Water Use, Conservation,
and Quality
New York City is fortunate to be located in a water-rich environment. The city’s water is supplied from three upstate reservoir systems (Delaware, Catskill, and Croton) that have a combined capacity of 550 billion gallons of water, according to the New York City Department of Environmental Protection (NYCDEP). The New York City Panel on Climate Change’s 2019 report predicts that precipitation will increase in the coming years, including a higher rate of extreme precipitation events. Unlike many areas of the United States today, water management in our region is not about scarcity. Regardless, we strive to reduce our water consumption, and water conservation efforts are factored into our business planning.
The vast majority of CECONY’s water footprint is converted into a product, steam, which is an integral source of clean, efficient energy.
Steam is distributed to our customers for a variety of uses, such as heat, hot water, air conditioning, sterilization, and food processing. As one of NYCDEP’s largest water customers, we are committed to minimizing the amount of water used to produce steam. We aim to reduce our water footprint by improving the efficiency of our steam system and implementing water treatment system enhancements. As part of our policy, personnel in Steam Operations have an obligation to utilize water efficiently and economically at all times, and management oversees the water utilization program. Currently, Steam Operations tracks water usage versus steam produced to manage overall water consumption. It is anticipated that the data will be tracked and trended on a monthly basis. We are in the process of realigning targets due to new treatment systems and operating profiles. If drought conditions impact our operations, Steam Operations has a drought emergency procedure that requires the stations to monitor water utilization and ensure compliance with any restrictions.
Our water usage has decreased by more than 10% over the past decade. This is due in part to a decrease in demand for steam and due to several major technology upgrades that have reduced our water consumption. At the East River Generating Station, we completed the installation of ultrafiltration (UF) and reverse-osmosis (RO) filtration systems for two of our generating units. Before upgrading to include this pre-filtration system, a considerable amount of water was used to clean the original filtration system at least once daily. Now, our UF and RO filtration systems efficiently remove minerals and debris from the water early in the purification process, significantly reducing demineralizer cleanings. This upgrade has enabled us to reduce our overall water consumption and use water more efficiently. We are already seeing savings of approximately 1 million gallons of water each month.
As part of our decarbonization efforts, we are evaluating and starting to implement various energy efficiency measures on our production side, distribution side and customer side that will improve our performance and reduce steam usage and water usage. Specifically, there are existing energy efficiency programs as well as proposed steam energy efficiency programs that will reduce our overall water consumption through reduced customer demand. At East River Generating Station, a research and development effort is looking to incorporate Capacitive Electrodialysis Reversal (C-EDR) Treatment Technology into the water treatment process. This technology can purify water that is currently discarded as part of the water treatment process so that it can be reused to create steam. The water used to produce steam must be exceptionally pure. The current process results in a certain amount of reject water from the RO system that is properly discharged as effluent in accordance with applicable permits. The C-EDR has the potential to refilter 95% of the RO reject water to be of sufficient quality to be sent to the final water treatment stage to produce steam. C-EDR reduces energy consumption while providing high quality boiler and steam distribution make up water at a fraction of the cost of existing reverse osmosis or demineralizer technologies. We are preparing to pilot several of these units at the start of 2023.
Note: This chart displays steam operations data only.
On average, more than 65% of Steam Operations’ water footprint is distributed to customers as steam energy purchased for their needs.
Water Quality and Effluent Management
At Con Edison, it is our policy to comply with all federal, state, and local regulations pertaining to wastewater discharge. At CECONY, we responsibly manage our effluent, which is primarily discharged from our steam plants into the Hudson River or East River. Every CECONY steam plant has a State Pollution Discharge Elimination System (SPDES) permit from the NYSDEC that allows our facilities to discharge water into the river, subject to designated criteria for each station. The SPDES permit specifies the location, sample type, frequency, and limit(s) of each effluent parameter to be monitored, and establishes effluent parameters and discharge limitations for pollutants. Each facility monitors compliance with these limitations and other requirements through continuous monitoring and sampling as specified in the permit and reports the results to the NYSDEC. In addition, the Company has detailed incident response and corrective action policies and plans in place to ensure compliance with its SPDES permits, and a non-compliance with any SPDES permit requirement is reported promptly.
Preventing Spills to Waterways
Utility operations entail the use of equipment that contains oil. These operations include the storage of petroleum fuels needed to maintain utility service during gas supply contingencies and the use of dielectric fluids (mineral oil or natural and synthetic esters) to provide electrical insulation, suppress arcing and serve as a coolant for operating equipment. CECONY has robust plans to quickly contain accidental oil spills before they reach waterways and impact the aquatic environment. The adequacy of these plans is regularly reviewed and, as needed, operational improvements are implemented to enhance spill response capabilities. CECONY is nearing the completion of a multi-year $237 million program to upgrade 193 spill containment structures to further reduce the risk of spills from oil-filled equipment. The 2022 year end estimate for spend is $53.8 million. CECONY recently completed the installation of containment structures around 44 oil-containing large power transformers (LPTs) at its waterfront substations. CECONY is now working to complete the construction of containment structures around LPTs system-wide by Q1 2023.
CECONY and O&R also maintain rigorous spill prevention, management, and reporting measures. These include facility and asset inspection and repair programs; trained response employees, drills and exercises; operations-specific response plans; and contracted land and water remediation resources. As applicable, these measures are periodically assessed, benchmarked, and updated for best practices.