'Stark Findings' Raise Alarm About Croton Reservoir Water Quality

NEW YORK — A new study is pointing to a potential crisis with the water supply in the Hudson Valley and New York City, according to state officials.

The New York City Department of Environmental Protection (DEP) has released a new study sounding alarms about rising salinity levels in the water supply. The survey results show salinity levels in the Croton System reservoirs, which is one of NYC's primary water sources, have been steadily rising due to road salt runoff and other human activities.

Salinity levels in the system's main New Croton Reservoir have tripled in just 30 years, according to the recent findings. Officials say if the trend continues, the New Croton Reservoir could exceed the state's maximum allowable chloride levels at the turn of the century.

"Our study found a clear and troubling trend of increasing salinity in and around the Croton water supply region," DEP Commissioner Rohit T. Aggarwala explained. "As the nation’s largest municipal water supply system serving half of the state’s population with the gold standard in water quality, we must do everything possible to protect this most precious resource. It is imperative that we work closely with state and local governments, and our environmental partners, to develop and implement policies to slow and hopefully stop this trend."

The DEP "Salinity Management Assessment" study reviewed almost 33 years of data and found steadily increasing salinity levels in all 12 reservoirs and three controlled lakes in the water supply's Croton System, which is the oldest and smallest of the reservoir systems which typically provides an estimated 10 percent of the water supply to NYC.

All of the Croton System's reservoirs and lakes throughout Westchester and Putnam counties feed into the New Croton Reservoir. The study found that at the current rate of increase, the New Croton Reservoir would reach the state's maximum contaminant level for chloride, a main component of salt, by the year 2108.

High levels of salinity in fresh water supplies can affect human health by contributing to high blood pressure and can also significantly impact watershed biodiversity and ecosystems with potentially harmful effects on water quality, officials said.

"We thank DEP for their partnership in taking action to safeguard the health of our ecosystem and our communities," Riverkeeper President and Hudson Riverkeeper Tracy Brown said. "The problems identified in the Croton watershed are unfortunately common statewide, and we must use the stark findings in this report to address the issue statewide. Now is the time for smarter use of road salt and the equipment upgrades that will protect our friends, family, and neighbors with high blood pressure, and those on low sodium diets, throughout New York. This is also critical for ecosystem and human health as salt changes water chemistry, leading to increased risk of lead leaching from pipes that carry drinking water, other heavy metals being mobilized from source waters, and the formation of Harmful Algal Blooms."

The DEP study found winter de-icing of roadways and parking lots, wastewater treatment plant discharges, and private water softening systems to be likely main contributors to increased salinization. Water filtration plants are unable to remove salt from water. Instead, salinity can only be reduced through an expensive and heavily energy-dependent desalinization process.

"Millions of New Yorkers, including many of my constituents in Northern Westchester and Putnam County, are impacted by rapidly rising salinity in the East of Hudson Watershed, which affects their source of clean water," New York State Senator Pete Harckham, Chairman of the Senate Committee on the Environment, said. "In less than 30 years, the Amawalk Reservoir will exceed the maximum allowable levels for salt. Once contaminated, it could take decades for the reservoir to return to acceptable levels. All levels of government must work collaboratively and with all deliberate speed to protect our precious drinking water."