Understanding Site Cleanup

Cleanup Process:  Major Phases & Definitions

The cleanup of contaminated sites is complex and costly. This page is provided as a reference guide that shows (in one convenient location):

  Heading: Pre-Remedial  

Related Rules, Policies, and Other References

  Site Discovery & Reporting:  Sites may be discovered in a variety of ways. Most contamination problems are reported by business owners, operators, employees, or concerned citizens. Releases of hazardous substances from Leaking Underground Storage Tanks must be reported to Ecology within 24 hours of discovery. All other incidents or releases must be reported within 90 days of discovery.   Rule: 
WAC 173-340-300 and -450(5)
WAC 173-360-360, -372, and -375

Site Discovery & Reporting Policy 300

See also "How to report":
Spills & Emergencies
Other Environmental Problems

  Initial Investigation (II):  A brief investigation conducted within 90 days after receiving a site discovery report. This step provides enough information to determine if the site needs further investigation, emergency cleanup, or no further action. If further action is required, early notice letters are sent to site owners, operators, etc., inviting them to work cooperatively with us to resolve the contamination problems.      Rule:  WAC 173-340-310

Policy:  310A

  Site Hazard Assessment (SHA):  An assessment to confirm the presence of hazardous substances and to determine the relative risk the site poses to human health and the environment. (Note:  Some SHAs are conducted by Ecology staff while others are conducted by local health districts / departments.)   Rule:  WAC 173-340-320

Procedures:  320, 321

See also:
Local Health Districts / Departments

  Hazard Ranking (WARM Score):  The results of the Site Hazard Assessment are used in the Washington Ranking Method (WARM) to yield a WARM score. This is a number between 1 and 5, where a "1" represents the highest level of risk and a "5" the lowest. Generally, federal Superfund sites and sites ranked 1 or 2 are considered higher priority for cleanup. Some factors that enter into site hazard ranking include:  the amount and type of contaminants present, and how easily contaminants could come into contact with people and the environment. The level of public concern is also considered.   Rule:  WAC 173-340-330

Policy:  340

Focus Sheet:  WARM

  Listing on Hazardous Sites List (HSL):  Ranked sites are placed on the state Hazardous Sites List, a semi-annual list of contaminated sites that shows sites ranked and slated for cleanup under the Model Toxics Control Act.    Rule:  WAC 173-340-330

Policy:  330A



  Heading: At Any Time
  Emergency Action:  Emergency situations such as spills of hazardous substances and drug lab cleanups are referred to another program for immediate action.   Spill Prevention, Preparedness & Response Program  
  Interim Action:  Any remedial action that reduces risk to human health and the environment, and partially addresses the cleanup of a site.   Rule:  WAC 173-340-430  


  Heading: Active Cleanup
  Heading: Site Characterization & Remedy Selection      
  Remedial Investigation / Feasibility Study (RI/FS):  An in-depth study conducted to: 
  • Determine detailed site characteristics and define the extent and magnitude of contamination;
  • Evaluate potential impacts to human health & the environment;
  • Establish cleanup criteria; and
  • Evaluate cleanup alternatives.

The RI/FS may be conducted as two separate steps, but they are often combined into one study. A draft of the RI/FS report is made available for public review and comment before finalizing. 
In some cases, a "SEPA Review" may be needed. This is an evaluation of the environmental impacts of the proposed cleanup to ensure that the proposed work meets the requirements of the State Environmental Policy Act (SEPA).

WAC 173-340-350, and -355 through -370

See also: 
Voluntary Cleanup Program (VCP)
Cleanup Levels and Risk Calculation (CLARC) Tool

  Cleanup Action Plan (CAP):  A document that describes the selected cleanup method(s) and specifies cleanup standards and other requirements. It is based on information and technical analyses from the RI/FS and consideration of public comments and community concerns. A draft of the CAP is made available for public review and comment before finalizing.   Rule:  WAC 173-340-380  
  Heading: Cleanup Implementation      
  Engineering Design:  A cleanup step that includes development of detailed plans and specifications to carry out the selected method of cleanup, including development of an engineering design report.
Synonym:  Remedial Design (RD).
  Rule:  WAC 173-340-400  
  Cleanup Construction:  The implementation of the selected cleanup action (meaning actions taken to eliminate, render less toxic, stabilize, contain, immobilize, isolate, treat, destroy, or remove a hazardous substance). A few examples of cleanup actions are:
  • Removal of contaminated soils or sediment for off-site treatment or disposal;
  • Pumping and treatment of contaminated ground water;
  • Sealing off contaminated soils or sediment beneath a cap or barrier;
  • The addition of chemicals or enhancement of the growth of microorganisms that break down contaminants in place.
Synonyms:  Cleanup Action, Remedial Action.
  Rule:  WAC 173-340-400 and -410  
  Cleanup Operation & Maintenance:  Activities conducted at a site after cleanup construction is completed to ensure that the cleanup or containment system is functioning properly. (Note: This definition differs from the definition of Operation & Maintenance used in the federal CERCLA law.)   Rule:  WAC 173-340-400 and -410  


  Heading: Post-Cleanup
  Environmental Covenants:  Measures taken to limit or prohibit activities that may interfere with the integrity of a cleanup action or cause exposure to hazardous substances.
Synonyms:  Institutional Controls, Restrictive Covenants.
  Examples in Rule: 
WAC 173-340-440 (1)

See also: Financial Assurances
WAC 173-340-400 (6c) and -440 (11)

  Periodic (5-Year) Reviews:  A review of post-cleanup conditions and monitoring data that may be required at least every five years to ensure that human health and the environment are being protected.   Rule:  WAC 173-340-420  
  Removal from Hazardous Sites List (de-listing):  Sites may be removed  from the state Hazardous Sites List (a semi-annual listing of contaminated sites), when cleanup standards have been achieved and all requirements have been met.   Rule:  WAC 173-340-330 (7)

Policy:  330B

  [Note:  Cleanup Operation & Maintenance or other forms of monitoring may continue after cleanup standards are met and site has been removed from the Hazardous Sites List.]      


  Heading: Legal Options
  Agreed Order:  A legal document issued by Ecology which formalizes an agreement between the department and potentially liable persons (PLPs) for the actions needed at a site. (Subject to public comment.)   Rule:  WAC 173-340-530  
  Consent Decree:  A legal document, approved and issued by a court of law. The Consent Decree formalizes an agreement reached between the state and potentially liable persons (PLPs) on the actions needed at a site. (Subject to public comment.)   Rule:  WAC 173-340-520  
  De Minimus Consent Decree:  A unique type of Consent Decree that may be entered into in the case of a "de minimus" Contribution Settlement (where "de minimus" means that the amount of contamination contributed by one or more Potentially Liable Parties is insignificant in amount or toxicity). (Subject to public comment.)   Rule:  RCW 70.105D.040 (4a)

Policy:  520B

  Prospective Purchaser Consent Decree:  A particular type of consent decree entered into with a person not currently liable for remedial action at a site who proposes to purchase, redevelop, or reuse the site.  (Subject to public comment.)   Rule:  RCW 70.105D.040 (5)
and WAC 173-340-520 (1c)

Policy:  520A

  Enforcement Order:  A legal document issued by the department requiring remedial action. Failure to comply with an enforcement order may result in substantial liability for costs and penalties. (Subject to public comment.)   Rule:  WAC 173-340-540

Policy:  540A


See also: 

Focus Article:  Model Toxics Control Act Cleanup Regulation:  Process for Cleanup of Hazardous Waste Sites
Voluntary Cleanup Program (VCP)
Cleanup Levels and Risk Calculation (CLARC) Tool
Toxics Cleanup Program Policies & Guidance page
Toxics Cleanup Program Laws and Rules page
Toxics Cleanup Program Tools & Resources page
Acronym List