Pushing a wheelbarrow filled with 350,000 petition signatures, concerned Californians gathered outside the capitol Tuesday to urge Gov. Brown and the California Water Resources Control Board to stop the potentially dangerous practice of using wastewater from oil drilling to irrigate California’s crops.

The wastewater, sold by Chevron and California Resources Corporation, is now being used to irrigate more than 90,000 acres in the Cawelo Irrigation District and the North Kern Water Management District and is slated to expand in the near future to other districts.