Businesses in sanitation and similar activities manage sewage and wastewater systems, helping to collect, convey and treat waste water from homes, commercial premises and other sites. Services may include operating or maintaining sewers, pumping stations and treatment facilities, as well as inspecting pipework and clearing blockages that affect the flow of wastewater. Some providers empty and clean septic tanks, cesspools and other private waste-water systems, and service portable or chemical toilets. Related work can include removing accumulated sludge, cleaning tanks and arranging the safe transport and disposal of waste. Customers may be households, landlords, businesses, construction sites or public bodies, depending on the type of service offered. These activities concern wastewater and sanitary waste rather than general refuse collection or routine domestic cleaning.