Eureka’s poor water quality is due to its groundwater source that is naturally high in mineral content (see information on total dissolved solids). Once a pipeline connection is complete, Missouri American Water will supply water from its St. Louis County system, whose water is obtained from the Missouri and Meramec Rivers. When the switch in source water is made, Missouri American Water will flush all of the Eureka pipes, systematically operating valves, hydrants and water tanks to remove all of the well water from the system. During the system flush, the water will move through the pipes at an accelerated velocity to scour the inside of the mains and remove any sediment. Additional steps may be taken to clean and/or replace certain sections of pipe as needed.