Journal ‐ American Water Works Association最新文献

On April 10, 2024, the US Environmental Protection Agency (EPA) announced the final rule setting standards for six per- and polyfluoroalkyl substances (PFAS). Water systems will have three years to conduct initial monitoring requirements and prepare to issue public notifications annually.

The new standards for PFAS include five MCLs and MCL goals (MCLGs), for a total of six PFAS. For perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), EPA set each of the MCLs at 4.0 ng/L and the MCLGs at 0 ng/L, based on a determination that PFOA and PFOS are carcinogenic. EPA also set individual MCLs and MCLGs for perfluorohexanesulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and hexafluoropropylene oxide dimer acid (HFPO-DA) acid at 10 ng/L. Finally, EPA set an MCLG and MCL using a hazard index of 1 (note the significant figures) for PFHxS, PFNA, HFPO-DA, and perfluorobutanesulfonic acid (PFBS).

The NPDWR also establishes monitoring requirements for compliance and to determine eligibility for reduced monitoring using EPA's Standardized Monitoring Framework. Initial and ongoing compliance monitoring must be conducted quarterly for any large system serving more than 10,000 people and for small systems that do not rely on groundwater sources. Compliance with the MCLs is based on the running annual average (RAA) of the monitoring results for each entry point to the distribution system (EPTDS), where monitoring results below the practical quantification limits for the six PFAS will be treated as zero for the purposes of calculating RAA.

Similar to the Standardized Monitoring Framework, EPA has established requirements for a system to be eligible for a reduced monitoring schedule at an EPTDS if PFAS levels are below one-third of the corresponding MCL (2.0 ng/L PFOA, 2.0 ng/L PFOS, and a hazard index of 0.5 for PFBS, PFNA, PFHxS, and HFPO-DA). EPTDSs that are eligible for reduced monitoring will be required to sample triennially (one sample per three-year period). If a triennial sample exceeds the trigger level, the system must revert to quarterly monitoring.

Water systems are required to issue public notifications using consumer confidence reports (CCRs) and in response to violations, consistent with previous NPDWR. Violations of the MCL(s) will require a Tier 2 notification to the public within 30 days of the system learning of the violation as well as a Tier 3 notification through the CCR. The CCR must also include information relevant to detections of any of the six PFAS.

Water systems will need to begin conducting initial monitoring of these PFAS in accordance with the requirements and determine whether next steps, such as installing PFAS drinking water treatment facilities, will be necessary. The rulemaking does not limit the types of treatment technologies systems may use to comply with the MCLs, but the most used treatment technologies for PFAS, including powder and granular activated carbon, ion exchan

Maybe each era of water seems complicated in its time. Things certainly seem complicated now. In fact, I think it is reasonable to believe we are entering a new water era, one that will need new responses, such as Water 2050's vision for creating a sustainable and resilient water future.

Interestingly, we are also at a historic moment when we can look back and recognize the 50th anniversary of the Safe Drinking Water Act (SDWA). The creation of the SDWA in 1974 started an amazing era for water, one that surely was, and is, complicated. The good news is that today, about two-thirds of the US population has never lived a day without the protections of the SDWA.

It makes sense that as we move from one era to another, the change brings with it uncertainty. That is a possible explanation for the three-year downward trend in the optimism chart included in AWWA's 2024 State of the Water Industry (SOTWI) report.

There are indicators other than just the dip in optimism that lead me to think a new era is upon us. For example, in the past decade, the SOTWI report's most cited challenge facing the water sector has been renewal and replacement of aging infrastructure. Not so now—it has dropped to the third position, and it has been replaced by watershed and source water protection—which made an unprecedented jump up from fifth position.

Maybe this is a one-year anomaly—certainly there is still a strong need for infrastructure replacement—or it may indicate a shifting focus from the built infrastructure to protecting the natural infrastructure. That shift seems logical to me given the growing concern and focus on such hazards as per- and polyfluoroalkyl substances (PFAS), lead, and microplastics. All three of these have dominated the rankings in the SOTWI report for water quality concerns over the past three years—with PFAS consistently rated the highest since 2020.

This year the SOTWI survey introduced “financial sustainability” as an option for survey respondents, and they ranked it the fifth highest concern. That is a strong starting place. When coupling financial sustainability with financing capital improvements—which continues to be the second greatest concern facing the water sector—the two concerns ring the bell for stronger revenue streams going forward.

Of course, utility financial sustainability is directly related to setting water rates that cover the cost of water service. While this year's data show some improvement from 10 years ago, there is still more to accomplish. On the plus side, this year's survey shows that about 44% of utilities are very able or fully able to cover costs. On the negative side, however, one of every four utilities reports they are at best only slightly able to cover their costs, indicating the need to boost their rates and financial sustainability.

We cannot talk about rate increases without simultaneously acknowledging the challenges of affordability. It was not