# Taxies Information 

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# Cleaning Up Hazardous Waste' Sites:

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### E

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# Cleanup 

# Standards and Cleanup Actions Background Washington's hazardous waste cleanup law, the Model Toxies Control Act, mandates that 

### sitedeanups protect the state's citizens 

### and environment. 

### In developing the Act's cleanupregulation, Ecology establishedcleanup standards and requirements for cleanup actions that fulfill this mandate. 

### Amajor portion of 

### this effort was completed 

### in 

### February, 1991. ' The DepartmentofEcology has worked with the state Science Advisory Board 

### and representatives from business, localgovernment andenvironmental groups to define site cleanup levels. 

## Determining Cleanup Requirements The 

### ModelTaxies Control Act cleanupregulation defines a 

### two-stepapproach 

### for
... establishing cleanup requirements for

## individual sites: ' '

.• Establishing Oeanup Standam5: The standards provide a uniform, statewide approach to cleanup that can

### beapplied on a site-by-site

### basis. The two primary components ofthe standards, cleanup levels and points ofcompliance, must

### be established for eachsite. Oeanup levels determine atwhat level

### a particular hazardous substance does 

### notthreaten 

### humanhealth orthe environment. 

### Points of compliance designate the location on the site where the cleanup levels must 

### be met.

• Selecting Oeanup Actions: Thisstep involves evaluating methods that could be used to clean a site and then deciding which ofthose methods wouldbest achieve deanup standards. Aside from meeting the standards, the cleanup actions 

### must also provide permanentcleanup solutions, a reasonable time frame for cleanup and indude monitoring to ensure effectiveness. ' 

## STEP 1 - How Cleanup Levels Are Set Eliminating all risks at a contaminated site often is not possible, even after cleanup. And since 

### any level of exposure to a hazardous substance is assumed to result in some 

### risk. Mdean" generally means that a site is cleaned up to 

### the point that contamination no longer

### poses an unacceptable threat to human healthand the environment.

• For

### cancer-causingsubstances, the acceptable risk level is defined as a conservative estimate of a person's chances ofdeveloping cancer during a lifetime ofconsistent exposure to a hazardous substance. Umore thanone contaminant is present ona site, the total healthrisk for aU

### cancer-causing substances must be considered when setting cleanuplevels.

• For

### non-carcinogenicsubstances, the cleanup level for each substance ata site mustbe below that which could causeillness in humans. 

### H more than one substanceat a site affects the body in the same

### way, the effect of aDofthose substances combined must 

### be mnsidered when 

### setting cleanup levels.
April 1991**Pu~inzlil;r< N~!-r(l!·r;** 

# • STEP 2 - Selecting Cleanup Actions Step two of the cleanup process involves choosing the method or methods used to clean up a site.

• Permanent Oeanups: Ecology will require use ofpermanent cleanup methods wherever practical. The regulation lists preferred technologies in this order: 1) Reuse or recycling, 2) Destruction or detoxification, 3) Reduction of the amount ofwaste, 4) Containment of waste on-site, 5)On-site or off-site disposal.

• The Role ofCost: While cost cannotjustify establishing cleanup levels that 

### may compromise human health or the environment, it can playa role in determining points ofcompliance and cleanup actions. Pennitting less stringent cleanup levels based on cost would be inconsistent with the intent ofthe Model Toxies Control Act.

• Public Review: Ecology describes the method of

### site cleanup in a 

### draft "cleanup action plan", which is circulated (or public review and comment, 11Us plan is then finalized 

### and used as the basis for any negotiations with potentially liable persons who will 

### be doing the site cleanup..
.. 

### Other 

## Factors Mfecting Cleanup Requirements

• Property Use: Factors such as zoning, past site use and how adjacent properties are used are important considerations when determining appropriate cleanup levels. For most sites. cleanup levels will be set low enough that uses ofthe property will not be restrided in the future. Properties in heavy industrial areas may utilize a higher risk level. Usite use changes after cleanup, the standards will be reviewed to ensure that deanup levels protect human health and the environment.
.
• Applicable Slate and Federal Laws: Cleanup levels and methods 

### used must comply with existing state or federal laws.

• Environmental Conditions: Washington's diverse environmentpresents many variables 

### in soil conditions, water tables, climate, and plantand animaJ
. communities. These variables need to 

### beconsideredbecause 

### they effect the way hazardous substances interacton a site and how 

### they impacthumans and wildlife.

• Technology: Although cleanup technologies are developing rapidly, many contaminants are still difficult or impossible to remove from soil and water. For 

### this reason, someflexibility is provided to consider technological limitations when setting cleanup levels. Additionally, in some cases, cleanup levels are sefat concentrations lower than what can 

### bereliably measured using today's sampling and analytical procedures. In those situations, the lowest reliable measurement would initially be 

### used. The availability ofimproved analytical methods will be periodicaJIy reviewed. 

## Protection After.Cleanup

• ConfinnationalMonitoring: Monitoring must 

### be conducted ateach site to verify that cleanup actions worked and remain effective over time.

• Periodic Review: 

### Uhazardous materials remain at a site at levels which exceed

--- Method A orBdeanup levels, Ecology will review the site everyfive years to ensure -- continued protection ofhumanhealth and the environment. 

### Ecology will publish a ".-- notice of all periodic reviews in the site register and provide an opportunity for public review and comment.