Code of Colorado Regulations
1000 - Department of Public Health and Environment
1002 - Water Quality Control Commission (1002 Series)
5 CCR 1002-64 - REGULATION NO. 64 - BIOSOLIDS REGULATION
Section 5 CCR 1002-64.23 - STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY, AND PURPOSE (January, 1996)

Current through Register Vol. 47, No. 17, September 10, 2024

The provisions of Colorado Revised Statute Sections 25-8-202(1)(c) and (2), 25-8-205(1)(e), 25-8-501(1) and (2), and 25-8-509 C.R.S., (1989 Repl. Vol. and 1993 Supp.) provide the specific statutory authority for the Colorado Biosolids Regulations adopted by the Commission. The Commission has also adopted, in compliance with Colorado Revised Statute Section 24-4-203(4) C.R.S., (1988 Repl. Vol. and 1992 Supp.), the following Statement of Basis and Purpose.

BASIS AND PURPOSE

The Colorado Water Quality Control Commission adopted the Colorado Biosolids Regulation, 4.9.0 on November 2, 1993. Subsequently, Water Quality Control Division and the Colorado Attorney General's Office staff developed the additional materials necessary to request delegation of the National Sludge Management Program. During the development of the delegation package several items were identified which had either been omitted from the regulation, or for which clarification is appropriate. A number of additional changes are best characterized as corrected or expanded cross references, or as minor corrections, and are not addressed below.

Section 4.9.3.B is amended to ensure that any facility or person treating or using biosolids, including a treatment works treating or applying biosolids which are generated elsewhere, are subject to the requirements of the regulation.

Language is also added at Section 4.9.3 , as well as at Section 4.9.9.K , to clarify the applicability of the regulation and to modify the definition of biosolids to conform with the definition which appears in the Water Quality Control Act. Language added to section 4.9.3 excludes "hazardous sewage sludge" from the regulation. This language is added so as to restrict the applicability of the regulation in a manner which is consistent with the federal regulation at 40 CFR 503.

The Metro Wastewater Reclamation District raised a concern relative to a potential interpretation of the applicability section (4.9.3) and the biosolids definition to absolutely exclude grit, screenings or grease. The District noted that while it is appropriate to exclude those grit or screenings which are generated during primary treatment processes, a fraction of the materials which are typically characterized as grit and screenings are not removed during primary treatment and ultimately become a component of the treated biosolids. Similarly, there is some grease present in biosolids which is not removed earlier in the treatment process, or which has been re-introduced into the biosolids treatment train to enhance the efficiency of biosolids treatment processes and/or as an alternative to other disposal options. The criteria contained in the Biosolids Regulation are not applicable to the land application of grit or screenings removed during the primary treatment of domestic wastewater. Nor are they applicable to the land application of grease removed during the treatment of domestic wastewater which is not treated in a biosolids treatment unit, or from other sources. The land application of these materials, should such an activity be undertaken, would be subject to the requirements of the Colorado Regulations pertaining to Solid Waste Disposal Sites and Facilities. It is the intent of the Commission that the land application of these materials be clearly excluded from the Biosolids Regulation. It is not the Commission's intent to bar the land application of biosolids which may contain grease or insignificant amounts of grit which is present as a result of normal treatment operations and which meets all applicable state and federal requirements for land application.

The definition of "Annual Biosolids Application Rate" at 4.9.9.E is amended to address multi-year cropping practices, i.e. dryland wheat.

Language is added at 4.9.15.B to conform with federal requirements that the preparer of the biosolids provide the applier with the information necessary to allow the applier to determine the appropriate means to maintain compliance with the regulation. Section 4.9.15.B is specifically added so as to assure conformance with federal requirements at 40 CFR 503.7 which require the preparer to assure that all applicable regulatory requirements are met.

Section 4.9.15.C is amended to specify a required 30 foot separation between a biosolids application area and a dry streambed. Federal regulations require a ten meter separation between land to which biosolids are applied and Waters of the United States. Dry streambed have been determined to be Waters of the United States and are therefore subject to the 10 meter requirement.

Table 4 is amended to allow application of biosolids of less than fourteen percent solids by subsurface injection to sites which exhibit a surface slope of greater than nine to fifteen percent. Such application was allowed under the Domestic Sewage Sludge Regulations, which proceeded this regulation, and has been demonstrated to be an acceptable application method on slopes of less fifteen percent or less.

Table 6 is amended to specify that the frequency of required monitoring is based upon the annual biosolids production expressed as "short" tons as opposed to "metric" tons.

Language is added to Section 4.9.17.A to require documentation that the biosolids producer has provided notification to the applier of information necessary to comply with the requirements of the regulation be maintained in producer records.

A specific certification statement is added at Section 4.9.16.C to address instances where the producer is not also the applier of the biosolids.

Comments were submitted during the public notice period suggesting the addition of language clarifying state regulatory requirements relative to co-disposal of biosolids at municipal solid waste facilities. The author correctly pointed out the federal regulations at 40 CFR Part 258 address co-disposal. Similarly, co-disposal of biosolids is addressed within the state regulatory framework via the Colorado Regulations pertaining to Solid Waste Disposal Sites and Facilities, 6 CCR 1007-2. Criteria contained within the Colorado Biosolids Regulation do not apply to biosolids which are co-disposed with other wastestreams in municipal solid waste facilities. Section 4.9.3 specifically limits the applicability of the Biosolids Regulation to biosolids which are used beneficially. Co-disposal is not considered beneficial use and is therefore not governed by this regulation. It should be noted that the application of biosolids at a municipal solid waste facility for the purpose of reclaiming closed portions of the facility is considered beneficial use. The requirements of the Biosolids Regulation would be applicable in that instance.

The Commission adopted the Biosolids Regulation on November 2, 1993. While the regulation was being heard there was also ongoing litigation at the federal level concerning the technical basis for numeric chromium and selenium criteria contained in the federal regulations at 40 CFR Part 503 . The Commission opted to incorporate the federal chromium and selenium standards into the Biosolids Regulation as they appeared in the federal Part 503 regulations at that time. The Statement of Basis, Specific Statutory Authority, and Purpose (section 4.9.18) adopted with the November 2, 1995 Biosolids Regulation anticipated potential future action relative to the federal chromium and selenium standards and indicated the Commission's intention to consider appropriate action upon resolution of the issues relating to the federal standards.

The United States Court of Appeals for the District of Columbia Circuit issued a decision on November 15, 1994 concerning the technical basis for the chromium and selenium limitations set forth in the 40 CFR Part 503 regulations. See Leather Industries of America, Inc. v. Environmental Protection Agency, 40 F.3d 392 (D.C.Cir. 1994). The Court held that the chromium and selenium "clean sludge" caps (40 CFR 503.13, Table 3), equivalent to the Colorado Grade I maximum metals concentrations identified at section 4.9.12.A , Table 1 of the Biosolids Regulation, were developed in a manner which exceeded EPA's statutory mandate because they were not based upon risk to human health or to the environment. The Court remanded the "clean sludge" numeric limits, as well as the maximum concentration limits (40 CFR 503.13, Table 1; section 4.9.12.A(1), Table 1 Grade II limits) and the annual loading limits (40 CFR 503.13, Table 4; section 4.9.14.B , Table 2) for chromium and selenium to EPA for "modification or additional justification". Following the Court's decision, the City of Pueblo petitioned the Commission to amend the Biosolids Regulation to delete the remanded federal "clean sludge" limitations for chromium and selenium and the maximum concentration limit for selenium. The City's petition resulted, in part, in this rulemaking.

The USEPA, on October 25, 1995 promulgated amendments to the federal sludge management regulations at 40 CFR Part 503 which partially implement the Court's decision in Leather Industries. (60 Fed. Reg. 54764). These revisions address maximum allowable concentration limits, annual pollutant loading limits, and cumulative pollutant loading limits for chromium and "clean sludge" concentrations for selenium. All numeric limitations for chromium were struck from the Part 503 rule. The EPA action relaxed the federal Table 3 limitation for selenium from 36 mg/kg to 100 mg/kg. These revisions to the Colorado Biosolids Regulation incorporate revisions to the Grade I and Grade II metals concentration limits identified in Table 1, section 4.9.12.A , to the annual pollutant loading limits expressed in Table 2, section 4.9.15.B , and the cumulative pollutant loading limits in Table 3, section 4.9.15.A so as to conform with the federal rule.

With regard to the maximum concentration and annual loading limitations for selenium which were remanded to EPA, the City of Pueblo and EPA have been negotiating an amendment to the federal regulation which will establish variance procedures to allow the use of biosolids exceeding the maximum ceiling concentration (Colorado Grade II) where (1) the high concentration of a metal in the biosolids is due to unusual natural conditions and (2) the permitting authority adopts an alternative ceiling concentration sufficient to protect public health and the environment based upon the intended use and the risk assessments that reasonably apply to such use. EPA has expressed an intention to publish a proposed amendment to the federal sludge regulations in early 1996 for the purpose of incorporating this variance procedure, and to thereafter adopt the variance procedure in a final rule to be published after the close of a 60 day comment period. As a consequence of these factors, and in order to avoid delaying delegation of federal program authorities to the State, the City of Pueblo has withdrawn, for purposes of this rulemaking, its request to delete the remaining selenium limits in Tables 1 and 2. It is the Commission's intent to subsequently conduct a future rulemaking to either consider incorporation of the EPA variance procedure when finally adopted, or to consider other resolution of the selenium issue should negotiations between EPA and the City fail. During the interval between EPA adoption of a variance procedure and a new Commission rulemaking to consider incorporation of those procedures into the Biosolids Regulation, the Division has indicated that the EPA approved procedure will be applied under the existing authority of section 4.9.6.

PARTIES TO THE RULEMAKING HEARING