigated and documented:
• Population data, growth, and flow justifications
• Participation in a regional system
The EA should address effluent reuse, wastewater reduction efforts, land use restrictions, Infiltration and
Inflow (1/I) reduction, urban run off reductions, and wetlands restoration initiatives.
In accordance with North Carolina General Statutes, the preferred alternative must be the practicable
waste treatment and disposal alternative with the least adverse impact on the environment. If the EA
demonstrates that the project may result in a significant adverse impact on the quality of the environment,
you must then prepare an Environmental Impact Statement (EIS). The Water Quality Planning Branch
can provide additional information regarding the requirements of the N.C. Environmental Policy Act.
Please contact our EA coordinator, Ms. Gloria Putnam, directly at (919) 733-5083, ext. 567 for more
information.
Ammonia Toxicity
Our analysis of the proposed discharge at Site #1 (1.6 miles above the confluence with Logan Creek)
indicates that ammonia toxicity in the receiving stream is a very serious concern. Because of the smaller
-1
drainage area and lower flows at Site #1, NH3-N limits of 2.0/4.0 mg/l (summer/winter) may not protect
aquatic life against ammonia toxicity in the receiving stream at low flow. For this reason, DWQ
strongly discourages developing the discharge at Site #1 and recommends Site #2 instead. Further,
approval of a NPDES permit for a new discharge at Site #1 may be problematic.
Speculative Effluent Limits
Based on the available information, tentative limits for the proposed discharge to the UT to Logan Creek
at 0.2 MGD are attached in a draft effluent limits page format. The speculative limits are explained
below.
Site #1 (1.6 miles above confluence with Logan Creek)
DWQ strongly discourages the development of the discharge at this site.
Flow Limits. The flow will be limited to 0.2 MGD, as requested. Detailed justification for this
level of flow must be provided.
BOD, 5 day. Minimum treatment required by federal regulations.
Nutrients: Total Phosphorus. Although specific limits have yet to be developed for dischargers
in the High Rock Lake watershed, it is likely that Total Phosphorus limits of 2 mg/l or lower will
be required.
NH3-N. The 2.0/4.0 mg/I (summer/winter) limits were developed to protect aquatic life against
ammonia toxicity in the receiving stream at low flow.
TSS. The limits for total suspended solids are standard for secondary treatment of municipal
wastewater.
Total Residual Chlorine. To protect the receiving stream from high concentrations of chlorine, a
TRC limit of 28 ug/l would be required at this site.
Fecal Coliform, pH. The limits for fecal coliform bacteria and pH are derived to protect water
quality in the receiving stream.
Site #2 (1.2 miles above confluence with Logan Creek)
DWQ recommends the development of the discharge at this site.
Flow Limits. The flow will be limited to 0.2 MGD, as requested. Detailed justification for this
level of flow must be provided.
BOD, 5 day. Minimum treatment required by federal regulations.
Nutrients: Total Phosphorus. Although specific limits have yet to be developed for dischargers
in the High Rock Lake watershed, it is likely that Total Phosphorus limits of 2 mg/l or lower will
be required.
NH3-N. The 2.0/5.0 mg/I (summer/winter) limits were developed to protect aquatic life against
ammonia toxicity in the receiving stream at low flow.
TSS. The limits for total suspended solids are standard for secondary treatment of municipal
wastewater.
Total Residual Chlorine. To protect the receiving stream from high concentrations of chlorine, a
TRC limit of 28 ug/I would be required at this site.
Fecal Coliform, pH. The limits for fecal coliform bacteria and pH are derived to protect water
quality in the receiving stream.
I trust this response offers sufficient guidance for the Town's proposed treatment plant construction. If
you have any additional questions about these limits, feel free to contact Mark McIntire at (919) 733-
5083, extension 553.
Sincerely,
David A. Goodrich
Supervisor, NPDES Unit
Water Quality Section
cc: Winston-Salem Regional Office
Point Source Branch
Central Files
cNPUES_Unit Files
A (1). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS speculative limits SPEC SITE #1 �4`
During the period after construction to 0.2 MGD and lasting until expiration, the Permittee is authorized to discharge from outfall(s) serial numbej001. Sd ch'
discharges shall be limited and monitored by the Permittee as specified below: V '�
EFFLUENT CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTSI
Monthly
Average
Weekly
Average
Daily
Maximum
Measurement
Fre uenc `�
Sample U
n,=T`y eJ
Sample
Location'
Flow
0.2 MGD
ContiriuousPl
1—Aqbdordinq
I or E
BOD, 5 day, 20°C (April 1 — October 31 2
30.0 m /I
45.0 m /I
Weekly I !
Composite
E, I
BOD, 5 day, 20°C November 1 - March 31 z
30.0 m /I
45.0 m /I
Weekl"
Composite
E, I
Total Suspended Residuez
30 m /I
45.0 m /I
Weekly
Composite
E, I
NH3 as N (April 1 - October 31)
2.0 mg/I
`•, j r �i
Weekly
Composite
E
NH3 as N (November 1 — March 31)
4.0 mg/I
A,
Weekly
Composite
E
Dissolved Oxygen Aril 1 - October 31
5.0 rr '/I i
I
Weekly
Grab
E
Dissolved Oxygen November 1 — March 31
f i :1
Weekly
Grab
U, D'
H4
Weekly
Grab
E
Fecal Coliform(geometric mean
200 /.100 ml i
l 400 / 100 ml
Weekly
Grab
E
Fecal Coliform(geometric mean
r200 /i100 ml%'
400 / 100 ml
Weekly
Grab
U, D'
Temperature 'C ( I
i
Daily
Grab
E
Temperature °C i > I'
- rJ
Daily
Grab
U, DI
Total Nitrogen (NO2+NO3+TKN)' '( 7 °
Weekly5
Composite
E
Total Nitrogen (NO2+140;`t';TKN)",:%
Weekly5
Grab
U, D
Total Phosphorus- , (:'` ram"
Weekly5
Composite
E
Total Phos hornsN 'I
Weekly5
Grab
U, D
Total,Residual Chlbrinee
28,u/I
2/Week
Grab
E
Coriductivit i. C`
Weekly
Grab
E
Notes:-'-
rj
Sample locations: E - Effluent, I - Influent, U - Upstream in the pool formed immediately upstream of the instream flow weir, D - Downstream on the existing
dam structure in a location so as to avoid contact between the ground and the sample bottle.
Upstream and Downstream samples of Dissolved Oxygen, Temperature, Fecal Coliform, and Conductivity shall be collected three times per week during the
months of June through September and once per week during the remaining months of the year.
2 The monthly average effluent BOD5 and Total Suspended Residue concentrations shall not exceed 15% of the respective influent value (85% removal).
4 The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
5 Effluent and Instream monitoring for Total Nitrogen and Total Phosphorous shall be conducted on the same day. -
6 Chronic Toxicity (Ceriodaphnia) P/F at 90%; February, May, August, and November, See Part III, Condition F.
Chlorophyll -a shall be monitored weekly during the months June through September, during the remaining months of the year, no monitoring is required.
8 Total Residual Chlorine shall be monitored only if chlorine is added to the effluent.
There shall be no discharge of floating solids or visible foam in other than trace amounts.
A (1). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS speculative limits
SPEC SITE #2
During the period after construction to 0.2 MGD and lasting until expiration, the Permittee is authorized to discharge from outfall(s) serial number 001. Such,
discharges shall be limited and monitored by the Permittee as specified below:
Q rJ
EFFLUENT CHARACTERISTICS
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Weekly
Average
Daily
Maximum
Measurement-1
Fre uencj��5
✓Sample
I, t1, T' 'e
Sample
Location'
Flow
0.2 MGD
Contiriuousi, l
I 1Re6ordin
I or E
BOD, 5 day, 20°C (April 1 — October 31 2
30.0 m /I
45.0 m /I
Weekl' ! J
Composite
E, I
BOD, 5 day, 20°C November 1 - March 31 2
30.0 mg/1
45.0 m /I
Wedkl'
Composite
E, I
Total Suspended Residue2
30 m /I
45.0 m /I
J.fj:J
Weekly
Composite
E, I
NH3 as N (April 1 - October 31)
2.0 mg/I
Weekly
Composite
E
NH3 as N (November 1 — March 31)
5.0 mg/I
A �
I
Weekly
Composite
E
Dissolved Oxygen Aril 1 - October 31
5.0 m'/I t,i
I
Weekly
Grab
E
Dissolved Oxygen November 1 — March 31
ut"'il 1``
1
Weekly
Grab
E
H41
,%:�.;I
1<:)
Weekly
Grab
E
Fecal Coliform(geometric mean
200 /,,l00 ml;-
400 / 100 ml
Weekly
Grab
E
Fecal Coliform(geometric mean
(200 /1100 in15
400 / 100 ml
Weekly
Grab
U, D'
Temperature °C i I
i LJ
Daily
Grab
E
Temperature °C
Daily
Grab
U, D'
Total Nitrogen (NO2+NO3+TKN)' (,—i `
Weekly5
Composite
E
Total Nitrogen (NO2+NO_'3tTKN),' /
Weeklys
Grab
U,D
Total Phos horus—� l:.%
Weekl s
Composite
E
Total Phos hor6s\
Weekl 5
Grab
U, D
Total.Residu6l;Chlorine8
28p /I
2/Week
Grab
E
Coriductivi I 7"
Weekly
Grab
E
Notes` V
Sample locations: E - Effluent, I - Influent, U - Upstream in the pool formed immediately upstream of the instream flow weir, D - Downstream on the existing
dam structure in a location so as to avoid contact between the ground and the sample bottle.
r Upstream and Downstream samples of Dissolved Oxygen, Temperature; Fecal Coliform, and Conductivity shall be collected three times per week during the
months of June through September and once per week during the remaining months of the year.
2 The monthly average effluent BOD5 and Total Suspended Residue concentrations shall not exceed 15% of the respective influent value (85% removal).
4 The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units.
5 Effluent and Instream monitoring for Total Nitrogen and Total Phosphorous shall be conducted on the same day.
6 Chronic Toxicity (Ceriodaphnia) P/F at 90%; February, May, August, and November, See Part III, Condition F.
7 Chlorophyll -a shall be monitored weekly during the months June through September; during the remaining months of the year, no monitoring is required.
8 Total Residual Chlorine shall be monitored only if chlorine is added to the effluent.
There shall be no discharge of floating solids or visible foam in other than trace amounts.