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Toxics Cleanup Program

Photographer:  Marv Coleman

Policies, Procedures and Implementation Memoranda

The policies, procedures, and implementation memoranda listed below reflect the Toxics Cleanup Program’s interpretation of the Model Toxics Control Act (MTCA), Chapter 70.105D RCW, and the regulations adopted under MTCA, including the MTCA Cleanup Regulations, Chapter 173-340 WAC, and the Sediment Management Standards, Chapter 173-204 WAC.  They should be read in conjunction with the statute and regulations.

Disclaimer: These documents are not intended, and cannot be relied on, to create rights, substantive or procedural, enforceable by any party in litigation with the state of Washington.  Ecology may act at variance with them depending on site-specific circumstances, or modify or withdraw them at any time.  Changes to the statute or regulations may affect the statements contained in these documents.

For more information, please contact the Toxics Cleanup Program’s Policy and Technical Support Unit at 360-407-7170.

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Program Policies

Number Title Revised
120A Independent Remedial Actions December 2016
130A Coordination of MTCA and SEPA July 2004
300 Site Discovery June 2004
310A Initial Investigations December 2009
310B Creating or Changing the Name, Address, or Identification Number for a Facility or Site October 2011
330A Listing of Sites on the Hazardous Sites List October 2004
330B Removal of Sites from the Hazardous Sites List October 2004
340 Priority Setting for Sites Withdrawn March 2016
Update planned
340B Managing TCP's Program Plan October 2008
500A Identification of Potentially Liable Persons (formerly Policy 500B) May 2016
520A Consent Decrees December 2016
520B Prospective Purchaser Agreements August 1994
520C  De Minimis Consent Decrees December 2016
530A  Agreed Orders December 2016
540A  Enforcement Orders December 2016
550A Cost Recovery February 2015
550C Prepaid Cleanup Oversight June 2006
560B Granting Mixed Funding for LUST Cleanups  
600A Site Register Publication August 2008
710A Permit Exemptions for Remedial Actions under MTCA  (formerly Policy 130B) November 2015
800A Property Access February 1991
800B Information Access February 1991
840 Data Submittal Requirements April 2016
900 Underground Storage Tank (UST) Enforcement September 1992
920 Providing Public Participation in UST Settlements  
930 Investigation and Response to Complaints of UST Violations  

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Program Procedures

Number Title Revised
320 Site Hazard Assessment and Ranking of MTCA Sites by Ecology Staff June 2004
321 Site Hazard Assessment of MTCA Sites by Local Health Districts/Departments June 2004
Establishing Environmental Covenants under the Model Toxics Control Act
  • Environmental Covenant - Template and Instructions (MS Word)
  • December 2016
    Releasing Environmental Covenants under the Model Toxics Control Act
  • Termination and Release of Environmental Covenant – Template and Instructions (MS Word)
  • December 2016
    500A Identification of Potentially Liable Persons (formerly Procedure 500B) May 2016
    550A Cost Recovery under a MTCA Order or Decree February 2015
    550B Property Liens under RCW 70.105D.055 July 2012

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    Implementation Memoranda

    Number Title Revised
    Memo #1 Guidance on the Use of Maximum Contaminant Levels as Cleanup Levels
    [The procedure for using MCLs is described in WAC 173-340-720(7)(b).  See also focus sheet on Developing Ground Water Cleanup Standards under MTCA, available at:]
    Withdrawn 02/2001
    Rule amended
    Memo #2 Applicability of WAC 173-340-706 August 1993
    Memo #3 Practical Quantitation Limits as Cleanup Standards   Withdrawn 08/2012 Update planned
    Memo #4 Determining Compliance with Method A Cleanup Levels for Diesel and Heavy Oil June 2004
    Memo #5 Collecting and Preparing Soil Samples for VOC Analysis June 2004
    Memo #6 Nematode Bioassay Protocol for Soil Toxicity Screening August 2004
    Memo #7 Soil Moisture Corrected Reporting by EPA Method 8000C February 2008
    Memo #8 Natural Background for Dioxins/Furans in WA Soils  August 2010
    Memo #9 Building Code Compliance for Factory Built Commercial Structures  May 2011
    Memo #10 Evaluating the Human Health Toxicity of cPAHs using TEFs April 2015
    Memo #11 Dioxins, Furans, and Dioxin-Like PCB Congeners: Addressing Non-Detects and Establishing PQLs for Ecological Risk Assessments in Upland Soil July 2015
    Memo #12 When to Use EPA Method 1668 for PCB Congener Analyses July 2015
    Memo #13 Dioxins, Furans, and Dioxin-Like PCB Congeners: Ecological Risk Calculation Methodology for Upland Soil (Implementation Memorandum No. 13) July 2016
    Memo #14 Updated Process for Initially Assessing the Potential for Petroleum Vapor Intrusion March 2016
    Memo #15 Frequently Asked Questions (FAQ’s) Regarding Empirical Demonstrations and Related Issues June 2016
    Memo #16

    Developing Conditional Points of Compliance at MTCA Sites Where Groundwater Discharges to Surface Water

    July 2017
    Memo #18 DRAFT Petroleum Vapor Intrusion (VI): Updated Screening Levels, Cleanup Levels, and Sampling August 2017
    Draft available for comment through
    Sept 22
    Memo #19 Gasoline and Diesel Soil Concentrations Predicted to be Protective of Upland Ecological Receptors August 2017 NEW!
    Memo #20 Frequently Asked Questions (FAQs) Regarding Model Remedy Implementation March 2017

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    This page last updated August 17, 2017