AWWA QTC98229

This paper explores short- and long-term exposure to disinfection byproducts (DBPs) of health and regulatory concern in US waters. Occurrence of DBPs (class sums and individual species) was examined on both a running-annual-average basis and without averaging over time and space. Seasonal variations in DBP occurrence (class sums) were also examined. In addition, the databases were examined for variations in water quality parameters that affect DBP formation. Three databases were studied: a "regulation negotiation" ("reg neg") national database provided information on the occurrence of DBPs, presented as cumulative probability distributions (system- and population-based); the American Water Works Service Company (AWWSCo) database, representing 21 utilities over 10 US states, provided an opportunity to explore seasonal variability of DBP class sums and the temporal and spatial variability of individual DBPs; and, the Utah database represented the breadth of data that will be available in the Information Collection Rule (ICR) and provided an opportunity to preliminarily explore ICR-type data for one region in the country. The information in this study will help stakeholders assess the implications of setting future maximum contaminant levels (MCLs) based on: individual DBPs, because of differences in the toxicity of the different species; or, the elimination of running annual averages, as some DBPs have been associated with adverse reproductive/developmental health effects. Future treatment practices will be affected if MCLs are set for individual DBPs or if MCLs do not allow for the calculation of running annual averages. Individual systems may need to pay closer attention to source water quality (especially bromide content) and modify their treatment practices based on their seasonal and distribution-system variability in DBP formation.

Product Details

Published:

01/01/1998

ISBN(s):

0898679796

Number of Pages:

26

File Size:

1 file , 240 KB