Overall the report is deficient and incomplete, with many important data gaps. It is not clear why this level was set. At some other sites, the levels decided upon have been six times more stringent, as low as 160 ppb. One of the problems with PCBs is that they may contain dioxins and furans, or similar molecules. Dioxins and furans are generally cleaned up to 1 ppb, and may be toxic at 1 part per quadrillion.
Monitoring is needed.
There is a potential that these soils will run-off into Arroyo Las Positas and the industrial waste water system during heavy rains. We recommend that all run-off be monitored for PCBs for at least one year, and detection limits be set in the low parts per billion. We also recommend that run-off controls be placed around the redeposited soil. Livermore Lab is a Superfund site. Groundwater below the NIF construction site is significantly contaminated.