AWWA WQTC58895

The broadly stated objectives of this project are to identify benefits and encourage usage ofaerobic spore monitoring as a tool to supplement other tools available to water plant operatorsfor evaluation and optimization of drinking water treatment. This includes evaluation of thetreatment facility as a whole (raw through filtration) as well as individual unit processes. Oneparticular application to be specifically addressed during this project is the use of sporemonitoring for the demonstration of performance (DOP) credit allowed in the LT2ESWTR. DOPusing aerobic spore monitoring is a potentially valuable and cost-effective tool (Cornwell et al.2003) for regulatory compliance in the upcoming LT2ESWTR, particularly facilities needingcredits without extensive monitoring and capital improvement requirements. The DOP credit canestablish a 4 log or higher Cryptosporidium removal credit using existing facilities.Existing historical data indicate that spore concentrations in the filtered water at drinking waterplants are frequently below the detection limit typically used (1 spore per 100 or 200 mL). Sincemany U.S. source waters also have low raw water spore concentrations, a key issue to beaddressed in this project was to evaluate whether the current method can be refined by usinglarger filtered water sample volumes, resulting in lower detection limits, or whether developmentof an alternative sample collection and analysis protocol is needed to handle larger samplevolumes. Modifications that would result in lowering the detection limit would increase theusefulness of spore monitoring.This project investigated raw water concentrations in order to evaluate how low the filtered waterdetection limits need to go in order to mathematically demonstrate a particular target spore logremoval (e.g., typically facilities may want to evaluate whether they meet the 4-log target for theDOP credit). In addition, finished water data was investigated to see if spores are detected atlevels below the current 1 cfu/200-mL detection limit but above the detection limit needed todemonstrate the target log removal. Includes 18 references, table, figure.

Product Details

Edition:

Vol. - No.

Published:

11/02/2003

Number of Pages:

10

File Size:

1 file , 300 KB