Memorandum

City of Lawrence

Municipal Services & Operations

Rapid Inflow/Infiltration (I/I) Reduction Program Background

The area of focus for the I/I program is an older part of the City and has the largest influence on the peak wet weather flows at the KRWWTP due to its proximity to the plant and higher levels of I/I. The goal of the program is to reduce wet weather flows from this area by 35% in order to eliminate the need for large-scale capacity expansion projects in the Burroughs Creek interceptors and the KRWWTP. Obtaining this reduction goal is not feasible by only addressing issues within the public sanitary sewer system.

The Private I/I Abatement Program was branded as the Ecoflow Program, and private plumbing evaluations were started in June 2014. Department staff along with TREKK Design Group, have conducted private plumbing evaluations for over four years. To date, over 5,700 private properties have been evaluated, and over 1,900 repairs have been completed. The response from the public, including property owners, property managers, real estate agents, USD 497, and neighborhood associations, has been overwhelmingly positive. The program has achieved response rates between 70 percent and 91 percent in targeted areas with only 427 property owners declining to participate.

In 2018, program staff targeted Old West Lawrence, the Oread Neighborhood, and other parts of East Lawrence adjacent to Downtown Lawrence. In 2019, program staff will finish targeting the residential neighborhoods surrounding Downtown Lawrence and then transition into the commercial properties as a follow up to the previously completed sanitary sewer smoke testing.

In the previously targeted areas, program staff completed evaluations and planned for repairs on an individual property basis. Due to the unique conditions in Downtown Lawrence and the anticipated difficulty in finding suitable discharge locations for sump pumps, program staff anticipates proceeding with evaluations, repair planning and potential group discharge solutions on a block by block basis. This will allow program staff to determine the cost-effectiveness of repairs for the entire block before proceeding with any individual repair. Program staff will start this new approach between Vermont and Massachusetts Streets from 8th Street to 9th Street in conjunction with the Overhead Walkway “Canopy” Removal Project (PW17BCIP). As evaluations move into other areas of Downtown, program staff will continue to coordinate closely with the MSO’s storm water group in order to identify potential locations to improve existing storm water problem areas and reduce the chances of creating new problem areas.

Program staff has also recently incorporated a backflow inspection component for all City-owned properties. These backflow inspections are completed in concurrence to the I/I evaluation with the goal of ensuring compliance at City-owned properties to the Cross Connection Control Program.