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Chemical Waste Management

Chemical Waste Management of the Northwest, also known as a CWM, is Oregon's only hazardous waste landfill. It is located near Arlington, in Gilliam County. The hazardous waste landfill is operated by Waste Management, which also operates the adjacent Columbia Ridge solid waste landfill.

DEQ regulates the treatment, storage and disposal of hazardous waste at the landfill using the following programs:


​CWM submits hazardous waste permit modification application and schedules public information meeting  

DEQ received a hazardous waste permit modification request from CWM on April 29, 2024. CWM scheduled a public information meeting about the proposed permit modification for May 15 in Arlington. DEQ staff will be available to answer questions about the permit process. 

Public information meeting details: 

When: Wednesday, May 15, 2024, 6 p.m. 
Where: Sturgeon Room at the Gronquist Building, 1665 Railroad Ave., Arlington 

What's proposed: CWM is in the process of renewing its hazardous waste landfill permit with DEQ. While that renewal is being processed, CWM is seeking a permit modification to expand its existing landfill so it can continue properly disposing of hazardous waste. Permit modifications are more limited in scope than renewals, and this modification would be focused on expanding an existing landfill unit. Waste streams would remain the same as what CWM currently accepts.   

The public may submit comments by July 1, 2024 on the proposed modification application by email at or by mail to:   

Permit Coordinator
Oregon DEQ
400 E. Scenic Dr., Ste. 307
The Dalles, OR 97058  

DEQ will review all comments received by the deadline, and then draft the permit modification. The draft permit modification will also have a public comment opportunity.​

​DEQ received a hazardous waste permit renewal application from CWM on May 2, 2022. 

What happens next: DEQ is reviewing the application for completeness. If DEQ determines the application is complete, DEQ will begin drafting a permit renewal. Once drafted, DEQ will make the draft permit available for public review and will host a public hearing to accept verbal and written comments on the conditions of the draft permit. DEQ will review and respond to all comments received by the comment deadline and may revise the draft permit based on comments.

After the public comment period, if the permit conditions meet all requirements of the U.S. EPA and the State of Oregon, DEQ will recommend the Oregon Environmental Quality Commission approve the hazardous waste permit renewal. The Environment Quality Commission makes the ultimate decision on whether to issue the hazardous waste permit renewal.​​

​CWM to host public information meeting for proposed permit renewal

CWM notified DEQ on March 10, 2022, that it plans to submit a hazardous waste permit renewal application.

CWM hosted a public information meeting prior to submitting its permit renewal application to DEQ. DEQ staff attended the meeting and was available for questions about DEQ's permitting process.


DEQ approves hazardous waste permit modification for additional storage unit

DEQ approved a Class 2 permit modification for Chemical Waste Management of the Northwest on Dec. 16, 2021, following a 60-day public comment period. The permit modification allows CWM to add a container storage unit at its hazardous waste Treatment, Storage and Disposal Facility in Arlington. The additional storage unit expands the facility's waste storage capacity.

CWM hosted a virtual public information meeting via Zoom on Oct. 21, 2021, to discuss the proposal and answer questions. DEQ hazardous waste staff also attended the meeting to answer questions and provide information about next steps. DEQ received no official public comments on the proposed permit modification. DEQ received comments from EPA Region 10 as part of an interdepartmental agreement and in response made changes to the permit and attachments.

Find additional permit information and records in Your DEQ Online, Project Number: 6321

​​​Proposed hazardous waste permit modification for additional container storage unit

Chemical Waste Management, also known as CWM, is proposing to modify its hazardous waste permit to add a container storage unit at the company's Arlington Treatment, Storage and Disposal Facility. This is to address a shortage of storage capacity and new contracts recently awarded to the company.

​​This is a different permit modification proposal than the one DEQ provided an update about in March 2021. That proposal would have expanded CWM's landfill capacity by adding an additional landfill unit to address emerging pollutants. CWM still plans to add an additional landfill unit to handle both general hazardous waste and emerging pollutants, but the project and permit modification application for the expansion is delayed while CWM works to obtain land use compatibility approval from Gilliam County. ​

​DEQ anticipates receiving hazardous waste permit modification application

Chemical Waste Management, known as CWM, has notified DEQ it’s seeking to modify its Arlington landfill permit to add a new disposal unit that would expand its capacity to properly dispose of hazardous waste and chemicals of emerging concern. The facility has an existing landfill unit that accepts this kind of waste and anticipates needing additional capacity. 

Much of the waste would arrive in the form of contaminated soil from large-scale cleanup operations occurring at former industrial sites including Superfund sites, firefighting training centers and military sites. Contaminants would include PFAS, a component of some firefighting foams and many consumer goods.

The facility would build the landfill unit to the same hazardous waste specifications as its existing units, including a triple-lined system that protects against groundwater contamination.

When DEQ receives the permit modification application, DEQ will analyze the application to ensure it meets DEQ and EPA hazardous waste requirements and Oregon environmental laws and regulations.

As part of this process, DEQ will work with CWM to hold a public information meeting (date TBD) and request comments on the permit application. DEQ will review the comments and draft the permit modification. Once the permit modification is drafted, DEQ will hold a public hearing and request comments on the draft permit modification.

Frequently asked questions

​CWM opened in 1976 to provide hazardous waste treatment, storage and disposal. EPA and DEQ jointly issued the site’s first hazardous waste permit in 1988.

​CWM is located in a very isolated, dry part of the state. The dry climate and low annual rainfall prevent potential pollutants from reaching waterways or groundwater, which is hundreds of feet underground. The facility is near a major interstate and railroad, making transportation to and from the site relatively easy.

​The hazardous waste landfill receives a wide range of both hazardous and non-hazardous waste, including solids and liquids, industrial waste and asbestos. Hazardous waste must be treated to meet land disposal requirements prior to disposal in the triple lined landfill or evaporation ponds. The evaporation ponds do not discharge off site.

​As of spring 2021, CWM receives on average approximately 15,000 tons of hazardous waste per month.

The landfill has the area and capacity to remain open for at least another several decades.

State and federal law require CWM to maintain financial assurance to properly care for the facility. This process ensures there is a source of revenue to properly close, manage and monitor the facility for many years in the future. The current requirements are for a post-closure monitoring period of 30 years.

​Leachate is collected and treated at the site, and a network of groundwater monitoring wells would detect any potential releases from the site. The distance to the river, combined with the depth to groundwater, the direction of local groundwater flow, low precipitation and triple-lined landfill design reduce the risk of potential impacts to surface water, including the Columbia River.

​Depending upon the type of transportation, the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA), Oregon Department of Transportation (ODOT), and other public safety transportation authorities primarily regulate road transport. The Surface Transportation Board and the Federal Railroad Administration as part of the U.S. Department of Transportation have oversight of rail transport. ODOT also has some oversight of railroad safety and at-grade crossings.

The spill would be managed and cleaned up similar to any type of emergency spill. Oregon's emergency response system involves capable responders and resources from local, state and federal agencies, including Oregon DEQ, Health Authority, State Fire Marshal, U.S. Environmental Protection Agency, U.S. Coast Guard, and more. These agencies work with local communities to respond to the threat and ensure the safety of people and the environment.

Additionally, CWM's hazardous waste permit includes provisions that require CWM to retain a spill contractor to respond to and clean up any spills at the site or during transportation.


Additional information

Your DEQ Online Project Number: 6321