EPA held a one-day meeting to discuss its ongoing review of the Long Term 2 Enhanced Surface Water Treatment Rule (LT2) in accordance with both the Safe Drinking Water Act’s (SDWA’s) Six-Year Review requirements and President Obama’s Executive Order 13563, which requires a retrospective review of regulations to identify potential efficiencies. The April 24th meeting was the second addressing the LT2 review and focused specifically on the uncovered finished water reservoir provisions of the rule, which requires all uncovered finished water reservoirs to be covered or have additional treatment installed to meet LT2 removal or inactivation requirements for viruses (4-log), Giardia (3-log) andCryptosporidium (2-log).
According to EPA data, only 38 finished water reservoirs remain uncovered across the country and all of those are under enforceable schedules to be covered in the years ahead. However, several utilities under such compliance schedules continue to debate whether incurring the substantial costs of covering reservoirs is justified given the minimal risks posed to public health relative to other pressing water management issues that are competing for the limited dollars in municipal budgets. Presentations and discussions during the day’s meeting explored these issues in greater detail.
To start the meeting, EPA presented an overview of the current regulatory review process(es) for LT2, a review of LT2’s regulatory history and an assessment of the potential routes of exposure and associated risks from leaving finished water reservoirs uncovered. The remainder of the day focused largely on presentations from utilities highlighting potential benefits and risks (or lack thereof) involved in requiring that finished water reservoirs be covered. Presenters from Seattle Public Utilities and the City of Tacoma presented data on the water quality changes experienced before and after they covered finished water reservoirs at their water utilities. Both utilities saw substantial improvements across a range of water quality parameters after covering their reservoirs, however, the majority of those improvements were not in the microbial parameters specifically covered by LT2. Tacoma in particular has never found Cryptosporidium (a particular focus of LT2) in its reservoirs but emphasized the benefits of covers in addressing other long-standing concerns such as preventing midge fly larvae introduction, eliminating algal blooms (and associated taste and odor problems) and maintaining chlorine residual levels as water passes through its reservoirs.
Contrasting the Seattle and Tacoma presentations, representatives from the New York City Department of Environmental Protection (NYC DEP), which still operates uncovered finished water reservoirs, presented data on the success of its risk management strategies for ensuring public health goals are met. Data presented by NYC DEP suggest that they do not experience a statistically significant increase in microbial contaminants as water passes through its uncovered Hillview reservoir. Presenters also summarized public health surveillance data showing that the rates of illnesses from Giardia and Cryptosporidiumexposure have decreased to all time lows in NYC, suggesting that risk mitigation programs such as aggressive animal (particularly bird) control programs, tight security, and a rigorous monitoring program can provide the necessary level of public health protection, absent a cover or more aggressive treatment, for a significant finished water source.
The day wrapped up with a panel comprising representatives from the utility, state, academic and public advocacy communities who discussed the information presented during the meeting. While there was no consensus solution from the panel on whether the uncovered reservoir provisions of LT2 should be revised, there was some agreement that the issue should be further evaluated to assess the potential for less costly risk management options that are tailored to the individual circumstances at a particular water utility. However, panelists also acknowledged that further research and data collection may be difficult, but is necessary to inform any scientifically sound reassessment.
Despite a good amount of agreement throughout the day among speakers and panelists that there may be viable options to covering reservoirs based on circumstances unique to individual water systems, it is not clear if EPA is ultimately willing or able to move from the requirements to cover reservoirs as currently structured under LT2. Several times during the meeting discussions, EPA emphasized the SDWA mandate that does not allow any increase in health risk or “backsliding” when revising a rulemaking under the SDWA. EPA staff also made clear that any evaluation of such backsliding must be scientifically defensible based on sound data and research. In the absence of conclusive scientific evidence that backsliding would not occur, EPA would need to comply with the existing uncovered reservoir requirements. This point was made clear in EPA’s closing remarks for the day which again emphasized EPA’s anti-backsliding obligations as well as previous legal victories in challenges to the existing uncovered finished water reservoir provisions under LT2.
AMWA continues to support the evaluation of the need to cover finished water reservoirs at the individual water utility level, taking into account the unique circumstances of each system within a comprehensive risk-management context. Going forward, EPA will continue to solicit data and research to better evaluate potential revisions to all LT2 provisions. EPA is currently planning another public meeting (tentatively scheduled for fall 2012) at which it will delve deeper into additional LT2 provisions, including an evaluation of binning requirements based on results from Round 1 Cryptosporidium monitoring.