NC0025381_Fact Sheet_20220811

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FACT SHEET FOR NPDES PERMIT RENEWAL
NPDES Permit NC0025381
Facility Information
Applicant/Facility Name:
Town of Lake Lure/Town of Lake Lure WWTP
Applicant Address:
P.O. Box 255; Lake Lure, NC 28746
Facility Address:
US Highway 64/74; Lake Lure, NC 28746
Permitted Flow
0.995 MGD
Type of Waste:
100 % domestic
Facility/Permit Status:
Grade II (physical/chemical) / Renewal
County:
Rutherford County
Miscellaneous
Receiving Stream:
Stream Classification:
Broad River
C
Regional Office:
State Grid / USGS Quad:
Asheville (ARO)
Lake Lure
303(d) Listed?
Subbasin:
Drainage Area (mi2):
Yes
03-08-01
96
7Q10 (cfs)
30Q2 (cfs)
Average Flow (cfs):
IWC (%):
6.6
33.4
169
19%
Permit Writer:
Date:
•
Charles H. Weaver
July 13, 2022
Latitude 35° 25' 28" N Longitude 81° 10' 45" W
SUMMARY
The Town of Lake Lure WWTP is a Grade II physical/chemical plant with a design flow of 0.995
MGD. The permit was last reissued on February 10, 2015. The Permittee submitted EPA Form 2A on
February 25, 2018 to request renewal of the permit. The design flow of this plant is below 1.0 MGD,
and the discharge consists entirely of domestic wastewater. Consequently, sections E-G of Form 2A
do not apply.
The existing WWTP consists of:
• Mechanical bar screen
• Flash mixer
• Flocculation basin
• Sediment basin
• Clarifier
• Sludge digester
• Sludge pump station
• Chlorination / De -chlorination and
• Continuous flow measurement
RECEIVING STREAM
The facility discharges to the Broad River just downstream of the Lake Lure dam. The Town of Lake
Lure is the only NPDES permitted discharger in the subbasin.
This subbasin includes the headwaters of the Broad River from its source in Buncombe County to the
confluence with Cove Creek in Rutherford County. The segment of the river where the discharge
occurs is on North Carolina's 303(d) list. This is due to a downstream site receiving a "fair"
classification resulting from a benthic stream assessment in 2005. There was some speculation that the
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lower rating was a function of the assessment being performed later in the season than had been done
previously. A 2010 evaluation at the same site yielded a classification of "good," and found water
quality to be much improved. Excellent water quality conditions have been found within the basin
above Lake Lure. Most of the high gradient tributary streams in this subbasin are classified as Trout
waters and are capable of supporting wild trout populations. Water quality in Lake Lure is also good.
PRETREATMENT
The facility has no permitted discharging Industries and no pretreatment program.
EXISTING PERMIT CONDITIONS
Oxygen -Consuming Waste Limitations
Limitations for oxygen -consuming waste (e.g., BOD) are generally based on water quality modeling to
ensure protection of the instream dissolved oxygen (DO) water quality standard. Secondary TBEL limits
(e.g., BOD = 30 mg/L for Municipals) may be appropriate if deemed more stringent based on dilution
and model results.
BOD and TSS limits are TBELs, established in 1981. TBEL requirements for municipal WWTPs
(POTWs) are documented in 15A NCAC 02B.0406.
Ammonia and Total Residual Chlorine Limitations
Limitations [monthly average] for ammonia are based on protection of aquatic life utilizing an ammonia
chronic criterion of 1.0 mg/L (summer) and 1.8 mg/L (winter). Acute [weekly average] ammonia limits
are derived from chronic criteria, utilizing a multiplication factor of 3 for Municipals and a multiplication
factor of 5 for Non -Municipals.
Limitations for Total Residual Chlorine (TRC) are based on the NC water quality standard for protection
of aquatic life (17 µg/L) and capped at 28 µg/L (acute impacts). Due to analytical issues, all TRC values
reported below 50 µg/L are considered compliant with their permit limit.
Describe any proposed changes to ammonia and/or TRC limits for this permit renewal: The current
NH3-N summer limits were set in 2015. The summer limits are consistent with the July 2016 permitting
guidance memo for ammonia criteria implementation [attached to fact sheet]. Winter limits have been
added at the 0.995 MGD flow, based upon the 2016 guidance. No winter limits are required at the 0.495
MGD flow phase.
The current TRC limit was established in 1991. It is consistent with the Division's 2003 TRC policy
COMPLIANCE SUMMARY
The facility has a decaying collection system which allows massive inflow & infiltration to the
WWTP. The I&I has caused ongoing operational challenges relative to the WWTP being able to
consistently comply with permitted effluent limitations, including:
> Much of the Town's collection system is under the lake; potential impacts of small leaks are
exacerbated, and I&I is a constant problem.
> The influent to the WWTP is largely diluted with lake water, especially in winter when the
tourist population is reduced.
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> The location of the collection system causes influent flow to be chilled throughout the year,
inhibiting biological activity.
> Between the characteristics of the lake water and the contribution provided by the cast iron pipe
of the collection system, the influent contains high concentrations of iron. With the addition of
chlorine during the treatment process the iron oxidizes and falls out as a solid, leaving the
Town with high volumes of inert solids that can interfere with disinfection, and must be
disposed of for reliable operation.
> As a result of its unique circumstances the Town has operated the WWTP as a
physical/chemical plant since 2008, with mixed results.
> The facility received 22 civil penalty enforcements, 11 Notices of Violation and 2 Notices of
Deficiency since issuance of the last permit.
> The Division and the Town agreed to impose Special Order by Consent (SOC) S20-004. This
SOC requires replacement of a portion of the collection system. It is the first step toward the
goal of replacing the existing WWTP with an entirely new treatment system.
CHANGES SINCE LAST PERMIT RENEWAL
The Town has committed to repair and upgrade of both the collection system and the WWTP and has
secured >$12 million in grant funding.
PROPOSED PERMIT CHANGES:
• The previous lower flow phase of 0.495 MGD has been moved to a potential future date, if
reduction of I&I via the prescribed actions in the SOC results in lower flow from the WWTP.
PROPOSED SCHEDULE FOR PERMIT ISSUANCE
Draft Permit to Public Notice:
Permit Scheduled to Issue:
May 17, 2022
July 2022
COMMENTS ON DRAFT PERMIT
The Division received comments from the Southern Environmental Law Center (SELC) on the draft permit. The
comments included the following statements [in italics]:
"TBELs are a required element of NPDES permits; rather than impose and enforce limits appropriate
to a facility undergoing improvements, DEQ has apparently not imposed technology -based limits."
The permit has TBELs for BOD and TSS consistent with 15A NCAC 02B.0406. They have been in the permit
since 1981.
"The Broad Riverkeeper has fielded numerous complaints about downstream water quality including
concerns about "suds" in the water and a "septic tank type smell "—conditions potentially attributable
to WWTP discharges."
The Riverkeeper has no investigative staff and no enforcement authority. If such complaints are not reported to
the Division, no follow-up investigations can be conducted. Suds and odor can be indicative of illegal wastewater
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discharges to the stream [straight -piping]. Any future complaints of this nature should be directed to the staff at
the Asheville Regional Office for investigation.
"The ammonia limits have been in place since the 2015 permit, and the fecal coliform and chlorine limits are
based on an analysis from 1991. The agency must reassess these limits —via an RPA and otherwise —to determine
if more stringent limits are necessary to protect downstream water quality and ameliorate impairment of the
Broad River."
The ammonia limits in the permit are WQBELs based on EPA criteria for ammonia toxicity. The EPA criteria
provide a more environmentally conservative WQBEL than a TBEL. The calculation spreadsheet used for the
draft permit's ammonia toxicity calculations was provided to SELC prior to the submission of their
comment letter. The ammonia WQBELs are consistent with the most recent guidance for EPA criteria
implementation from 2016 [attached to this Fact Sheet].
The current TRC limit was established in 1991. It is consistent with the Division's 2003 TRC policy.
The current fecal coliform limit was established in 1991. It is consistent with the Division's 1999 fecal coliform
policy.
Regarding the need for a Reasonable Potential Analysis (RPA):
The need for toxicant limits is based upon a demonstration of reasonable potential to exceed water quality
standards, a statistical evaluation that is conducted during every permit renewal utilizing the most recent effluent
data for each outfall. The RPA is conducted in accordance with 40 CFR 122.44 (d) (i). The NC RPA procedure
utilizes the following: 1) 95% Confidence Level/95% Probability; 2) assumption of zero background; 3) use of/2
detection limit for "less than" values; and 4) streamflows used for dilution consideration based on 15A NCAC
2B.0206. Effective April 6, 2016, NC began implementation of dissolved metals criteria in the RPA process in
accordance with guidance titled NPDES Implementation of Instream Dissolved Metals Standards, dated June 10,
2016.
No toxicant parameters are discharged by the Lake Lure WWTP. While two metal parameters (iron and
aluminum) are monitored in the permit, neither parameter has a WQ standard. No RPA is necessary.
"We respectfully request that DEQ perform the rigorous analysis the Clean Water Act requires to set technology
and water quality -based limits, even during this transitional time while the SOC is in operation."
The limits in the permit include both TBELs and WQBELs. There is currently no basis for changes to these
effluent limits. There has been no increase is wastewater flow - nor a significant decrease; no change to the
treatment technology at the WWTP; no change to the composition of the water flowing to the WWTP; and no
DEQ policy changes that would affect the limits for this permit.
Until the collection system is repaired, the discharge from the Lake Lure WWTP will remain mostly lake water
with an unknown amount of wastewater. Repairs to the collection system must be made if the WWTP is to
function more efficiently, and in order to meet the existing permit limits. Once the lake water has been removed
from the collection system, data can be assessed to determine if limit changes are appropriate.
CHANGES TO FINAL PERMIT
Winter ammonia limits have been added at the 0.995 MGD flow.
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PAT MCCRORY
Governor
DONALD R. VAN DER VAART
Water Resources
ENVIRONMENTAL QUALITY
Memorandum
To: NPDES Complex Unit
From: Tom Belnick
Date: July 20, 2016
Subject: NPDES Permitting Guidance
NPDES Implementation of Ammonia Criteria- Update
Q
secrermry
S. JAY ZIMMERMAN
Director
NC has still not adopted an ammonia standard, though it is on our WQS Triennial List for next
round. NC did establish ammonia chronic criteria for use in NPDES permitting back in 1989/90,
which was based on EPA's 1986 criteria development document that factored in pH/Temp across
three regions of the State (see attached). This evaluation resulted in ammonia chronic criteria of
1.0 mg/1 NH3-N (summer) and 1.8 mg/1 NH3-N (winter) for use in permitting purposes. NC
implements these chronic criteria as Monthly Averages limits utilizing instream dilution. In
2002, NC developed procedures for complimentary acute permit limits (discussed below).
The current ammonia permitting procedures should be as follows:
• The NH3/TRC Wasteload Allocation (WLA) spreadsheet automatically calculates
appropriate ammonia Monthly Average limits for summer and winter. The spreadsheet
assumes a background ammonia concentration of 0.22 mg/1.
• For any permit (new/renewal), always run the NH3/TRC WLA spreadsheet to verify
appropriate Monthly Average Ammonia Limits for protection of aquatic life.
• If the allowable ammonia concentration is greater than 35 mg/1, no limit should be
imposed.
• If the allowable concentration is less than 35 mg/1, then the allowable limit is needed and
the spreadsheet will automatically calculate it.
• For Municipal facilities, the acute limit will be expressed as a Weekly Average, and is
based on multiplying the Monthly Average limit by a factor of 3.
• For non -Municipal facilities, the acute limit will be expressed as a Daily Maximum, and
is based on multiplying the Monthly Average limit by a factor of 5.
• If a new more stringent ammonia limit is required, discuss the need for a Compliance
Schedule with senior staff and then with the Permittee.
• There is no RPA procedure used for ammonia; it is implemented strictly based on WLA
spreadsheet results (similar to TRC).
State of North Carolina I Environmental Quality I Water Resources
1617 Mail Service Center I Raleigh, North Carolina 27699-1617
919 707 9000

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• A sample NH3/TRC WLA is attached. In this example, the spreadsheet indicates that
Monthly Average ammonia limits of 3.2 mg/1 and 12.7 mg/1 should be imposed for
summer and winter, respectively, in order to protect for NC's chronic ammonia criteria.
Some additional considerations:
• This guidance will need to be revisited after NC formally adopts an ammonia standard for
both chronic and acute aquatic life protection.
• In the past, some ammonia limits were based strictly on protection of our DO standard
rather than ammonia toxicity, and that is why the permit writer should always verify the
correct ammonia limit with any permit renewal using the WLA spreadsheet.
• In the past, some practices allowed for maintaining a less stringent ammonia limit if the
facility was consistently passing the WET test (i.e., biology trumps chemistry). This is
no longer a valid approach and EPA would object. In April 2016 EPA expressly stated
that NC cannot use biology to override chemical results. EPA also disallowed the use of
Action Levels in permitting, in which toxicity test results (if passing) were used to
override the need for permit limits for copper/zinc/silver/iron/chloride.

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AMMONIA CRITERIA TABLES (NH3 as N)
Based on EPA recommended 4-day maximum average concentration criteria
and Trout 'Waters
pH
6.8
7.5
TEMPERATURE
12°C 23°C .
1.8084 1.0028
1..8084 1.0111
Total Ammonia
(mg/I NH3 as N)
Piedmont Freshwaters
pH
2 6,94
. J44 /1 xIJH3
TEMPERATURE
14°C 26°C
6.8
7.5 •
1.8084 1.1344
1.8084 1.1541
Total Ammonia
(mg/1 NH3 as N)
Coast:alj Plain and Sandhills Freshwaters
pH
6.8
7.5
TEMPERATURE
16°C • 28°C
1.7920 0.9700
1.7920 0.9864
•
(Un�� ifr�riit%
fm91/1/N ?,'a
Total Ammonia
(mg/1 •NH3 as N)
\A) mim Sonme4
10/19/89
1.8 mil/

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NH3/TRC WLA Calculations
Facility: Anywhere USA
NC00
Prepared By: Tom Belnick
Enter Design Flow (MGD):
Enter s7Q10 (cfs):
Enterw7Q10 (cfs):
0.03
0.13
0.32
Total Residual Chlorine (TRC)
Daily Maximum Limit (ug/I)
s7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (UG/L)
Upstream Bkgd (ug/I)
IWC (%)
Allowable Conc. (ug/I)
Fecal Coliform
Monthly Average Limit:
(If DF >331; Monitor)
(If DF<331; Limit)
Dilution Factor (DF)
0.13
0.03
0.0465
17.0
0
26.35
65
Ammonia (Summer)
Monthly Average Limit (mg NH3-N/I)
s7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
Upstream Bkgd (mg/I)
IWC (%)
Allowable Conc. (mg/I)
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/I)
w7Q10 (CFS)
200/100m1 DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
3.80 Upstream Bkgd (mg/I)
IWC (%)
Allowable Conc. (mg/I)
Total Residual Chlorine
1. Cap Daily Max limit at 28 ug/I to protect for acute toxicity
Ammonia (as NH3-N)
1. If Allowable Conc > 35 mg/I, Monitor Only
2. Monthly Avg limit x 3 = Weekly Avg limit (Municipals); capped at 35 mg/I
3. Monthly Avg limit x 5 = Daily Max limit (Non-Munis); capped at 35 mg/I
0.13
0.03
0.0465
1.0
0.22
26.35
3.2
0.32
0.03
0.0465
1.8
0.22
12.69
12.7
Fecal Coliform
1. Monthly Avg limit x 2 = 400/100 ml = Weekly Avg limit (Municipals) = Daily Max limit (Non -Muni)

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IWC Calculations
Lake Lure WWTP
NC0025381
Prepared By: Charles Weaver, NPDES
Enter Design Flow (MGD):
Enter s7Q10(cfs):
Enter w7Q10 (cfs):
0.995
6.61
33.4
Residual Chlorine
7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (UG/L)
UPS BACKGROUND LEVEL (l
IWC (%)
Allowable Conc. (ug/I)
Fecal Limit
(If DF >331; Monitor)
(If DF <331; Limit)
Dilution Factor (DF)
NPDES Servor/Current Versions/IWC
6.61
0.995
1.54225
17.0
0
18.92
90
200/100m1
5.29
Ammonia (NH3 as N)
(summer)
7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
UPS BACKGROUND LEVEL
IWC (%)
Allowable Conc. (mg/I)
Ammonia (NH3 as N)
(winter)
7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
UPS BACKGROUND LEVEL
IWC (%)
Allowable Conc. (mg/I)
6.61
0.995
1.54225
1.0
0.02
18.92
5.2
33.4
0.995
1.54225
1.0
0.02
4.41
22.2