In the Owens study area, trace elements with human-health benchmarks were present at high concentrations in 15% of the primary aquifers, on an areal basis, and at moderate concentrations in 13%. Of the 17 trace elements with human-health benchmarks analyzed in this study, 4 were detected at high concentrations: arsenic, boron, fluoride, and molybdenum.
Radioactivity is the release of energy or energetic particles during structural changes in the nucleus of an atom. Most of the radioactivity in groundwater comes from decay of naturally occurring isotopes of uranium and thorium that are present in minerals in the aquifer. In the Owens study area, radioactive constituents were found at concentrations above benchmarks in 10% of the primary aquifers, and at moderate concentrations in 15%. Six radioactive constituents were analyzed; of these, gross alpha radioactivity and uranium were detected above human-health benchmarks. Radon was detected at values within one-half of the proposed upper benchmark.
Los Angeles Department of Water and Power
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As the morning haze peeled off the northern corner of the San Fernando Valley, Fred Barker walked along remnants of an engineering marvel that transformed a dusty railhead into a metropolis — rusting pipes, wooden walkways and a concrete spout that wound serpent-like down a hillside.
One hundred years ago — Nov. 5, 1913 — 40,000 people gathered on this spot in Sylmar to watch the water arrive for the first time from the Owens Valley.
Barker, an engineer with the Los Angeles Department of Water and Power, trudged a few yards up the hill.
“This is the exact spot,”he said.
At 1:15 p.m. that day, William Mulholland, the city’s chief water engineer, gave a signal, and crews turned two steel wheels, opening gates that sent the first sparkling water into the waiting San Fernando Reservoir
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