working rusty pump aerating and filtering contaminated water in wastewater treatment facility pond

aerating aeration america area bay california cleaning close closeup contaminated control corrosion dissolved drop facility filtering filtration francisco gases green industrial industry lake metal nobody outdoor outdoors plant pollutant pollutants polluted pollution pond pump quality recycled release remove replenishment reservoir river rusty san service sewage silicon states sunny sunnyvale system treatment united usa valley waste wastewater water working