WALNUT CREEK, CALIF. — Seattle Public Utilities (SPU) and Brown and Caldwell received the Award for Excellence in Innovation from the Water Environment Research Foundation (WERF) at the Water Environment Federation Technical Exhibition and Conference (WEFTEC) in Chicago. The award recognizes the team’s work to improve the flood grouting process that has allowed Seattle Public Utilities to cope with frequent wet weather sanitary sewer backups and overflows in the city’s Broadview neighborhood. This project adds a new tool to the infiltration reduction toolbox.
“The flood grouting project is a successful example of applying asset management principles, through the business case process,” said Bob Jacobsen, senior engineer with Brown and Caldwell. “This has been a very successful project, through both the application of a new technology to reduce backups and the use of asset management to assess the project’s costs and benefits.”
For SPU, the project has had significant impacts: It reduced sewage volumes by 66 percent and reduced peak flow rates by 41 percent, shaving the odds of basement backups and SSOs. Through the business case process, the project resulted in a positive net present value — all with overwhelming public support.
“SPU is already putting to use the lessons learned from this project,” said Andrew Lee, capital portfolio management manager for SPU. “We are considering expanding the use of flood grouting throughout the Broadview basin to cost effectively reduce infiltration and thereby reduce the frequency of sewer backups.”
The project’s success in large part is due to the information developed and published in previous WERF-funded projects. Those projects used included:
• Reducing Peak Rainfall-Derived Infiltration/Inflow Rates — Case Studies and Protocol, 99-WWF-8
• Methods for Cost-Effective Rehabilitation of Private Lateral Sewers, 02-CTS-5
• Legal and Funding Issues During Private Lateral Rehabilitation, 02-CTS-5d
• Documenting the Effectiveness of Greencastle, Ind.’s Private Property Inflow and Infiltration Policy, U3R06
These WERF-funded projects helped to lay the groundwork for the SPU infiltration reduction project. “Many jurisdictions have experience with pipes bursting, CIPP lining, joint grouting, or open trench replacement. But almost no one has experience with flood grouting,” said Walter Graf, Program Director – Infrastructure Management at WERF. “This is a great example of asset management practice where the business case evaluation selects an innovative technology and the post-project analysis validates the original decision. This project yielded results that others can use and build upon to develop their own infiltration reduction programs.”
This is Brown and Caldwell’s second WERF award for innovation. The company also was recognized for its collaborative work on DC Water’s Biosolids Program, which won the inaugural WERF award in 2011.
The Award for Excellence in Innovation recognizes organizations that have made improvements to wastewater and stormwater collection, storage or treatment operations, facilities, or processes by applying WERF research. A team of WERF volunteers selected the recipients from a field of well-qualified organizations.