NC0085812_EMC SOC WQS20-001_20220411

Union County—Grassy Branch WWTP
EMC SOC WQ S20-001
NORTH CAROLINA
ENVIRONMENTAL MANAGEMENT COMMISSION
COUNTY OF UNION
IN THE MATTER OF )
NORTH CAROLINA ) SPECIAL ORDER BY CONSENT
NPDES PERMIT NO. NC0085812 ) EMC SOC WQ S20-001
PERMIT NO.WQCS00054 )
)
HELD BY )
UNION COUNTY )
Pursuant to provisions of North Carolina General Statute(G.S.) 143-215.2 and G.S. 143-215.67,this
Special Order by Consent ("SOC") is entered into by Union County, hereinafter referred to as the
County,and the North Carolina Environmental Management Commission,an agency of the State of
North Carolina created by G.S. 143B-282,hereinafter referred to as the Commission:
1. The County and the Commission hereby stipulate the following:
a. The County holds North Carolina NPDES Permit NC0085812 (the "NPDES Permit") for
operation of an existing wastewater treatment works and for making an outlet therefrom for
the discharge of treated wastewater to Crooked Creek, Class C waters of the State in the
Yadkin-Pee Dee River Basin (the "Grassy Branch WWTP"). The County also holds
Collection System Permit WQCS00054 for the existing wastewater collection system
throughout its utility system(the"Collection System Permit").
b. The County has been issued Notices of Violation, on certain occasions, for exceeding certain
final effluent limits set forth in the NPDES Permit, including Biochemical Oxygen Demand
(BOD), Ammonia Nitrogen, Total Suspended Solids (TSS), Fecal Coliform and Flow. The
Notices of Violation concerning the County exceeding certain operational requirements as
set forth in the NPDES Permit are largely due to high levels of inflow and infiltration
entering the County's sewer collection system being treated at the Grassy Branch WWTP
which is capacity limited. The County has also been issued Notices of Violation, on certain
occasions, for not having complied with Condition 1.2 regarding sanitary sewer overflows
(SSOs) as set forth in Collection System Permit. The County agrees to address these issues
outlined in the Notices of Violation through continued I&I abatement efforts conducted in the
sanitary sewer basin served by the Grassy Branch WWTP ("Grassy Branch Basin").
c. Noncompliance with final effluent limitations is considered constituting, causing, and
contributing to pollution of the waters of the State named above. Enforcement actions
concerning noncompliance with final effluent limits with the NPDES Permit and the
Collection System Permit is within the jurisdiction of the Commission as set forth in G.S.
Chapter 143,Article 21.
d. The County has secured financing for planning, design, and construction/repairs of the
following:
i. Expansion of wastewater treatment and disposal system components as described in
Attachment B which,once constructed and operated,will be sufficient to adequately provide
Page 1 of 9

Union County—Grassy Branch WWTP
EMC SOC WQ S20-001
for capacity to convey and treat wastewater presently being discharged,to such an extent
that County will be able to comply with the final effluent limits and operational requirements
as set forth in the NPDES Permit. Funding is available in the Union County Public Works
Capital Improvements Program.
ii. Continued I&I abatement efforts on the wastewater collection system within the portion of
the collection system that collects wastewater in the Grassy Branch Basin will attenuate capacity
restrictions at the Grassy Branch WWTP. Funding for operation and maintenance is
appropriated annually by the Board of County Commissioners.
e. Since this Special Order is by Consent, neither party will file a petition for a contested case
or for judicial review concerning its terms.
2. The County, desiring to comply with the NPDES Permit and the Collection System Permit,
hereby agrees to do the following:
a. Undertake the following activities in accordance with the indicated time schedule:
Scheduled Activity SOC Due Date
Submit Quarterly Progress Reports Beginning May 15, 2022
For Collection System Permit WQCS00054
Ongoing inflow and infiltration(I&I)rehabilitation in
the Grassy Branch basin
Complete the CCTV camera investigation of the December 31, 2021 (MET)
entire Grassy Branch sanitary sewer collection system
For NPDES Permit NC0085812:
Submit contract documents for regulatory approval
for Grassy Branch WWTP upgrade project December 31, 2023
Upon receipt of the required Division of Water
Resources permit(s), begin construction of Grassy September 30, 2024
Branch WWTP upgrades
Complete construction of the upgrades to the
wastewater treatment plant and submit a certification
of completion(Engineer's Certification) from a March 31, 2027
professional engineer verifying that the construction
has been completed. Begin use of new UV
disinfection system.
Attain compliance with NPDES permit final limits June 30, 2027
b. The County will submit quarterly progress reports detailing the work and activities undertaken and
completed on the upgrades to the collection system under the Collection System Permit in the
Grassy Branch Basin and the NPDES Permit as described in this SOC. The reports are to be
submitted as follows:one copy must be mailed to the Mooresville Regional Office Supervisor,
Division of Water Resources/Water Quality Regional Operations Section,610 East Center
Avenue,Suite 301,Mooresville,NC 28115,and one copy must be mailed to the Water Quality
Permitting Section/NPDES,1617 Mail Service Center Raleigh,NC 27699-1617.
The quarterly reports are due in each respective office no later than the fifteenth(15th)day of
Febniary,May,August and November for the duration of this SOC.
Page 2 of 9

Union County—Grassy Branch WWTP
EMC SOC WQ S20-001
c. The County will comply with all terms and conditions of the NPDES Permit except effluent
limits for parameters identified in paragraph 1(b)above and as set forth in this paragraph below.
See Attachment A for all current monitoring requirements and effluent limits,including interim
effluent limits applicable through the term of this SOC.During the time in which this SOC is
effective,the County shall be required to comply with the interim effluent limits, rather than
the final permit effluent limits, for Total Suspended Solids (TSS), Biochemical Oxygen
Demand(BOD),Ammonia Nitrogen, Fecal Coliform, and Flow as listed in the table below.
Under this SOC, only the parameters listed below have been modified from the most
current NPDES Permit in effect for Outfall 001.
Permit Limits Interim Limits
Parameters Units Monthly Weekly Monthly Weekly
Avg. Avg. Avg. Avg.
Flow mgd 0.050 NA 0.120 NA
BOD(s) mg/L 5.0 7.5 30.0 45.0
BOD (w) mg/L 10.0 15.0 30.0 45.0
TSS mg/L 30.0 45.0 75.0 100.0
Ammonia Nitrogen(s) mg/L 2.0 6.0 4.0 12.0
Ammonia Nitrogen(w) mg/L 4.0 12.0 6.0 18.0
Fecal Coliform #/100 mL 200* 400* 400* 800*
s=summer(April 1 —October 31); w=winter(November 1 —March 31)
* = geometric mean
d. No later than fifteen (15) calendar days after any date identified for accomplishment of any
activity listed in 2(a)above(other than the Quarterly Progress Report Requirement),the County
shall submit to the Water Quality Regional Operations Section Regional Supervisor for the
Division of Water Resources' (DWR) Mooresville Regional Office (the "Regional
Supervisor") written notice of compliance or noncompliance therewith. In the case of
noncompliance, the notice shall include a statement of the reason(s) for noncompliance,
remedial action(s)taken, and a statement identifying the extent to which subsequent dates or
times for accomplishment of listed activities may be affected.
e. The County will continue to operate the Grassy Branch WWTP using commercially
reasonable efforts, including requirements described in this SOC, to the greatest extent
possible to prevent/minimize any adverse impacts to the surface waters.
3. The County,desiring to comply with the Permits identified in paragraph 1(a)above,hereby agrees
to the following settlement of outstanding civil penalties through an upfront penalty,and stipulated
penalties:
a. The County has outstanding civil penalty assessments from certain Notices of Violation that
total$8,789.32. As full and final settlement and satisfaction of all alleged violations and any
and all claims or prospective claims that the Commission has or may have for violations of
the NPDES Permit or the Collection System Permit in the Grassy Branch Basin prior to the
date the Commission enters into this SOC(which specifically includes,without limitation,all
Notices of Violations issued, or which may have been issued, for alleged violations of the
NPDES Permit and the Collection System Permit in the Grassy Branch Basin as described
in paragraph 1 above), the County agrees to pay an upfront penalty amount of$1,964.32,
Page 3 of 9

Union County—Grassy Branch WWTP
EMC SOC WQ S20-001
with the remaining amount of $6,825.00 to be held in abeyance until the successful
completion of this SOC.A certified check in the amount of$1,964.32 must be made payable
to the North Carolina Department of Environmental Quality and forwarded to the Director of
DWR by no later than fifteen (15) days following the date on which this SOC is approved
and executed by the Commission and received by the County.
b. At the successful conclusion of this SOC, the penalty amount held in abeyance ($6,825.00)
will be remitted by the Commission and Department of Environmental Quality. Should the
SOC not reach a successful conclusion, including consideration of any amendments to the
SOC or modifications granted hereunder, the full remaining penalty amount of$6,825.00
will be due immediately by check payable to the North Carolina Department of
Environmental Quality and forwarded to the Director.
c. The County agrees that unless excused under paragraph 2(d) or paragraph 4, the County will
pay the Director of DWR, by check payable to the North Carolina Department of
Environmental Quality,stipulated penalties according to the following schedule for failure to
meet the deadlines set out in paragraphs 2(a), 2(b), and 2(d); and interim effluent limits and
monitoring requirements set out in paragraph 2(c)during the term of this SOC:
Violation Description Stipulated
Any reportable Sanitary • $250 per SSO greater than 1,000 gallons and less than
Sewer Overflow(SSO) 100,000gallons. (to be paid on a monthly basis)
in the Grassy Branch • $500 per SSO greater than 100,001 gallons (to be paid on a
Basin monthly basis)
Failure to meet $500 per day
a scheduled
Failure to comply
with the modified $3,000 (monthly average)
effluent flow limit
Failure to comply with • $1,000 for exceeding monthly average(or geometric mean)
a modified effluent limit
limit • $500 for exceeding weekly average(or geometric mean)
limits (to be paid on a monthly basis).
Monitoring frequency $100 per omitted value per parameter(to be paid on a
violations for monthly basis)
modified parameters
Failure to Submit Status $500 for the first violation;penalty doubles with each
Reports subsequent assessment for late reports
Failure to achieve
compliance with $5,000 (single penalty)
final effluent limits
d. Certified checks are to be made payable to the North Carolina Department of
Environmental Quality and forwarded to Director of DWR at 1617 Mail Service Center,
Raleigh, North Carolina 27699-1617.
4. The County and the Commission agree that the stipulated penalties are not due if the County
satisfies DWR that noncompliance was caused solely by:
Page 4 of 9

Union County—Grassy Branch WWTP
EMC SOC WQ S20-001
a. An act of God;
b. An act of war;
c. An intentional act or omission of a third party, but this defense shall not be available if the
act or omission is that of an employee or agent of the County or if the act or omission occurs
in connection with a contractual relationship with the permittee;
d. An extraordinary event beyond the County's control. Contractor delays or failure to obtain
funding will not be considered as events beyond the County's control;or
e. Any combination of the above causes.
Failure within thirty (30) days of receipt of written demand to pay the penalties, or challenge
them by a contested case petition pursuant to G.S. 150B-23, will be grounds for a collection
action, which the Attorney General is hereby authorized to initiate. The only issue in such an
action will be whether the thirty(30) days has elapsed.
5. Noncompliance with the terms of this SOC is subject to enforcement action in addition to the
above stipulations, including injunctive relief pursuant to G.S. 143-215.6.C. Noncompliance
with the terms of this Special Order will not be subject to civil penalties in addition to the above
stipulated penalties.
6. This SOC and any terms or conditions contained herein, hereby supersede any and all previous
Special Orders, Enforcement Compliance Schedule Letters, terms, conditions, and limits
contained therein issued in connection with the NPDES Permit and the Collection System Permit
(in the Grassy Branch Basin). In the event of an NPDES Permit modification or renewal, any
effluent limit or monitoring requirements contained therein shall supersede those contained in
Attachment A of this SOC, except as modified and contained in paragraph 2(c) above.
7. This SOC may be amended provided the County has made good faith efforts to secure funding,
complete all construction and achieve compliance within the dates specified. Such amendment
may include, without limitation, modification to the improvements project described in
Attachment B if such modifications are reasonably determined by County and Commission to
be designed to meet the final effluent limits of the NPDES permit and the schedule set forth in
paragraph 2(a).
8. During the term of this SOC, the County will not be permitted to accept additional wastewater
from any domestic, industrial, or commercial sources within the Grassy Branch Basin without
prior approval from the Mooresville Regional Supervisor and the Water Quality Permitting
Section.
9. Failure to meet the scheduled dates identified in paragraph 2(a),as may be modified as described
in this SOC, after notice from the Commission and failure to cure by the County within fifteen
(15) days of such notice, the Commission may terminate this SOC and require the County to
comply with the terms and conditions contained in the permits identified in paragraph 1(a).
10. The County, upon signature of this SOC, will be expected to comply with all schedule dates,
terms,and conditions of this document.
Page 5 of 9

Union County—Grassy Branch WWTP
EMC SOC WQ S20-001
This Special Order by Consent shall expire September 30,2027.
For Union County:
ga6rA O D 67U 7iz
William M. Watson, County Manager Date
For the North Carolina Environmental Management Commission:
S. Daniel Smith, Director Date
Division of Water Resources
i I IS ridai.datu in The
Manner Required By The Local Government
Budget And Fiscal o trol Act
Deputy Fi ceOfficer
Page 6 of 9

ATTACHMENT A NPDES Permit NC0085812
EMC SOC WQ S20-001
PART I
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B .0400 et seq., 15A NCAC 02B .0500 et seq.]
Grade II Biological Water Pollution Control System [15A NCAC 08G.0302]
During the period beginning on the effective date of this permit and lasting until expansion above 0.050 MGD is
operational, or expiration,the Permittee is authorized to discharge treated wastewater from Outfall 001. Such
discharges shall be limited and monitored) by the Permittee as specified below:
EFFLUENT CHARACTERISTICS LIMITS MONITORING REQUIREMENTS1
[PARAMETER CODES] Monthly Weekly Daily Measurement Sample Sample
Average Average Maximum Frequency Type Location2
g 9 Y YP
Influent or
Flow(MGD) 50050 0.120 MGD* Continuous Recording
Effluent
BOD,5-day,20°C(mg/L)3 C0310 30.0 mg/L* 45.0 mg/L* Weekly Composite Effluent,
(April 1—October 31) Influent
° 3 Effluent,
BOD,5-day,20 C(mg/L.)
Y C0310 30.0 mg/L* 45.0 mg/L* Weekly Composite
(November 1—March 31) Influent
Total Suspended Solids 3 75.0 mg/L* 100.0 mg/L* Weekly Composite Effluent,
C0530
(TSS)(mg/L) Influent
NH3 as N(mg/L) C0610
(April 1—October 31) 4.0 mg/L 12.0 mg/L Weekly Composite Effluent
NH3 as N(mg/L) C0610 6.0 mg/L* 18.0 mg/L* Weekly Composite Effluent
(November 1—March 31)
Dissolved Oxygen(DO) 00300 Daily Average>6.0 mg/L Weekly Grab Effluent
(mg/L)
Fecal Coliform(#/100 ml) 31616ml* ml* WeeklyGrab Effluent
(geometric mean) 400/100 800/100
Temperature(°C) 00010 Monitoring&Report Weekly Grab Effluent
Total Residual Chlorine 4,5 50060 5
(TRC)(pg/L) 17 µg/L 2/Week Grab Effluent
pH(su) 0040o >6.0 and<9.0 standard units Weekly Grab Effluent
Mercury,Total(ng/L)6 COMER Once Per Permit Cycle 6 Once per Grab Effluent
permit cycle
Dissolved Oxygen(DO) 00300 Monitor&Report Variable 2 Grab U,D
(mgfL)
Temperature(°C) 00010 Monitor&Report Variable 2 Grab U,D
* SOC Limits are effective beginning on the effective date of the SOC and lasting until the SOC compliance date
June 30,2027. The SOC shall expire on September 30,2027.
Footnotes:
1. The permittee shall submit discharge monitoring reports electronically using the Division's eDMR system [see
A. (4)].
2. Sample locations: U-Upstream 50 feet above discharge point,D-Downstream at NC 218 bridge.
Upstream/downstream samples shall be collected 3/Week during June,July,August, September,and Weekly
during the remaining months of the year.
Instream monitoring requirements shall be provisionally waived so long as the permittee remains a member of
the Yadkin Pee Dee River Basin Association and the Association continues to function as approved by the
Division and Environmental Management Commission.
Page 7 of 9

ATTACHMENT A NPDES Permit NC0085812
EMC SOC WQ S20-001
3. The monthly average effluent BOD5 and TSS concentrations shall not exceed 15%of the respective influent
value(85%removal).
4. Total Residual Chlorine monitoring is required only if chlorine is added to the effluent.
5. The Division shall consider all effluent TRC values reported below 50 µg/1 to be in compliance with the permit.
However,the Permittee shall continue to record and submit all values reported by a North Carolina certified
laboratory(including field certified),even if these values fall below 50 µg/L.
6. Compliance with this limit shall be determined in accordance with A. (3).
Conditions:
• There shall be no discharge of floating solids or visible foam in other than trace amounts.
Page 8 of 9

ATTACHMENT B
EMC SOC WQ S20-001
Union County—Grassy Branch WWTP Improvements
Brief Project Description
The Grassy Branch WWTP improvements will include implementation and/or construction
of the following items:
• Larger influent pumps.
• A retrofit of the existing aeration basin coarse bubble diffusers to the fine bubble diffuser
equipment.
• One additional package plant secondary treatment train to include volume for flow
equalization.
• New positive displacement blowers serving the existing and new aeration basins.
• An additional secondary clarifier.
• A new cloth disk filter. (Upgrade of existing sand filter with cloth disk filters.)
• A new UV disinfection system. (Upgrade of UV disinfection system.)
• Additional volume for aerobic digestion.
Page 9 of 9