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Toxics Cleanup Program

MTCA/SMS Issues

February 12, 2009

What issues are being considered as part of this rule-making effort?

Ecology is considering a number of policy, technical, and scientific issues during this rule-making effort.  These include simplifying the rule and making it easier to use; rethinking some of the decision making steps; and evaluating whether changes to the MTCA cleanup regulation added as part of the 2001 amendments have had the intended effects. 

Ecology is considering a number of changes to simplify the cleanup regulation


The MTCA Cleanup Regulation includes a two-step process for establishing site cleanup requirements: (1) setting cleanup standards and (2) selecting remedies. Ecology is considering several ways to simplify and streamline the decision-making processes for site cleanup. Issues being considered include:

  • What rule revisions (if any) are needed to make it easier to use Method A at a broader range of sites?


  • Should Ecology consider simplifying the MTCA rule by eliminating modified Method B and incorporating site-specific adjustments into the standard Method B procedures?

  • Should Ecology consider simplifying the MTCA rule by eliminating Method C and clarifying how remediation levels can be used at industrial or other sites?


  • How can Ecology modify the rule (or guidance materials) to better integrate the terrestrial ecological evaluation (TEE) process with requirements for establishing tor establishing cleanup levels?


  • What rule revisions (if any) are needed to clarify the requirements for remedy selection?

What rule revisions being considered may affect cleanup standards

A number of issues come up frequently at cleanup sites, and Ecology is considering rule revisions to better address these issues.

Protecting human health

What rule revisions (if any) are needed to ensure that cleanup standards protect human health?

  • What rule revision (if any) are needed to update the Method A cleanup levels to reflect new toxicity values developed by EPA, changes to applicable state and federal requirements, and new scientific or regulatory information?


  • Should Method B soil cleanup level calculations include multiple exposure pathways: direct contact, dermal, and inhalation?


  • Should the Method B soil cleanup level calculations take into account that exposure varies for different age groups?


  • Should Ecology revise the rule to take into account risks associated with exposure at early life stages?


Evaluating exposure to lead


What rule revisions (if any) are needed given current scientific information on child and adult health risks associated with lead exposure?

  • What are acceptable blood lead concentrations and incremental concentrations?


  • How should we estimate exposure to lead-contaminated soils or groundwater?


  • Should Ecology revise Method A cleanup levels for lead in groundwater, soil, and industrial soil?


Addressing the potential for vapor intrusion


What rule revisions are needed to protect against health risks posed by vapors from contaminated soil or groundwater?

  • What rule revisions (if any) are needed to incorporate new scientific information about the potential for vapors from the subsurface to contaminate indoor air?


  • What rule revisions (if any) are needed to clarify when to evaluate the vapor intrusion pathway?


  • What does Ecology require for vapor assessments as part of the remedial investigation?


  • What methods are appropriate for establishing groundwater and soil cleanup levels protective of indoor air?


  • Are there model remedies that can be used for common situations?


Revising fish consumption rates


What rule revisions are needed to incorporate new scientific information and federal guidance on the health risks for persons consuming larger amounts of fish and shellfish?

  • Does the MTCA cleanup regulation default fish consumption rate provide a reasonable maximum exposure?


  • How will Ecology establish fish consumption rates, fish diet fractions, and other exposure parameters protective of high exposure groups?


  • What considerations go into establishing site-specific fish consumption rates?

Protecting groundwater


What rule revisions (if any) are needed to adequately protect Washington’s groundwater resources?

  • Should Ecology update the MTCA cleanup regulation Method A cleanup standards for groundwater?


  • Is there new toxicity data about contaminants in groundwater that Ecology should consider?


  • Do the current regulations provide adequate protection for children?


  • Should the effects of dermal (skin) contact with groundwater be more specifically included when establishing cleanup levels for contaminated groundwater?


  • What revisions (if any) are needed to protect groundwater from contamination from leaking underground storage tanks?


Leaking underground storage tanks


Should Ecology revise the rules pertaining to cleanup of leaking underground storage tanks?

  • What revisions (if any) are needed to ensure more timely and complete cleanups resulting from leaking underground storage tanks?


  • Should the rule be revised to require that contaminated soil be removed when a tank is removed?


Cleanup of contaminated sediments: See Sediment Management Standards/MTCA Cleanup Regulation (link at left)


Protecting plants and animals


What rule revisions (if any) are needed to update the Terrestrial Ecological Evaluation (TEE) process?

  • Should Ecology update table values to incorporate new toxicity data developed by US EPA or other agencies?


  • What rule revisions (if any) would help clarify requirements of the TEE process?


  • What rule revisions (if any) would help readers to understand when exclusions apply?


  • Should Ecology consider allowing gravel parking lots with institutional controls to qualify for an exclusion to the TEE process?


Updating data analysis methods


What rule revisions (if any) are needed to update the statistical methods for evaluating compliance with cleanup levels?

  • Should Ecology update the data analysis requirements to include currently available statistical software?


  • Should Ecology base updates on currently available federal guidance?


  • What rule revisions (if any) are needed to address using non-parametric statistics?


  • How should the rule be revised for treating non-detects?


  • What rule revisions (if any) are needed to the three part statistical compliance test?


What issues need resolving to coordinate how the Sediment Management Standards and the MTCA Cleanup Regulation address contaminated sediments?

Ecology is evaluating what rule revisions (if any) in the Sediment Management Standards and the MTCA Cleanup Regulation are needed to provide an efficient decision making process and clear and predictable sediment cleanup standards at contaminated sediment sites.

  • What revisions (if any) are needed to provide clear and predictable standards for cleanup of freshwater sediments?


  • What revisions (if any) are needed to provide a process to develop clear and predictable sediment cleanup standards that protect human and ecological health from bioaccumulative contaminants?


  • What rule revisions (if any) are needed in the Sediment Management Standards to clarify the cleanup decision making process and better harmonize terminology with the MTCA Cleanup Regulation for cleanup of contaminated sediments?


  • How should we consider background concentrations when making decisions about sediment cleanup standards at cleanup sites?


  • How should Ecology update the MTCA Cleanup Regulation and the Sediment Management Standards to more specifically address cleanup of other toxic, radioactive, biological, and deleterious substances (such as wood waste) in the aquatic environment?


What changes are being considered for the MTCA cleanup regulation legal and administrative processes?

Recently enacted laws and regulations


The Washington State Legislature amended the Model Toxics Control Act several times since the cleanup regulation was amended in 2001. Several rule revisions are needed to comply with the new statutory requirements. Ecology has also identified several potential rulemaking issues based on situations at individual cleanup sites and on certain recent court decisions.

  • What revisions are needed to implement the lien authority (added to MTCA in 2006 by SSB 5449) for recovery of remedial action costs?


  • What revisions are needed to implement Ecology’s authority to issue property-specific opinions for cleanup of a portion of a site (added to MTCA in 2007 by SHB 1039)?


  • What revisions are needed to the MTCA cleanup regulation to implement the Uniform Environmental Covenants Act (passed in 2007 as SB 5421 and codified as Chapter 64.70 RCW)?


  • What rule revisions (if any) are needed to reflect recent court cases?


Area wide contamination


What rule revisions (if any) are needed to address area-wide soil contamination from former smelters or agricultural operations?

  • What rule revisions (if any) are needed to implement recommendations made by the Area-wide Soil Contamination Task Force?


  • What rule revisions (if any) are needed to implement legislation protecting children from area-wide soil contamination (passed in 2005 HB 1605as and codified as Chapter 70.140 RCW)?


How will Ecology decide which issues to address as part of this rule-making effort?