… In Hinkley, water at nine of the 44 wells tested this year as part of PG&E’s state-mandated cleanup efforts were found to have chromium-6 levels more than five times higher than the state’s legal maximum and 2,500 times higher than what the state deems safe for public consumption. The regional water board, an arm of the state, has given the company until 2032 to bring the water’s chemical content down to legal levels — 36 years after Brockovich’s lawsuit and 80 years after the toxic substance was first dumped into the ground by PG&E, the state’s largest utility. … Experts, lawyers and local residents here said the long timeline for the cleanup stems partly from the logistical difficulty of removing a toxic substance that has swirled for years in the groundwater but also because the effort has been largely the undertaking of a small regional government water board in charge of regulating a corporate behemoth.