Research & Data

Use this portal to filter and search for all of our scientific information.

Ecology provides the high-quality science that is the foundation of Washington state environmental policy. Our monitoring, assessment, and modeling services provide a data-rich understanding of our state’s land, air, and water. We provide access to that data through reports, databases, maps and user-friendly online tools.

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Cleanup Rule comments received from the public, Ecology staff, and AGO (2009-2018)

This July 2019 document compiles the Cleanup Rule comments received from the public, Ecology staff and Office of the Attorney General from 2009 through 2018.

https://ecology.wa.gov/cleanup-rule-comments-received-2009-2018-july-201

Proposed Rule Text without Tracked Changes (WAC 173-340) 02/15/23

This document displays WAC 173-340, Model Toxics Control Act (MTCA) Cleanup Regulations, as if the proposed rule changes were adopted. This document does not track or footnote the changes.

https://ecology.wa.gov/proposed-rule-text-with-no-tracked-changes-to-curr

Proposed Rule Text with Tracked and Footnoted Changes (WAC 173-340) 02/15/23

This document tracks and footnotes proposed changes to WAC 173-340, Model Toxics Control Act (MTCA) Cleanup Regulations.

https://ecology.wa.gov/proposed-rule-text-with-tracked-and-footnoted-chan

MTCAStat97: Site Module

A statistical analysis tool / workbook for calculating compliance statistics for sites cleaned up under the Model Toxics Control Act.

https://ecology.wa.gov/mtcastat97sitemodule

MTCASTtat97: Technical supplement #1

Statistical guidance for using MTCAStat97 for sites cleaned up under the Model Toxics Control Act.

https://ecology.wa.gov/mtcastattechsupplement

Rulemaking Announcement (WAC 173-340) 12/20/18

This is a rulemaking announcement (CR-101) for WAC 173-340, Model Toxics Control Act - Cleanup

https://ecology.wa.gov/rulemaking-announcement-wac-173-340-12-20-18

Rulemaking Proposal (WAC 173-340) 02/15/23

This is a rulemaking proposal (CR-102) for WAC 173-340, Model Toxics Control Act (MTCA) Cleanup Regulations.

https://ecology.wa.gov/rulemaking-proposal-wac-173-340-02-15-23

Package A - Natural Attenuation Tool (Modules 1,2,3)

A calculation tool for demonstrating natural attenuation of groundwater is occurring and help predict when groundwater cleanup levels will be met under the Model Toxics Control Act.

https://ecology.wa.gov/pkganaturalattenuation

Rulemaking proposed language (WAC 173-340) 02/15/23

This is proposed rule language for WAC 173-340, Model Toxics Control Act (MTCA) Cleanup Regulations.

https://ecology.wa.gov/rulemaking-proposed-language-wac-173-340-02-15-23

Package B - Natural Attenuation (Modules 4,5,6)

A calculation tool for demonstrating natural attenuation of groundwater is occurring and help predict when groundwater cleanup levels will be met under the Model Toxics Control Act.

https://ecology.wa.gov/pkgbnaturalattenuation

Public hearing presentation (WAC 173-360; 173-360A) 02/28/18

This is the presentation provided at the public hearings on the rulemaking proposal for the underground storage tank regulations (WAC 173-360; 173-360A). The hearings occurred on February 28, 2018 and March 2, 2018.

https://ecology.wa.gov/public-hearing-presentation-wac-173-360;-173-360a

Repealed rule language (WAC 173-360; WAC 173-360A) 07/17/18

This is the repealed rule language for WAC 173-360; WAC 173-360A, Underground Storage Tank (UST) Regulations.

https://ecology.wa.gov/repealed-rule-language-wac-173-360;-wac-173-360a

Rulemaking Adoption Notice (WAC 173-360; WAC 173-360A) 07/17/18

This is the rulemaking adoption (CR-103) WAC 173-360; WAC 173-360A, Underground Storage Tank (UST) Regulations.

https://ecology.wa.gov/rulemaking-adoption-notice-wac-173-360;-wac-173-3

Rulemaking Adoption Notice (WAC 173-360; WAC 173-360A) 07/18/2018

This is a rulemaking adoption (CR-103) for WAC 173-360A, Underground Storage Tank Regulations.

https://ecology.wa.gov/rulemaking-adoption-notice-wac-173-360;-wac-1-1

Rulemaking Adoption Notice (WAC 173-340) 08/23/23

This is a rulemaking adoption (CR-103) for WAC 173-340, Model Toxics Control Act (MTCA) Cleanup Regulations.

https://ecology.wa.gov/rulemaking-adoption-notice-wac-173-340-08-23-23

Northeast West Plains PFAS March 2024 well sampling results meeting slides

Download the slides for the 6/6/24 NE West Plains drinking water sampling results meeting

https://ecology.wa.gov/west-plains-pfas-sampling-results-slides

Railroad Creek monitoring

Our scientists are studying how mine remediation affects aquatic life uses along Railroad Creek.

https://ecology.wa.gov/research-data/monitoring-assessment/water-quality-improvement-effectiveness-monitoring/railroad-creek

Black Lake Grocery groundwater monitoring

We monitor groundwater for petroleum hydrocarbons at the Black Lake Grocery site.

https://ecology.wa.gov/research-data/monitoring-assessment/groundwater-quality-assessment/active-studies-index/black-lake-grocery

Sumas-Blaine surficial aquifer long-term ambient groundwater monitoring

We sample 25 wells in the Sumas-Blaine aquifer annually for nitrate, chloride, and bromide.

https://ecology.wa.gov/research-data/monitoring-assessment/groundwater-quality-assessment/active-studies-index/sumas-blaine

Yakima Railroad Area groundwater performance monitoring

We're monitoring legacy pollution in central Yakima and Union Gap to measure cleanup effectiveness.

https://ecology.wa.gov/research-data/monitoring-assessment/groundwater-quality-assessment/active-studies-index/yakima-rail