Section 602 Sizing Soil Absorption Systems

Effluent from septic tanks and other approved treatment tanks shall be disposed of by soil absorption or an approved manner. Sizing shall be in accordance with this chapter for systems with a daily effluent application of 5,000 gallons (18 925 L) or less. Two systems of equal size shall be required for systems receiving effluents exceeding 5,000 gallons (18 925 L) per day. Each system shall have a minimum capacity of 75 percent of the area required for a single system. An approved means of alternating waste application shall be provided. A dual system shall be considered as one system.

A pressure distribution system shall be permitted in place of a conventional or dosing conventional soil absorption system where a site is suitable for a conventional private sewage disposal system. A pressure distribution system shall be approved as an alternative private sewage disposal system where the site is unsuitable for conventional treatment (for sizing and design criteria, see Chapter 7).

Flow from the septic or treatment tank to the soil absorption system shall be by gravity or dosing for facilities with a daily effluent application of 1,500 gallons (5678 L) or less. The tank effluent shall be discharged by pumping or an automatic siphon for systems over 1,500 gallons (5678 L).