C:\Users\KBartell.CHA-KBARTELL\Desktop\Work Files\304m 2015 Analyses\Preliminary Category Reviews\Landfills\SC0046175 - SCGENCO\SC0046175-

Permits\SC0046175 2013-Aug issued rationale.doc date printed 11/16/2015

Template updated 7-23-09

South Carolina Generating Company (SCGENCO)

A.M. Williams Station-Highway 52 Ash Disposal Facility

NPDES Permit No. SC0046175

 

Permitting Engineer: Byron M Amick August 29, 2013

Facility Rating: Major Minor 

Issuance (New) Reissuance Modification Minor Modification

If any part of this application is for a new facility or expansion of an existing facility or increase in permitted limits, an 

antidegradation review may be required per the requirements of R.61-68.D. If required, the antidegradation review will be 

included as part of the permit application.

Site Address: 2300 Block, US Highway 52, Station 445, Moncks Corner, SC 29461

County: Berkeley

Watershed: Basin 03 (Catawba-Santee River Basin)

Facility Description (include SIC code): This facility is a landfill for the disposal of coal ash and gypsum from the 

SCGENCO/AM Williams Station in Goose Creek, SC. SIC Code is 4952; Refuse Systems

Receiving Waters and Classification by outfall: 001- Wappoola Swamp to Molly Branch to the West Branch of the Cooper 

River (FW) Is any discharge to Impaired Waters? Yes (see State 303(d) list for impaired waters)

If Yes, list the monitoring station number(s) and parameter(s) causing impairment: The entire West Branch Cooper River 

from the Lake Moultrie Dam to the "T" is listed as impaired for mercury in the 2010 South Carolina Fish Consumption 

Advisory.

Is any discharge to a waterbody or for a parameter listed in an approved TMDL? Yes 

If Yes, list the parameter(s) for which the TMDL is written and the waterbody segments impacted: Dissolved Oxygen for 

the Charleston Harbor, Cooper River and Wando River

Does any discharge have the potential to affect a threatened or endangered species? Yes (endangered species information 

from SCDNR Heritage Trust, 2008)

If Yes, list the species and the waterbody in which the species resides: Shortnose Sturgeon - Cooper River (including the 

West Branch)

Outfalls are discussed in Section I of this rationale with a general description of the discharge, treatment system, stream 

flows and other pertinent information about each outfall.

EPA review of the draft permit is required if any box below is checked (Mark all that apply)

Permits with discharges which may adversely affect the waters of another State (Coordination with the other State is 

also required) 

List State and name of waterbody(ies) that reach affected state: NA

Major permits 

Permits with any discharge subject to any of the primary industrial categories (see R.61-9.122, Appendix A)

Permits with any discharge with an average flow exceeding 0.5 MGD

Permits for federal facilities with a daily average discharge exceeding 0.05 MGD

Priority permits

Modification(s) to any permit listed above or a mod that changes a permit to put it into one of the above categories 

(where it previously was not)

Modification to any permit where the schedule of compliance interim dates are extended more than once

FACT SHEET 

AND 

PERMIT RATIONALE
Rationale

Page 2 of 30

Permit No. SC0046175

List of Attachments to this Rationale:

Attachment 1 Permit Application

Attachment 2 Water Quality Spreadsheets

Attachment 3 Map of Drinking Water Intake/Source Water Protection Area Relative to Discharge

I. PERMIT LIMITATIONS AND MONITORING REQUIREMENTS

Outfall 001

Description of outfall, receiving water and wastewater treatment system: The Williams Highway 52 Ash Disposal Facility 

is a landfill for the disposal of coal ash from SCGENCO’s Williams Station in Goose Creek, SC. This landfill has a 

sedimentation pond for the collection of ash landfill runoff, ash landfill leachate, and truck wash water. The discharge 

from the pond will flow to Wappoola Swamp to Molly Branch, then to the west branch of the Cooper River (Class FW). 

This facility began operation in July 2010 and will eventually replace the Williams Highway 17A Ash Disposal Facility. 

Since this facility began discharging in August 2010, the actually DMR data collected since that date and the follow-up 2C 

application will be used to determine permit limitations. The sanitary wastewater at the site is collected and hauled off-site 

for disposal, and therefore is not considered part of this discharge.

Operator requirements: Based on the treatment system described above and the Pollution Control Act (PCA), the treatment 

system is classified as Group I-Physical/Chemical. The Environmental Certification Board Rules require that a Grade DPhysical/Chemical operator be assigned to operate this facility. This is a passive treatment system that requires little to no 

supervision. Therefore, inspections of the sediment pond system will be required once per week and anytime that discharge 

occurs, per Regulation 61-9.122.41(e)(3)(ii)(C) due to the sites ability to stop the discharge for an appropriate period when 

necessary. The wastewater treatment system was permitted under the follow Permit to Construct: #19,330-IW issued 

November 20, 2009.

Information for this outfall is based on NPDES Permit Application: 2D dated 3/26/10 and the follow-up 2C dated 5/6/11

Data from Discharge Monitoring Reports (DMRs) and NPDES permit application (including all subsequent data presented) 

from 8/1/10 - 2/28/11 has been used to evaluate permit limitations.

This outfall is outside a state-approved source water protection area (SWPA) for a surface water drinking water intake, but 

has the potential to affect the intake. The affected intake (Intake #S10104) is owned by the Charleston Water System. The 

7Q10 and AAF to be used for permitting MCL and water/organism criteria are given on the spreadsheet. Additional 

information on source water protection is provided in sections III.B and G of this rationale.

Previous permit limits are based on the permit (or modification) effective date of April 1, 2009.

All waterbody data is provided on the attached Water Quality Spreadsheets. This data includes 7Q10, annual average flow, 

dilution factors, hardness, TSS and other information as explained in this rationale. Additional information as necessary to

explain the values used will be provided below.

A. Flow

1. Previous permit limits:

Monthly Average: MR, MGD

Daily Maximum: MR, MGD

Sampling Frequency: 1/month

Sample Type: instantaneous

2. NPDES Application: (No. of flow analyses: 7)

Long Term Average Value: 0.698 MGD

Maximum 30-day Value: 1.331 mg/l 

Maximum Daily Value: 1.331 MGD
Rationale

Page 3 of 30

Permit No. SC0046175

3. DMR Data: The highest flow was reported in 9/10 as 1.331 MGD

4. Actual long-term average flow (from DMR): 0.6678 MGD

5. Conclusion: Due to the large flows and variable nature of the discharge, flow monitoring shall continue as 

previously permitted. Since the nature of the discharge is very dependent upon storm activity, the Department 

needs to document how often discharge occurs, therefore the permit will include a requirement to report the 

number of days the discharge occurs each month. 

Monthly Average: MR, MGD

Daily Maximum: MR, MGD

Sampling Frequency: 1/month

Sample Type: instantaneous

B. Dissolved Oxygen (DO)

1. Previous permit limits: not limited

2. NPDES Application: reporting not required

3. DMR Data: not limited

4. Water Quality Modeling Recommendation (Wasteload Allocation): not modeled

5. Stream Background Information: The Charleston Harbor, Cooper River and Wando River basins have a TMDL for 

Dissolved Oxygen (DO).

6. S.C. Water Classifications and Standards (S.C. Reg. 61-68): This discharge is to an unclassified tributary of the 

Cooper River, the Regulation states in section C.8; “Where surface waters are not classified by name (unlisted) in 

R.61-69, Classified Waters, the water quality standards of the class of the stream to which they are tributary shall 

apply, disregarding any site specific numeric criteria for the named waterbody.” The Cooper River in this area is a 

listed Class Freshwaters (FW) stream with an instream standard for DO of “daily average not less than 5.0 mg/l 

with a low of 4.0 mg/l”.

7. Conclusion: Non-continuous stormwater discharges do not contribute to the DO deficit as identified in the 

Charleston Harbor TMDL; therefore no limit will be established for DO.

C. pH

1. Previous permit limits: Minimum-6.0 standard units; Maximum-8.5 standard units.

Sampling Frequency: 1/month

Sample Type: grab

2. NPDES Application: (No. of pH analyses: 6)

minimum: 7.8 standard unit

maximum: 8.4 standard units

3. DMR Data: The lowest and highest values were reported as 7.8 in 9/10 and 8.4 in 10/10, respectively.

4. S.C. Water Classifications and Standards (S.C. Reg. 61-68): This discharge is to an unclassified tributary of the 

Cooper River, the Regulation states in section C.8; “Where surface waters are not classified by name (unlisted) in 

R.61-69, Classified Waters, the water quality standards of the class of the stream to which they are tributary shall 

apply, disregarding any site specific numeric criteria for the named waterbody.” The Cooper River in this area is a 

listed Class Freshwaters (FW) stream with an instream standard for pH of “between 6.0 and 8.5”.

5. Conclusion: The pH limit will remain as previously permitted.

pH shall be between 6.0 and 8.5

Sampling Frequency: 1/month

Sample Type: grab
Rationale

Page 4 of 30

Permit No. SC0046175

D. Total Suspended Solids (TSS)

1. Previous permit limits:

Monthly Average: MR, mg/l

Daily Maximum: 50 mg/l

Sampling Frequency: 1/month

Sample Type: grab

2. NPDES Application: (No. of TSS analyses: 6)

Long Term Average Value: 5.4 mg/l

Maximum 30-day Value: 9.0 mg/l 

Maximum Daily Value: 9.0 mg/l

3. DMR Data: The highest value was reported as 9 mg/l in 1/11.

4. NPDES General Permit for Storm Water Discharges Associated with Industrial Activity Part 4.1. Coal Pile 

Runoff - Any discharge composed of coal pile runoff shall not exceed a maximum concentration for any time of 

50 mg/l total suspended solids.

5. Due to wastewater characteristic similarities the following guidance is used as a basis for the historical engineering 

judgment limitations. 

40 CFR Part 411-Cement Manufacturing Point Source Category

Subpart C-Materials Storage Piles Runoff Subcategory

Sections: § 411.32, § 411.35 and § 411.37, “TSS.......Not to exceed 50 mg/l.”

40 CFR Part 423-Steam Electric Power Generating Point Sources Category

Sections: § 423.12 and § 423.15, “... the following effluent limitations shall apply to the point source discharge 

of coal pile runoff:” Maximum concentration for any time of TSS will be 50 mg/l

6. PQL: 1.0 mg/l (Method SM2540D)

7. Conclusion: This facility does not have coal pile runoff or cement storage pile runoff, though fly ash is a raw 

material in the cement manufacturing industry and is a likely material stored at such sites. The Department has 

used these industry sources as guidance and applied this limit based on engineering judgment. Therefore based on 

the historical engineering judgment and anti-backsliding regulations the limit will remain as previously permitted.

Monthly Average: MR mg/l

Daily Maximum: 50 mg/l

Sampling Frequency: 1/month

Sample Type: grab

E. Oil and Grease

1. Previous permit limits:

Monthly Average: 10 mg/l

Daily Maximum: 15 mg/l

Sampling Frequency: 1/month

Sample Type: grab

2. NPDES Application: (No. of analyses: 6)

Long Term Average Value: <5.0 mg/l

Maximum 30-day Value: <5.0 mg/l

Maximum Daily Value: <5.0 mg/l

3. DMR Data: All results were reported as 0.0 mg/l

4. S.C. Water Classifications and Standards (S.C. Reg. 61-68): Section E.5.b. states that all ground waters and 

surface waters of the State shall at all times, regardless of flow, be free from floating debris, oil, grease, scum, and 

other floating material attributable to sewage, industrial waste, or other water in amounts sufficient to be unsightly 

to such a degree as to create a nuisance or interfere with classified water uses or existing water uses.

5. PQL: 5.0 mg/l (Method 1664A)
Rationale

Page 5 of 30

Permit No. SC0046175

6. Conclusion: Due to the truck wash contributing water to the ash leachate/runoff sedimentation pond the discharge 

limitations must be consistent with other vehicle wash activities, therefore the Oil and Grease limit will remain as 

previously permitted.

Monthly Average: 10 mg/l

Daily Maximum: 15 mg/l

Sampling Frequency: 1/quarter

Sample Type: grab

F. Mercury, total

1. Previous permit limits: not limited

2. NPDES Application: (No. of analyses: 1)

Long Term Average Value: -- mg/l

Maximum 30-day Value: -- mg/l 

Maximum Daily Value: 0.00000182 mg/l

3. DMR Data: not limited

4. Water Quality Criteria: See Spreadsheet in Appendix 2.

5. Does the discharge cause, have the Reasonable Potential to Cause or Contribute: No

6. PQL: 0.0005 μg/l

7. Conclusion: Due to the impairment for mercury in the West Branch of the Cooper River the reasonable potential 

calculation was run with zero dilution. Based on the adjusted reasonable potential and the 2008 edition of S.C. 

Water Classifications and Standards (S.C. Reg. 61-68), this parameter will not be in the permit.

G. Thallium, total

1. Previous permit limits: not limited

2. NPDES Application: (No. of analyses: 1)

Long Term Average Value: -- mg/l

Maximum 30-day Value: -- mg/l

Maximum Daily Value: 0.703 g/l

3. DMR Data: not limited

4. Water Quality Criteria: See Spreadsheet in Appendix 2.

5. Does the discharge cause, have the Reasonable Potential to Cause or Contribute (based on the 2C): Yes

6. Other information: The facility believes the result reported on the 2C was the result of a lab error, and submitted 

new sample results that showed less than the PQL. Lab data was submitted from both the original sampling and 

the follow-up sampling, which has been reviewed by the Department’s Office of Laboratory Certification. The 

Laboratory Certification Officer has agreed that the sample result reported on the 2C can be attributed to carryover 

from the LCS analyzed prior to the sample used on the 2C. The Officer also agrees that the follow-up results are 

accurate. 

7. Does the discharge cause, have the Reasonable Potential to Cause or Contribute (based on follow-up results): No

8. PQL: 0.5 μg/l

9. Conclusion: Based on the conclusions made in the Department’s review of the Laboratory data, the follow-up 

results will be used to determine reasonable potential. Based on the adjusted reasonable potential, this parameter

will not be in the permit.

H. Other Parameters

All other parameters reported on the 2C show no reasonable potential to cause or contribute to a water quality violation.

Therefore no additional limits will be placed in the permit.
Rationale

Page 6 of 30

Permit No. SC0046175

I. Floating Materials

1. Previous permit limits: Part V.D.6 states “The permittee shall report all visible discharges of floating materials, 

such as ash or an oil sheen, to SCDHEC when submitting DMR’s.” 

2. Conclusion: This visual observation is to be reported on the DMR monthly, and will be separated into a visual 

report of floating solids, such as ash, and another report for oil and grease to account for the potential oil sheen.

Whole Effluent Toxicity (WET)

1. Previous permit requirements: 

Chronic whole effluent toxicity testing at a CTC = 100% using the dilution series 0%(control) 50%, 60%, 71%, 

84%, 100%

Quarterly Average: 25% effect (total, reproduction, & mortality)

Maximum: 40% effect (total, reproduction, & mortality)

Sampling Frequency: 1/quarter

Sample Type: grab

2. NPDES Application: No mixing requested

3. DMR Data: The maximum percent effect was reported in the last quarter of 2010 as 14.7%.

4. Mixing Zone and Zone of Initial Dilution (ZID) Information: discharge to a zero (0) 7Q10 stream, therefore no mixing 

zone or dilution is allowed.

5. Conclusion: This is a complex wastewater with metals; therefore the WET limits will remain as previously permitted. 

The limitations are 

Monthly average* = 25%

Daily Maximum = 40%

Chronic whole effluent toxicity testing shall be performed at a CTC = 100% using the dilution series 

0%(control) 50%, 60%, 71%, 84%, 100% 

Sampling Frequency: 1/month

Sample Type: grab

* Please note that monthly average is being used per the requirements of R.61-9.122.45.d. This may be 

different than was included in previous permits issued to this facility.

Groundwater Monitoring Requirements

Based on the facility’s comments on the draft permit reissuance, the Department’s Groundwater Management Section 

reviewed the current information on the site made the following recommendations:

The permittee shall monitor and report results semi-annually from four (4) groundwater monitoring wells (MW-16, MW17, MW-18 and MW-19) for the following parameters:

Water Table Elevation Arsenic

Depth to the Water Table Cadmium

Field pH Chromium

Field Specific Conductance Selenium

Field Turbidity Mercury
Rationale

Page 7 of 30

Permit No. SC0046175

Threatened and Endangered Species Information

Both the federal and state authorities have listed the shortnose sturgeon as legally Endangered.

The Atlantic and shortnose sturgeons are identified with rankings of G3 and S3 (NatureServe 2005), meaning that 

populations for both species are “vulnerable,” both globally and in South Carolina. In general, populations of both species 

of sturgeon along the entire Atlantic Coast are reduced from historical levels for at least the past half-century (ASMFC 

1990; ASMFC 1998; NMFS 1998). The Atlantic sturgeon was considered for listing under the Endangered Species Act 

(ESA) in 1998, but the National Marine Fisheries Service (NMFS) determined that listing was unwarranted. However, the 

gulf sturgeon (Acipenser oxyrinchus desotoi), a subspecies of the Atlantic sturgeon restricted to rivers and adjacent waters 

of the Gulf of Mexico, remains on the candidate list and is currently listed as “threatened” under the ESA. The shortnose 

sturgeon has been listed as “endangered” under the ESA since 1967 and the American Fisheries Society deemed it 

“threatened” in 1989.

Previously SC DNR was contacted concerning the shortnose sturgeon in the Cooper River. It is known that shortnose 

sturgeons, particularly juveniles, are sensitive to low dissolved oxygen levels. As stated earlier in this rationale when 

developing the Charleston Harbor TMDL for DO, it was determined that this facility does not contribute to the DO deficit. 

Aside from DO, there is no information showing that the shortnose sturgeon is more sensitive than the established 

Saltwater Aquatic Life criteria used to evaluate the permit limitations. Therefore based on known information this permit is 

protective of the shortnose sturgeon.

Within a 5-mile radius of the site there are plant species that are “of concern”, the plants, with their global and state 

rankings are as follows:

Species Ranking Species Ranking

Nutmeg Hickory G4, S2 Virginia Bunchflower G5, S2

Reclined Meadow-Rue G1G2Q, S1S2 Bottom-Land Post Oak G4, S1

Long-Horn Orchid G4G5, S1 Southeastern Tickseed G4G5, SNR

Biltmore Greenbrier G4?, S2 Coastal-Plain Water-Hyssop G3G5, S1

Slender-Leaved Dragon-Head G4?, SNR Southern Twayblade G4, S2

There is also one vertebrate animal listed within the 5-mile radius, which has both a global and state ranking and a State 

legal status. This animal is:

Species Ranking Legal Status

Bald Eagle G5, S2 SE – Endangered, State

 

Global rankings:

G1 - Critically imperiled globally because of extreme rarity or because of some factor(s) making it especially vulnerable to extinction

G2 - Imperiled globally because of rarity or factor(s) making it vulnerable

G3 - Either very rare throughout its range or found locally in a restricted range, or having factors making it vulnerable

G4 - Apparently secure globally, though it may be rare in parts of its range

G5 - Demonstrably secure globally, though it may be rare in parts of its range

G? - Status unknown

Q - Questionable taxonomy that may reduce conservation priority - Distinctiveness of this entity as a taxon or ecosystem type at 

the current level is questionable; resolution of this uncertainty may result in change from a species to a subspecies or hybrid, or 

inclusion of this taxon or type in another taxon or type, with the resulting taxon having a lower-priority (numerically higher) 

conservation status rank. The “Q” modifier is only used at a global level and not at a national or subnational level. 
Rationale

Page 8 of 30

Permit No. SC0046175

State rankings:

S1 -Critically imperiled state-wide because of extreme rarity or because of some factor(s) making it especially vulnerable to extirpation 

S2 -Imperiled state-wide because of rarity or factor(s) making it vulnerable

S3 - Rare or uncommon in state

S4 - Apparently secure in state

S5 - Demonstrably secure in state

SNR - State Not Ranked

There does not appear to be any limitations that could be placed in this permit, which will have any impact on any of the 

species listed above.

Coal Ash Basins Operation and Maintenance (Part V.D.6)

Coal ash basins are used to treat or store wastewater and thus are included in the permit’s operation and maintenance 

requirements. Regulation 61-9.122.41(e) requires the permittee to properly operate and maintain all facilities of treatment 

and control used to achieve compliance with their permits. 

The permit includes new requirements to address coal ash basin operation and maintenance. The permit requires monthly 

inspections by trained personnel. Increased monitoring is required after large precipitation events, when there is an 

increased stress to impoundments and a greater potential for impacts on integrity. In addition, annual inspections by a 

qualified professional engineer are required. In response to any changes, such as cracks, erosion, bulges, and changes in 

seepage that may compromise the structural integrity, the permittee is also required to respond in a timely manner. The 

permit requires annual reporting of inspection and remedial activities as well as timely reporting of changes to integrity and 

associated corrective actions. These new requirements are intended to increase the permittee’s focus on operation and 

maintenance to reduce future risks of basin compromise. Inspections which are required by some other agency may be 

used to meet the permit requirements as long as they meet all the requirements of this permit. 

II. GENERAL INFORMATION

A. The effluent from this facility may be subject to the requirements of any of the following regulations: R.61-68, 

R.61-69, R.61-9.122, 124, 125, 129, 133, and 403; 40 CFR Part 136; Subchapter N (40 CFR Parts 400 through 

402 and 404 through 471); and R.61-9.503, 504 and 505.

B. Authority: This permit is written in accordance with applicable laws and regulations including, but not limited to, 

Regulation 61-9, Regulation 61-68, Pollution Control Act and Clean Water Act.

C. Under R.61-9.124.8 (Fact Sheet), a fact sheet shall be prepared for every draft permit for a major NPDES facility or 

activity, for every Class I sludge management facility, for every NPDES draft permit that incorporates a variance or 

requires an explanation under section 124.56(b), and for every draft permit which the Department finds is the subject 

of wide-spread public interest or raises major issues. 

D. The conclusions noted in the Rationale establish proposed effluent limitations and permit requirements addressed 

in R.61-9.122.43 (Establishing Permit Conditions), R.61-9.122.44 (Establishing Limitations, Standards and other 

permit conditions) and other appropriate sections of R.61-9.
Rationale

Page 9 of 30

Permit No. SC0046175

III. BACKGROUND AND PROCEDURES FOR PERMIT LIMIT DEVELOPMENT

A. The receiving waterbody 7Q10, annual average flow or other critical flow condition at the discharge point, and 

7Q10, annual average flow, or other critical flow condition for source water protection are determined by the 

SCDHEC’s Wasteload Allocation Section. The 7Q10, Annual Average Flow or other critical flow conditions are 

based on information published or verified by the USGS, an estimate extrapolation from published or verified 

USGS data or from data provided by the permittee. These flows may be adjusted by the Wasteload Allocation 

Section to account for existing water withdrawals that impact the flow. The 7Q10 (or 30Q5 if provided by the 

applicant), annual average flow at the discharge point, or other critical flow condition or 7Q10 (or 30Q5 if 

provided by the applicant), annual average flow or other critical flow condition for source water protection for a 

proposed or existing surface water drinking water intake will be used to determine dilution factors, as appropriate, 

in accordance with R.61-68.C.4.a & 4.b for aquatic life, human health, and organoleptic effects respectively. 

B. Water and organism consumption and drinking water MCL criteria will be evaluated for protection of human 

health when calculating dilution factors. “The Department may, after Notice of Intent included in a notice of a 

proposed NPDES permit in accordance with Regulation 61-9.124.10, determine that drinking water MCLs or W/O 

shall not apply to discharges to those waterbodies where there is: no potential to affect an existing or proposed 

drinking water source and no state-approved source water protection area.” For permitting purposes, “a proposed 

drinking water source is one for which a complete permit application, including plans and specifications for the 

intake, is on file with the Department at the time of consideration of an NPDES permit application for a discharge 

that will affect or has the potential to affect the drinking water source” (R.61-68.E.14.c(5)). 

The Department will implement this protection in NPDES permits using the source water protection program 

already developed for the drinking water program. A source water protection program was developed originally in 

1999 to define the source water protection areas for each drinking water intake. The program was designed to 

identify source water protection areas (SWPAs) to aid drinking water systems in identifying sources of potential 

contamination that could affect their intakes. In September 2009, this program was modified to redefine the 

SWPAs as smaller, more manageable areas. The revised document developed in September 2009 is entitled 

“South Carolina Drinking Water Source Assessment and Protection Program.” For the purposes of NPDES 

permitting, the SWPA referred to in Regulation 61-68.E.14.c(5) is the Primary Protection Area defined in the 

revised assessment and protection document. More information regarding the use of these protection areas is 

provided later in this rationale with the discussion of the procedure for establishing permit limits in Section G.2.

C. Application of numeric criteria to protect human health: If separate numeric criteria are given for organism 

consumption, water and organism consumption (W/O), and drinking water Maximum Contaminant Levels 

(MCLs), they shall be applied as appropriate. The most stringent of the criteria shall be applied to protect the 

existing and classified uses of the waters of the State (R.61-68.E.14.b(1)).

D. Numeric criteria have been established in R.61-68 based on organoleptic data (prevention of undesirable taste and 

odor). For those substances which have aquatic life and/or human health numeric criteria and organoleptic numeric 

criteria, the most stringent of the three shall be used for derivation of permit effluent limitations. See R.61-68.E.13.

E. Sampling Frequency: Samples and measurements taken for the purpose of monitoring shall be representative of the 

monitored activity. Monitoring results must be conducted according to test procedures approved under 40 CFR Part

136, unless other test procedures have been specified in the permit (R.61-9.122.41(j)(4)). Typically, requirements 

to report monitoring results shall be established on a case-by-case basis with a frequency dependent on the nature 

and effect of the discharge but in no case less than once a year (R.61-9.122.44(i)(2)).
Rationale

Page 10 of 30

Permit No. SC0046175

F. Compliance Schedules:

1. A person issued an NPDES permit by the Department who is not in compliance with applicable effluent standards 

and limitations or other requirements contained therein at the time the permit is issued, shall be required to 

achieve compliance within a period of time as set forth by the Department, with effluent standards and limitations, 

with water quality standards, or with specific requirements or conditions set by the Department. The Department 

shall require compliance with terms and conditions of the permit in the shortest reasonable period of time as 

determined thereby or within a time schedule for compliance which shall be specified in the issued permit. (R.61-

9.122.47(c)(1))

2. If a time schedule for compliance specified in an NPDES permit which is established by the Department, exceeds 

nine (9) months, the time schedule shall provide for interim dates of achievement for compliance with certain 

applicable terms and conditions of the permit. (R.61-9.122.47(c)(2))

G. Procedure for establishing effluent limitations:

1. Effluent limits (mass and concentration) for Five day Biochemical Oxygen Demand (BOD5), Ultimate Oxygen 

Demand (UOD), Dissolved Oxygen (DO), Total Ammonia Nitrogen (as N), and Nutrients (e.g., nitrogen and 

phosphorus) are established by the Wasteload Allocation (WLA) Section, with consideration given to 

technology-based limitations.

a. Five day Biochemical Oxygen Demand BOD5, Ultimate Oxygen Demand (UOD), Dissolved Oxygen 

(DO):

Effluent limits for conventional oxygen demanding constituents (BOD5, UOD and DO) are established to 

protect in-stream water quality, while utilizing a portion of the assimilative capacity of the receiving water. 

The ability of a water body to assimilate oxygen-demanding substances is a function of its physical and 

chemical characteristics above and below the discharge point. Various mathematical techniques, called 

models, have been developed to estimate this capacity. The Department follows the procedures as outlined 

in the “State/EPA Region IV Agreement on the Development of Wasteload Allocations/Total Maximum 

Daily Loads and NPDES Permit Limitations” dated October 30, 1991 (as updated) for determining the 

assimilative capacity of a given water body. Mathematical models such as QUAL2E and QUAL2EUNCAS are used in accordance with “Enhanced Stream Water Quality Models QUAL2E and QUAL2EUNCAS: Documentation and Users Manual” (EPA/600/3-87/007; dated May 1987) as updated. BOD5

and UOD values determined from modeling results will be used in permitting as monthly average derived 

limits (Cwla). Daily maximum derived limits will typically be determined by multiplying the monthly 

average value by two.

For facilities subject to effluent guidelines limitations or other technology-based limitations, BOD5 will 

also be evaluated in accordance with the applicable industrial categorical guidelines. These guidelines will 

be identified in Part I of this rationale when they are applicable to the permit.

b. Total Ammonia Nitrogen (as N):

Ammonia limitations based on oxygen demand will be determined from modeling information as described 

above. These values will be used as monthly average derived limits and a daily maximum will typically be 

determined by multiplying the monthly average derived limit by two. These values will be compared with 

the ammonia water quality criteria for protection of aquatic life from Regulation 61-68, Attachment 3 and 

any categorical limitations. The more stringent of the limitations will be imposed. Calculations for aquatic 

life criteria and other wasteload recommendations are shown in Part I of this rationale when ammonia is a 

pollutant of concern.
Rationale

Page 11 of 30

Permit No. SC0046175

c. Discharges of Nutrients:

In order to protect and maintain lakes and other waters of the State, consideration is given to the control of 

nutrients reaching the waters of the State. Therefore, in accordance with regulation R.61-68.E.11, the 

Department controls the nutrients as prescribed below. Nutrient limitations will be determined from the 

best available information and/or modeling performed by the Wasteload Allocation Section to meet these 

water quality standards.

i. Discharges of nutrients from all sources, including point and nonpoint, to waters of the State shall be 

prohibited or limited if the discharge would result in or if the waters experience growths of 

microscopic or macroscopic vegetation such that the water quality standards would be violated or the 

existing or classified uses of the waters would be impaired. Loading of nutrients shall be addressed on 

an individual basis as necessary to ensure compliance with the narrative and numeric criteria.

ii. Numeric nutrient criteria for lakes are based on an ecoregional approach which takes into account the 

geographic location of the lakes within the State and are listed below. These numeric criteria are 

applicable to lakes of 40 acres or more. Lakes of less than 40 acres will continue to be protected by 

the narrative criteria.

1. For the Blue Ridge Mountains ecoregion of the State, total phosphorus shall not exceed 0.02 mg/l, 

chlorophyll a shall not exceed 10 ug/l, and total nitrogen shall not exceed 0.35 mg/l

2. For the Piedmont and Southeastern Plains ecoregions of the State, total phosphorus shall not 

exceed 0.06 mg/l, chlorophyll a shall not exceed 40 ug/l, and total nitrogen shall not exceed 1.50 

mg/l

3. For the Middle Atlantic Coastal Plains ecoregion of the State, total phosphorus shall not exceed 

0.09 mg/l, chlorophyll a shall not exceed 40 ug/l, and total nitrogen shall not exceed 1.50 mg/l.

iii. In evaluating the effects of nutrients upon the quality of lakes and other waters of the State, the 

Department may consider, but not be limited to, such factors as the hydrology and morphometry of the 

waterbody, the existing and projected trophic state, characteristics of the loadings, and other control 

mechanisms in order to protect the existing and classified uses of the waters.

iv. The Department shall take appropriate action, to include, but not limited to: establishing numeric 

effluent limitations in permits, establishing Total Maximum Daily Loads, establishing waste load 

allocations, and establishing load allocations for nutrients to ensure that the lakes attain and maintain 

the narrative and numeric criteria and other applicable water quality standards.

v. The criteria specific to lakes shall be applicable to all portions of the lake. For this purpose, the 

Department shall define the applicable area to be that area covered when measured at full pool 

elevation.

2. Effluent concentration limits (Cefflim) for parameters other than the parameters listed in G.1.a-c (except 

ammonia toxicity calculations) above are established using the following procedures:

Q7Q10 7Q10 or other critical flow condition of the receiving water at the discharge point in mgd. 

(may require adjustment for withdrawals) 

AAFd Average Annual Flow (AAF) or other critical flow condition of the receiving water at the 

discharge point in mgd. (may require adjustment for withdrawals) 

Q7Q10i 7Q10 or other critical flow condition of the receiving water at either the SWP Area 15-river 

mile boundary or at the intake, as appropriate, in mgd.
Rationale

Page 12 of 30

Permit No. SC0046175

AAFi Average Annual Flow (AAF) of the receiving water at either the SWP Area 15-river mile 

boundary or at the intake, as appropriate, in mgd.

Qd Long term average discharge flow in mgd. 

a. Determine dilution factors:

The following information is to be used (where applicable) for establishing effluent concentration limits:

DF1: This dilution factor is based on 7Q10 or other critical flow condition of the receiving water at the 

discharge point (Q7Q10). This dilution factor is used to determine the derived limits for protection of 

the following aquatic life and human health concerns for the reasons indicated:

i. Aquatic Life (see R.61-68.C.4.a(1)). Protection of aquatic life on a short-term basis is needed 

at the point where aquatic organisms become exposed to the discharge.

ii. Human Health – Organism Consumption for parameters identified as non-carcinogens per 

R.61-68.C.4.b(1). Protection for human health on a short-term basis for consumption of 

aquatic organisms is needed at the point the aquatic organisms become exposed to the 

discharge.















 



d

Q d

Q

Q Q

DF 7 10

1

DF2: This dilution factor is based on the Average Annual Flow or other critical flow of the receiving 

water at the discharge point (AAFd). This dilution factor is used to determine the derived limits for 

protection of the following human health and organoleptic concerns for the reasons indicated:

i. Human Health – Organism Consumption for parameters identified as carcinogens per R.61-

68.C.4.b(1). Protection for human health on a long-term basis to prevent cancer due to 

consumption of aquatic organisms is needed at the point the aquatic organisms become 

exposed to the discharge.

ii. Organoleptic effects per R.61-68.C.4.b(1). Protection for taste and odor issues related to the 

discharge is needed at the point where the discharge enters the receiving water. 















 



d

d d

Q

AAF Q

DF2

DF3: This dilution factor is based on the 7Q10 or other critical flow condition (Q7Q10i) for protection of a 

proposed or existing surface water drinking water intake that the discharge has the potential to 

affect. This dilution factor is used to determine the derived limits for protection of the following 

human health concerns for the reasons indicated:

i. Human Health – Water and Organism (W/O) Consumption for parameters identified as noncarcinogens per R.61-68.C.4.b(1) and E.14.c(5) to protect for short-term health effects when 

the discharge has the potential to affect a surface water drinking water intake. Protection of 

human health relative to drinking the water from the waterbody and consuming aquatic 

organisms from the same waterbody is provided by this criterion, but drinking the water 

withdrawn from the waterbody may require a higher level of protection in terms of applicable 

dilution than consumption of organisms. 
Rationale

Page 13 of 30

Permit No. SC0046175

ii. Human Health - Drinking Water Maximum Contaminant Level (MCL) for parameters 

identified as non-carcinogens per R.61-68.C.4.b(1) and E.14.c(5) to protect for short-term 

health effects when the discharge has the potential to affect a surface water drinking water 

intake. Protection of human health relative to drinking the water from the waterbody after 

conventional treatment per R.61-68.G is provided by this criterion. 















 



d

Q i d

Q

Q Q

DF 7 10

3

DF4: This dilution factor is based on the Average Annual Flow or other critical flow condition (AAFi) 

for protection of a proposed or existing surface water drinking water intake that the discharge has 

the potential to affect. This dilution factor is used to determine the derived limits for protection of 

the following human health concerns for the reasons indicated:

i. Human Health–Water and Organism Consumption for parameters identified as carcinogens 

per R.61-68.C.4.b(1) and E.14.c(5) to protect for long-term health effects due to cancer when 

the discharge has the potential to affect a surface water drinking water intake. Protection of 

human health relative to drinking the water from the waterbody and consuming aquatic 

organisms from the same waterbody is provided by this criterion, but drinking the water 

withdrawn from the waterbody may require a higher level of protection in terms of applicable 

dilution than consumption of organisms. 

ii. Human Health - Drinking Water Maximum Contaminant Level (MCL) for parameters 

identified as carcinogens per R.61-68.C.4.b(1) and E.14.c(5) to protect for long-term health 

effects due to cancer when the discharge has the potential to affect a surface water drinking 

water intake. Protection of human health relative to drinking the water from the waterbody 

after conventional treatment per R.61-68.G is provided by this criterion. 















 



d

i d

Q

AAF Q

DF4

For both DF3 and DF4, to satisfy the mixing zone requirements of R.61-68.C.10(a) for both W/O and MCL 

criteria, the Department will use the following flows to determine dilution:

1. The following applies to discharges and intakes in flowing rivers:

a. Where the discharge is within the SWPA (15 river miles) of the intake, the flow at the 15-river 

mile boundary of the tributary with the largest applicable critical flow will be used. 

b. Where the discharge is outside the SWPA (15 river miles) of the intake, the applicable critical 

flow at the intake will be used. 

2. When the discharge is either in the tributary to a lake or in a lake and the intake is in the same lake that 

does not behave as a run-of- river impoundment*, the flow is determined using the sum of the 

applicable critical flows of all tributaries entering the lake. 

3. The following applies when both the discharge and the intake are in a lake arm that behaves as a runof-river impoundment*:
Rationale

Page 14 of 30

Permit No. SC0046175

a. Where the discharge is within the SWPA (15-mile buffer which may include both lake and river 

miles) of the intake, the flow at the 15-mile boundary of the tributary with the largest applicable 

critical flow will be used.

b. Where the discharge is outside the SWPA (15-mile buffer which may include both lake and river 

miles) of the intake, the applicable critical flow at the intake will be used. 

4. Where the discharge is in the arm of a lake and the intake is in the upper reach of another arm of the 

lake, no protection of W/O or MCL criteria is needed because the discharge does not have the potential 

to affect the intake,

5. If the discharge has the potential to affect multiple intakes, the SWPA of the intake closest to the 

discharge will be protected. However, the permittee may be required to provide notification to all 

potentially affected intakes.

* Run-of-river impoundment is defined as a lake or reservoir (or arm of a lake or reservoir) that is 

narrow and/or shallow offering little dilution or delay in contaminant flow toward an intake.

b. Determine derived limits using the following procedures:

WQSal Freshwater Standard (based on an established criteria or other published data per R.61-68) for 

protection of Aquatic Life; may be a CCC or CMC as defined below

WQSorg Standard (based on an established criteria or other published data per R.61-68) for protection of 

Human Health – Organism Consumption

WQSwo Standard (based on an established criteria or other published data per R.61-68) for protection of 

Human Health – Water & Organism Consumption. 

WQSmcl Standard (based on an established criteria or other published data per R.61-68) for Drinking Water 

MCL (Maximum Contaminant Level). 

WQSol: Standard (based on an established criteria or other published data per R.61-68) based on 

Organoleptic Data.

Caqlife Concentration limit derived from aquatic life data

CHH Concentration limit derived from human health data as determined from organism (Corg), 

water/organism (Cwo)and MCL (Cmcl) data

Col Concentration limit derived from organoleptic data

Cb The background concentration of the concerned parameter in mg/l is typically determined from 

ambient monitoring data or data provided by applicant. If the waterbody to which the discharge 

flows is not on the 303(d) list, the 90th percentile of ambient monitoring data for aquatic life 

protection for the parameters identified in the Appendix (Water Quality Numeric Criteria) to 

Regulation 61-68 from the last 3 years, or whatever is available if less than 3 years, will typically 

be used. If the waterbody to which the discharge flows is not on the 303(d) list, the median value 

of ambient monitoring data for human health protection for the parameters identified in the 

Appendix (Water Quality Numeric Criteria) to Regulation 61-68 from the last 3 years, or whatever 

is available if less than 3 years, will typically be used. The background concentration is assumed to 

be zero (0) in the absence of actual data based on Departmental guidance and EPA 

recommendation.
Rationale

Page 15 of 30

Permit No. SC0046175

i. Determine the derived limits for protection of Aquatic Life (Caqlife)

1. The following guidelines apply to determining aquatic life limits using this basic equation:

































   

d

Q

aqlife a l b Q

Q

C DF WQS C

7 1 0

1

( )

a. Typically, the Criterion Maximum Concentration (CMC) is applied as a daily maximum 

derived limit and the Criterion Continuous Concentration (CCC) is applied as a monthly 

average derived limit, after consideration of dilution and background concentrations. The 

CMC and CCC for specific metals will be adjusted using the procedures in 60 FR 22229, 

“Water Quality Standards; Establishment of Numeric Criteria for Priority Toxic Pollutants; 

States’ Compliance-Revision of Metals Criteria,” May 4, 1995 and the “Technical Guidance 

on Interpretation and Implementation of Aquatic Life Metals Criteria,” Oct. 1, 1993 and 

applied as a daily maximum and monthly average, respectively, after consideration of dilution 

and background concentrations. For specific metals, this calculation is explained in detail 

later in this rationale.

monthly average = Caqlife using CCC as WQSal

daily maximum = Caqlife using CMC as WQSal

b. If only a CMC exists for a particular parameter, the daily maximum derived permit limit will 

be set using that value, after consideration of dilution and background concentrations. If no 

other values (e.g., human health) exist for that parameter on which to base a monthly average 

limit and the discharge is continuous, the monthly average will be set equal to the daily 

maximum to satisfy Regulation 61-9.122.45(d). In no case shall the monthly average limit be 

set higher than the daily maximum limit. If only a CCC is given, it will be used as a monthly 

average derived limit and the daily maximum derived limit will be two (2) times the value 

obtained for the monthly average based on a simplified statistical procedure for determining 

permit limits recommended in Section 5.4.2 of the US EPA’s “Technical Support Document 

for Water Quality-based Toxics Control”, EPA/505/2-90-001, March 1991 (hereafter known

as the TSD). 

If a CCC exists and no CMC exists and no other acute or chronic data exists, the aquatic life 

limits are 

monthly average = Caqlife using CCC as WQSal

daily maximum = 2 x Caqlife

If a CMC and no CCC exists, and no other acute or chronic data exists, the aquatic life limits 

are 

monthly average = Caqlife using CMC as WQSal

daily maximum = Caqlife using CMC as WQSal
Rationale

Page 16 of 30

Permit No. SC0046175

c. If only an acute toxicity effect concentration for a number of species for a particular pollutant 

is given as a LC50, the lowest concentration should be divided by an acute-to-chronic ratio 

(ACR) of 10 and a sensitivity factor of 3.3, for an acceptable instream concentration in order 

to protect against chronic toxicity effects (R.61-68.E.16.a(1)). Other acute toxicity data will be 

handled similarly. The value obtained from this calculation will be used as a monthly average 

derived limit after consideration of dilution and background concentrations. The daily 

maximum will be two (2) times the value obtained for the monthly average based on a 

simplified statistical procedure for determining permit limits recommended in Section 5.4.2 of 

the TSD. 

monthly average = Caqlife using other data as WQSal

daily maximum = 2 x Caqlife

d. If a chronic toxicity effect concentration for a number of species for a particular pollutant is 

given as a no observed effect concentration (NOEC), the lowest concentration should be 

divided by a sensitivity factor of 3.3 in order to protect against chronic toxicity to the most 

sensitive species (R.61-68.E.16.a(2)). Other chronic toxicity data will be handled similarly. 

The value obtained from this calculation will be used as a monthly average derived limit after 

consideration of dilution and background concentrations. The daily maximum will be two (2) 

times the value obtained for the monthly average based on a simplified statistical procedure for 

determining permit limits recommended in Section 5.4.2 of the TSD. 

monthly average = Caqlife using other data as WQSal

daily maximum = 2 x Caqlife

e. If both acute and chronic data are available for a particular pollutant, monthly average derived 

limit will be calculated as in c and d above for each acute and chronic, respectively. The more 

stringent of the monthly average derived limits will be the monthly average derived limit used 

after consideration of dilution and background concentrations. The daily maximum will be 

two (2) times the value obtained for the monthly average based on a simplified statistical 

procedure for determining permit limits recommended in Section 5.4.2 of the TSD.

monthly average = Caqlife using other data as WQSal

daily maximum = 2 x Caqlife

f. Consider the background concentration (Cb) of the parameter of concern. If the background 

concentration is equal to or greater than the applicable standard (WQS, as defined above) for 

the parameter of concern, then the derived concentration limit (Caqlife) for that parameter is 

established equal to the standard (WQS) so that no additional amount of that pollutant is added 

to the waterbody. An exception exists where the naturally occurring instream concentration for 

a substance is higher than the derived permit effluent limitation. In those situations, the 

Department may establish permit effluent limitations (Cefflim) at a level higher than the derived 

limit, but no higher than the natural background concentration (i.e. a “rise above background” 

limit). In such cases, the Department may require biological instream monitoring and/or whole 

effluent toxicity (WET) testing (R.61-68.E.14.c(2)). 

If Cb is not based on naturally occurring concentrations and

Cb  WQS

Then, generally,

Caqlife  WQS .
Rationale

Page 17 of 30

Permit No. SC0046175

If Cb is based on naturally occurring concentrations and

Cb WQS

Then, generally,

Caqlife  Ceff lim  Cb

.

2. Metals: Regulation 61-9.122.45(c) requires that permit limits be expressed in terms of total 

recoverable metal (with limited exceptions). In order to translate from the water quality criterion 

to a total recoverable metal, Regulation R.61-68.E.14.c(4) provides for the use of the EPA Office 

of Water Policy and "Technical Guidance on Interpretation and Implementation of Aquatic Life 

Metals Criteria", October 1, 1993. A subsequent revision published in the Federal Register (60 

FR 22229) on May 4, 1995 updated the data in the original report. See R.61-68 Appendix for 

CMC and CCC values and equations, Attachment 1 for “Conversion Factors for Dissolved 

Metals” and Attachment 2 “Parameters for Calculating Freshwater Dissolved Metals Criteria that 

are Hardness-Dependent”. 

Per R.61-68.E.14.a(3), the CMC and CCC are based on a hardness of 25 mg/l if the ambient or 

mixed stream hardness is equal to or less than 25 mg/l. Concentrations of hardness less than 400 

mg/l may be based on the mixed stream hardness if it is greater than 25 mg/l and less than 400 

mg/l and 400 mg/l if the ambient stream hardness is greater than 400 mg/l. The ambient stream 

hardness is assumed to be 25 mg/l in the absence of actual stream data. Mixed stream hardness 

may be determined using flow-weighted effluent hardness and stream hardness.

The following equations and constants will be used to calculate aquatic life metals limits based on 

these documents. The values of the terms referenced in this section and determined from the 

equations below are included in the Metals spreadsheet attached to this rationale. The following 

metals are subject to this section:

arsenic lead

cadmium mercury

chromium (III & VI) nickel 

copper zinc

The equation for Cd below changes the total metal to dissolved metal. From Technical Guidance 

Manual for Performing Waste Load Allocations Book II, Rivers and Streams, EPA/440/484/022, 

S  CCC orCMC

(adjusted for hardness)

Cd  S CF

where Cd = Dissolved metal concentration (μg/l)

S = a constant to represent the CCC or CMC (μg/l)

CF = Conversion factor considered most relevant in fresh water for aquatic life as 

defined by EPA for each metal 

Once the dissolved metal concentration is known, determine Cp using the equation for Cd above 

and the following equations. 

  

6

1 10 Cp Cd   Kpb TSSb 

a

po b b

Kp K (TSS )
Rationale

Page 18 of 30

Permit No. SC0046175

where Cp = Particulate sorbed metal concentration (μg/l). This value represents the 

revised water quality criterion for the metal to be used for ambient data 

comparison. 

Kpb= Linear partition coefficient using the stream TSS (liters/mg)

Kpo = Metal-specific equilibrium constant (liters/mg)

a = Metal-specific constant 

TSSb = Background or in-stream Total Suspended Solids (TSS) concentration 

(mg/l). The background TSS is assumed to be 1 mg/l in the absence of 

actual instream data based on the 5th percentile of ambient TSS data on 

South Carolina waterbodies from 1993-2000.

To determine the effluent limit (Caqlife), use the following equations to translate the limits into a 

total recoverable metal concentration. 

 

7 1 0

7 1 0 ( )

d Q

d e Q b

avg Q Q

Q TSS Q TSS

TSS



  



where TSSe = Effluent Total Suspended Solids (TSS) concentration (mg/l) determined 

from actual long-term average data or proposed permit limits if no data 

available.

TSSavg = Average in-stream (mixed) TSS concentration (mg/l)

  

6

1 10 Ct Cd   KpTSSavg

a Kp Kpo TSSavg

 ( )

where Ct = Total metal concentration (μg/l)

Kp = Linear partition coefficient (liters/mg). This is the distribution of metal at 

equilibrium between the particulate and dissolved forms.

Once Ct has been calculated, it is multiplied by DF1 and background concentrations are accounted 

for to obtain the derived limit (max or avg) (Caqlife):

































   

d

Q

aqlife t b Q

Q

C C DF C

7 1 0

1

( )

monthly average = Caqlife based on CCC

daily maximum = Caqlife based on CMC

3. Where a Water Effects Ratio (WER) is used to adjust a criterion, derived limits for the adjusted 

aquatic life criterion (Caqlife-adj) are calculated as follows. The WER is a type of site-specific permit 

effluent limit (as allowed by R.61-68.E.14.c(7)) derived using a ratio determined from EPA 

methodology. Both DHEC and EPA must approve the WER prior to implementation. See EPA's 

1994 “Interim Guidance on the Determination and Use of Water-Effect Ratios (WERs) for 

Metals.” The approved WER will be shown in the water quality spreadsheets on the Data sheet. 

The revised aquatic life value will be shown with the WER, hardness and dissolved metals 

adjustments, as appropriate, in the aquatic life columns on the Pollutant spreadsheet. 
Rationale

Page 19 of 30

Permit No. SC0046175

a. For metals identified in #2 above, revise the equation for S as follows:

S = [CCC or CMC (adjusted for hardness)] x WER

Follow the remaining calculations in #2 above to get an adjusted Caqlife value that will be used 

to determine derived limits:

monthly average = Caqlife-adj based on CCC

daily maximum = Caqlife-adj based on CMC

b. For other parameters, use the appropriate equation in #1 above to derive an adjusted Caqlife

value. The monthly average will be calculated as follows using the appropriate WQSal and the 

daily maximum calculated using the appropriate equations in #1 above.

































     

d

Q

aqlife adj a l b Q

Q

C DF WQS WER C

7 1 0

1

( )

4. Where the Recalculation Procedure is used to adjust a criterion, derived limits for the adjusted 

aquatic life criterion (Caqlife-adj) are calculated as follows. The Recalculation Procedure is intended 

to cause a site-specific criterion to appropriately differ from the State-adopted national aquatic life 

criterion if justified by demonstrated pertinent toxicological differences between the aquatic 

species that occur at the site and those that were used in the derivation of the criterion. It is 

important to note that the site (the portion of the waterbody or watershed being affected) must be 

clearly defined. This procedure is used to develop site-specific criteria in accordance with R.61-

68.C.12. Both DHEC and EPA must approve the recalculated criterion prior to implementation. 

The recalculated criterion will require an update to the Water Classifications and Standards 

Regulations, R.61-68 and 61-69.

The approved recalculated aquatic life criteria (SS-CCC and SS-CMC, as appropriate) will be 

shown adjusted for hardness on the Data spreadsheet. The additional dissolved metals adjustments, 

as appropriate, will be shown in the aquatic life columns on the Pollutant spreadsheet. If the 

parameter being adjusted is one of the metals in #2 above, SS will include all the appropriate 

metals adjustments.

































    

d

Q

aqlife adj b Q

Q

C DF SS C

7 1 0

1

(

monthly average = Caqlife-adj based on CCC

daily maximum = Caqlife-adj based on CMC

5. Where a WER and recalculation procedure are combined to adjust a criterion, derived limits 

(Caqlife-adj) for aquatic life protection are calculated by combining the calculations in #3 and #4.

































     

d

Q

aqlife adj b Q

Q

C DF SS WER C

7 1 0

1

( )

monthly average = Caqlife-adj based on CCC

daily maximum = Caqlife-adj based on CMC
Rationale

Page 20 of 30

Permit No. SC0046175

6. Other scientifically defensible methods for developing site-specific aquatic life effluent limits or 

site-specific criterion may be used on a case-by-case basis.

ii. Determine derived limits for protection of Human Health

1. The following guidelines apply to determining human health limits:

a. The human health criterion given by Regulation 61-68 will be applied as a monthly average 

derived limit after consideration of dilution and background concentrations (CHH-avg). 

Exceptions exist based on EPA criteria and are indicated for specific parameters. No limits on 

human health based on water and organism consumption or drinking water MCLs will be 

imposed if there is no potential to affect an existing or proposed surface water drinking water 

intake and no state-approved source water protection area in accordance with Regulation 61-

68.E.14.c(5).

b. The daily maximum permit limit will be determined from the monthly average value from (a) 

above and a multiplier (M) determined using a statistical procedure recommended in Section 

5.5 using average = 95th percentile from Table 5-3 in the TSD. The permitted or proposed 

number of samples per month (n) is used with the coefficient of variation (CV) to determine

M. 

( 0.5 )

( 0.5 )

2

2

a n n

m

Z

Z

e

e M

 

 







where:

















 ln 1

2

2

n

CV

 n

ln 1

2 2   CV 

CV = coefficient of variation of the effluent concentration. For a data set where 

n>10, the CV is calculated as standard deviation divided by mean for the data 

set being evaluated. For data set where n<10, the CV is estimated to equal 

0.6. For less than 10 items of data, the uncertainty in the CV is too large to 

calculate a standard deviation or mean with sufficient confidence.

n = the number of effluent samples per month (where frequency is less than 

1/month, n =1) 

zm = the percentile exceedance probability for the daily maximum permit limit 

(=2.326 for 99th percentile basis)

za = the percentile exceedance probability for the monthly average permit limit 

(=1.645 for 95th percentile basis)

CHH-max = M * CHH-avg

c. Consider the background concentration (Cb) of the parameter of concern. If the background 

concentration is equal to or greater than the applicable standard (WQS, as defined above) for 

the parameter of concern, then the derived concentration limit (CHHe) for that parameter and for 

the protection of that standard is established equal to the standard (WQS). An exception exists 

where the naturally occurring instream concentration for a substance is higher than the derived 

permit effluent limitation. In those situations, the Department may establish permit effluent 
Rationale

Page 21 of 30

Permit No. SC0046175

limitations (Cefflim) at a level higher than the derived limit, but no higher than the natural 

background concentration (i.e. a “rise above background” limit). In such cases, the 

Department may require biological instream monitoring and/or whole effluent toxicity (WET) 

testing (See R.61-68.E.14.c(3)). 

If Cb is not based on naturally occurring concentrations and

Cb  WQS

Then, generally,

CHH WQS .

If Cb is based on naturally occurring concentrations and

Cb WQS

Then, generally,

CHH  Ceff lim  Cb

.

2. Human Health – Organism Consumption (Corg).

a. For Carcinogens 

The Monthly Average is calculated as follows:

































   

d

d

org org b Q

AAF C (DF2 WQS ) C

The Daily Maximum is calculated as

Corg-max = M * Corg

b. For Non-carcinogens

The Monthly Average is calculated as follows:

































   

d

Q

org org b Q

Q

C DF WQS C

7 1 0

1

( )

The Daily Maximum is calculated as

Corg-max = M * Corg

3. Human Health – Water and Organism Consumption (Cwo) 

a. For Carcinogens 

The Monthly Average is calculated as follows:

































   

d

i

wo wo b Q

AAF C (DF4 WQS ) C
Rationale

Page 22 of 30

Permit No. SC0046175

The Daily Maximum is calculated as

Cwo-max = M * Cwo

b. For Non-carcinogens 

The Monthly Average is calculated as follows:

































   

d

Q i

wo wo b Q

Q

C DF WQS C

7 1 0

3

( )

The Daily Maximum is calculated as

Cwo-max = M * Cwo

4. Human Health – Drinking Water Maximum Contaminant Level (MCL) (Cmcl).

a. For Carcinogens 

The Monthly Average is calculated as follows:

































   

d

i

mcl mcl b Q

AAF C (DF4 WQS ) C

The Daily Maximum is calculated as

Cmcl-max = M * Cmcl

b. For Non-carcinogens 

The Monthly Average is calculated as follows:

































   

d

Q i

mcl mcl b Q

Q

C DF WQS C

7 1 0

3

( )

The Daily Maximum is calculated as

Cmcl-max = M * Cmcl

5. Organoleptic criteria (Col).

The Monthly Average is calculated as follows:

































   

d

d

o l o l b Q

AAF C (DF2 WQS ) C

The Daily Maximum is calculated as

Col-max = M * Col
Rationale

Page 23 of 30

Permit No. SC0046175

iii. Parameters given in a wasteload allocation for oxygen-demanding pollutants and nutrients will be 

limited as

monthly average = Cwla

daily maximum = 2 x Cwla

c. Determine the most stringent of applicable water quality data using the derived limits determined above:

monthly average Cefflim = minimum of derived monthly averages (Caqlife, Corg, Cwo, Cmcl, Col , Cwla) 

daily maximum Cefflim = minimum of derived daily maximums (Caqlife, Corg-max, Cwo-max, Cmcl-max, Col-max , Cwla-max) 

d. Determine whether the discharge causes, has the reasonable potential to cause or contributes to a water 

quality violation.

Regulation 61-9.122.44(d)(1)(i) states: “Limitations must control all pollutants or pollutant parameters 

(either conventional, nonconventional, or toxic pollutants) which the Department determines are or may be 

discharged at a level which will cause, have the reasonable potential to cause, or contribute to an excursion 

above any State water quality standard, including State narrative criteria for water quality.” 

When determining whether a discharge causes, has the reasonable potential to cause or contributes to an 

instream excursion, the Department will use procedures which account for controls on point and nonpoint 

sources of pollution, the variability of the pollutant in the effluent, the sensitivity of the species to toxicity 

testing (when evaluating whole effluent toxicity), and, where appropriate, the dilution of the effluent in the 

receiving water (R.61-9.122.44(d)(1)(ii)).

Based on the above statements, there are three scenarios when limitations are required, as follows:

i. When data provided by the permit applicant indicates discharge values greater than the proposed 

limitation derived above, that discharge may cause an excursion above a narrative or numeric water 

quality criterion. 

ii. A discharge may be determined to contribute to an excursion of a water quality criterion when the 

waterbody is impaired (e.g., on the 303(d) list) for the parameter of concern and that parameter is also 

being discharged at levels above the water quality criterion.

iii. Reasonable potential to cause a water quality violation is determined using the following information:

The Department will primarily use EPA’s Technical Support Document (TSD) for determining 

reasonable potential using effluent data. Other methods may be used as well to evaluate data sets. All 

pollutants given in a wasteload allocation or an effluent limitation guideline will be limited in the 

permit.

When effluent data consists of non-quantifiable/non-detectable values or when no effluent data is 

available, other factors and information are considered to determine reasonable potential. In situations 

where a pollutant is known to be present in the wastestream (due to production data or other 

information), we know it is being discharged and has the potential to impact even though it may not be 

quantifiable. The fact that it is present will be enough information to say reasonable potential exists for 

that pollutant. Therefore, a reasonable potential decision is based on various data and information, and 

not just non-quantifiable/non-detectable data. Consideration is given to existing data, dilution in the 

waterbody, type of receiving water, designated use, type of industry/wastestream, ambient data, history 

of compliance, and history of toxic impact. If any source of information indicates reasonable potential 

to cause or contribute to an exceedance of the water quality standard, a water quality limit will be 

established.
Rationale

Page 24 of 30

Permit No. SC0046175

Note: The result of the following calculations may indicate that reasonable potential does not exist. 

However, as stated above, other information may “override” this numerical determination to justify the 

need for a limit.

1. The procedure for determining reasonable potential from actual effluent data is explained in Box 

3-2 on page 53 of the TSD. Multiplying factors are determined from Table 3-2 at a 95% 

confidence level and 95% probability in Section 3.3.2. The following describes the procedures 

used for determining reasonable potential for chemical-specific parameters and WET, under 

certain circumstances. More information on determining reasonable potential for WET is given in 

Item 2 below. 

Step 1: Data Analysis: The statistical calculations involved in the “Reasonable Potential” analysis 

require discrete numerical data. The following describes how the effluent data will be 

used in determining reasonable potential.

Actual analytical results should be used whenever possible. Results less than detection and 

quantification should be used as follows:

a. If the permittee reports results below the practical quantitation limit (PQL) (as defined by 

the permit), then the reported “less than PQL” value for a given sample is generally 

assumed to be zero.

b. If the permittee uses a detection/quantification level that is greater than the PQL, then the 

reported “less than” value for a given sample is generally assumed to be a discrete value 

equal to the detection/quantification level used by the permittee.

c. If the reported data consists of both discrete and non-discrete values and/or the data is 

reported using varying detection/quantification levels, then, generally, a combination of 

the above two approaches is used, or the data is evaluated in a manner that is most 

appropriate for that data set.

Note: For information on the acceptable analytical methods and PQLs please refer to 

NPDES permit application attachment titled “Practical Quantitation Limits (PQL) and 

Approved Test Methods.”

Step 2: Using data from the permit application, other data supplied by the applicant and/or 

Discharge Monitoring Report (DMR) data, determine the total number of observations (n) 

for a particular set of effluent data and determine the highest value (Cmax) from that data 

set. For the monthly average comparison, the data set will include monthly average results 

and n will be the number of months in which they sampled in the time period being 

evaluated. For the daily maximum comparison, the data set will include daily maximum 

results and n will be the total number of samples in the time period being evaluated. 

Individual results may not necessarily be used in the calculation.

Step 3: Determine the coefficient of variation (CV) for the data set. For a data set where n>10, the 

CV is calculated as standard deviation divided by mean for the data set being evaluated. 

For data set where n<10, the CV is estimated to equal 0.6. For less than 10 items of data, 

the uncertainty in the CV is too large to calculate a standard deviation or mean with 

sufficient confidence.

CV  0.6 for n 10
Rationale

Page 25 of 30

Permit No. SC0046175





CV  for 

n 10

where:



= Standard Deviation of the samples



= Mean of the samples

Step 4: Determine the appropriate multiplying factor (MF) from either Table 3-2 or using the 

formulae in Section 3.3.2 of the TSD.

a. Determine the percentile represented by the highest concentration in the sample data.

n

pn Confidence Level 1/ (1 )

where: pn = Percentile represented by the highest concentration in the data

n = number of samples

Confidence Level = 0.95 i.e. 95%

b. Determine the multiplying factor (MF), which is the relationship between the percentile 

described above (Cp) and the selected upper bound of the lognormal effluent distribution, 

which in this case will be the 95th percentile (C95).

( 0.5 )

( 0.5 )

95

2

2

9 5

 

 





 

Z p

Z

p e

e

C

C

MF

where: Z95 is the standardized Z-score for the 95th percentile of the standardized 

normal distribution = 1.645

Zp is the standardized Z-score for the p

th percentile of the standardized normal 

distribution.(determined in (b) above) 

Note: The values of Z-scores are listed in tables for the normal distribution. If using 

Microsoft® Excel, this can be calculated using the NORMSINV function.

ln( 1)

2 2   CV 

ln( 1)

2   CV 

Step 5: Multiply the highest value from the data set (Cmax) by the multiplying factor (MF) 

determined in Step 4 to obtain the maximum receiving water concentration (RWC).

RWC  Cmax MF

Step 6: RWC ≤ Derived limit (Cefflim) implies that reasonable potential does not exist.

RWC > Derived limit (Cefflim) implies that reasonable potential exists.
Rationale

Page 26 of 30

Permit No. SC0046175

2. Reasonable potential for Whole Effluent Toxicity (WET) may be determined from numerical data 

using the following procedure:

a. When the effluent data is given in terms of percent effluent as an IC25, LC50 and/or NOEC 

values:

Step 1: Convert the given values to toxic units: TUa for acute data and TUc for chronic data, 

respectively, using the following formulae. Please note that an NOEC derived using the 

IC25 is approximately the analogue of an NOEC derived using hypothesis testing. The IC25

is the preferred statistical method for determining the NOEC (EPA TSD, March 1991, 

p.6). 

50

100

LC

TUa

NOEC

TUc

100

 or 

25

100

IC

TUc

if IC25 available

Step 2: Using DMR data or other data provided by the applicant, determine the total number of 

observations (n) for a particular set of effluent data and determine the highest value (TUa, 

max or TUc, max) from that data set. 

Step 3: Determine the coefficient of variation (CV) for the data set. For a data set where n>10, the 

CV is calculated as standard deviation divided by mean. For data set where n<10, the CV

is estimated to equal 0.6. For less than 10 items of data, the uncertainty in the CV is too 

large to calculate a standard deviation or mean with sufficient confidence.

Step 4: Determine the appropriate multiplying factor (MF) from either Table 3-2 or using the 

formulae in Section 3.3.2. (see iii.1, Step 4 above).

Step 5: Multiply the highest value of TUa, max or TUc, max from the data set by the multiplying factor 

(MF) determined in Step 4 and the dilution at the edge of the mixing zone (the test 

concentration obtained from mixing zone modeling or demonstration) to obtain the 

maximum receiving water concentration (RWC)

RWC for Acute Toxicity = [TUa, max * MF * conc. at MZ boundary]

RWC for Chronic Toxicity = [TUc, max * MF * conc. at MZ boundary]

Step 6: RWC for Acute Toxicity ≤ 0.3TUa implies that a reasonable potential does not exist

RWC for Acute Toxicity > 0.3TUa implies that a reasonable potential exists

RWC for Chronic Toxicity ≤ 1.0TUc implies that a reasonable potential does not exist 

RWC for Chronic Toxicity >1.0TUc implies that a reasonable potential exists 

b. Other methods for determining reasonable potential may be used if appropriately justified.

e. Consider Effluent Limitations Guidelines (ELG or Categorical guidelines)

The more stringent of the effluent limitations guidelines average and maximum derived limits and water 

quality-derived average and maximum limits shall be used as permit limits, unless other information 

indicates more stringent limits are needed (e.g. previous permit limits due to backsliding). Categorical 

limitations based on mass may be converted to concentration using the long-term average flow of the 

discharge for comparison to the monthly average and daily maximum derived limits.
Rationale

Page 27 of 30

Permit No. SC0046175

1. For effluent guidelines based on production, limits will be calculated as follows:

ELG lim  (ELGprod)(ELG)

where

ELGlim: the mass limit, in lbs/day, for an applicable pollutant based on the production

ELGprod: the production rate, in lbs, for the applicable guideline(s), usually based on long-term 

average data

ELG: the effluent guideline limitation, given as a measure of production (e.g. lbs/1000 lbs), for an 

applicable pollutant 

2. For effluent guidelines based on flow, limits will typically be calculated as follows:

ELGlim  (ELGflow)(ELG)8.345 

ELGlim: the mass limit, in lbs/day, for the applicable pollutant based on the applicable flow

ELGflow: the long-term average process flow rate, in MGD, for the applicable guideline(s) (unless 

otherwise specified in the guideline)

ELG: the concentration limitation, in mg/l, for the applicable pollutant from the applicable guideline(s)

H. Other considerations

1. When the derived permit effluent limitation based on aquatic life numeric criteria is below the practical 

quantitation limit for a substance, the derived permit effluent limitation shall include an accompanying 

statement in the permit that the practical quantitation limit using approved analytical methods shall be 

considered as being in compliance with the limit. Appropriate biological monitoring requirements shall be 

incorporated into the permit to determine compliance with appropriate water quality standards (R.61-

68.E.14.c(2)).

2. When the derived permit effluent limitation based on human health numeric criteria is below the practical 

quantitation limit for a substance, the derived permit effluent limitation shall include an accompanying 

statement in the permit that the practical quantitation limit using approved analytical methods shall be 

considered as being in compliance with the limit (R.61-68.E.14.c(3)).

3. The effluent concentration limits determined above may not necessarily be the NPDES permit limit. NPDES 

Permit limits are determined after a reasonable potential analysis is conducted using these derived limits and 

also after evaluating other issues such as anti-backsliding and antidegradation.

4. When mass limits are calculated, the formula to be used is as follows. 

Mass (lb/day) = Flow (mgd) * Concentration (mg/l) * 8.345

5. Per Regulation 61-9.122.45(d), for continuous discharges all permit effluent limitations, standards, and 

prohibitions, including those necessary to achieve water quality standards, shall unless impracticable be stated 

as maximum daily and average monthly discharge limitations for all dischargers other than publicly owned 

treatment works.

6. Antibacksliding: When a permit is reissued, the terms and conditions of the reissued permit must be at least as 

stringent as those final limits in the previous permit unless certain exceptions are met (see Regulation 61-

9.122.44.l).
Rationale

Page 28 of 30

Permit No. SC0046175

IV. PROCEDURES FOR REACHING A FINAL PERMIT DECISION

A. Comment Period (R.61-9.124.10 and 11)

The Department of Health and Environmental Control proposes to issue an NPDES permit to this applicant subject 

to the effluent limitations and special conditions outlined in this document. These determinations are tentative.

During the public comment period, any interested person may submit written comments on the draft permit to the 

following address:

SC Dept. of Health and Environmental Control

Water Facilities Permitting Division

Bureau of Water

2600 Bull Street

Columbia, South Carolina 29201

For additional information, interested persons may contact Byron M Amick at 803-898-4236.

All written comments received during the public comment period shall be considered in making the final decision 

and shall be responded to as prescribed below. 

Per R.61-9.124.17, the Department is only required to issue a response to comments when a final permit is issued. 

This response shall:

1. Specify which provisions, if any, of the draft permit have been changed in the final permit decision, and the 

reasons for the change; and

2. Briefly describe and respond to all significant comments on the draft permit raised during the public comment 

period, or during any hearing.

The response to comments shall be available to the public.

B. Public Hearings (R.61-9.124.11 and 12)

During the public comment period, any interested person may request a public hearing, if no hearing has already 

been scheduled. A request for a public hearing shall be in writing and shall state the nature of the issues proposed 

to be raised in the hearing. 

Determinations and Scheduling.

1. Within the thirty (30) day comment period or other applicable comment period provided after posting or 

publishing of a public notice, an applicant, any affected state or interstate agency, the Regional Administrator 

or any other interested person or agency may file a petition with the Department for a public hearing on an 

application for a permit. A petition for a public hearing shall indicate the specific reasons why a hearing is 

requested, the existing or proposed discharge identified therein and specifically indicate which portions of the 

application or other permit form or information constitutes necessity for a public hearing. If the Department 

determines that a petition constitutes significant cause or that there is sufficient public interest in an application 

for a public hearing, it may direct the scheduling of a hearing thereon.
Rationale

Page 29 of 30

Permit No. SC0046175

2. A hearing shall be scheduled not less than four (4) nor more than eight (8) weeks after the Department 

determines the necessity of the hearing in the geographical location of the applicant or, at the discretion of the 

Department, at another appropriate location, and shall be noticed at least thirty (30) days before the hearing. 

The notice of public hearing shall be transmitted to the applicant and shall be published in at least one (1) 

newspaper of general circulation in the geographical area of the existing or proposed discharge identified on 

the permit application and shall be mailed to any person or group upon request thereof. Notice shall be mailed 

to all persons and governmental agencies which received a copy of the notice or the fact sheet for the permit 

application.

3. The Department may hold a single public hearing on related groups of permit applications.

4. The Department may also hold a public hearing at its discretion, whenever, for instance, such a hearing might 

clarify one or more issues involved in the permit decision;

5. Public notice of the hearing shall be given in accordance with R.61-9.124.10.

Any person may submit oral or written statements and data concerning the draft permit. Reasonable limits may be 

set upon the time allowed for oral statements, and the submission of statements in writing may be required. The 

public comment period under R.61-9.124.10 shall automatically be extended to the close of any public hearing 

under this section. The hearing officer may also extend the comment period by so stating at the hearing.

A tape recording or written transcript of the hearing shall be made available to the public.

C. Obligation to raise issues and provide information during the public comment period. (R.61-9.124.13)

All persons, including applicants, who believe any condition of a draft permit is inappropriate or that the 

Department’s tentative decision to deny an application, terminate a permit, or prepare a draft permit is 

inappropriate, must raise all reasonably ascertainable issues and submit all reasonably available arguments 

supporting their position by the close of the public comment period (including any public hearing). No issue shall 

be raised during an appeal by any party that was not submitted to the administrative record as part of the 

preparation and comment on a draft permit, unless good cause is shown for the failure to submit it. Any supporting 

materials which are submitted shall be included in full and may not be incorporated by reference, unless they are 

already part of the administrative record in the same proceeding, or consist of State or Federal statutes and 

regulations, Department and EPA documents of general applicability, or other generally available reference 

materials. Commenters shall make supporting materials not already included in the administrative record available. 

(A comment period longer than 30 days may be necessary to give commenters a reasonable opportunity to comply 

with the requirements of this section. Additional time shall be granted under R.61-9.124.10 to the extent that a 

commenter who requests additional time demonstrates the need for such time).

D. Issuance and Effective Date of the Permit

1. After the close of the public comment period on a draft permit, the Department shall issue a final permit 

decision. The Department shall notify the applicant and each person who has submitted written comments or 

requested notice of the final permit decision. This notice shall include reference to the procedures for 

appealing a decision on a permit. For the purposes of this section, a final permit decision means a final 

decision to issue, deny, modify, revoke and reissue, or terminate a permit.

2. A final permit decision shall become effective 30 days after the service of notice of the decision unless:

(a) A later effective date is specified in the decision; or
Rationale

Page 30 of 30

Permit No. SC0046175

(b) No comments requested a change in the draft permit, in which case the permit shall become effective on 

the effective date shown in the issued permit.

3. Issuance or Denial of Permits. An appeal to a final determination of the Department or to a condition of a 

permit issued or the denial of a permit pursuant to the State law and Regulation 61-9, shall be in accordance 

with and subject to 48-1-200 of the SC Code (see E below). 

E. Adjudicatory Hearings

The issuance of this permit by the S.C. Department of Health and Environmental Control (Department) becomes 

the final agency decision 15 calendar days after notice of the decision has been mailed or otherwise sent to the 

applicant, permittee, licensee and affected persons who have requested in writing to be notified, unless a written 

request for final review accompanied by a filing fee in the amount of $100 is filed with the Department by the 

applicant, permittee, licensee, or affected person. This Department decision relies on the administrative record, 

which includes the permit rationale, and other supporting documentation contained in the permit file.

An applicant, permittee, licensee, or affected person who wishes to appeal this decision must file a timely written 

request for final review with the Clerk of the Board at the following address or by facsimile at 803-898-3393. A 

filing fee in the amount of $100 made payable to SC DHEC must also be received by the Clerk within the time 

allowed for filing a request for final review. However, if a request for final review is filed by facsimile, the filing 

fee may be mailed to the Clerk of the Board if the envelope is postmarked within the time allowed for filing a 

request for final review. 

Clerk of the Board 

SC DHEC 

2600 Bull Street 

Columbia, SC 29201

In order to be timely, a request for final review must be received by the Clerk of the Board within 15 calendar days 

after notice of the decision has been mailed or otherwise sent to persons entitled to receive notice. If the 15th day 

occurs on a weekend or State holiday, the request is due to be received by the Clerk of the Board on the next 

working day. The request for final review must be received by the Clerk of the Board by 5:00 p.m. on the date it is 

due. A request for final review will be returned to the requestor if the filing fee is not received on time as described 

above. 

The request for final review should include the following: 

a. The grounds on which the Department’s decision is challenged and the specific changes sought in the 

decision; 

b. A statement of any significant issues or factors the Board should consider in deciding whether to conduct a 

final review conference; and

c. A copy of the Department’s decision for which review is requested.

If a timely request for final review is filed with the Clerk of the Board, the Clerk will provide additional 

information regarding procedures. If the Board declines in writing to schedule a final review conference, the 

Department’s decision becomes the final agency decision and an applicant, permittee, licensee, or affected person 

may request a contested case hearing before the Administrative Law Court within 30 calendar days after notice is 

mailed that the Board declined to hold a final review conference. 

Information pertaining to adjudicatory matters may be obtained by contacting the Legal Office of the Department 

of Health and Environmental Control, 2600 Bull Street, Columbia, South Carolina or by calling 803-898-3350.