Published in December 2019 Focus on the Environment Newsletter
On December 2, 2019, the Ohio EPA and Ohio Department of Health (ODH) released the Ohio Per- and Polyfluoroalkyl Substances (PFAS) Action Plan for Drinking Water. The Action Plan was called for by Governor DeWine and its stated focus is to evaluate the potential risk of PFAS in both public and private drinking water systems in Ohio and assist communities in addressing these risks. To this end, the Action Plan lists the following objectives:
The plan includes strategies for achieving these objectives and provides the general course for plan implementation. In general, Objectives 1 through 3 address data collection and analysis, and Objectives 4 through 6 outline Ohio EPA and ODH responsibilities, post-sampling technical assistance, public education and outreach and plan review/updates. To coincide with the release of the Action Plan, Ohio EPA added a PFAS information/resource page on their website.
To implement the plan, Ohio EPA will coordinate sampling of approximately 1,500 public water systems (of the estimated 4,800) serving approximately 90 percent of Ohio’s population. Sampling will include both raw and finished water with a goal of completing sampling efforts by the end of 2020. Established action levels for six PFAS compounds (PFOA, PFOS, PFBS, PFHxS, PFNA, and GenX) will be used as thresholds for providing guidance to drinking water system owners/operators for mitigating potential health risks.
Action levels for PFOS and PFOA will be the U.S. EPA Health Advisory Level (HAL) of 70 parts per trillion (ppt) (when both PFOA and PFOS are detected, their combined concentration will be compared to the action level). Action levels for GenX, PFBS, PFHxS, and PFNA, will be 700 ppt, 140,000 ppt, 140 ppt and 21 ppt, respectively, and were calculated using the U.S. EPA’s established Drinking Water Equivalent Level method.
Sampling under the Action Plan builds upon and, to some degree, duplicates the data collected under U.S. EPA’s third Unregulated Contaminant Monitoring Rule 3 (UCMR 3) in 2013 and 2015. Five of the PFAS compounds listed in the Action Plan, PFOA, PFOS, PFBS, PFHxS, and PFNA, were included in the list of six PFAS compounds in UCMR 3. Under USMR 3, all large community and non-transient non community water systems serving more than 10,000 people were required to sample for the listed constituents. Of the over 170 water systems sampled in Ohio in 2013 and 2015, only two had PFOA/PFOS concentrations exceeding the HAL.
The Ohio Action Plan states that the laboratory analysis of both the raw and finished water samples from the public water systems will be performed in accordance with U.S. EPA approved methods for drinking water. Currently, the only U.S. EPA approved laboratory method for PFAS analysis is Method SW-846 537.1, which is a drinking water method. While appropriate for analyzing the finished (drinking) water samples, Method SW-846 537.1 is not approved for analysis of raw water (surface or groundwater) samples. In fact, there is no U.S. EPA-approved methods for PFAS analysis of non-drinking water matrices. Although the U.S. EPA is currently in the process of developing Draft Method 8327 for PFAS analysis of non-drinking water (groundwater, surface water and wastewater), it is unclear when the final method will be formally approved. Further complicating matters is the fact that individual commercial laboratories have developed their own “modified” Method 537.1 for PFAS analysis of non-drinking water samples. These “modified” methods are laboratory specific, utilizing proprietary methods developed in-house with sample preparation and processing protocols that may vary from lab to lab. Until U.S. EPA approves a non-drinking water method, it is recommended that public water systems seek further guidance from Ohio EPA regarding the appropriate laboratory method(s) for analyzing their raw water samples.
In addition to the laboratory method, the Action Plan is not clear with regard to how systems with multiple raw water sources should be sampled. Should the raw water samples be collected at the point where the sources are combined prior to treatment or at each individual collection point (i.e. surface water intake or production well)? The former approach would reflect raw water conditions consistent with “normal” operational practice, whereas the latter measures water quality at the collection point.
With regard to private water systems (Objective 2), the strategy states that ODH will review the public water system PFAS sampling results and identify any nearby private water systems that may potentially be contaminated. ODH will then coordinate with local health districts and private water system owners to provide guidance on sampling/testing recommendations and steps to reduce risk, such as treatment options.
The strategy of using the public system sampling results as the sole means to identify/screen for potentially at risk nearby private water systems assumes that the public and private water systems utilize the same water source (i.e. wells tapping the same aquifer) and therefore might not be appropriate in areas where the source water for the public water system is different from the private water system. For example, water quality data from a public water system with a surface water intake is probably not comparable to nearby private water systems utilizing groundwater. Similarly, water quality from a large capacity public supply well completed in a deep, semi-confined aquifer may not be comparable to nearby residential wells utilizing groundwater from the overlying, unconfined aquifer. It is not clear how these differences will be addressed in the Ohio EPA/ODH evaluation process. Because the onus and expense of sampling for PFAS will be placed on the private water system owner, it is important that recommendations for testing be based on sampling results from a public water system utilizing the same or comparable water source.
Although the approach presented in the Action Plan has the potential to screen areas near public water systems for PFAS contamination, it ignores the potential threat posed to private water systems that are in proximity to known PFAS source areas. The use of PFAS in industrial and consumer products is widespread and the list of potential PFAS sources is broad and includes fire training/response sites, industrial sites, wastewater discharge/biosolids, and landfills. Considering how widespread these source areas are, it is reasonable to assume that some could be in close proximity to private water systems. Experience tells us that PFAS contamination (or any contamination for that matter) in private water systems is dependent on their proximity to the source as opposed to their proximity to the nearby public water system. Consequently, although it may provide the best bang for the buck, the strategy of using the public water system data as the “canary in the coal mine” for private water systems may not be the best approach for screening all at risk private water systems.
Although the Action Plan may not be perfect, it is a start, and one component of the plan is to adapt the objectives and strategies as needed to reflect the current understanding of the evolving PFAS science and national regulatory framework. As a result, some of the kinks should work themselves out during the initial implementation efforts. Hopefully additional clarification on these and other issues will be forthcoming as we move closer to plan implementation.
Doug is a licensed professional geologist in Indiana and North Carolina. As a consulting hydrogeologist, Doug specializes in aquifer characterization and yield determinations, well and wellfield performance evaluations, and the design and testing of both vertical well and horizontal collector well systems. Additional areas of expertise include environmental assessment and remedial system evaluation and design. He has worked throughout the United States on a wide variety of groundwater supply and environmental contamination related projects. Doug’s wide-ranging expertise and extensive experience in the groundwater supply industry add another dimension to Cox-Colvin’s technical staff and provide additional opportunity to support our clients in meeting their needs and reaching their business goals.