Landau Associates News

Changes are Coming to Washington State Solid Waste Handling Regulations in 2017

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The Washington State Department of Ecology is in the process of revising the "350" Rule for managing solid waste (Chapter 173-350 of the Washington Administration Code)—the most significant revisions since the rule was adopted in 2003. Sections 235 and 995 were added in the preliminary draft rule and propose to regulate impacted soil and sediment.


Anyone involved in the import to or export of soil from a property, including:

  • Agricultural producers
  • Architectural/engineering consultants
  • Land use and environmental attorneys
  • Construction companies
  • Developers
  • Ports
  • Public agencies
  • Property owners
  • Solid waste handling and recycling facilities
  • Utilities


A formal proposed rule is scheduled for release for public comment in late 2016. The new 350 Rule is scheduled to take effect in Spring 2017.


The new rule proposes regulation of soil with concentrations below the Model Toxics Control Act (MTCA) cleanup levels and above natural background levels (i.e., "impacted soil") as a solid waste. If implemented as currently drafted, these new regulations would:

  • Establish a new, broad category of environmental liability for any soil or sediment determined to be impacted soil.
  • Define new background and screening levels for over 200 parameters.
  • Introduce potential extensive testing requirements on soil for both source and receiving site.
  • Not allow exemptions for "impacted soil" fill at properties filled with impacted soil prior to the effective date of the regulation. This restriction would likely exclude many previously filled urban properties from being used as receiving sites for impacted soil
  • Establish penalties for non-compliance.
  • There are several additional conditions and requirements including definitions, exemptions, due diligence, limited access properties, testing, representative sampling, re-use restrictions, and penalties from RCW 70.95. Let us know if you would like us to discuss these with you.


  • New sections 235 and 995 apply to soil materials, including street waste, petroleum-contaminated soil, engineered soil, "impacted soil," and sediment from impacted waterways to be managed in upland locations.
  • There will be five sets of contaminant limits, or soil and sediment screening levels (SSLs), including "clean" (defined by natural background) and four exposure/use options listed in section 995.
  • The rule revision requires "representative sampling," and references existing guidance documents that establish rigorous procedures to define and implement a sampling program. Depending on the size of the project and the nature of the source and receiving sites, "representative sampling" could cost upward of $100,000 on large earthwork projects.
  • The rule revision is essentially an anti-degradation regulation that requires soil quality of both the import soil and the soil at the receiving site be documented to demonstrate that import soil will not degrade the fill site.
  • The rule revision provides for use of "due diligence" inquiry to determine that testing is not needed, and identifies many of the activities required for a Phase I ESA as appropriate due diligence inquiry (e.g., review of government records, review of property ownership, review of site use history, visual inspection).
  • The regulation does not appear to provide any protection against fines or other actions if SSLs are exceeded in spite of appropriate due diligence inquiries.
  • While Ecology anticipates that the rule would be self-implementing, any need for clarification or review by the regulatory authority could result in extensive project delays.
  • The rule revision establishes fines up to $1,000 a day for non-compliance with the regulations (RCW 90.45), and could establish environmental liabilities similar to those associated with the MTCA regulations.


We’re involved in closely tracking and commenting on the proposed changes. There are a number of questions our clients are asking that need answers, such as:

  • How would the rule revision affect my development projects’ cost and schedule?
  • Will accepting impacted soil affect whether a property can be redeveloped?
  • Which agency will approve results of soil testing identified in sections 235 and 995?
  • Who is liable if impacted soil is imported to a property and fines, permitting requirements, and/or soil removal are incurred?
  • What records will be required and how long must they be retained?
  • Is due diligence really a protection from penalties?
  • How will requirements of sections 235 and 995 affect real estate sales and purchases?
  • Will solid waste screening levels become the new standard for determining "how clean is clean?"

The proposed new rule text and supporting documents are available for review at Ecology’s website:

We will let you know as answers become available to these questions. If you have other questions you would like answered, would like to discuss how the proposed rule revisions could affect your property or projects, or would like assistance in commenting during the rule revision process, please contact us.

Larry Beard, PE, LHG, Principal

Brian Butler, LHG, LEG, Principal

(425) 778-0907