Site work and new construction of a water / sewer project in Casper, Wyoming. Conceptual plans call for the construction of a water / sewer project.

This project will provide supplemental disinfection for the groundwater supplies. The ultraviolet disinfection facility would provide disinfection of up to 18 MGD of groundwater supplies. The Environmental Protection Agency over the last 20 years has questioned the treatment capability of the RWS groundwater disinfection system. The RWS has groundwater under the influence of a surface source (GWUDI). The enhanced surface water treatment rule and Long Term 2 surface water treatment rule need to be met by the RWS groundwater system. At the current time (issued in 2005), EPA has granted to the RWS a variance to utilize riverbank filtration in conjunction with ozonation, chloramination, and corrosion control for the RWS groundwater source. Even though no cryptosporidium or giardia has ever shown up in the groundwater finished water, EPA still has concerns. The use of ultraviolet disinfection either alone as a primary disinfectant or as an additional barrier in conjunction with ozone in addition to chloramination would ensure inactivation of cryptosporidium and giardia. Ozone is critical to the surface water Acti-Flo process and cannot be switched to a different process. The RWS groundwater supply is used on a year around basis. The RWS surface water treatment plant is used only as a peaking plant during high demand periods from mid-May through Mid-September. As of November 17, 2022, this project is in the conceptual phase. An engineer will not be selected until funding is secured, which is anticipated to take a year. A firm timeline for construction has not been determined.