Allegany Wastewater Treatment Plant

Increased development and growth occurring within the Allegany Territory of the Seneca Nation of Indians, as a result of new gaming and entertainment enterprises of the nation, have given rise to a need for improved water and wastewater infrastructure to responsibly address environmental concerns. The nation has decided to construct new, state-of-the-art facilities to collect, convey, and treat wastewater generated within the newly formed Allegany service area. The nation selected C&S as the consultant to provide facilities planning, design, and construction administrative services for the wastewater treatment facility.

This new wastewater treatment facility is a 200,000 gpd sequencing batch reactor plant serving the local housing communities, the Allegany administration and health complex, sports center, and Seneca Allegany Hotel and Casino. The new wastewater treatment facility is designed to accommodate the flows and loadings from these facilities and configured to allow for efficient expansion, should additional capacity be required in the future.

Two sequencing batch reactors will provide nitrification, denitrification, and BOD consumption. The SBR process was selected due to the facility’s elevated influent BOD concentrations resulting wastewater discharges from the casino’s restaurants.

The effluent filtration system consists of two cloth media filters, located in the filter/UV disinfection room. Each filter comprises a stainless steel tank, two cloth media covered disks, a backwash system, and disk drive assembly.

The disinfected effluent is pumped to the soil infiltration system for final discharge from the WWTF. The soil infiltration system consists of a group subsurface HDPE chambers set in clean gravel bedding. WWTF effluent also flows into the chambers and then flows downward by gravity into the vadose zone aquifer beneath the project site.

This project was designed using building information modeling, which benefitted the project by taking advantage of custom BIM-based specialty items that could be connected to adjacent systems to test performance and determine proper pipe sizing to accommodate the equipment.