The City of Mesquite is required by law to furnish 120 bacteriological samples per month for testing. These samples are taken weekly and delivered to the State-certified lab in Wylie. If a bad sample is found, immediate retesting is required. If repeat testing fails the public would immediately be notified. The City is also required to take other water samples that include: lead & copper, chlorine residual, trihalomethanes & haloacetic acids, nitrification and Unregulated Contaminants (chloroform, bromoform, bromodichloromethane, dibromochloromethane). Total samples taken by Utilities for 2019 was 4,252.