The quality of the water in the distribution system has been checked many times prior to reaching the customer's tap. The water treatment plant must meet all the quality guidelines set forth by federal and state regulatory agencies. Treated water comes to the City of Coppell through a 54" pipeline. When it reaches City holding facilities, Utility Division personnel continuously sample and test the water to ensure it meets system quality standards until it reaches the customer. The Utility Operations Division tests water samples for bacteriological quality, lead and copper, trihalomethanes (a by-product of chlorine that causes health effects) and chlorine residuals, and also performs other tests to ensure disinfectant residuals are properly maintained.