On June 25, EPA held a full-day public meeting and webinar to discuss its current thinking regarding the development of the fourth Unregulated Contaminant Monitoring Rule (UCMR4). Presentations started with an overview and historical review of the Contaminant Candidate List (CCL) and UCMR development processes before giving an overview of potential changes in UCMR4 compared to previous cycles and the potential contaminants that would be monitored under UCMR4.
The most significant process-related changes under consideration for UCMR4 are related to the sampling design. EPA is considering adopting seasonal, targeted monitoring strategies for certain contaminants to better reflect occurrence patterns (i.e., summer and surface water focused sampling for algal toxins) as well as compressing the overall monitoring window from the traditional three years under previous UCMRs to a tighter two-year window. The latter change is premised on speeding up the process to have more timely access to data when making regulatory determinations. Other changes include sampling location changes within the distribution system and updated processes for quality control data submission.
EPA’s presentation on potential contaminants for inclusion in UCMR4 included a discussion of over 50 candidates, a list that needs to be further narrowed to the Safe Drinking Water Act statutory limit of 30 contaminants. Contaminants under consideration come largely from the CCL (both CCL3 carryovers and CCL4 nominations) with additional candidates added based on current drinking water regulatory priorities. In addition to the lists of metals, pesticides, pharmaceuticals and other types of contaminants covered in past UCMRs, several cyanotoxins are under consideration as well as Legionella, reflecting recent EPA policy statements about concerns related to these contaminants. Four unregulated brominated disinfection byproducts are also under consideration, most likely with an eye toward the upcoming six-year review process for disinfection byproduct rules.
The selection of the final 30 UCMR4 contaminants is currently scheduled to continue over the next year, working toward a July 2015 proposal. Following public comment and revisions, the final UCMR4 is slated for publication in December 2016 with monitoring commencing in 2018.
Copies of all EPA presentations from the meeting/webinar are available on AMWA’s website, and include full lists and descriptions of the contaminants under consideration for UCMR4.
Many of the changes in UCMR4 put forth by EPA respond to recommendations laid out in a recent U.S. Government Accountability Office (GAO) report for improved implementation of the UCMR. Recommendations in the GAO report include expanding the number of monitored contaminants beyond the current limit of 30 (when it can be done with minimal additional burden) and making alterations to sampling frequencies to better reflect variable or sporadic occurrence.
A significant portion of the GAO report also focuses on the usability of UCMR data in support of regulatory development. The report recommends that EPA take a closer look at the alignment of UCMR data collection (and subsequent analyses) with regulatory determinations, noting that current statutory schedules may require EPA to make determinations for a contaminant before the corresponding UCMR data are fully collected and analyzed. In other instances, the lag between data collection for a contaminant and subsequent regulation may result in inaccurate representation of occurrence, particularly for certain agricultural or industrial contaminants which may see significant changes in usage patterns in a short period of time.
Recommendations from the report also include possible Congressional action, which would be required to change certain aspects of the contaminant identification process, including changes to the number of contaminants monitored and changes to certain statutory schedules. Several additional recommendations focus on EPA working within existing statutory limitations to increase the efficiency of the program.