Current through Register Vol. 48, No. 39, March 25, 2024
Subpart
1.
Sewage.
This chapter provides design standards for ISTS that
exclusively receive sewage. If ISTS receive both sewage and nonsewage, the
requirements of this chapter and requirements governing the nonsewage portion
of the waste apply.
Subp.
2.
System influent.
A. Footing or roof drainage and chemically
treated hot tub and pool water must not be discharged into any part of a
system. Products containing hazardous chemicals and hazardous waste must not be
discharged to a system other than in normal amounts of household products and
cleaners designed for household use. Substances not intended for use in
household cleaning, including but not limited to solvents, pesticides,
flammables, photo finishing chemicals, paint, and dry-cleaning chemicals must
not be discharged to the system. Other unused products or substances, or unused
medicines, must not be discharged to the system solely as a method of disposal.
Floor drains from garages serving dwellings must not be connected to the
system.
B. An ISTS must be designed
to provide additional treatment if:
(1) raw
sewage exceeds 300 mg/l BOD, 200 mg/l TSS, or 50 mg/l oil and grease;
or
(2) sewage tank effluent applied
to the soil from the sewage tank or other secondary treatment device is greater
than the concentrations in part
7080.2150, subpart 3, item K.
Additional treatment must be designed by a Minnesota licensed
professional engineer or according to the recommendations in the Prescriptive
Designs and Design Guidance for Advanced Designers, which is incorporated by
reference in item C, or must use a product registered under chapter
7083.
C.
Prescriptive Designs and Design Guidance for Advanced Designers, Minnesota
Pollution Control Agency (September 2009 and as subsequently amended), is
incorporated by reference, is subject to frequent change, and is available at
www.pca.state.mn.us/programs/ists/technical.html.
