As our waters face new and unregulated threats, so does our health and the health of the ecosystem.

For every chemical regulated to protect safe drinking water, there are roughly 1,000 unregulated chemicals in use. Our region’s high population density and industrial history along with ongoing use of risky chemicals in certain industries and consumer products, has led to the release of chemicals into our environment that can be measured in our rivers, groundwater — and even in our blood.

Though the Clean Water Act and New York Environmental Conservation Law regulations limit discharges of a far greater number of chemicals, regulations often lag decades behind scientific evidence showing risks from chemicals to human health or aquatic life. Many pollution discharge permits in New York State often go decades without being updated. And potential harm is typically measured chemical by chemical, without a clear understanding of cumulative risks that likely come from exposure to low levels of multiple contaminants.

Many of these contaminants will become more difficult to manage due to climate change, as temperature, precipitation patterns, changes in soil composition, and other cascading impacts increase the likelihood of exposure.

PFAS (per- and poly-fluoroalkyl substances) are a large group of synthetic chemicals that have been used in a dizzying array of industries and consumer products such as nonstick cookware, grease-resistant food packaging, firefighting foams, and stain-resistant clothing and upholstery. Known as “forever chemicals,” many persist in the environment rather than degrading over time. This means that PFAS can travel throughout waterways without breaking down, and accumulate in the fatty tissues of aquatic species, such as fish, as well as humans. Although often occurring at low concentrations, PFAS in drinking water and consumer products can increase the risk of negative health effects, such as cancer and reproductive health effects. These risks are ongoing and occur over a lifetime.

Harmful Algal Blooms, known as HABs, are actually caused by cyanobacteria (not algae, which is a natural part of freshwater ecosystems). One of the oldest lifeforms on Earth, cyanobacteria can, under certain conditions, overtake a waterbody, creating bright green mats that release toxins into the water. These toxins can cause skin irritation or gastrointestinal symptoms in swimmers and pets, and the more potent toxins can cause permanent neurological damage and even mortality. Dogs are particularly at risk, as they can get a double dose from swimming in contaminated water, and then grooming their fur. Some of these toxins can be difficult to remove from drinking water supplies. While not all HABs have the same triggers, a common recipe includes still, warm water that has an excess of nutrients — often from farm and lawn fertilizers, manure, erosion, and both treated and untreated sewage. As climate change progresses, warmer waters and precipitation extremes increase run-off and the likelihood of sewage releases. Cyanotoxins and the cyanobacteria blooms that create them are not currently regulated in surface and drinking water.

The first drinking water treatment plant to add chlorine to kill pathogens was in a Hudson River community — Jersey City in 1908. While disinfection has protected millions from illness, chlorine can react with organic matter in drinking water sources to form byproducts that are carcinogenic. Increased water temperatures and precipitation extremes consistent with climate change also contribute to increased disinfection byproduct formation. It is very difficult to remove disinfection byproducts from drinking water once they are formed, so it is critical to control their sources and ensure effective regulation. Though two types of disinfection byproducts are currently regulated in drinking water, other more or equally toxic ones are not.

While road salt has been used to reduce driving hazards from snow and ice for nearly a century, its impact on aquatic ecosystems and drinking water quality is an urgent global concern. Already in the Hudson River watershed, many streams are as salty as some of the waters in the tidal estuary, and Riverkeeper research has found that of the 145 upstate water supplies in the Hudson River watershed serving 2.65 million New Yorkers, more than half delivered tap water with sodium levels exceeding state and federal health guidelines. Disadvantaged communities were more likely to have higher sodium tap water, reflecting the environmental justice issues associated with drinking water source protection.

Pharmaceuticals and personal care products make their way into our waterways through wastewater. Shampoos, soaps, sunscreens, and other personal care products flow down the drain; we excrete most of the medicines we take; and people often flush unused medicines down the toilet. Our wastewater treatment plants generally don’t remove these chemicals, which have a biological effect. While concentrations of individual pharmaceuticals and personal care products in drinking water tend to be below levels of human health concern, more research is needed to understand health risks associated with exposure to low levels of a large number of these chemicals over a lifetime. The harmful effects on aquatic life — especially on fish reproductive health and coral health and growth — are more well-documented. Alongside partners, Riverkeeper has detected and documented dozens of pharmaceutical compounds and personal care products in the Hudson River watershed.