If you have ever wondered why one state bans a chemical in drinking water while the state next door has no rule at all, a new resource from The Water Center at the University of Pennsylvania is worth bookmarking.
The Water Center has released Contaminants of Emerging Concern in U.S. Drinking Water: A State-by-State Regulatory Reference, a report mapping how the country is (and is not) acting on contaminants of emerging concern, or CECs. These are the unregulated or newly regulated chemicals turning up in our water with growing evidence of adverse health effects, from microplastics and pharmaceuticals to the industrial solvent 1,4-dioxane. An accompanying interactive StoryMap turns that regulatory picture into something you can actually see and click through.
The report reviews federal and state action along with treatment options for the most prevalent CECs. It is built for decision makers, regulators, and water system stakeholders trying to navigate a fast-moving and confusing area of environmental governance, but it reads clearly enough to be useful to anyone who cares about what comes out of their tap.
The central finding will not surprise anyone who follows water policy: absent strong enforceable guidelines from the EPA, the regulatory landscape is fragmented, with the level of action varying widely by state and by contaminant. California, Minnesota, and New Jersey have taken the most action, both in the number of contaminants they regulate and how strict those rules are, with California leading the way. Two chemicals, 1,4-dioxane and 1,2,3-trichloropropane (TCP), have the strongest enforceable standards across states. Others, including lithium, the disinfection byproduct NDMA, and hexavalent chromium, still lack meaningful regulation almost everywhere. The report’s bottom line is that more research on health effects, treatment technologies, and policy is needed before stronger rules take hold at either the federal or state level.
For those of us working on water access and infrastructure in southwestern Pennsylvania, this is a valuable reference to have on hand. It names the contaminants worth watching, shows which states have built the playbooks worth borrowing, and makes the case for why this work matters even where the rules have not caught up yet.
The Water Center credits Caroline Barnhart, former PFAS and Emerging Contaminants Graduate Research Fellow, for her work on the report and StoryMap, along with Bree Callahan and Maya Halma for their support.
Explore the resources:
Read the full report: Contaminants of Emerging Concern in U.S. Drinking Water: A State-by-State Regulatory Reference
