This part must be used when conducting existing system compliance inspections. This part defines what constitutes seepage pit, drywell, or leaching pit systems. Seepage pit, drywell, or leaching pit systems are not considered compliant systems as determined in part 7080.1500, subpart 4, item B, but these existing systems may be allowed continued use under Minnesota Statutes, section 115.55, subdivision 5a, paragraph (f), by local units of government that have adopted alternative local standards for these systems under part 7082.0050, subpart 5.
A seepage pit, drywell, or leaching pit is a system that:
has a sewage tank that does not obviously leak below the designed liquid capacity preceding the pit;
has a pit that is not located in a geologic formation that is used as a source of drinking water;
has at least three feet of vertical separation from the bottom of the pit to the periodically saturated soil or bedrock;
has an absorption area that has been determined by dividing the design flow in parts 7080.1850 to 7080.1885 by the soil loading rate under Table IX or IXa in part 7080.2150, subpart 3, item E, based on the weighted average of each vertical stratum penetrated by the seepage pit, drywell, or leaching pit;
has a pit that has not been placed in a soil stratum with any of the United States Department of Agriculture textures classified as a sand or loamy sand, or a percolation rate of less than five minutes per inch;
has a pit with a minimum inside diameter of five feet; and
meets all setback requirements.
32 SR 1347; 35 SR 1353
October 10, 2013