To comply with new nutrient-discharge limits imposed by the Pennsylvania Dept. of Environmental Protection related to the restoration of Chesapeake Bay, the Altoona Water Authority undertook $65 million in upgrades and the expansion of two wastewater treatment facilities at which existing processes were inadequate.

Gwin, Dobson & Foreman designed the compliance project, which upgraded the authority's Easterly and Westerly plants by converting existing tankage to nutrient-removal technology reactors; constructing additional reactors; renovating and adding new final clarifiers; and installing new, high-efficiency aeration systems, UV disinfection systems, headworks and SCADA systems.

The project also boosted each facility's capacity, with peak flow now at 60 MGD for the Westerly plant and at 35 MGD for the Easterly plant. To date, both plants are performing as planned, requiring less energy and operating at a lower cost while keeping nutrient discharges well under the new state limits.

According to GD&F, the Altoona plants are among the first to fully integrate nutrient removal with high pollutant loads from a combined sewer system during all seasonal conditions. The American Academy of Environmental Engineers and Scientists honored the Westerly plant as one of the country's top environmental projects.

Altoona Wastewater Treatment Facilities BNR Upgrade and Expansion, Altoona, Pa.

Key Players

Owner Altoona Water Authority

Design Firm Gwin, Dobson & Foreman

General Contractor HRI Inc. (Easterly contract); Galway Bay Corp. (Westerly contract)

Electrical Contractor Kirby Electric Inc. (Easterly contract); Bob Biter Electrical Enterprises (Westerly contract)