Memorandum

City of Lawrence

Utilities Department

TO:	David L. Corliss – City Manager Cynthia Wagner - Assistant City Manager Diane Stoddard - Assistant City Manager
FROM:	Dave Wagner – Director of Utilities
CC:	Mike Lawless – Asst. Director of Utilities Philip Ciesielski - Asst. Director of Utilities Dave King, Utilities Maintenance Superintendant Alan Landis – Purchasing Specialist
Date:	July 26, 2011
RE:	Emergency Repairs to the Kaw Intake, Low Service Pump Station 2, and the Presedimentation Basin Clarifier Drive

Background:

The lone intake to the Kaw Water Plant (KWP) lost the ability to draw water from the river twice this summer due to unknown causes. To date aggressive backflushing has eventually restored service. We do know there are significant amounts of sand in the Low Service Pump Station 2 (LS2). In addition, the KWP has been operating without the traveling debris screen in LS2 due to a failed gearbox and sand accumulation since July 1. The gearbox was repaired in mid July; however, the screen remains inoperable due to sand accumulation. Attempts to remove sand were partially successful but water demands required us to discontinue the effort and put the Kaw Plant back in service. Additionally the clarifier drive on the KWP presedimentation basin has failed and today it has been determined the drive is beyond repair. The KWP can remain in service under specific conditions without the presedimentation basin; however, treatment is more tedious and subject to upset or interruption. 

Because the river flows have been low there is currently little debris coming into the intake. We expect as the US Corp increases reservoir releases large amounts of grass, leaves, and other debris will come into the intake. It is critical that the traveling screen is operational when the releases begin; otherwise, we expect the intake to clog, likely causing flow restrictions or complete stoppage to the KWP.

Project Description:

Staff has been working on emergency procurement of equipment and services necessary to:

1) Remove the sand from LS2. 

2) Perform additional mechanical inspection of the traveling debris screen.

3) Facilitate more detailed inspection of the Kaw Intake structure at the river.

4) Concurrently to the above, provide a temporary water supply to allow the Kaw Water Plant to remain in limited production while performing repairs and evaluations.

5) Order and install a new presedimentation clarifier drive.

As we mentioned last week due to the emergency nature of this work we are proceeding to perform this work on a time and materials basis with qualified and available contractors working with City staff. It is estimated that the cost could exceed $100,000 for items 1-4. The basin clarifier drive is estimated at an additional $100,000. Please note cost estimates are very preliminary. Also, the scope of the work, depending on what is discovered, is variable.

Staff will provide a full report of the work performed at the completion of the project as well as request approval for payment of the services provided.

Project Funding:

This project will be funded from the Department of Utilities Operations and Maintenance budget for the Kaw Water Treatment Plant.

Action Request:  No action is requested at this time.