About Septic SystemsCummings Plumbing Heating and Cooling services and installs septic tanks and systems. A properly designed, installed and maintained septic tank and effluent treatment system is an approved method of wastewater treatment for private residences in areas where public wastewater treatment systems are not available. The system includes the building sewer line (which starts 30 inches from the house and extends to the septic tank), the septic tank, the effluent treatment component, and all piping in between.