Regional water regulators have approved Berkeley’s plans to measure radiation levels in Cesar Chavez Park using a drone. The San Francisco Regional Water Quality Control Board rejected Berkeley’s initial proposal for radiation testing in May, citing concerns that its methodology was too lenient. Regulators wrote that the proposed tests, which called for an inspector to walk around with a detector, could miss a “significant portion” of the park.  The water board, working in consultation with the California Department of Public Health, signed off on Berkeley’s revised work plan on Aug. 13. The city has until Nov. 11 to complete the testing and submit a completion report that includes a three-dimensional map of the site.  The radiation testing follows revelations in January that the now-defunct Stauffer Chemical Company may have dumped radioactive industrial waste in the landfill between 1960 and 1971.