Memorandum

City of Lawrence

 

TO:

Mayor and City Commissioners

FROM:

City Manager David L. Corliss                            

CC:

Dave Wagner, Director of Utilities

Date:

December 6 , 2007

RE:

Timing and Scope of Sanitary Sewer projects

 

 

This year has seen tremendous investment in our water and wastewater utility providing a solid response to the community’s current and future infrastructure needs.  These projects include the completion of sanitary sewer upgrades and improvements in North Lawrence, the expansion of treatment capabilities at the Clinton Water treatment plan which is currently under construction, and the completion of several regional sanitary sewer improvements in the western portion of the community.  A number of other projects are under design and bidding, including the southeast sewer project in cooperation with Douglas County, the Northeast water transmission project, the Stoneridge and West 6th Street water tower, and improvements to the pump station located at East Hills Business Park.   City staff is recommending a review of the timing and scope of other sanitary sewer projects as we continuously evaluate the need for facility improvements in light of community growth projections and patterns.  This review includes the timing and scope of the Wakarusa Water Reclamation Facility (WWRF) and related improvements particularly focused on the Four Seasons pump station facility generally located west of Kasold near 31st Street.  

 

Because of a recent slow down in growth, the sizing of certain facilities may need to be altered along with the timing of when these facilities will be in place.  The City is well positioned for the construction of the WWRF facility, with land acquisition, land use approvals and regulatory approvals in place.  We are well positioned to proceed to final design and construction for this facility at the appropriate time.  However, construction of the facility beginning in 2008 may not be in the best interests of the city if neither the growth nor the rate base is present to support the facility. (For example, if the City’s population averages a 1% growth our population will not exceed 100,000 until approximately 2017. Without counting a 10,000 population reserve – and necessary other improvements to the system - our current wastewater treatment facility is rated for a population of 100,000.  The recent Census challenge confirmed a 0.5% growth rate for 2006.)  The WWRF should be built – the question is one of timing and what other projects (potentially less expensive at this time) can be constructed to respond to sanitary sewer needs.

 

Staff is proposing a multi-task approach:

 

-          Further refine the timing and scope of the WWRF and other sanitary sewer facilities through a study in the first part of 2008, this requires delaying the WWRF work until completion of the study      Staff Memo

 

-          Proceed with the planned improvements at the Four Season Sanitary Sewer facility under a construction management delivery system   Staff Memo

 

-          Proceed with the planned West Baldwin Creek gravity sewer line improvements under the Design/Bid/Build delivery system   Staff Memo & Attachments

 

Aspects of Additional Wastewater System Study

 

We are better poised today to undertake additional study that would reevaluate overall system needs. We have completed technical GPS/GIS work and have a comprehensive map and database of system asset details identified to make hydraulic network models and runs extremely accurate. Additionally, the permanent flow meter program has been in place for more than a year continuously monitoring over 25 key points across the system. This flow data is the base information on which current system capacity and utilization is evaluated. We have never had this quality and quantity of information available for use in a Master Facilities Plan. In fact few communities have this quality of information available. With this data collected much of the upfront work is completed to evaluate system needs and reaffirm, modify, or adjust the timing and scope of the WWRF and all other CIP projects for the wastewater system. This level of system and flow data will allow us to more accurately model various development scenarios and have a better engineering basis for recommended system improvements to serve the community.