Illustration of a septic system with a rectangular tank and incoming and outgoing pipes
Illustration of a house with an underground septic system draining to groundwater
Illustration of a cylindrical tank with pipes leaving it
Illustration of a primary sewage treatment plant
3-D Illustration of a sewage treatment plant with pools
Illustration of a house
Illustration of an upright water pipe
Illustration of a dam
Illustration of a 3-D white lighthouse with entrance