Wastewater Treatment Process

LUS currently has four wastewater treatment plants: South with a capacity of 7 MGD, East with a capacity of 4 MGD, Ambassador with a capacity of 6 MGD, and Northeast with a capacity of 1.5 MGD. All four plants discharge into the Vermilion River. Operators monitor the plants 24/7 to check equipment, gauges, and flow to ensure everything is operating properly. They also frequently run ammonia and PH tests, which is a good indicator of untreated wastewater. All tests are logged and analyzed to resolve any issues that may arise.

Wastewater from homes and businesses is collected through the sewer system and is pumped to the treatment plant.

The first step is removing large debris. Wastewater passes through screens that catch items such as rags, wipes, trash, and leaves. These materials cannot be treated and are disposed of properly.

Next, the wastewater enters a grit chamber where sand, rocks, and other heavy materials settle to the bottom and are removed. This helps protect equipment and keeps the treatment process running efficiently.

The wastewater then flows into large settling tanks, which are also called clarifiers. Here, oils and grease float to the surface and are removed, while heavier solids settle to the bottom. These solids, called biosolids, are sent for further treatment.

Next, the wastewater enters the biological treatment process. Air is added to the water to encourage the growth of beneficial microorganisms that naturally break down pollutants and remove contaminants.

The water then moves to another clarifier. Any remaining solids settle to the bottom. Some of these microorganisms are returned to the treatment process to be reused, while the excess is sent for biosolids treatment.

Before the treated water is returned to the environment, it is disinfected to eliminate harmful bacteria and other microorganisms.

Chlorine is added to the water and is given sufficient time to work as the water moves through a specially designed contact chamber. After disinfection, sulfur dioxide is added to remove any remaining chlorine, protecting fish and other aquatic life.

The treated water is then safely discharged into the Vermilion River.

The biosolids removed during treatment are further processed in digesters where natural biological activity breaks them down and stabilizes them.

The biosolids are then dewatered. A conditioning agent is added to help separate the water from the solids. The resulting material is loaded onto trucks and transported to land farms for reuse.

For approximately 50 years, LUS has beneficially reused biosolids through a land application program.

The treated biosolids are transported to permitted agricultural sites in Lafayette Parish where they are applied to pastureland as a nutrient-rich fertilizer. The biosolids help support hay production and cattle grazing while reducing the need for commercial fertilizers.

LUS currently operates three land application sites permitted by the Louisiana Department of Environmental Quality (LDEQ). The program has a long history of environmental stewardship and regulatory compliance. It has received numerous awards and recognition over the years.

By recycling nutrients back into the soil, LUS helps protect the environment while providing a valuable resource to local agriculture.