Overview

Soil-absorptions systems are the most common type of private sewage disposal systems. Sizing this type of system requires the use of language and tables that exist in local code requirements. When a system has a daily effluent application of 5,000 gallons or less, the sizing is fairly simple. It is possible to use two systems of equal size when the daily effluent application exceeds 5,000 gallons. When this is done, each system must have a minimum capacity of 75 percent of the area required for a single system. Dual systems can be considered as one system, but an approved means of alternating waste application must be provided when such a system is used to accommodate a usage of more than 5,000 gallons a day.

Pressure-distribution systems are permitted in place of a conventional or dosing soil absorption system as long as a site is suitable for the conventional system. When a site is unsuitable for conventional treatment, a pressure distribution system can be used as an alternative system. The result is that a pressure distribution system can be used in either case, but must be used when a conventional system is not feasible.

Flow from a septic or treatment tank to a soil absorption system must be by gravity or dosing for systems receiving 1,500 gallons or less of effluent a day. A tank that discharges effluent at a rate of more than 1,500 gallons a day must be equipped to pump the effluent or to create an automatic...