Minnesota Administrative Rules
Agency 167 - Pollution Control Agency
Chapter 7081 - MIDSIZED SUBSURFACE SEWAGE TREATMENT SYSTEMS
Part 7081.0240 - SEWAGE TANKS

Subpart 1. General.

All holding or treatment tanks or vessels, including lined vessels and grease interceptors serving MSTS, must conform to the applicable requirements of part 7080.1900 except as modified in this part or as designed by a professional engineer and approved by the local unit of government.

Subp. 2. [Repealed, 35 SR 1353]

Subp. 3. Lint filters, effluent screens, and pressure filters.

An effluent screen or pressure filter must be used on all systems. If multiple septic tanks are used, the effluent screen must be placed in the last tank in the series and provided with an alarm. Lint filters are recommended if the sewage contains laundry waste.

Subp. 4. Tank geometry.

The maximum liquid depth of septic tanks to determine liquid capacity must be no greater than 84 inches. The length-to-width ratio and the length-to-depth ratio must facilitate settling of solids.

Subp. 5. Tank testing.

All tanks used for MSTS must be tested for watertightness according to part 7080.2010, subpart 3. The test shall be conducted to include the watertightness of all connections and risers.

Subp. 6. Liners.

Liners used as watertight barriers for treatment devices must be designed and constructed according to liner requirements developed by the commissioner of the Pollution Control Agency. If conflicts exist between this chapter and those requirements, this chapter applies. Compacted soil liners must not be used as watertight barriers for treatment devices. Liners must be tested and must hold water without loss for 24 hours after being filled to the top of the liner.

Subp. 7. [Repealed, 35 SR 1353]