WAC 173-350-410 - Inert waste landfills

Agendas and meeting notes from the advisory committee on section 410 on the WAC 173-350 rulemaking.


WAC 173-350-410 - Inert waste landfills

Ecology staff lead: Bill Harris 

Work group members 

Name Organization
Kathy Pierson Snohomish Health District
Chris Martin WA Department of Ecology - WQ
John Bromley WA Department of Natural Resources
Rod Whittaker Washington Refuse and Recycling Association
Jody Snyder Waste Connections
Jana McDonald Central Pre-mix
Ted Silvestri Yakima County Health District
David Lowe Waste Management
Kevin Scott Port Townsend Paper


Focus: Section 410 establishes standards, criteria and requirements for landfills receiving inert wastes as they are defined in WAC 173-350-990 (also under review). These wastes may include monolithic concrete and asphalt from construction and demolition projects, and other materials determined to be inert. While these materials can sometimes be recycled in certain markets, it is anticipated that many jurisdictions will have a continuing need to dispose of them as wastes. 

Inert waste materials are used for fill material in construction projects, including large transportation projects. Section 410 provides a categorical exemption from permitting for the placement or disposal of inert wastes in a facility with a total capacity of 250 cubic yards or less. Technically, any construction project that uses more than 250 cubic yards of inert wastes as fill also requires permitting as an inert waste landfill. In practice, project owner/operators or constructors often ignore the requirement to obtain a solid waste permit for this type of filling. The work group will explore developing a more practical framework for exemptions from permitting requirements for these types of inert wastes. 

Inert wastes are often used for reclamation of surface mines permitted by the Washington Department of Natural Resources. DNR has no volume limits on inert waste used in fill for reclamation. This presents mine operators with an unclear regulatory landscape and may lead to potential compliance issues. Also, a clarification is needed to address a conflict between section 410 and the 2006 revision to WAC 173-160, Minimum Standards for Construction of Wells, which modified that rule's setback requirements when siting water wells near landfills permitted under WAC 173-350. 

Update: The work group began meeting in March 2015. Draft revisions to sections 400 and 410 have been proposed to the workgroup, based largely on two determinations coming out of the broader rule process. First, inert materials and consequently what is acceptable in an inert waste landfill, are both determined by statute (RCW 70.95.030(10)). Ecology cannot make any adjustments that would allow non-inert materials to be disposed in those facilities. Secondly, a new section 235 is being developed to address "impacted" soils. Those are soils that have characteristics which make them solid wastes - but not inert solid wastes. Some adjustments will be proposed in sections 400 and 410 to accommodate the specifics of the new section 235. Please send questions to w2rrulemaking@ecy.wa.gov

Work group meetings and notes

March 16, 2015 1-4 p.m., Ecology Headquarters, Lacey