Notice: All Ecology offices remain closed to walk-in service due to COVID-19.
This page contains links to guidance documents and tools used by our permit writers and permittees.
The Permit Writer’s Manual (Ecology Publication Number 92-109) is meant to guide permit writers and the public through our process of developing and issuing wastewater discharge permits.
Wastewater comes from water used in industries, businesses, or homes. We regulate these discharges to protect surface and groundwater. Permit writers develop permit limits from facility-specific discharge quality information and water quality standards.
These documents assist all permittees in design development of conveyance, treatment, and discharge infrastructure.
We are updating the Design Criteria for Municipal Wastewater Land Treatment Systems for Public Health Protection, also called the "Green Book."
Quality Assurance Project Plans (QAPPs) ensure systematic data collection that meets our standards and provides credible environmental data.
Engineering reports, plans, and specifications must meet requirements of Chapter 173-240 WAC before approval.
Resources for delegated pretreatment programs and permittees that must conduct industrial user surveys.
We require all permittees to report permit data electronically.
Water Quality Permitting Specialist