AWWA WQTC50404

Two regions of elevated E. coli concentrations were identified during an earlier study conducted at a tidally-influenced river located in Ft. Lauderdale, Florida. These elevated levels were attributed to regrowth of E. coli within river bank soils. The focus of this study was to further evaluate regrowth of E. coli by identifying whether high nutrient concentrations are found within these "hot-spot" areas. Furthermore, C. perfringens levels were measured to determine whether concentrations correlated with E. coli concentrations in the water column. C. perfringens is an obligate anaerobe and incapable of regrowth under aerobic river conditions. Large ratios of E. coli to C. perfringens would be therefore expected in areas characterized by E. coli regrowth. Results show that the "hot-spot" areas coincide with a sharp increase in salinity and with elevated phosphate concentrations within the water column. The ratio of E. coli to C. perfringens was found to vary significantly within the river. Samples collected from high salinity areas were characterized by a small ratio of E. coli to C. perfringens (less than 2), whereas in the "hot-spot" areas where regrowth is believed to occur, the ratio was relatively large (greater than 6). This observation suggests that the ratio of E. coli to C. perfringens may be a valuable tool for evaluating the fate of E. coli withing the water column. Includes 20 references, figures.

Product Details

Edition:

Vol. - No.

Published:

01/01/1999

File Size:

1 file , 300 KB