By Christina Stringer

In 1962, the landmark work “Silent Spring” posed the question, “Can anyone believe it is possible to lay down such a barrage of poisons on the surface of the Earth without making it unfit for all life?” Rachel Carson’s exploration of the negative effects of DDT — an insecticide used in agriculture — on animal health is perhaps the first time an emerging contaminant was brought to the forefront of the public consciousness. Emerging contaminants, or contaminants of emerging concern (CECs), are unregulated substances found in waterbodies that may cause ecological or human health impacts.

There have been many CECs that have been the focus of environmentalists and regulators throughout modern history. Lead and arsenic are both legacy contaminants that humans have been producing for thousands of years. Lead mining is believed to predate the Bronze or Iron Ages and ancient Romans used the metals extensively for pipes and baths. The negative health impacts of lead exposure, however, weren’t recognized until the 1970s. Environmental lead concentrations have declined due to global efforts to curtail usage yet lead in drinking water remains an active area of scientific research today.

Arsenic compounds were first used as a pesticide in China as early as 900 A.D. and have been used in the United States for the same purposes for hundreds of years, until DDT became popular and was thought to be a less harmful replacement. Today, arsenic is still considered to be a CEC in some geographic regions, including areas of the Northeast, as changes in aquifer usage cause mobilization of geochemical arsenic.

In the past 30 years, the environmental community has faced many more CEC challenges, including mercury, acid rain, PCBs, dioxins, and pharmaceuticals and personal care products (PPCPs). Today, we are squarely focused on challenges related to per-and polyfluoroalkyl substances (PFAS) and microplastics. CECs are especially challenging; by definition we are dealing with the unknown. Having to wait for science and technology to catch up to regulatory needs takes time and patience. The data needed to make informed and scientifically defensible management choices is costly and time consuming. The general public often doesn’t fully comprehend the extent of information that is needed to inform regulation and the amount of time it truly takes. Often these efforts are happening in the background, and the public isn’t aware of the pollutant issue until researchers have more information, and regulators and legislators are able to make progress as quickly as the bureaucratic red tape allows. PFAS has been unique because it received attention in the mainstream news early on, and legislators have been forced to take action quickly due to the outcry and concerns of their constituencies.

fingers with microplastics on them
Microplastics are small plastic pieces less than five millimeters long which can be harmful to aquatic life.

Tackling emerging contaminants is a complex issue that involves regulators, researchers, and operators. Multiple federal state statutes, including the Clean Water Act (CWA), issue authorities to the Environmental Protection Agency (EPA) and states that can be used to address CECs. The primary mechanism to control any kind of contaminant, emerging or otherwise, in surface water is through National Pollutant Discharge Elimination System (NPDES) permits, or the state equivalents in those states with an authorized program. The CWA allows CECs to be addressed through technology-based effluent limitations and water-quality-based requirements. However, those authorizations are often difficult to utilize because of a lack of data needed to support criteria.

Finally, and of the utmost importance, the CWA authorizes the EPA to designate CECs as toxic pollutants (Section 307) or hazardous substances (Section 311). These designations are especially important because they establish liability for their release, including responsibility for costs and damages.

In “Silent Spring,” Rachel Carson observed, “We stand now where two roads diverge. But unlike the roads in Robert Frost‘s familiar poem, they are not equally fair. The road we have long been traveling is deceptively easy, a smooth superhighway on which we progress with great speed, but at its end lies disaster. The other fork of the road — the one less traveled by — offers our last, our only chance to reach a destination that assures the preservation of the earth.”

Despite all of the progress we’ve made in the 50 years of the CWA, it still feels like we are standing at that proverbial fork in the road. As we spend this year celebrating this landmark approach to protecting our waters, we also need to spend time reflecting how we can improve the CWA to better prepare us to address the CECs of today and tomorrow.

Christina Stringer is NEIWPCC’s director of wastewater and onsite programs. This article was originally published in the Spring 2022 edition of “Interstate Waters” magazine.