AWWA WQTC71342

The objective of this study was to develop a systematic approach that could estimate target flushingfrequencies for specified areas of Madison Water Utility's (MWU) distribution system, based on distribution systemproperties, water production, and water quality. This extended abstract summarizes the resultsobtained from an initial evaluation of several areas in the distribution system. Water quality was tested on over 40 unidirectional flushingruns in areas served by 4 of the 23 operating wells. Roughly half of the flushing runs werelocated in a portion of the distribution system served by a well with high Fe and Mn and by pipethat was predominantly unlined cast iron. Data from this sampling included turbidity, freechlorine residual, heterotrophic plate count, pH, and temperature. MWU's hydraulic model andgeographic information system were used to determine independent variables for each pipesegment in the sampled flushing runs, including pipe material, presence of liner, pipe diameter,typical flow velocities, typical number of flow reversals, and water age from the local well.Other utility records were used to estimate independent variables such as volume of waterpumped by the local well since the pipe segment was last flushed. Multi-variable regressionanalysis was used to estimate how the turbidity produced by flushing was dependent on thesevariables. Includes reference, extended abstract only.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

2

File Size:

1 file , 720 KB