The Throop wastewater treatment plant uses anaerobic digesters to process the waste solids generated during the treatment process. This digestion breaks down the organic material in the sludge, making it suitable for disposal either in a sanitary landfill or as a soil supplement and fertilizer for agricultural use. A byproduct of this process is methane gas, which is harnessed as a fuel source for heating and electricity generation, helping to power a portion of the facility.

The plant’s existing steel floating covers on the digester tanks were over 45 years old, having been refurbished once, and were nearing the end of their service life. Additionally, these steel covers had limited gas storage capacity, reducing their efficiency for methane use as a fuel source. To improve this, the old steel covers are being replaced with new inflatable membrane covers. These new covers will significantly increase methane gas storage capacity, providing a more consistent fuel source for the on-site heating and power generation systems, ultimately optimizing their performance.

Completed: September 2019

Construction Cost: $1,735,278