Multiple barrier protection of drinking water begins with watershed control.
Accordingly, one element of the Long Term 2 Enhanced Surface Water Treatment Rule (LT2) toolbox is a watershed survey to identify
Cryptosporidium sources to allow efficient management action. An 18-month
watershed pathogen survey was completed in advance of the LT2 compliance
period, to examine the watershed of five public water suppliers.
Twenty-four sample sites were established, including PWS intakes, wastewater
treatment plant (WWTP) outfalls and adjacent river sites, public access areas and
tributaries. Five sites were potential LT2 sites, and these protozoa samples were
sampled and analyzed in strict accordance with US Environmental Protection Agency Method 1623. At 18 sites, samples were collected and analyzed for
coliform/E.coli, enterococci, and Salmonella. Methods employed included Colilert™ /
Quanti-Tray™, Enterolert™ / Quanti-Tray™ (IDEXX, Portland, Maine) and modified
Standard Methods 9260D (20th ed., APHA, AWWA, WEF, 1998), for coliforms/E.
coli, enterococci and Salmonella, respectively. At six sites, samples were collected
for coliform/E.coli and enterococci only. Where protozoa samples were collected
from non-LT2 sites, ColorSeed™ (BioTech Frontiers, No. Ryde, Australia) was used to
estimate recovery efficiency.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 100 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 3 |
| Published : | 11/01/2005 |
