II. Background

In 1991 the Commission opened an investigation (I.91-01-012) in response to concerns raised by members of the public about the possible health effects of EMFs emanating from existing and planned utility facilities. The concerns were prompted by inconclusive research results, some of which suggested a link of probable risk between EMF exposure and various illnesses, and others of which failed to establish such a link.

In 1993, in Decision (D.) 93-11-013, the Commission found that while the evidence of direct harm from EMFs was not conclusive, there was enough public concern to warrant further review (D.93-11-013, p.3.). Accordingly, the Commission adopted several EMF policies and programs to address the public concern, despite the scientific uncertainty. The Commission required the utilities to undertake no-cost EMF mitigation measures and implement low-cost mitigation measures to the extent approved as part of a project's certification process. "Low-cost" was defined to be within the range of 4% of the total project cost but the Commission specified that this 4% benchmark is not an absolute cap. (D.93-11-013, p.13.)

The Commission found that for a mitigation measure to be implemented, it should achieve some noticeable reduction in EMF exposure, but declined to adopt a specific goal for EMF reduction, pending further scientific evidence. (D.93-11-013, p.15.) Workshops were held and utilities developed EMF design guidelines for new transmission facilities. The Commission also adopted several EMF measurement, education, and research programs and chose the California Department of Health Services (DHS) to manage the education and research programs. The Commission declined to establish a measurement of EMF exposure that would be harmful to public health until there was a firm scientific basis for adopting any particular standard. (D.93-11-013, p.11.) To date, it has been determined that there is a potential EMF source mix resulting from potential exposures from living near power lines, from the internal wiring of homes, and from common household appliances¹ (2002 DHS Report, p. 11.)