The proposed Stage 2 Microbial/Disinfection Byproducts
Rules are intended to reduce peak concentrations of disinfection
byproducts (DBPs) in distribution systems and ensure safe drinking
water for all consumers. Under this rule, water utilities conducting
their initial distribution system evaluations (IDSEs) must
choose sampling sites that capture peak DBP concentrations. As
this study shows, however, selection of monitoring locations is
complicated by the fact that trihalomethane (THM) and haloacetic
acid (HAA) concentrations vary over time and space in a distribution
system.
Data were collected from five distribution systems that had
undergone DBP sampling for a variety of reasons, including
research studies, operational assessments, and the monitoring
required for regulatory compliance. Analysis of these data
indicated that HAAs degraded in the distribution system, most
frequently when chlorine or chloramine residuals were low.
THM concentrations were generally high at these same sample
locations.
The findings presented here should provide an impetus for
additional study of DBP fate and occurrence in distribution systems
as well as more extensive sampling efforts. The reduction in
HAA concentrations observed in this study might have gone unnoticed
in the typical utility sampling program. In addition to considering
more extensive sampling, water suppliers may want to
implement study findings in the design of their IDSE studies or
other distribution system investigations.
Includes 22 references, tables.
| Edition : | Vol. 97 - No. 2 |
| File Size : | 1
file
, 110 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 10 |
| Published : | 02/01/2005 |
