AWWA DSS63724

The Philadelphia Water Department (PWD) employed divers and a remotely operatedunderwater vehicle to inspect, diagnose, and repair the polyethylene liner of a 150-million gallon water storage basin without draining the basin or removing it from service.Inspection of the basin was triggered when residual chlorine values in the basin effluentsamples were unexplainably lower than normal. Using a camera mounted on a remotelyoperated underwater vehicle inserted through a hatch in the floating cover, it wasdetermined that the polyethylene liner was torn in three critical locations. At the influentend of the reservoir, water was seeping under the bottom liner due to a large tear. Atthe two effluent locations, water underneath the liner was being drawn into the effluentpiping through two additional tears. Divers made repairs quickly with the reservoir still inservice to safely and effectively meet system water demands. Includes figures, appendix.

Product Details

Edition:

Vol. - No.

Published:

09/01/2006

Number of Pages:

9

File Size:

1 file , 750 KB