ROCK SPRINGS — The city of Rock Springs addressed odors generated by its water reclamation facility.
The facility receives wastewater through a collection of underground pipe from the city, White Mountain Water and Sewer District and Clearview Improvement and Service District. The water is mechanically treated through several processes.
Clean water is discharged to the Bitter Creek, which flows into the Green River. A byproduct of this process is the production of bio-solids, which are beneficially reused for land application at the Rock Springs landfill, according to the city.
Bio-solids are organic materials that result from the treatment of domestic sewage in a treatment facility. When treated and processed, these residuals can be recycled and applied as fertilizer to improve and maintain productive soils and stimulate plant growth, according to the U.S. Environmental Protection Agency.
The water reclamation facility’s current process and equipment produces bio-solids that are about 20% solid. They are worked with mechanical aeration equipment, being windrowed and turned daily. This aeration process exposes the bio-solids to fresh air, allowing further drying. Once the bio-solids are dried to 50% solids, the odors are almost eliminated, the release states.
The EPA requires bio-solids to be 75% solid content and held onsite for two years before land applying. Once the 75% is reached, the dry bio-solids are moved to an onsite storage location until hauling off-site is allowed. However, through the winter bio-solids processing is halted due to freezing conditions and snow accumulation. Bio-solids are stockpiled until the weather breaks and the drying process can start again. Stockpiling them promotes microbiological breakdown, creating the odors; and breaking into the piles releases the odor that is carried into Rock Springs.