6 CCR 1007-3-8.69 - Basis and Purpose

This amendment to 6 CCR 1007-3, Part 261, Appendix IX is made pursuant to the authority granted to the Solid and Hazardous Waste Commission in § 25-15-302(2), C.R.S.

Amendment of Part 261, Appendix IX to Conditionally Delist F006 and F019 Hazardous Wastewater Treatment Sludge Generated by Advanced Surface Technologies, Inc. located at 6155 West 54th Avenue in Arvada, Colorado 80002

Appendix IX of Part 261 is being amended at this time to conditionally delist F006 and F019 hazardous wastewater treatment sludge generated by Advanced Surface Technologies, Inc. ("Advanced Surface Technologies" or "AST") at its industrial metal finishing facility located at 6155 West 54th Avenue in Arvada, Colorado (the "Facility").

This delisting will allow Advanced Surface Technologies to dispose of this waste at a Subtitle D solid waste landfill that meets the requirements of the Colorado Solid Waste Regulations (6 CCR 1007-2), provided it complies with the conditions of the delisting specifying disposal, record keeping, storage and sampling requirements for the delisted sludge. The Commission is requiring that annual verification sampling of the delisted waste be submitted to the Division within sixty (60) days of the sampling event for review against initial delisting criteria and sampling methodology. As an alternative to disposal in a Subtitle D solid waste landfill, the sludge could be sent to a metal recycling facility. Recycling the wastewater treatment sludge to reclaim heavy metals would further reduce the potential harm to human health and the environment posed by this waste.

On August 19, 2008, the Solid and Hazardous Waste Commission (the "Commission") tentatively approved a petition submitted by Advanced Surface Technologies to exclude or "delist" F006 and F019 hazardous wastewater treatment sludge generated at AST's Arvada, Colorado facility. Pursuant to the provisions of § 25-15-302(2), C.R.S. and 6 CCR 1007-3, § 260.20(c), a public notice of the Commission's tentative decision to approve the delisting was published in the Colorado Register for written public comment. The public comment period closed on October 10, 2008. No comments were received. On November 18, 2008, the Commission voted to make the decision final. The delisting will become effective twenty (20) days after publication in the Code of Colorado Regulations ("CCR") at 6 CCR 1007-3.

AST operates 11 metal finishing lines at its Arvada facility. Metal plating operations include nickel, tin, copper and precious metals. Burnishing, passivation and anodizing finishing operations are also conducted on-site.

Rinse wastewater from AST's metal finishing lines is conveyed to an on-site pretreatment system for metals removal. The rinse wastewaters undergo pH adjustment, filter pressing and micro-filtration prior to being discharged to the sanitary sewer under an industrial discharge permit issued by Metro.

AST's on-site wastewater pretreatment of electrolytic and electroless plating rinses generates approximately 1,400 pounds of wastewater treatment sludge on a weekly basis. The wastewater treatment sludge is regulated as an F006 and F019 listed hazardous waste.

Pursuant to the listing descriptions at 6 CCR 1007-3, section 261.31, wastewater treatment sludge generated from electroplating operations is classified as F006 hazardous waste. Wastewater treatment sludge generated from chemical conversion coating operations conducted on aluminum is classified as F019 hazardous waste.

The basis for the F006 and F019 hazardous waste listings are described in Appendix VII of Part 261of the regulations. Each listing is based on the hazardous constituents that are generally contained in the wastes described by the listing. The hazardous constituents that form the basis for the F006 listing include cadmium, hexavalent chromium (Chromium VI), nickel and complexed cyanide. Hexavalent chromium and complexed cyanide are the hazardous constituents that form the basis for the F019 listing.

Analytical sampling of AST's wastewater treatment sludge was conducted prior to the submittal of its delisting petition. Metal finishing operations and wastewater treatment processes at the Facility do not significantly change on a day-to-day basis, and the collected samples adequately represented the waste in question. The Hazardous Materials and Waste Management Division at the Colorado Department of Public Health and Environment (the Division), evaluated the sampling results and the request for petitioning of the waste in accordance with the delisting criteria in § 260.22. This evaluation was presented to the Commission.

Four discrete samples of AST's wastewater treatment sludge were collected in May and June of 2007. The samples were collected in general accordance with the Sampling and Analysis Plan (SAP), dated April 23, 2007.

Analytical results of AST's wastewater treatment sludge samples indicated that the petitioned sludge contains hazardous constituents (cadmium, nickel, cyanide and chromium VI) that are a basis for listing the waste as an F006/F019 hazardous waste. Based on the chemical analysis of the waste samples, the average total concentration of cadmium, cyanide, chromium VI, and nickel is 10.55 mg/kg, 0.28 mg/kg, 39.5 mg/kg, and 20,450 mg/kg, respectively. Other constituents at or above detection limits in the petitioned waste included arsenic (7.17 mg/kg), barium (3.43 mg/kg), copper (17,500 mg/kg), lead (17.20 mg/kg) and silver 42.33 mg/kg). With the exception of nickel, the concentrations are reported to be below their respective EPA Risk-Based Concentration (RBC) guidance values.

Using the average total concentration of the constituents in the waste, health based risk calculations were determined for residential exposure to the waste. The risk calculations were determined using the assumptions and rational outlined in the CDPHE Hazardous Materials and Waste Management Guidance on Risk Assessment, and current health based toxicity data obtained from EPA's Integrated Risk Information System (IRIS).

The results of the waste sampling indicated that the waste does not contain concentrations of any of the constituents which formed a basis for the F006/F019 listing at levels which exceed health based levels assuming direct exposure in a residential setting. Excluding arsenic and nickel, evaluation of the combined risk for all constituents in the waste indicated that the waste is within the allowable risk range for a residential land use setting.

A total carcinogenic risk greater than 1 x 10-6 of one added cancer death per million exposed individually, represents an unacceptable risk to human health. With the exception of arsenic, the calculated carcinogenic risk due to cadmium and chromium is 5.16 x 10-8. The calculated risk including arsenic is 1.87 x 10-5.

The risk assessment calculations for the non-carcinogenic risk or accumulative total hazard quotient posed by the concentrations of detected metals in AST's wastewater treatment sludge were calculated at a level of 2.13, which exceeds the hazard quotient index (HI) of 1 for the Residential Soil exposure scenario. When nickel is excluded however, the HI is calculated to be 0.71.

The potential for constituents in the waste to leach out and contaminate groundwater at concentrations that represent a threat to human health and the environment was evaluated using a toxicity characteristic leaching procedure (TCLP) analysis of the waste. The results of the TCLP analysis indicated that the waste does not leach metals at concentrations above regulatory standards. However, as a condition of this delisting petition, all delisted sludge will be disposed in a solid waste landfill or recycled at an appropriate metal reclamation facility.

Analysis of AST's waste treatment sludge also indicated that the waste sludge does not contain any organic constituents. Therefore, consideration of the potential health effects caused by exposure to organic constituents was not considered in evaluating the petition by the Division. In addition, the samples did not exhibit the corrosivity, ignitability, reactivity, or toxicity characteristics of hazardous waste.

This delisting is being granted under conditions specifying disposal, record keeping, storage and sampling requirements for the delisted sludge. Conditional delisting of the waste also prohibits any major changes to the electrolytic and electroless plating operations or wastewater treatment process without prior notification, evaluation, and approval by the Division.

This delisting does not apply to waste that demonstrates "significant changes" as defined in Delisting #008 in Part 261, Appendix IX--Wastes Excluded Under § 260.20 and § 260.22(d), or if any of the conditions specified in Part 261, Appendix IX for this delisting are not met. Should either of these occur, the waste is and must be managed as a hazardous waste. While the Commission is approving this conditional delisting for this specific waste at this specific site, the findings and criteria associated with the approval are unique. Other petitions for delisting, even if similar in material or use, will be reviewed by the Division on a case-by-case basis.

Statement of Basis and Purpose - Rulemaking Hearing of May 19, 2009

Notes

6 CCR 1007-3-8.69
37 CR 24, December 25, 2014, effective 3/2/2015 38 CR 11, June 10, 2015, effective 6/30/2015 39 CR 05, March 10, 2016, effective 3/30/2016 39 CR 11, June 10, 2016, effective 6/30/2016 40 CR 06, March 25, 2017, effective 4/14/2017 40 CR 11, June 10, 2017, effective 6/30/2017 40 CR 21, November 10, 2017, effective 11/30/2017 41 CR 06, March 25, 2018, effective 4/14/2018 41 CR 11, June 10, 2018, effective 6/30/2018 41 CR 24, December 25, 2018, effective 1/14/2019 42 CR 06, March 25, 2019, effective 4/14/2019 42 CR 06, March 25, 2019, effective 5/30/2019 42 CR 11, June 10, 2019, effective 6/30/2019 43 CR 12, June 25, 2020, effective 7/15/2020 44 CR 06, March 25, 2021, effective 4/14/2021 44 CR 11, June 10, 2021, effective 6/30/2021 44 CR 24, December 25, 2021, effective 1/14/2022 45 CR 11, June 10, 2022, effective 6/30/2022 45 CR 17, September 10, 2022, effective 9/10/2022 45 CR 17, September 10, 2022, effective 9/30/2022 45 CR 23, December 10, 2022, effective 1/30/2023

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