Code of Colorado Regulations
1000 - Department of Public Health and Environment
1002 - Water Quality Control Commission (1002 Series)
5 CCR 1002-61 - REGULATION NO. 61 - COLORADO DISCHARGE PERMIT SYSTEM REGULATIONS
Section 5 CCR 1002-61.36 - STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE (Phase I -Stormwater Permit Application Regulations - 1993)

1. National Perspective: The "National Water Quality Inventory, 1988 Report to Congress" ("Report") provides a general assessment of water quality based on the biennial reports submitted by the states under Section 305(b) of the Clean Water Act. The Report indicates that stormwater runoff from a number of diffuse sources, including agricultural areas, urban areas, construction sites, land disposal activities, and resource extraction activities, is the leading cause of water quality impairment cited by the states (EPA, 1990).

2. Statewide Perspective: Colorado's Nonpoint Source Assessment Report of 1989 identifies impacts of nonpoint source water pollution throughout Colorado. Nonpoint sources have historically included those sources which are diffuse in nature, and have not been regulated through the conventional permit programs of the Clean Water Act until recently. These sources include runoff from: urban areas, agricultural activities, forestry and logging activities, construction activities and areas of abandoned/inactive mining. All of these sources except agricultural activities and forestry and logging activities are included to some extent in Phase I of the stormwater permitting program. The Nonpoint Source Assessment Report indicates that 1,434 stream miles of Colorado's streams have been affected by resource extraction activities and urban/construction activities (WQCD, 1989).

3. Dillon Reservoir Perspective: Water quality at Dillon Reservoir has deteriorated over its 20-year life span. The Clean Lakes Study of Dillon Reservoir has identified phosphorous as the primary contributor to the water quality problem. A major portion of the phosphorous loading was found to be attributable to urban sources including runoff from residential areas, Interstate Highway 70, and construction sites, as well as leakage from septic tanks (WEA, 1983).

4. Metropolitan Denver Perspective: The Denver area was selected for inclusion in the Nationwide Urban Runoff Program (NURP), a program sponsored by the U.S. Environmental Protection Agency and the U.S. Geological Survey. In the analysis of the contributions of urban storm runoff to the South Platte River, it was determined that storm runoff was the major contributor of total suspended solids, total organic carbon, and total lead and a significant contributor of total zinc (USGS, 1984). The study also showed that the storm event mean concentration of total cadmium, total copper, total iron, total manganese, total lead and total zinc exceeded the established water-quality standards in 100 percent of the storm-runoff periods.

1. Regulation of Industries and Municipalities: Designated industries and municipalities with populations greater than 100,000 will be required to obtain stormwater discharge permits regardless of whether or not the State of Colorado develops regulations for the stormwater program. If the state does not adopt its own regulations, the Federal regulations still apply to the municipalities and industries within the state. State regulations allow for the regulated community to participate in the formation of a state program.

2. Maintaining a State-Delegated Program: In order to maintain the integrity of the state CDPS program, it is necessary to develop regulations and implement the stormwater program. The Clean Water Act, NPDES program, specifically defines stormwater discharges as point sources which require permits. The Clean Water Act, which is the statutory authority for the NPDES program, also requires that in order to maintain delegated authority, a state must have regulations that are consistent with the federal regulations. Including stormwater discharges in an efficient manner in the CDPS program in the State of Colorado requires the promulgation of regulations which address stormwater discharges, and further, requires that the regulations be consistent with the federal rules.

1. Potential Overlap with Other State Regulations: The Administrative Procedures Act (24-4- 103(4)(b)(V) C.R.S. (1988 Repl.Vol.10A) requires the rulemaking entity to explain any apparent duplication or overlap that might be created between the proposed regulations and any existing State regulations.

The Commission recognizes that other state agencies may also have jurisdiction concerning matters covered by CDPS permits issued by the Division regarding stormwater discharges. For example, the Hazardous Materials and Waste Management Division addresses run-on and runoff controls for solid and hazardous waste disposal sites. The Stormwater Permit Application Regulations require that operators of landfills also must obtain permits to discharge stormwater to state waters.

In addition, the Division of Minerals and Geology (DMG) of the Department of Natural Resources is specifically mandated to ensure that "disturbances to the prevailing hydrologic balance of the affected land and surrounding area and to the quality and quantity of water in surface and ground water systems both during and after mining operations (are) minimized." Section 34-32-116(i)(h), C.R.S. (1984). Pursuant to this statute, DMG requires that measures be taken to protect the hydrologic balance as a condition of granting a Mined Land Reclamation Board permit.

Phase I of the Stormwater Permit Application Regulations requires that mining activities obtain stormwater discharge permits if they have a point source discharge of stormwater that is contaminated by contact with any overburden, raw material, intermediate products, byproducts, finished products or waste products located at the mining site. These permits require that measures be taken to control the sources of stormwater pollution.

According to state statute, the Division is solely responsible for the issuance and enforcement of permits authorizing point source discharges to state waters, Section 25-8-202(7)(b)(l), C.R.S. (1989 Repl.Vol.11 A). Also, stormwater permit applications are a federal requirement and the proposed regulations are necessary to assure compliance with the federal act. See Section 25-8-202(7)(b)(ll)(A), C.R.S. (1989 Repl. Vol. 11 A). Finally, the Division may not transfer any of its stormwater permitting and enforcement functions to other state agencies unless those agencies are delegated authority to perform such functions by the EPA. 40 C.F.R. Sections 123.1(g)(1) and 123.62(c) (1992).

2. NRDC v. EPA - Light Industry Exemption: A significant issue in the federal stormwater regulation is a provision exempting industries in federal category (xi) from the permit application requirement. Under the federal rule, these industries do not have to apply for a permit during Phase I, provided that their industrial activities and materials are not exposed to stormwater. In Natural Resources Defense Council v. Environmental Protection Agency, 966 F.2d 1292 (1992), the Ninth Circuit Court of Appeals vacated the exemption and remanded the rule to EPA, apparently because the exemption was not supported by evidence in EPA's record. In a December 18, 1992 Federal Register Notice, EPA announced that it would not require category (xi) permit applications, pending further rulemaking on the subject.

The Commission has received extensive testimony and other evidence in support of the exemption from a coalition of industries within category (xi). The evidence indicates that, given the nature of their products, the represented industries must carry out their manufacturing in a clean and dry indoor environment. Likewise, given the nature of the materials used and the final product, these industries tend to protect incoming and outgoing materials from exposure to the elements. Compared with other facilities subject to Phase I permitting, these industries pose a relatively minor risk of water quality impacts associated with stormwater.

Considering the supporting evidence provided by the coalition of category (xi) industries at the hearing, the Commission finds that adoption of a category (xi) exemption from Phase I permitting at this time is appropriate. Accordingly, the rule adopted by the Commission divides the federal category (xi) into two state categories - one for which evidence was presented in this hearing (category (xi)) and one for which no evidence was presented (category (xii)). Only the industries in category (xi) adopted in this rule are subject to the exemption.

The adopted exemption clarifies the term "exposed to stormwater," as that term is used in the federal exemption, by describing the circumstances under which a material or material handling activity would not be considered to be exposed to stormwater. This clarification is intended to provide better guidance to both the regulated entities and the Division.

3. NRDC v. EPA - Exemption for Smaller Construction Sites: The federal stormwater permit application regulations also include an exemption from permitting for construction sites that disturb less than five acres. In the same opinion, the Court also found this exemption to be arbitrary and capricious because it was not supported by the record. The Phase I stormwater permit application rules duplicate the federal language regarding construction sites that disturb less than five acres. Independent information provided by the Division on this matter supports retention of this exemption for Phase I of the stormwater program. It is not the Commission's intention to define "industrial in nature" at this time. The Commission feels that retention of the exemption for construction activities that disturb less than five acres is consistent with the congressional intention to have a phased approach to stormwater permitting. The Commission intends to revisit this issue at the time that Phase II regulations are adopted.

4. Other Changes to the Permit System Regulations: These regulations include changes at several places in the Colorado Regulations for State Discharge Permit System. The first group of changes occurs at 6.2.2 and 6.2.3 regarding incorporation by reference and severability. Section 6.2.2 assures compliance with the Administrative Procedures Act Section 24-4-103(4) (1988 Repl.Vol.10A and 1992 Supp.). Section 6.2.3 assures the maintenance of the balance of the CDPS Program, if one or more provisions is found to be invalid.

The second group of changes occurs at 6.3.0. DEFINITIONS. Definitions of terms used in the new stormwater sections were added, including: co-permittee, illicit discharge, incorporated place, large municipal separate storm sewer system, major municipal separate storm sewer outfall, medium municipal separate storm sewer system, municipal separate storm sewer, overburden, runoff coefficient, significant materials, stormwater, stormwater associated with industrial activity, stormwater outfall, and uncontrolled sanitary landfill.

The definition of "municipality" was revised to be more consistent with the federal definition. However, the phrase "or an Indian tribe or an authorized Indian tribal organization," was deleted from the federal language since the EPA issues permits on Indian Lands. A definition of "Division" was added to clarify that the reference is to the Water Quality Control Division and not the Division of Administration as specified in the Water Quality Control Act.

The other changes from the federal definitions include modifications to "municipal separate storm sewer". The terms "borough" and "parish" were removed because they are inconsistent with Colorado law. Also, the reference to "Indian tribe or an authorized Indian tribal organization," was deleted from the federal language since the EPA issues permits on Indian lands. The definitions of "large" and "medium municipal separate storm sewer system" were slightly modified. Individual Colorado cities are named rather than to refer to an appendix in the Federal Register and the 1990 Census is referenced rather than the 1980 Census. Additionally, the portion of the definition of "stormwater discharges associated with industrial discharges" that enumerates the specific industrial categories was placed in the Applicability section of the regulations at 6.4.2.(5)(b). The definition of "separate storm sewer" was removed since it is now redundant with the new definitions

The third group of changes and additions occurs at 6.4.0 APPLICABILITY. This section was divided into two subsections, one dealing with general applicability (6.4.1) and one with stormwater applicability (6.4.2). The general applicability section contains the pre-existing applicability information.

The new stormwater information was added in its own section. Subsection 6.4.2 contains the identification of entities that are required to obtain permits in Phase I of the stormwater program. Subsection 6.4.2 identifies Phase I industrial categories (i)-(xi). Subsection 6.4.2 identifies large and medium municipalities. These sections contain the same provisions as the federal requirements. Subsection 6.4.2 is reserved for Phase II. When federal regulations regarding Phase II are promulgated, this section will be completed.

The fourth and fifth groups of changes occurs in Section 6.5.0 APPLICATION FOR A PERMIT. This section was divided into three subsections, one dealing with general application requirements (6.5.1), one with application requirements for existing manufacturing, commercial, mining and silvaculture discharges (6.5.2), and one with stormwater application requirements (6.5.3). The General Application Subsection (6.5.1) includes the pre-existing requirements and was amended to reconcile Colorado general application requirements with federal rules.

Subsection 6.5.2 was added to address requirements that are part of both the general and stormwater permit program. It is added in anticipation of requirements that may be added in the October 1993 hearing regarding the general CDPS program. These provisions are referenced in Subsection 6.5.3 and therefore are necessary to the stormwater program at this time.

Subsection 6.5.3 was added to address requirements unique to stormwater permit applications. Section 6.5.3 contains the application time frames for existing and new industrial stormwater permits and large and medium municipalities stormwater permits. Section 6.5.3 details the industrial stormwater permit application procedures. This section contains the same provisions as the federal requirements. Section 6.5.3 details the municipal stormwater permit application procedures. This section contains the same provisions as the federal requirements, except that references to the Great Lakes and estuaries were removed and the term "reservoirs" was added to 6.5.3(3)(iv)(C)IV).

The sixth group of changes relates to actual permit requirements, not to application requirements. Section 6.9.4 . MONITORING, RECORDING AND REPORTING, was amended to include new material. The new reporting requirements for municipalities and industries with stormwater permits are discussed in 6.9.4.(8) through (10), and are the same as the federal requirements.

The seventh and final group of changes occurs at 6.10.2 GENERAL PERMITS. These changes affect all general permits issued in the CDPS program, not just stormwater discharge general permits. This section was broken into a subsection on "Coverage" and one on "Administration". The Administration subsection contains additions from 40 C.F.R. 122.28(b)(2) (1992). The automatic general permit certification due to the Division's failure to act was broaden to included any time frames less than 30 days if specifically included in a general permit (6.10.2 (2)(d)).

(1) U.S. EPA, preamble to the National Pollutant Discharge Elimination System Permit Application Regulations for Stormwater Discharges, Final Rule. Federal Register, Nov. 16, 1990.

(2) USGS (U.S. Geological Survey), 1984. Analysis of Urban Storm Runoff Data and the Effects on the South Platte River, Denver Metropolitan Area, Colorado (WRI84-4159).

(3) WEA (Western Environmental Analysts), 1983. Clean Lakes Study of Dillon Reservoir in Summit County, Colorado, for Northwest Colorado Council of Governments.

(4) WQCD (Colorado Water Quality Control Division), 1989. Nonpoint Source Assessment Report.

The amendment also restructures the existing section. Application requirements which were previously found in the Section 6.6.1 were relocated to this section.

Provisions regarding minimum signatory and certification requirements have been added to the general application requirements section. The added provision are consistent with §122.22 of EPA's regulations. Other general application requirements consistent with §122.21 of EPA's regulations have been added.

Terms and Conditions of Permits

A substantial number of provisions have been added to this general section, reflecting minimum federal requirements found in § §122.41, 122.42, 122.43, 122.44 and 122.45 of EPA's regulations.

Two provisions restricting the Division's authority to issue permits have been added. The first added provision applies where the Regional Administrator timely and properly objects to the issuance of the permit. The Commission believes the addition of this prohibition is beneficial to the regulated entity because it relieves the entity from having to comply with two permits. The Commission does not intend this provision, however, to be interpreted so as to allow the violation of provisions of the CWQCA which have no federal counterpart, should an EPA-issued permit be obtained.

The second provision added restricts the Division's ability to issue a permit to a new source or new discharger unless the new source or discharger demonstrated that the new discharge will not cause or contribute to the violation of water quality standards.

Applicable technology-based effluent limitations for specific categories of industries adopted by EPA pursuant to §304(b) of the federal act have been incorporated by reference in Section 6.9.2 . Additional applicable effluent limitations and guidelines adopted by EPA in Parts 125 and 129 of 40 C.F.R. have also been incorporated by reference.

PARTIES TO THE RULEMAKING HEARING July 6, 1993