"Providing Innovative Water and Wastewater Solutions"

The St. Lucie West Facility utilizes (3) deep wells as a raw water source. Reject water from the RO process is disposed of through deep well injection. U.S. Water Services Corporation (USWSC) was retained shortly after the system went into operation to resolve serious problems that were being encountered and related to system startup and water stability. The District had invested heavily in this substantial capital improvement project and expected high quality and reliable treatment. Shortly after placing the new facility on line, the District began experiencing lead exceedences in the drinking water being distributed to its customers. Problems with lead in the water supply were highly publicized in local newspapers and became a public relations problem for the District Board and staff. USWSC was retained to troubleshoot the system and to provide a single source of responsibility to diagnose, evaluate and provide design and operations support to solve the problems thereby utilizing USWSC’s ability to provide an entire design-build, operations and technical team in-house. Although USWSC was able to quickly identify numerous technical and design issues with the facility, we determined that the primary cause of lead dissolution into the water supply was improper stabilization and buffering of the finished water. As a result of our investigation, we discovered that the finished water pH was near 10 S.U. during the time in which high corrosion was experienced. After extensive on-site and hands-on investigation it was determined that the new Calcite Reactors designed to stabilize the R/O permeate, by adding alkalinity and hardness back into the permeate, were not working properly. USWSC then provided an in-house team of both professional and trade level specialists to perform a detailed process evaluation of the calcite media. Through this evaluation, USWSC was able to determine solubility and to then propose and implement a design-build solution to quickly repair and refit the resources; identifying the problem quickly, designing a solution, and making the required piping and control system modifications without any delay for outside procurement. In critical situations where customer service and public health and safety are at issue, the capability to diagnose and resolve plant operation problems quickly can be absolutely critical. After the crisis had been averted, USWSC then provided an overall R/O system evaluation, operator training, revised Operation and Maintenance manuals, revised SCADA controls, design/build of a polyphosphate feed system and performed various repairs and redesigns to the system hydraulics. The RO system has been performing well and USWSC continues to work for the District providing support and technical resources to the treatment system as needed.