If you live in an urban area or city, then you may be familiar with paying a water bill for the water you utilize in your home. For the most part, this water bill covers the cost of water testing, treatment, and transportation from your regional water facility to your home. When you look at the life cycle of your tap water, the journey it takes to make it to your home is quite amazing.
Drinking water testing is a critical step in the life cycle and journey of your home tap water. Many cities and Urban areas have highly technical water testing facilities which screen for contaminants that are regulated by state and regional authorities. Now this sounds all well and good, however, we only screen for contaminants that are known and regulated in that region. The reason for this is that the analytical systems and technology we use are limited by two main parameters: range and sensitivity. Basically, if you look for a large range of contaminants, you will start to lose the ability (or sensitivity) required to detect the compounds. A similar analogy is like looking at the stars. With your eyes you will be able to see a broad range of stars, planets, and galaxies. With a telescope you will see much less, but what you do see is in much more detail, meaning you gained more sensitivity. Since the same issue is demonstrated in testing drinking water, a compromise is made between the quantity of contaminants we screen for and the sensitivity at which regulate them.
For the most part, we screen for contamination that is or has been known to exist in the environment. Unfortunately, as the lives of humankind evolve through time, so does our waste and environmental contamination. Recognizing this, the United States Environmental Protection Agency (USEPA) created the Unregulated Contaminant Monitoring Rule (UCMR) to identify new contamination in the environment and adapt our environmental monitoring requirements accordingly. From 1988 – 1997, the program kicked off with a multi-state assessment of roughly 110 then-unregulated contaminants as an initial baseline. Since original assessment in 1997, the EPA has continued to assess unregulated contaminants with new lists of compounds being assessed roughly every five years.
The goal of the UCMR program is to identify any potential hazardous contamination before it affects the lives of US citizens. An example of the disturbing impacts unregulated contaminants can have on our lives is found in the 2018 investigative documentary “The Devil We Know”. This documentary shows how per-and polyfluoroalkyl substances (PFAS) released in the environment had severely impacted the lives of a community in West Virginia. At the time, PFAS compounds were not routinely monitored for in the environment and therefore information on our exposure to these contaminants was poorly understood.
We are now entering into the fifth assessment program for unregulated compounds, UCMR 5. This program will collect and analyze water samples from thousands of municipalities across the nation from January 2023 – December 2025. The UCMR 5 list contains 29 PFAS contaminants which are suspected to be present in the environment and could eventually end up in our drinking water supply. This program will require over 10,000 US public water systems (PWS) to collect several samples each year over the course of 3 years. To perform the PFAS testing for UCMR 5, laboratories must be able to run both EPA Method 537.1 & 533. The data received from the assessment will provide a baseline understanding of the current levels and distribution of PFAS contamination across the nation.
So how will the UCMR 5 program help determine if your drinking water is safe?
Well unfortunately in environmental science, what you don’t know could hurt you. The UCMR program allows chemists to learn more about contamination in our environment, especially when the compounds are not currently regulated. The severity of PFAS contamination in North America needs to be documented to assess the impact it will have on the public health of US citizens. In the past, the UCMR program has helped drive updates to the maximum contamination levels (MCLs) and the regulation of other compounds. I hope that the UCMR 5 program will provide the information needed to help environmental authorities improve the safety of drinking water in the United States, as seen with previous UCMR programs.