Sewer gas escapes through a vent pipe attached to the sewer line. Sewer gas is vented through a separate vent pipe attached to the sewer line. Wastewater may be conveyed in a sanitary sewer that conveys only sewage. Larger municipalities often include factories discharging industrial wastewater into the municipal sewer system. Storm drains are separate and distinct from sanitary sewer systems. Sanitation drainage was through a closed system leading to a sewer apart from the hill. Others tried to catch water from the city's sewer drains. It was capable of cleaning large industrial and municipal sewer pipes. Pumps may discharge to the sanitary sewer in older installations. Rats have the ability to swim up sewer pipes into toilets. The maintenance requirements vary with the type of sanitary sewer. All new construction in areas without waste sewer systems use these new precast cesspools. It provides electricity, water and sewer services. The water in the bowl acts as a barrier to sewer gas entering the building. The landslides seem to have been provoked by works of infrastructure, sewer and water systems.