Regulations & Permits

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

We oversee many state and federal laws designed to protect Washington's land, air, and water. See our laws, rules, & rulemaking page for more information about our current rules and rulemaking.

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Estimaging Load Reductions using STEPL

Spreadsheet tool for the estimation of pollutant load

https://ecology.wa.gov/estimaging-load-reductions-using-stepl

EPA Motion 063021

This is the legal motion filed.

https://ecology.wa.gov/epa-motion-063021

Error Analysis for Water Quality Policy 1-11: Pertaining to the Water Quality Assessment December 2016

Water Quality Policy 1-11 is the policy that guides listing decisions for Washington’s Water Quality Assessment to meet Clean Water Act requirements for sections 303(d) and 305(b). During updates to Policy 1-11 in 2012, several comments were received about the risk of listing errors for waters that were placed on the 303(d) list based on limited data.

https://ecology.wa.gov/erroranalysispolicy1-11

Webinar Agenda July 10 2018

Agenda for the July 10, 2018 Manual Update Webinar

https://ecology.wa.gov/e-wa-manual-public-meeting-agenda-7-10-18

Richland Public Meeting Handout 1

Presentation slides handout at Richland Public Meeting

https://ecology.wa.gov/e-wa-richland-public-meeting-handout-1

Richland Public Meeting Handout 2

Summary of changes handout for Richland Public Meeting

https://ecology.wa.gov/e-wa-richland-public-meeting-handout-2

Richland Public Meeting Agenda

Public Meeting Agenda for Stormwater Manual Update

https://ecology.wa.gov/ewa-manual-public-meeting-agenda-6-26-18

Richland Public Meeting Parking Map

Map of parking area for public meeting

https://ecology.wa.gov/ewa-manual-public-meeting-parking-map

Eastern WA Manual Update Spring Newsletter

Spring 2018 Newsletter on the EWA Manual Update

https://ecology.wa.gov/ewa-manual-spring-newsletter

Ecology Water Quality Funded Facility Projects EPA Signage Memo

https://ecology.wa.gov/epa-signage-memo-for-cwsrf-funded-projects

Evaporation calculation spreadsheet

Evaporation calculation spreadsheet for Eastern WA Stormwater Management Manual

https://ecology.wa.gov/evaporativepondspreadsheet

EarthGuard Fiber Matrix Equivalency

Ecology letter finding EarthGuard Fiber Matrix can be used as temporary erosion control mechanism.

https://ecology.wa.gov/equivalency-earthguard-bmpc120

Detalok Equivalency Letter

Letter showing Deltalok product can be used to meet Element 6 (Protect Slopes) of the Stormwater Pollution Prevention Plan for construction sites.

https://ecology.wa.gov/equivalencyletter

Erosian Eel

Letter stating that Erosion EEL is equivalent to straw wattle for use in stormwater control.

https://ecology.wa.gov/erosioneel

Aquatic Noxious Weed Control NPDES General Permit Errata

Corrections and Clarifications for the Aquatic Noxious Weed Control NPDES General Permit.

https://ecology.wa.gov/erratanoxiousweedpermit

Errata for 2013-2018 Western Washington Municipal Stormwater Permits

Clarifications and corrections to Western Washington Phase II Municipal Stormwater Permit

https://ecology.wa.gov/errata2015-02

EPA letter to Washington Agencies Lower Yakima Valley

EPA letter to Washington state agencies on Lower Yakima Valley

https://ecology.wa.gov/epa-letter-to-washington-agencies-2022

Zostera japonica Management General Permit Errata and fact sheet addendum

Corrections and Clarifications on the Zostera japonica Management General Permit.

https://ecology.wa.gov/erratazjfactsheetaddendum

Errata for Draft Permits

Errata sheet for discrepencies between the blackline and redline versions of the formal draft 2019 Municipal Stormwater Permits

https://ecology.wa.gov/errata-for-redline-versions-of-the-formal-drafts

Phase I Municipal Stormwater Permit Errata

Errata issued February 2015

https://ecology.wa.gov/errata2015-02-939c377a6ff974c6559b9b0b9a3128b5