Mike Rogge

Tighter trichloroethylene public health goal considered

By Mike Rogge

Capitol Update, March 11, 2016 Share this on FacebookTweet thisEmail this to a friend

The California Office of Environmental Health Hazard Assessment (OEHHA) is working on an update to its 2009 Public Health Goal (PHG) for Trichloroethylene (TCE) in drinking water of 1.7 parts per billion (ppb). The PHG is the foundation for our TCE drinking water standard or Maximum Contaminant Level (MCL), currently set at 5 ppb. A revised PHG will be proposed late 2016 or early 2017.

In 2011 U.S. EPA’s Integrated Risk Information System (IRIS) program adopted a Reference Dose for TCE of 0.5 ppb, about 3 times lower than California’s current PHG, based on a study of animal data. If OEHHA uses the IRIS Reference Dose as the basis for a new TCE PHG, the level they propose could be 300 times lower than the current PHG. (OEHHA applies uncertainty factors when extrapolating from animal data to human health effects, to address variability within the human population, and/or to adjust consumption rates for children).

Manufacturers should be concerned. A change in the PHG of this magnitude would put political pressure on the State Water Resources Control Board to lower the current TCE Maximum Contaminant Level for drinking water. If lowered, responsible parties would face more stringent cleanup levels for soil and groundwater remediation projects. New requirements would govern discharges from groundwater treatment systems and vapor intrusion at TCE-impacted sites. Industrial and commercial facilities operating TCE contaminated water systems could face new treatment requirements and large water users would face higher water costs.

CMTA is considering the creation of a special project team to advocate for a reasonable approach to the PHG based on the best available science. If you believe your firm could be impacted, please contact Mike Rogge at mrogge@cmta.netfor further details.

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