Alternatives/Options Report

In December 1999, the King County Council approved the development of a Regional Infiltration and Inflow (I/I) Control Program as part of the Regional Wastewater Services Plan (RWSP). The presence of I/I in the separated sewer system takes up needed capacity for conveying and treating wastewater generated by homes and businesses. The purpose of the I/I program is to reduce the amount of flow, thereby reducing the risk of sanitary sewer overflows and the costs of conveying and treating wastewater.

In 2000, the County's Wastewater Treatment Division, in cooperation with the local component agencies that it serves, launched an ambitious six-year $41-million I/I control study. The study includes efforts to identify sources of I/I, test the effectiveness of various I/I control technologies, examine the benefits and costs of I/I control, and prepare a regional plan for reducing I/I in local agency collection systems.

Development of a set of alternative approaches to controlling regional I/I marks a major milestone in the study. This report presents these alternatives and the complex issues that affect I/I control in the region.

For more information, please contact Erica Jacobs at (206) 684-1138 or Erica.Jacobs@kingcounty.gov.

Table of Contents

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Report and Appendices A1-A8, issued March 2005 (2.3 MB)

Title Page, Acknowledgements (20 KB)
Contents (21 KB)
Acronyms and Abbreviations (11 KB)
Chapter 1. Executive Summary (81 KB)
Chapter 2. Direction and Process for Regional I/I Control Program (137 KB)
Chapter 3. Key Regional I/I Control Program Elements (50 KB)
Chapter 4. Summary of Alternatives and Program Components (55 KB)
Chapter 5. Public Outreach Program (22 KB)
Chapter 6. Next Steps (19 KB)
Glossary (25 KB)

List of Appendices and Appendices A1-A8 (1.6 MB)

Appendix A1 - Rates, Incentives, and Surcharges Technical Paper
Appendix A2 - Private Property Issues
Appendix A3 - Standards, Procedures, and Policies
Appendix A4 - Assumptions for Regional I/I Control Program
Appendix A5 - Environmental Issues
Appendix A5A - Potential Environmental Costs and Benefits of the King County Regional I/I Control Program
Appendix A6 - Selected Legal Authorities Related to Implementing and Funding an Infiltration and Inflow Reduction Program
Appendix A7 - Inflow and Infiltration Public Survey Report
Appendix A8 - Options Considered and Not Selected

Appendix B1 - 2001/2002 Wet Weather Flow Monitoring Report
(Available only on CD.)
Appendix B2 - Standards, Policies and Procedures and Intergovernmental Agreement (4.6 MB)
Appendix B3 - Pilot Project Report (located on separate Web page)