6 Colo. Code Regs. § 1007-3-8.44
These amendments to 6 CCR 1007-3, Part 261 are made pursuant to the authority granted to the Hazardous Waste Commission in § 25-15-302(2), C.R.S.
Amendment of Part 261. Appendix IX to Conditionally Delist F006/F019 Hazardous Waste Generated by AAA Plating. Inc. (AAA Plating), located at 7777 40th Avenue in Denver Colorado, 80205.
Appendix IX of Part 261 is being amended at this time to conditionally delist F006/F019 hazardous waste generated at AAA Plating in Denver, Colorado. This delisting will allow AAA Plating to dispose of its waste at a Solid Waste Landfill which meets the requirements of the Colorado Solid Waste Regulations 6 CCR 1007-2, provided it complies with the conditions of the delisting. Alternatively, AAA Plating may recycle the wastewater treatment sludge at a metal reclamation facility for the recovery of heavy metals.
AAA Plating operates a commercial electroplating and chemical conversion coating operation located in Denver, Colorado. The facility generates a wastewater treatment sludge that is classified as a F006/F019 listed hazardous waste. The F006 hazardous waste listing in § 261.31 describes wastewater treatment sludge that is generated from electroplating operations. The F019 hazardous waste listing in 261.31 describes wastewater treatment sludge that is generated from the chemical conversion coating of aluminum. Because the wastewater treatment sludge generated by AAA Plating is not segregated as to electroplating or chemical conversion coating, the sludge carries both the F006 and the F019 listed waste codes. The basis for each hazardous waste listing is described in Appendix VII of Part 261. Each listing is based on hazardous constituents which are generally contained in wastes described by the listing. The hazardous constituents that formed the basis for the F006 listing include cadmium, hexavalent chromium, nickel, and cyanide (complexed). The hazardous constituents that formed the basis for the F019 listing are hexavalent chromium and cyanide (complexed).
The wastewater treatment system at the plant generates a dry sludge weight of approximately 10 tons per month. Industrial wastewater produced from the electroplating and chemical conversion coating operations at the facility is collected by containment trenches which flow to large holding tanks. Wastewater proceeds through a series of processes in which the pH is adjusted, and metals are precipitated out with a reducing agent. The metals are then filtered out and concentrated using a microfiltration device and concentrate tank. Ultimately, the concentrated solids are processed through a filter press to remove the liquid and form the F006/F019 sludge cake, which is then dried further through the use of a sludge drying unit.
Analytical sampling of the F006/F019 sludge was conducted prior to the submission of the waste delisting petition. The electroplating and chemical conversion coating processes do not significantly change on a day-to-day basis. The collected samples adequately represent the waste stream. 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 § 260.22. This evaluation was provided to the Commission.
The results of the waste sampling indicated that the waste did not contain detectable concentrations of hexavalent chromium. The results of the analysis did indicate that the waste contained detectable concentrations of cadmium, complexed cyanide, and nickel. However, based on health based risk assessment calculations derived using the general assumptions outlined in the Division's current risk assessment policy, the waste did not contain concentrations of these constituents at levels which would be considered harmful to human health or the environment.
Analytical sampling of the waste also indicated that the waste contained detectable concentrations of arsenic, barium, lead, and silver. Based on health based risk assessment calculations and average background soil conditions, the Division determined that the waste did not contain concentrations of barium, lead, or silver at levels which would be considered harmful to human health or the environment. However, the results of the health based risk assessment indicated that the concentration of arsenic in the waste did pose an unacceptable risk to human health and the environment if humans were directly exposed to the waste in a residential setting. Although the assessment showed that the level of arsenic in the waste was too high to support an unconditional delisting of the waste, further evaluation of the physical and chemical nature of the waste indicated that the waste did not pose an unacceptable risk to human health or the environment if subject to certain conditions regarding its handling and disposal in a solid waste landfill or via reclamation of the heavy metals contained in the wastewater treatment sludge.
The potential for constituents in the waste to leach out and contaminate groundwater was evaluated by the Division using TCLP analytical tests which measure the maximum potential for constituents to be released from the waste. The results of the TCLP analysis indicated that hexavalent chromium, lead, mercury, selenium, and silver do not show any chemical potential to leach out of the waste, and that arsenic, barium, cadmium, and nickel showed only small potentials to be leached from the waste which are adequately protected against in a solid waste landfill setting or if the sludge is sent for reclamation of heavy metals.
Further, the results of the waste sampling indicated that the waste sludge does not contain any organic constituents. Consideration of the potential health effects caused by exposure to these constituents was therefore not considered in evaluating the petition by the Division.
This delisting is being granted under conditions which specify disposal requirements, specify recordkeeping requirements, and storage requirements for the delisted sludge. Conditional delisting of the waste also prohibits any major changes to the electroplating or chemical conversion coating processes or wastewater treatment process without prior notification, evaluation, and approval by the Division.
This delisting does not apply to waste which demonstrates "significant changes" as defined in Delisting #002 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 Division has approved a 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 November 21, 2000
6 CCR 1007-3-8.44