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Contact Pacific Southwest Waste Program

Pacific Southwest, Region 9

Serving: Arizona, California, Hawaii, Nevada, Pacific Islands, Tribal Nations

Evoqua Water Technologies
(formerly Siemens Carbon Regeneration Facility)

Frequent Questions and Background Information

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What is spent carbon?

Spent carbon is a granular material used in filtering systems to purify air and water. Contaminants adhere to (or stick to) the carbon, and so are removed from the air or water. When the carbon is no longer able to purify the air or water, it is called “spent” carbon. At Evoqua, the spent carbon is heated to high temperatures in a carbon regeneration furnace. This process removes most of the contaminants and reactivates the carbon. The reactivated carbon can be sold as a commercial product to be reused in filtering systems.

Are there air emissions from Evoqua?

Yes. Information on air emissions from this facility can be found in this website, on the Air Emissions page. 

Is there wastewater discharge from Evoqua?

Yes. Evoqua discharges waste waters that are used as part of the carbon regeneration process and that have been processed through the wastewater treatment plant.   Evoqua has a  wastewater treatment system which is designed to reduce the amount of contaminants in the wastewater before it is discharged to the local sewer system. This waste water is continuously monitored to ensure that it does not exceed allowable limits as part of the NPDES permit.  Please see the Risk Assessment page for more information.

Are hazardous waste operations at Evoqua subject to regulatory control?

Yes. Evoqua is subject to regulatory control under the Resource Conservation and Recovery Act (RCRA) and the Clean Air Act. RCRA is a federal statute governing the operation of hazardous waste facilities and the Clean Air Act specifies operation of air pollution control equipment and discharges from the stack. For more information about the stack and its emissions see the Air Emissions page. Using this and other information, EPA will make a permit decision at Evoqua. The permit decision could be a permit denial, or issuance of a permit to allow Evoqua to continue operating. Until EPA makes a permit decision, Evoqua must comply with interim status regulations. Interim status is a temporary authorization to operate until EPA makes a final permit decision. Interim status contains general requirements for Evoqua to operate safely. EPA’s fact sheet below provides further details about the permitting process. RCRA Permit fact sheet - March 2015 (PDF) (2 pp, 350K)

What other regulatory controls is Evoqua subject to?

Evoqua is also subject to the Clean Air Act, the Clean Water Act, and the Emergency Planning and Community Right-to-Know Act (EPCRA). Under the Clean Air Act, Evoqua must report estimated air emissions of certain contaminants annually to EPA. Under the Clean Water Act, Evoqua must treat waste waters before discharging them to the local waste water treatment system, and must have a storm water management plan. Under EPCRA, Evoqua must provide information to local emergency response agencies about hazardous materials stored at the facility. Under the Toxic Release Inventory (which is part of EPCRA), Evoqua must report to EPA releases of certain contaminants. For general information about each of these regulatory programs, see the following web pages:

What is the time frame for EPA's permit decision?

Evoqua conducted their air emissions test in March 2006 and submitted a revised Part B Permit Application in February 2007. Evoqua submitted their human health and ecological risk assessment to EPA in late July 2007. EPA provided comments on the Part B application to Evoqua on September 28, 2011 and comments on the Closure Plans and the Financial Assurance mechanism on December 14, 2011.

Evoqua incorporated EPA’s comments to their previous permit application and associated documents, and submitted a revised Part B to EPA on April 27th, 2012.

EPA is reviewing this revised permit application to determine if it is complete and technically accurate. After the review, EPA will make a proposed decision on whether to deny or grant the permit and open a 45 day Public Comment Period. EPA is expecting to propose a permit decision in early 2013.

Have there been any spills at Evoqua?

Yes. Evoqua has reported four spills since they began operating in 1992. Evoqua reports that these spills were controlled soon after they occurred, and that Evoqua removed affected soils and sampled remaining soils where necessary.

What is Evoqua's compliance history?

Evoqua has been inspected by EPA regularly since 1992, their first year of operation. This is a list of Evoqua’s recent inspection reports:

On June 30, 2006, EPA issued a Consent Agreement / Final Order (CA/FO) to Evoqua, alleging three violations. The CA/FO required Evoqua to pay a fine and make various safety upgrades.

Full text of the Consent Agreement / Final Order (CA/FO) dated June 30, 2006 (PDF) (16 pp, 545K)

Are there other carbon regeneration facilities in the United States?

In addition to Evoqua, there are two other permitted carbon regeneration facilities operating in the U.S. They are Calgon in Pittsburgh, PA and Evoqua in Sewickley, PA.


Evoqua Contact Information

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