Salinity levels in New York City's Croton water system have tripled since 1987. The system, which supplies 10% of the city's drinking water, has seen increased chloride concentrations linked to road salt, wastewater discharge, and home water softeners. The main reservoir, located about 20 miles north of the city, has experienced a significant rise in chloride levels. Officials are assessing potential impacts on water quality and possible mitigation measures, as reported by NBC New York and Gothamist.

The Department of Environmental Protection is recommending reduced road salt use and the adoption of alternatives to address rising salinity levels. The New York City sanitation department uses a salt brine solution to pre-treat roads in the five boroughs, which may help lower chloride levels in the reservoir system. DEP Commissioner Rohit Aggarwala stated that without changes, the Croton Water System may no longer be a source of drinking water by 2100, saying, "The conclusion of this study is that if we don’t change our ways, in 2100 the Croton Water System becomes a nice recreational facility." Rising salt levels are a concern, with the Amawalk Reservoir possibly exceeding limits within 30 years. Proposed solutions include reverse osmosis and blending water from other sources, but long-term solutions are needed. State Sen. Peter Harckham called for cooperation among state agencies and local governments, stating, "because this is a real challenge," as detailed by NBC New York.

A study found that road salt is affecting New York City's tap water, often referred to as the "champagne of tap water," raising concerns for those on low-sodium diets, as mentioned by NBC New York. Shannon Roback of Riverkeeper noted that this is common in areas with heavy salt use.