The Nassau County Department of Health in conjunction with New York State Department of Health set testing guidelines for all water suppliers. They dictate the frequency that the water is to be sampled in order to maintain safe drinking water. We routinely sample the water more than what is required. If it is required quarterly, we sample monthly. If it s required monthly, we sample weekly. This is not required but it is a level of protection the water district likes to utilize. Upon receiving the lab reports, we trend all of the results to see if anything is increasing in the ground water. More importantly, the monitoring of our filtration systems allows us to operate them more efficiently and forecast any break through BEFORE it happens.