CEC panel informs proposed update to recycled water policy

Posted May 4, 2018
Recycled water is sometimes placed into holding ponds, such as this one in Santa Clara County in Northern California, to allow the water to gradually infiltrate into groundwater. California’s policy on how to monitor CECs in recycled water was recently revisited by an expert advisory panel facilitated by SCCWRP.

The State Water Board will consider updating California’s policy on monitoring contaminants of emerging concern (CECs) in recycled water as early as this year based on the findings of an expert advisory panel convened and facilitated by SCCWRP.

State Water Board staff is scheduled to release a draft policy amendment in the coming weeks that incorporates recommendations issued by California’s CEC Recycled Water Advisory Panel; the draft amendment will undergo a 60-day public review period prior to coming before the Board, possibly this December.

Among the expert panel’s recommendations, which have been published in a SCCWRP technical report, is expanding CEC monitoring requirements to incorporate use of commercially available bioanalytical cell screening assays.

This prototype technology, which SCCWRP and its partners are working to adapt for aquatic monitoring applications, has the potential to provide a rapid, cost-effective approach to comprehensively screen recycled water for major classes of bioactive contaminants, including unknown chemicals that exert similar biological impacts on aquatic organisms.

Because new CECs are constantly entering production while others are phased out, the expert panel also has recommended that the State Water Board inject more flexibility into its CEC monitoring requirements. A more adaptable monitoring framework would enable individual contaminants to be added to or removed from the State’s priority CEC monitoring list, as researchers learn more about the potential health risks posed by individual emerging contaminants in recycled water.

Since the CEC Recycled Water Advisory Panel issued its original recommendations for recycled water monitoring in 2010, panelists have concluded that four additional CECs should be added to the State’s priority monitoring list, while five others from the original list should be dropped. The panel also has recommended that the CEC priority list be periodically revisited by independent experts.

California’s existing recycled water policy – originally unveiled in 2009 – requires recycled water to be monitored for eight priority CECs when the water is used for a handful of applications, including non-potable landscape irrigation and groundwater recharge for indirect potable reuse. SCCWRP also facilitated the panel’s original deliberations.

If the State Water Board adopts the panel’s updated recommendations for CEC monitoring, a list of seven priority CECs would continue to be monitored individually, plus recycled water agencies would be required to run two bioanalytical assays – the estrogen receptor assay and the aryl hydrocarbon receptor assay. SCCWRP and its partners have been at the forefront of adapting these assays for aquatic contaminant monitoring applications.

Prior to finalizing its recommendations in April, the panel circulated a draft of its recommendations for a 30-day public comment period. After some stakeholders expressed concerns that it would be premature to codify the bioanalytical tools in State policy, the panel revised its position, clarifying that the State should proceed slowly and not yet place any regulatory obligations on water recycling agencies based on their bioanalytical screening data.

For more information, contact Dr. Keith Maruya.

More news related to: Bioanalytical Cell Screening Assays, Emerging Contaminants, Top News