AWWA QTC97186

The Georgetown Municipal Water & Sewer Service (GMWSS) presently provides treated, potable water to over 18,000 customers in the City of Georgetown and rural Scott County, Kentucky. GMWSS employs packed air stripping towers in the first stage of water treatment, before the addition of chemicals/disinfectant in the rapid mixer. As part of a study of nitrifying bacteria in the rural distribution pipelines, a trial experiment was conducted to measure the heterotrophic plate count (HPC) concentration in raw spring source water and water leaving the air stripping towers. The test plate containing the water sample from the stripping towers exhibited a marked decrease in the number of colony-forming units of bacteria per milliliter when compared with the test plate containing the raw water sample. Subsequent examination of raw and below air stripping tower water samples validated the initial test results. This paper presents the results of an examination of the capability of the air stripping process to substantially reduce the HPC levels in water entering the rapid mix portion of the treatment process. The paper describes the procedures used by GMWSS to quantitatively measure the bacteria concentration in pre- and post-air stripping water samples. Other aspects that have been explored include the dissolved oxygen content in pre- and post-aerated water samples and the sudden rise in pH in post-aerated water samples.

Product Details

Published:

01/01/1997

ISBN(s):

0898679583

Number of Pages:

17

File Size:

1 file , 56 KB