NYC DEP Cooling Wastewater Allowance Program
April 25, 2023 Newsroom
Does your building have a cooling tower? If so, you may be eligible for a monthly allowance as part of the NYC Department of Environmental Protection’s (DEP) wastewater allowance program.
A space is cooled by removing “heat” energy using an HVAC system. The system rejects this “heat” to the condenser water system and eventually to the atmosphere through the cooling tower (typically located on the building’s rooftop). In the tower, condenser water is sprayed over a fill material increasing the water’s surface area while fans blow air through the fill evaporating a portion of the water and, in the process, reducing the temperature of the remaining portion. While there are other losses of water in a cooling tower system (drift and blow-dow) approximately 80-85% of the make-up water is lost through evaporation.
Currently, the cost of water is $11.14 per 100 cubic feet (748 gallons) made up of two charges: supply ($4.30) and wastewater treatment ($6.84). The wastewater treatment cost accounts for 61% of the water bill, but since the evaporated water never reaches the wastewater treatment plant, the DEP allows you to request an allowance for it. The case study (right) illustrates the potential savings.
There is an application that needs to be filed and a water meter with a remote reader that needs to be installed, but depending on the system size, payback is approximately a couple of years.