Orange County holds public hearing on $185 million plan to expand Harriman wastewater plant to 9 million gallons a day

Orange County legislators held a County Law §5-a public hearing on March 18, 2025, to receive comment on proposed improvements at the Harriman Wastewater Treatment Plant that would expand permitted treatment capacity from 6,000,000 gallons per day to 9,000,000 gallons per day and replace aging equipment.

The project, presented by Marybeth Bianconi, P.E., partner at Delaware Engineering, is currently estimated at "Our preliminary cost all in is a hundred and $85,000,000," she told the legislature. Bianconi said the work is intended to meet new New York State Department of Environmental Conservation permit requirements, extend the useful life of aging treatment trains, and accommodate forecasted flows from connected communities over the next 20 to 30 years.

County officials and the consultant said the upgrade package would replace the original treatment train on the site with a new 7,000,000 gallon-a-day sequencing batch reactor, upgrade the plant's newest train (Train 3), and make general site improvements. Bianconi said the project is in design, that a submittal to the Department of Environmental Conservation is planned for August 2026, and that construction is anticipated to take roughly 24 months (potentially discontinuous with winter shutdowns).

Why it matters: County staff said the plant cannot meet all conditions in its renewed State Pollutant Discharge…