VI. EMF Issues

During the proceeding, there was a great deal of public interest and concern regarding potential health effects from EMF exposure due to power lines.27 Several intervenors along the proposed Jefferson-Martin route ask that the Commission choose a route that reduces or eliminates the risks associated with EMF exposure, particularly to high priority groups including schools, day care centers, and residences.

The FEIR provided extensive information regarding EMFs. However, it did not consider EMF exposure in its determination of the environmentally superior routes on the basis that there is no agreement among scientists that EMF creates a potential health risk and there are no defined or adopted CEQA standards for defining health risk from EMF. As noted in D.90-09-059, § 1002 provides us with responsibility independent of CEQA to include environmental influences and community values in our consideration of a request for a CPCN.

In 1991, the Commission initiated an investigation, I.91-01-012, into EMFs associated with electric power facilities. In D.93-11-013 in that proceeding, we found that, while EMF studies available at that time did not conclude that an EMF health hazard exists, it was appropriate to adopt several EMF policies and programs because of public concern and scientific uncertainty. We required that utilities undertake no-cost EMF mitigation measures and that they implement low-cost mitigation measures to the extent approved through a project's certification process. The Commission's no-cost and low-cost EMF mitigation requirements were incorporated into G.O. 131-D. We defined "low-cost" to be in the range of 4% of the total project cost but specified that this 4% benchmark is not an absolute cap. We found that, to be implemented, a mitigation measure should achieve some noticeable reduction in EMF but declined to adopt a specific goal for EMF reduction. We instructed that workshops be held and that the utilities develop EMF design guidelines for new transmission facilities. We adopted several EMF measurement, education, and research programs and chose the California Department of Health Services (DHS) to manage the education and research programs.

A. Scientific Research Regarding EMF

The FEIR and the parties in this proceeding reported the results of a number of scientific studies related to EMF. Intervenors along possible Jefferson-Martin routes cite numerous scientific studies that, in their view, provide compelling reason for concern about the potential health risks associated with EMFs from power lines. They maintain that numerous studies have demonstrated an association between EMFs and serious diseases, even if causal links have not been established. These intervenors recommend that, in light of the studies and continued uncertainty, the Commission choose a route alternative that reduces or eliminates the risks associated with EMF exposure. 280 CCC asks that the Commission adopt a standard that transmission-related EMF exposure from the combined effect of the existing 60 kV and new 230 kV lines should not exceed 1 mG at residential property boundaries. It asks that the Commission route the southern segment away from residential areas and schools where feasible and, where that is not feasible, require that the lines be undergrounded in a manner that achieves this standard.

PG&E responds that there is no scientific basis that EMF exposure causes adverse health effects. Its expert witness testified that, despite decades of scientific inquiry, there remains insufficient scientific evidence to conclude that EMF causes any adverse health effects. PG&E asserts that the state of scientific knowledge remains where it was when the Commission adopted the precautionary approach of requiring no-cost and low-cost mitigation but declined to adopt a numerical limit. PG&E maintains that there is still no scientific basis to set any health-based EMF standard and concludes that there is no reason to depart from the Commission's 1993 no-cost, low-cost EMF reduction policy. CARE agrees with PG&E that EMF is not a serious consideration that would affect the balance of issues in this case.

While there is no definitive proof at this point, we must proceed with the knowledge that there is public concern that EMF exposure may increase the risk of certain health effects. However, we find that the state of scientific knowledge has not advanced to the point to support adoption of the numerical EMF exposure standard that 280 CCC and others propose.

B. EMF along Routes under Consideration

PG&E calculated the expected 2006 magnetic fields along the portions of the Proposed Project and AUA routes that would pass through residential and commercial areas. PG&E performed the calculations for four load scenarios: low loading (load is less 5% of the year), medium loading (load is less 50% of the year), high loading (load is less 95% of the year), and normal summer peak (highest expected loading of the year). In PG&E's view, the "medium" loading levels are the most apt for evaluation purposes. We agree, because magnetic field levels at medium loading conditions are the best indication in the record of what year-round EMF exposure levels may be.

Magnetic field levels depend on the distance from the line. For overhead configurations, magnetic field levels depend on tower placement and height in addition to horizontal distance from the line. PG&E reported magnetic field levels for buildings along the routes, with building locations determined from aerial photographs. PG&E cautioned that many buildings might be further from the transmission line than it assumed, due to roof overhangs or other factors that cause inaccuracies in interpreting the aerial photos.

PG&E provided two sets of magnetic field exposure data along the southern overhead portion of the proposed project: (1) for the existing double-circuit 60 kV line operating by itself and (2) if the Proposed Project is built, i.e., for rebuilt towers carrying the new 230 kV circuit and a single 60 kV circuit. PG&E provided only normal summer peak loading data for the existing 60 kV line, but provided data for all four loading scenarios for the Proposed Project. Thus, we can compare peak magnetic field estimates, but not exposures during medium loading conditions, before and after the project is built.

PG&E reports that during summer peak loading conditions, magnetic field exposure levels would be less than 1 mG for most residences along the route, between 1 mG and 3 mG along Lexington Avenue, and as high as 5.3 mG for homes along Skyline Boulevard. For the combined 60 kV and 230 kV circuits, the magnetic field levels during summer peak conditions would range up to 6.5 mG (4.5 mG during medium loading conditions) along Lexington Avenue and as high as 22.5 mG (15.5 mG during medium loading conditions) further north until the line crosses to the west of I-280 at mile point 10.7.

C. EMF Management Plan for the Jefferson-Martin Project

PG&E implemented EMF design guidelines in 1994 following workshops as required by D.93-11-013. PG&E's EMF design guidelines describe the no-cost and low-cost measures that it undertakes as follows:


No cost measures are those steps taken in the design stage, including changes in standard practices, which will not increase the project cost but will reduce the magnetic field strength.


Low cost measures are those steps that will cost about 4% or less of the total project cost and will reduce the magnetic field strength in an area (e.g., by a school, near residences, etc.) by approximately 15% or more at the edge of the right of way. The total project cost is defined as all costs associated with the siting, design and construction of those specific new or upgraded transmission, substation, or distribution project facilities. The total project cost figure used, as a basis for low cost determination, is only that particular component of the project being evaluated for magnetic field reduction steps. As an example, when a substation and a transmission line are being designed, 4% of the total cost for the transmission line will be considered for magnetic field reduction from the line and 4% of the total substation cost will be considered for reduction from the substation.

PG&E's EMF design guidelines establish a prioritization of areas for EMF reduction, based on its perception of public concern. Beginning with the groups of highest priority, PG&E's prioritization of areas for application of EMF mitigation measures is as follows:

The guidelines state that unless all areas within a priority group can receive equivalent treatment, no single area in that priority group will receive low cost measures, with "equivalent" defined as the application of some type of low-cost measure to all areas in a priority group.

PG&E prepared a preliminary EMF management plan for the Jefferson-Martin project. It established 4% benchmarks separately for each component of the Proposed Project, but stated during the hearings that it is willing to have a single EMF mitigation budget based on the total estimated cost of the entire project. We adopt a single 4% EMF mitigation benchmark for the entire project, as PG&E suggests, rather than allowing the funds to be divided and administered for each component of the project. We require that PG&E use a triangular configuration to reduce EMF levels as a zero-cost mitigation measure unless there are obstacles or other impediments that would preclude such a configuration. We instruct PG&E to undertake strategic line placement along the entire route (where feasible and cost-effective) to further reduce EMF exposure within buildings along the right of way. We request that PG&E locate the line a maximum distance from the edge of the right of way to the extent "safe, feasible, and cost-effective" as part of its EMF mitigation measures. Additionally, as part of its low cost, no cost EMF mitigation, PG&E should lower trench depths to the greatest extent possible (at least 11 feet underground) near schools and other high priority customers.

While the FEIR did not consider EMF exposure in its determination of the environmentally superior routes in this proceeding because there are no more defined or adopted CEQA standards for categorizing EMF impacts or for designing mitigation measures to reduce those impacts.

27 Electric fields are created whenever power lines are energized, whereas magnetic fields are created when current flows through the lines. Both electric and magnetic fields attenuate rapidly with distance from the source. Electric fields are effectively shielded by materials such as trees or buildings, whereas magnetic fields are not easily shielded by objects or materials. Therefore, concerns regarding potential power line EMF health effects arise primarily due to exposure to magnetic fields.

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