Current through Register Vol. 49, No. 13, September 23, 2024
Subpart 1.
General.
All ISTS must be operated under the regulatory requirements of
part
7082.0600. ISTS and all components
must be maintained in compliance with this chapter and manufacturer
requirements. Subpart
2, items A and B, are
intended to apply to ISTS and systems that do not qualify as an ISTS, but
receives sewage such as cesspools, drywells, leaching pits, or other
pits.
Subp. 2.
Frequency of assessment.
The owner of an ISTS or the owner's agent shall regularly, but
in no case less frequently than every three years:
A. assess whether sewage tanks leak below the
designed operating depth and whether sewage tank tops, riser joints, and riser
connections leak through visual evidence of major defects; and
B. measure or remove the accumulations of
scum, grease, and other floating materials at the top of each septic tank and
compartment, along with the sludge, which consists of the solids denser than
water.
Subp. 3.
Removal of material.
A. All
solids and liquids must be removed by pumping from all tanks or compartments in
which the top of the sludge layer is less than 12 inches from the bottom of the
outlet baffle or transfer hole or whenever the bottom of the scum layer is less
than three inches above the bottom of the outlet baffle or transfer hole. Total
sludge and scum volume must not be greater than 25 percent of the tank's liquid
capacity.
B. Removal of accumulated
sludge, scum, and liquids from septic tanks and pump tanks must be through the
maintenance hole. The removal of solids from any location other than the
maintenance hole is not a compliant method of solids removal from a sewage
tank, and this method does not fulfill the solids removal requirement of this
part or a management plan. Liquid and solids removal from clean-out pipes is
allowed for holding tanks.
C. After
removal of solids and liquids from a system installed after the adoption of a
local ordinance adopted after February 4, 2008, the maintenance hole cover must
be secured as described in part
7080.1970, item D. Covers secured
by screws must be refastened in all screw openings.
D. After removal of solids and liquids from a
system installed before the adoption of a local ordinance adopted after
February 4, 2008, maintenance hole covers must be sound, durable, and of
adequate strength as specified in part
7080.1970, item D, subitem (3),
and:
(1) be buried with a minimum of 12
inches of soil cover or, if the cover is currently at or above the ground
surface or within 12 inches from final grade, be secured by a method that was
deemed secure by the local ordinance that was in effect before February 4,
2008; or
(2) meet the requirements
of part
7080.1970, item D, if the cover is
to be raised to be at or above the ground surface or within 12 inches from
final grade.
E. Pump
tanks must be maintained according to this part. Sludge must be removed if
within one inch of the pump intake.
Subp. 4.
Toilet waste treatment devices
and privies.
A. For primitive dwellings
using toilet waste treatment devices in low dwelling density areas, septage
disposal from these devices by the owner must be in accordance with local
ordinances. If no ordinance exists, the septage must not be discharged to
surface waters, drainageways, steeply sloping areas, or wet areas in a manner
or volume that is harmful to the environment or public health or that creates a
nuisance. The material must be buried or covered with soil. For site conditions
not met in this subpart, the solids disposal from toilet waste treatment
devices shall be according to subpart
6 by a licensed maintenance
business.
B. When the privy is
filled to one-half of its capacity, the solids must be removed. Abandoned pits
must have the sewage solids and contaminated soil removed and must be filled
with clean earth and slightly mounded to allow for settling. Removed solids
shall be disposed of according to subpart
6.
Subp. 5.
Additives.
ISTS additives, which are products added to the sewage or to
the system with the intent to lower the accumulated solids in sewage, must not
be used as a means to reduce the frequency of proper maintenance and removal of
sewage solids from the sewage tanks as specified in this part. The use of
additives does not fulfill the solids removal requirement of this part or a
management plan. ISTS additives that contain hazardous materials must not be
used in an ISTS.
Subp. 6.
Septage disposal.
Septage or any waste mixed with septage must be disposed of in
accordance with state, federal, and local requirements for septage and other
wastes. If septage is disposed of into a sewage or septage treatment facility,
a written agreement must be provided between the accepting facility and the
maintenance business.
Subp.
7.
Use of soil treatment site.
Activities on the current soil dispersal and treatment system
or the reserve soil dispersal and treatment area as specified in part
7082.0100, subpart
3, item F, that impair the
current or future treatment abilities or hydraulic performance of the soil
treatment and dispersal system are prohibited. This includes, but is not
limited to, covering all or part of the soil treatment system with an
impermeable surface as determined by the local unit of government.
Subp. 8.
System
remediation.
Any maintenance activity used to increase the acceptance of
effluent to a soil treatment and dispersal system must:
A. not be used on a system failing to protect
groundwater as defined in part
7080.1500, subpart
4, item B, unless the
activities meet the requirements of parts
7080.2350 and
7080.2400;
B. not cause preferential flow from the soil
treatment and dispersal system bottom to the periodically saturated soil or
bedrock; and
C. be conducted by an
appropriately certified qualified employee or an appropriately licensed
business as specified in part
7083.0790.
Any substance added with the intent to increase the
infiltration rate of the soil treatment and dispersal system must not contain
hazardous substances.
Statutory Authority: MS s
115.03;
115.55
