Desotec US LLC (Formerly Evoqua Water Technologies LLC), Parker, AZ

• Background
• Performance Demonstration Test Plan
• Final RCRA Permit Decision (2020)
• Permit Modifications
• Revisions to the RCRA Permit on Remand
• Petition for Review by the Environmental Appeals Board
• Final RCRA Permit Decision (2018)
• Map and Process Description

Background

Desotec US LLC (Formerly Evoqua Water Technologies LLC) operates a carbon regeneration facility on the Colorado River Indian Tribes (CRIT) Reservation near Parker, Arizona. (See boxes below for a map and a description of Desotec's process). Desotec receives over 5,000 tons of spent carbon annually from across the United States. About 11% of this spent carbon is considered hazardous waste and is regulated by EPA under the Resource Conservation and Recovery Act (RCRA).

Under RCRA, EPA is responsible for permitting the facilities that manage RCRA-regulated hazardous wastes on tribal lands. In 1991, EPA required carbon regeneration furnaces to obtain hazardous waste permits. At that time, the Desotec facility (then known as US Filter/Westates) was already building a carbon regeneration furnace, which meant it was eligible to operate under “interim status” RCRA regulations while applying for a RCRA hazardous waste permit.

The facility is also regulated under other federal environmental laws including the Clean Air Act and the Emergency Planning and Community Right to Know Act.

Performance Demonstration Test

The scope and purpose of the Performance Demonstration Test (PDT) was to evaluate the performance of the facility located on the Colorado River Indian Tribes (CRIT) reservation near Parker, AZ. This evaluation included an assessment of the facility’s compliance with the performance and emissions standards set forth in the facility’s RCRA Permit as well as the ability of the facility to meet more stringent “replacement standards,” which are identified in the permit. During the PDT, Evoqua was also tasked with the collection of emission data to be used to update the site-specific human health and ecological risk assessment.

To accomplish the objectives of the PDT Plan, the Plant Operator performed 3 test runs. They used “worst case” operating limits, injecting surrogate contaminants to stress the system. The Plant Operator will use this information to demonstrate that continued operations within normal parameters do not pose an unacceptable risk to human health or the environment and to make any appropriate recommendations regarding modification of the facility’s permit limits. The test was conducted in October 2022 and EPA is in the process of evaluating the facility’s PDT Report.

EPA held an informational public meeting at the Bluewater Resort and Casino on September 7, 2022.

Final RCRA Permit Decision Notification (2020)

EPA is providing notice that the Permit Conditions that were stayed as a result of an appeal in this matter, including each of the Permit Conditions that were revised – to the extent of such revisions -- in the Final Remand Decision, are being put into effect through this Final Permit Decision, issued February 27, 2020. See 40 CFR § 124.19(l)(2). See also:

• Final Agency Action Notification: Evoqua Water Technologies LLC and Colorado River Indian Tribes, Parker, AZ (pdf) (173.41 KB, February 27, 2020)
  EPA is providing notice that the Permit Conditions that were stayed as a result of an appeal in this matter, including each of the Permit Conditions that were revised – to the extent of such revisions -- in the Final Remand Decision, are being put into effect through this Final Permit Decision, issued on February 27, 2020. .

Permit Modifications

A RCRA Permit can be modified by EPA or the Permittees as described in 40 CFR §§ 270.41 and 270.42. Permit modifications are classified as Class 1, Class 1*, Class 2, or Class 3. The Class 1 permit modification is the only permit modification that can be initiated by the Permittees and that does not require prior EPA Director approval. Class 1* requires prior EPA Director approval. Class 2 and Class 3 permit modifications are more involved and require public noticing, a 60-day public comment period, and other requirements that can be found in 40 CFR § 270.42.

The RCRA Permit, including the latest permit modifications, can be found at Desotec's website.