An investigation conducted by a regulatory agency that oversees regional waterways refutes various claims about water pollution at two Upvalley waste management sites. The “investigation report,” released Monday by the California Regional Water Quality Control Board’s San Francisco Bay Region, responds to complaints lodged between October 2022 and November of this year about operations at Clover Flat Landfill south of Calistoga and the Upper Valley Disposal and Recycling Facility on Whitehall Lane south of St. Helena. Based on inspections, water testing, interviews and document reviews, the water board concluded “that further investigation or pursuit of additional enforcement against Clover Flat Landfill or the Upper Valley Facility regarding the complaints is unwarranted.”