Wastewater Treatment Plant

Wastewater Treatment Plant Master Plan

A wastewater treatment plant is a complex system of processes that work together to treat and recycle wastewater. In order to be effective in protecting public health and water quality, the treatment plant has to meet the challenges of serving an increasing population.

In October 2022, NapaSan completed a Wastewater Treatment Plant Master Plan (master plan) to ensure that the plant is ready to meet these challenges. The master plan includes a review of existing treatment plant performance, focused condition assessment of critical facilities, evaluation of unit process capacity and identification of existing deficiencies, evaluation of operational vulnerabilities, and established triggers and prioritizes major capital projects for the planning period (over the next 20 years through year 2040) for nutrients, biosolids, energy, and recycled water.

View the Plan in Its Entirety or by Section:

• Wastewater Treatment Plant Master Plan (entire document) (PDF)
• Table of Contents, Abstract, and Frequently Asked Questions (PDF)
• Chapter 1: Introduction (PDF)
• Chapter 2: Basis of Planning (PDF)
• Chapter 3: Existing Facilities and Performance Assessment (PDF)
• Chapter 4: Capacity Analyses (PDF)
• Chapter 5: Alternatives Screening (PDF)
• Chapter 6: Business Case Evaluation of Alternatives (PDF)
• Chapter 7: Description of Recommended Project (PDF)
• Appendix A: References (PDF)
• Appendix B: NPDES Permit (PDF)
• Appendix C: Technical Memorandum (PDF)
• Appendix D: Capital Cost Estimate Details (PDF)
• Appendix E: Project Sheets (PDF)