AWWA ACE58088

Ten production wells drilled in a highly productive sand and gravel aquifer,recharged by an adjacent river, were evaluated for potential Giardia and Cryptosporidiumcontamination. The goal of this study was two-fold: to determine if a correlation existsbetween the occurrence of surface water indicators and Giardia and Cryptosporidium;and, to examine riverbank filtration as a microbial treatment process. Pathogenmonitoring was conducted sporadically over ten years. Intensive monitoring wasconducted for a twenty-month period at ten "flowpath wells" and two production wells.Algae, diatoms and other surface water indicators were found in 57% of 128 groundwater samples. Of 285 groundwater samples collected and analyzed for Giardia orCryptosporidium, no pathogens were detected. No correlation existed between Giardia,Cryptosporidium and surface water indicators. All surrogates demonstrated a minimum4-log reduction. Even though there is hydrologic influence, riverbank filtration is highlyeffective in removing pathogenic protozoa. Includes 26 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/15/2003

Number of Pages:

18

File Size:

1 file , 370 KB