About this map

Golden Pacific Powerlink: what it would bring to our valley

The South Mountain route traced from two SDG&E maps, with a blue dot at each illustrative tower position about 1,600 ft apart. The pink haze shows its magnetic field.

Why this matters

Fire danger comes first

Power lines can start wildfires. Cal Fire found that SDG&E power lines started the 2007 Witch, Guejito and Rice fires here in North County. This route would carry towers up to 200 feet tall across brush-covered hills above our homes and groves.

What the pink means

Pink haze = EMF exposure – INCREASED CANCER RISK

Inside the solid pink edge, the field is above the level linked in studies to childhood leukemia.

Walk the dots

Dot – of 145

Base map

Road and place names on the aerial

Layers

Pink haze: the line’s magnetic fieldDarkens the map so the field stands out Blue dots145 tower positions about 1,600 ft apart, numbered west to east Line through the dots Position ringsGround each dot could really be on Parcel lines and APNsLive county data; loads when zoomed in

SDG&E maps, rectifiedFade it over the base map to check the fit

60%

Parcels near the line

Key

Illustrative tower position on the line traced from the SDG&E maps, about 1,600 ft from the next Position ring: 410 ft radius from the west end to just past Lake Henshaw, 660 ft farther east Assessor parcel boundary Parcel on the “near the line” list

The science, in detail

The World Health Organization's cancer agency (IARC) classifies power-frequency magnetic fields as possibly carcinogenic to humans (Group 2B). That rests on studies finding childhood leukemia about twice as common where children's average exposure is above 3–4 mG. Along this line, that level reaches roughly 200 ft from the centerline.

A cause-and-effect link has not been established, and the international exposure limit for the public is 2,000 mG. The haze uses typical published values for 500 kV lines (87 mG under the line, 29 at 50 ft, 12.6 at 100 ft, 3.2 at 200 ft, 1.4 at 300 ft). Actual fields depend on SDG&E's final design and on how much current the line carries, and are higher at peak load.

The comparisons with a home use about 1 mG, a common level inside homes. The zones are drawn at about 100 ft (12.6 mG), about 195 ft (3.5 mG, the middle of the 3–4 mG range in the leukemia studies) and about 355 ft (1 mG).

How accurate this is

Parcel lines are exact; the dots are not. The line comes from SDG&E's corridor-level maps, and SDG&E has not published an engineered alignment or tower sites. The dots here are spaced evenly at about 1,600 ft, the middle of the 1,400 to 1,800 ft span range reported for this project; real spans vary with terrain.

From the west end to just past Lake Henshaw, the line is traced from a screenshot of SDG&E's map, placed by fitting 66 reservation boundary edges (Pala, Pauma, Rincon, La Jolla) to Census boundary coordinates. Boundaries left out of the fit as a test land within about 250 to 450 ft. Where this map overlaps the first one, the two independently placed traces are typically about 90 ft apart (270 ft at most points).

East of Lake Henshaw the line comes from a photo of SDG&E's map, rectified the same way with 43 boundary edges. There, positions are good to about 600 ft, possibly more near the east end. The map ends about 0.6 mi short of the Fallbrook boundary because the SDG&E map stops there.

Turn on the SDG&E maps layer and fade it to judge the fit yourself: their white roads should sit on the real roads.

Sources: magnetic-field values from Dominion Energy’s EMF brochure (typical 500 kV levels); IARC Monograph 80 and WHO Fact Sheet 322 on cancer classification; SDG&E corridor maps (screenshot and photo), U.S. Census Bureau 1:500k AIANNH boundaries, SANDAG/SanGIS parcels, Esri and USGS base maps.

move the pointer over the map

Is my property near the line?