Addressing cumulative impacts

By CMTA Staff

Capitol Update, Sept. 24, 2010 Share this on FacebookTweet thisEmail this to a friend

On August 19th, California’s Environmental Protection Agency (Cal-EPA)and their Office of Health Hazard Assessment (OEHHA) released their report on "Cumulative Impacts: Building a Scientific Foundation."

Cal-EPA is seeking to address the combined effects of various pollutants rather than considering them one at a time.  Cumulative impacts means exposures, public health or environmental effects from the combined emissions and discharges in a geographic area, including environmental pollution from all sources, whether single or multi-media, routinely, accidentally, or otherwise released.

While the report is described as a foundation for screening methodology, we believe that it lacks a science-based approach and is written from an advocacy perspective.  A coalition of 19 associations (including CMTA) submitted comments on September 23rd including an analysis prepared by an independent third party, Dr. John Bukowski, DVM, MPH.  He concluded that many of the report’s findings and conclusions contain extensive inconsistent and contradictory findings and assertions.

The screening methodology lacks scientific rigor in a number of ways:

  • The indicators selected seem to be based on political criteria as opposed to scientific criteria;
  • The indicators lack a full assessment of all the variables and dimensions that encompass the extent and breadth of the indicator;
  • The rationale for assigning weights to the different variables is weak and subjective; and
  • The rationale for combining the components is counterintuitive – Why is living near an underground storage tank with no exposure given the same value as another indicator with direct exposure?

We urged that the screening methodology incorporate a science-based process that better assesses, defines and estimates the cumulative impacts and the range of potential impacts.  We do not believe that the screening methodology will identify the priority drivers of cumulative impact necessary to address community issues or risk management decisions that will lead to a positive difference.

The screening method proposed by Cal-EPA and OEHHA will not enhance decision making. Instead, it will cause confusion and open the door to extensive litigation.  In addition, uneven implementation of this screening tool could lead to adverse economic impacts resulting in further harm to the communities it is striving to protect.A copy of the OEHHA report can be found at:

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