(1) The wastewater treatment systems described in (3) through (7) may be allowed only if the reviewing authority determines that:

(a) site constraints prevent the applicant from constructing any system described in Department Circular DEQ-4;

(b) all off-site treatment alternatives have been considered and are infeasible;

(c) the requirements of ARM 17.36.913 are met; and

(d) all other requirements in this subchapter applicable to the proposed system are met.

(2) Applications for permits for wastewater treatment systems described in (3) through (7) must include a demonstration that no other alternatives to wastewater disposal are feasible.

(3) Absorption beds may be used for replacement systems only and may not be constructed in unstabilized fill. Absorption beds must also meet the design and construction requirements in Department Circular DEQ-4.

(4) Seepage pits may be used for replacement systems only, and only when no other means of treatment and disposal is available.

(a) Seepage pits must have a minimum vertical separation of 25 feet between the bottom of the pit and ground water.

(b) Permit applications for seepage pits must include plans for the proposed pit. Seepage pits must meet the design and construction requirements in Department Circular DEQ-4.

(5) Holding tank systems may be approved only if the facility to be served is for seasonal use.

(a) For purposes of this rule "seasonal use" means use for not more than a total of four months (120 days) during any calendar year. Permit applications for holding tanks must show that the property use conforms to the "seasonal use" limitation or that a variance has been granted.

(b) Holding tanks must meet the design and construction requirements in Department Circular DEQ-4.

(c) Permit applications for holding tanks must include plans for the proposed holding tank system. The plans must include the following information:

(i) the method for monitoring tank levels;

(ii) the method for waterproofing the tank;

(iii) a maintenance plan, which must include annual water tightness testing and periodic pumping by a licensed septic tank pumper; and

(iv) the method for tank stabilization if seasonal high ground water is expected to be within 12 inches of tank's base.

(6) Sealed pit privy systems may be approved only if the facility to be served does not have a piped water supply, and the facility is a seasonal-use recreational site.

(a) Permit applications for sealed pit privies must include plans for the proposed sealed pit. Sealed pit privy systems must meet the design and construction requirements in Department Circular DEQ-4.

(7) Unsealed pit privies may be approved only for seasonal use in remote locations that are not accessible to septic tank pumpers.

(8) New construction or alteration of cesspools is prohibited.