AWWA QTC98345

The cities of Arlington, Dallas, and Fort Worth, Texas, joined with their electrical energy provider, Texas Utilities, in an effort to identify, implement and document characteristics and attributes of a successful on-line ozone residual monitoring program. The three issues the project addressed were: assessing meter accuracy; improving and maintaining meter reliability; and, detecting and protecting against sudden, unexpected meter malfunction when meters are utilized for automatic process control. The cities of Dallas and Fort Worth use ozone for disinfection compliance at the Elm Fork and Eagle Mountain Water Treatment Plants, respectively. Compliance is achieved by maintaining a minimum 2-log virus inactivation credit with ozone. Grab samples are collected at the required 4-hr interval at both utilities. Unfortunately, the original on-line ozone residual monitoring systems were abandoned. The single monitor for each contactor was installed on a common line that was connected to the individual cell sample lines. Sample flow from each cell was directed through the monitor via a solenoid valve. Three main problems caused the on-line residual monitoring systems to be abandoned. For this project, each plant emphasized a different aspect of residual monitor performance. The Fort Worth, Eagle Mountain WTP evaluated disinfection performance as determined by ozone residuals from the on-line monitors and by grab samples. The Dallas, Elm Fork WTP evaluated performance of three different monitors. The study approach at each plant is further described.

Product Details

Published:

01/01/1998

ISBN(s):

0898679796

Number of Pages:

17

File Size:

1 file , 510 KB