AWWA ACE68659

This poster presentation presents research on the variations of disinfection byproduct (DBP) levels in water between the distribution system (house entrance) and the consumer tap. The specific objectives were: to evaluate the impact of water stagnation within house plumbing pipes over night on trihalomethane (THM) and haloacetic acid (HAA) levels; and, to evaluate the effect of heating water on THM and HAA occurrence in hot tap water. Six residences (volunteers) of three different water distribution systems (two per system) were selected for the study. The waters in these systems have different historical levels of THMs and HAAs. In each residence, eight sampling campaigns were carried out during one year (every six weeks). During each sampling campaign, three types of water samples were collected at each residence, including: water from the distribution system (faucet turned on for about 5 minutes); tap hot water (water from the heater); and, first drawn (the first water when the faucet is open in the morning). Sampling was conducted in the evening after the last use of water by the home owners (sampling for distribution system water only) and before any use of water early the next morning (sampling for first drawn water, hot tap water and distribution system water). In each collected sample, water quality parameters were analyzed.