South Carolina Code of Regulations
Chapter 61 - DEPARTMENT OF HEALTH AND ENVIRONMENTAL CONTROL
Subchapter 61-9 - Water Pollution Control Permits
Subchapter 61-9.122 - THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
Part B - PERMIT APPLICATION AND SPECIAL NPDES PROGRAM REQUIREMENTS
Section 61-9.122.B.32 - Is an operator of a small MS4 regulated under the NPDES storm water program?

Universal Citation: SC Code Regs 61-9.122.B.32

Current through Register Vol. 48, No. 9, September 27, 2024

(a) Unless you qualify for a waiver under paragraph (c) of this section, you are regulated if you operate a small MS4, including but not limited to systems operated by federal, State, Tribal, and local governments, including State departments of transportation, and:

(1) Your small MS4 is located in an urbanized area as determined by the latest Decennial Census by the Bureau of the Census (If your small MS4 is not located entirely within an urbanized area, only the portion that is within the urbanized area is regulated.); or

(2) You are designated by the Department, including where the designation is pursuant to 40 CFR 123.35(b)(3) or (b)(4) or is based upon a petition under section122.26(f)(f).

(b) You may be the subject of a petition to the NPDES permitting authority to require an NPDES permit for your discharge of storm water. If the NPDES permitting authority determines that you need a permit, you are required to comply with sections122.33 through 122.35.

(c) The Department may waive the requirements otherwise applicable to you if you meet the criteria of paragraph (d) or (e) of this section. If you receive a waiver under this section, you may subsequently be required to seek coverage under an NPDES permit in accordance with section122.33(a)(a) if circumstances change. (See also section123.35(b)(b) of 40CFR123.)

(d) The Department may waive permit coverage if your MS4 serves a population of less than 1,000 within the urbanized area and you meet the following criteria:

(1) Your system is not contributing substantially to the pollutant loadings of a physically interconnected MS123.35(b)(4) that is regulated by the NPDES storm water program (see section123.35(b)(4)(b)(4) of 40CFR123) and

(2) If you discharge any pollutant(s) that have been identified as a cause of impairment of any water body to which you discharge, storm water controls are not needed based on wasteload allocations that are part of an EPA-approved or established total maximum daily load (TMDL) that addresses the pollutant(s) of concern.

(e) The Department may waive permit coverage if your MS4 serves a population under 10,000 and you meet the following criteria:

(1) The Department has evaluated all waters of the U.S., including small streams, tributaries, lakes, and ponds, that receive a discharge from your MS4;

(2) For all such waters, the Department has determined that storm water controls are not needed based on wasteload allocations that are part of an EPA-approved or established TMDL that addresses the pollutant(s) of concern or, if a TMDL has not been developed or approved, an equivalent analysis that determines sources and allocations for the pollutant(s) of concern;

(3) For the purpose of this paragraph (e), the pollutant(s) of concern include biochemical oxygen demand (BOD), sediment or a parameter that addresses sediment (such as total suspended solids, turbidity or siltation), pathogens, oil and grease, and any pollutant that has been identified as a cause of impairment of any water body that will receive a discharge from your MS4; and

(4) The Department has determined that future discharges from your MS4 do not have the potential to result in exceedances of water quality standards, including impairment of designated uses, or other significant water quality impacts, including habitat and biological impacts.

(f) Process for designating small MS4 to require storm water NPDES permitting. The Department will designate small MS4s according to the following criteria as a determination that a storm water discharge results in or has the potential to result in exceedances of water quality standards, including impairment of designated uses, or other significant water quality impacts, including habitat and biological impacts.

(1) The Department will make initial designations on a watershed basis but no later than December 8, 2004 [except see the phasing considerations in (h)(3) for MS4 with population less than 10,000], as follows:

(i) All MS4 which are located within an urbanized area as defined by the U.S. Bureau of the Census are to be designated and must obtain permits, unless a waiver is granted. (Many of the municipalities and counties which are small MS4 covered by this requirement are listed in Appendix 6 of 64FR68722, December 8, 1999.)

(ii) Consider all small MS4 with a population density of at least 1000 persons per square mile and a population of at least 10,000 located outside urban areas, according to the criteria. (Six municipalities which meet these descriptions are listed in Appendix 7 of 64FR68722.)

(iii) Consider small MS4 which are adjacent to and impact a designated MS4, according to criteria.

(iv) Consider other government entities which are MS4 relevant to criteria (e.g., military installations, prisons, and state, county, or municipal school, or hospital campuses).

(v)

(A) Consider MS4 for which petitions are received requesting that permitting be required.

(B) See section122.26(f)(5)(f)(5) as to the period for making a determination on designation.

(2) The Department will designate small MS4 to require permitting, as follows:

(i) Small MS4 within urbanized areas;

(ii) Entire municipalities which meet the criteria;

(iii) Counties, military installations, prisons, and state, county, or municipal school or hospital campuses, giving consideration to whether solely the urbanized areas should be designated;

(iv) Small MS4 physically interconnected with and substantially affecting regulated MS4, according to the criteria.

(3) In the process of designating small MS4, the Department will inform entities of the waiver requirements of 40 CFR 123.35(d) and evaluate any requested waiver in making a designation decision.

(4) The Department will evaluate any entity for which a petition is received requesting that a permit be required, based on criteria.

(5) The Department will reevaluate to designate appropriate, additional MS4 whenever the 303(d) list is revised.

(6) The Department will reevaluate at each census only to designate additional small MS4.

(g) Criteria for Designating Small MS4 for Storm Water NPDES Permitting

(1) Any small MS4 with a population of 10,000 or more and a population density of 1000 persons per square mile meeting any criterion will be designated, unless one or more of the exceptions in (1)(i) below applies. For smaller or less-densely populated MS4, the following criteria will be used in any evaluation of whether they should be designated to require a permit.

(i) Any water body receiving storm water from the MS4 is on the South Carolina {303(d)} list of impaired waters for a pollutant discharged in the storm water of the entity or a pollutant contributing to the standards violation leading to listing, unless the MS4 shows that it meets one of the following exceptions:

(A) The runoff from the MS4 caused by a 2-inch rainstorm would be less than one (1) percent of the annual average flow of each receiving stream on the 303(d) list;

(B) The MS4 has excellent BMP in place and presents data showing exemplary quality storm water runoff;

(D) The MS4 is shown to have a significantly lower percentage of impermeable area than would be expected for its level of development.

(ii) Any water body receiving storm water from the MS4 is classed ONRW, ORW, or Freshwater-Trout or is open for shellfish harvesting.

(iii) Population growth in the MS4 between the 1990 and 2000 (or the two most-recent) censuses has been 10 percent or more or growth has been 2 percent or more in each of the three (3) most-recent years.

(iv) The MS4 is located within 3 miles of an urbanized area, and the MS4 under consideration discharges storm water to one or more of the water bodies which receive storm water from the urbanized area.

(v) An MS4 which has been partly (at least 25%) designated (e.g., part lying within an urbanized area). Consideration will be give to designating only the portion of a county, military installation, prison, or state, county, or municipal school or hospital campus which is in the relevant urbanized area or, for the more extensively developed counties, designating areas up to three (3) miles from the boundary of the urbanized area.

(vi) The population density of the MS4 is at least 1500 persons per square mile.

(2) The following matters may also be considered in deciding whether a permit is required.

(i) The storm water discharge of an MS4 is causing or contributing to a violation of a water quality standard.

(ii) An MS4 is subject to activity contributing or expected to contribute to storm water contamination; for example, frequent military training exercises.

(iii) An MS4 includes industries with significant particulate emissions (such as battery manufacturing {e.g., lead}, steel manufacturing, etc.)

(iv) An MS4 includes a high percentage of impermeable area (pavement, roof).

(v) An MS4 owns or operates a wastewater treatment facility which has a history of being on the NPDES "Significant Non-compliance List" for effluent violations.

(vi) An MS4 approaches but does not reach two or more of the criteria in (1) above.

(3) Government-owned educational institutions, hospital and prison complexes, and military bases outside of urban areas will be considered in the same manner as municipalities outside urban areas. That is, if they have a population of 10,000 or more and a population density of 1500 persons per square mile, they will be designated. If they are less populated or less-densely populated, they will be considered based on the criteria, if a petition requests that a permit be required.

(4) As an initial decision, designate any small MS4 which has either greater than 2000 total population with a density of at least 1500 persons per square mile or greater than 4000 total population with a density of at least 1000 persons per square mile and which is within the boundaries of or whose boundaries touch, and which drains to at least one basin which receives drainage from, a permitted or designated MS4. However, consider exceptions and "other considerations" stated elsewhere in these criteria.

(h) Waivers and Phasing. The Department may waive or phase in the requirements otherwise applicable to regulated small MS4s, as defined in Sec.122.32(a)(1) and (2)(a)(1) and (2) of this item, under the following circumstances:

(1) The Department may waive permit coverage for each small MS4 in jurisdictions with a population under 1,000 within the urbanized area according to section122.32(d)(d).

(2) The Department may waive permit coverage for each small MS4 in jurisdictions with a population under 10,000 according to section122.32(e)(e).

(3) The Department may phase in permit coverage for small MS4s serving jurisdictions with a population under 10,000 on a schedule consistent with a State watershed permitting approach. Under this approach, the Department will permit coverage for small MS4s that qualify for such phased-in coverage during the year assigned for permitting in the basin where it is located. Under this option, all regulated small MS4s are required to have coverage under an NPDES permit no later than March 8, 2007.

(4) The Department will periodically review any waivers granted in accordance with paragraph (h)(2) of this section to determine whether any of the information required for granting the waiver has changed. At a minimum, the reviews will be conducted once every five years during pertinent years for basin permit issuance. In addition, the Department will consider any petition to review any waiver when the petitioner provides evidence that the information required for granting the waiver has substantially changed.

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