Water quality individual permit guidance

Wastewater discharge permit guidance

Permit Writer's Manual

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.

• Permit Writer's Manual Appendices include specific technical guidance for the individual permitting process.
• PermitCalc Workbook contains a complete list of useful spreadsheets and instructions for NPDES permit writers in the "intro" tab. These spreadsheets are referred to in the Permit Writer's Manual.
• Criteria for Sewage Works Design, also known as the "Orange Book," contains domestic wastewater treatment design guidance.
• Pipeline Separation Design and Installation Reference Guide (Version 9) describes required separations between wastewater and potable water infrastructure.
• Infiltration/Inflow Guidance is the U.S. Environmental Protection Agency (EPA) brochure on infiltration/inflow analysis and project certification.
• State Requirements for Submission of Engineering Reports and Plans for Industrial Wastewater Treatment Facilities.
• Vehicle and Equipment Washwater Discharges includes best management practices.
• Application of Water Quality Criteria in Brackish Waters includes thresholds for where freshwater/marine water standards apply (usually in estuaries).

Surface water discharge guidance

• Quality Assurance Project Plan (Template) for Temperature Study - Municipal
• Quality Assurance Project Plan (Template) for Temperature Study - Industrial
• Quality Assurance Project Plan (Template) for receiving water studies

Groundwater or land treatment guidance

• Implementation Guidance for the Ground Water Quality Standards.
• Design Criteria for Municipal Wastewater Land Treatment Systems for Public Health Protection. We are in the process of updating these requirements called the Green Book.
• Guidance on Land Treatment of Nutrients in Wastewater, with Emphasis on Nitrogen.
  • Fact Sheet - Guidance on Land Treatment of Nutrients
• Irrigation Management Practices to Protect Ground Water and Surface Water Quality
• Guidelines for Preparation of Engineering Reports for Industrial Wastewater Land Application Systems

Other topics

• Reclaimed Water rulemaking
• Wastewater comes from water used in industries, businesses or homes. We regulate these discharges to protect surface and groundwater.
• All domestic wastewater treatment plants must meet minimum performance standards, known as technology-based effluent limits.
• Stormwater permit, online reporting, and technical guidance
• Water quality permits database Permit and Reporting Information System (PARIS) contains information about water quality permits, inspections, enforcement actions, and discharge monitoring reports (DMRs).
• Water quality web portal guidance helps permittees apply for permits, report discharge data and submit other documents electronically to the WQWebPortal.

Pretreatment Tools

• Guidance Manual: Using NEWLLqq.xlsm to Develop Local Discharge Limitations Local limits spreadsheet instructions.
• Local Limits Spreadsheet
• Permit Writers Manual - Chapter X: Pretreatment
• Guidance Manual for Performing an Industrial User Survey
• Guidance Manual for Developing Local Discharge Limits