14 CAR § 21-1002. Aerobic treatment units (ATUs)

(a)(1) Only ATUs authorized by the Department of Health shall be utilized in onsite wastewater systems. (2) ATUs shall meet and be listed under current American National Standards Institute/National Sanitation Foundation (ANSI/NSF) Standard 40 requirements. (b)(1) ATUs shall be installed according to the manufacturer’s specifications as authorized by the department. (2) ATUs shall be installed as provided in 14 CAR § 21-904. (3) Some ATUs require installer certification provided by the manufacturer in order to install and/or maintain the unit. (c) Aerobic treatment units (ATUs) may be substituted for a septic tank under the following conditions: (1) The tank construction of an ATU shall comply with the requirements found within 14 CAR § 21-901 et seq.; (2) No aeration, filter media, or other treatment device within said tank shall: (A) Restrict the flow of effluent into or out of the tank; or (B) Reduce the capacity in gallons as stated in Appendix C; (3) No aeration, filter media, or other treatment device shall be connected directly or indirectly to the outlet baffle of the tank; and (4) The substitution of an ATU in place of septic tank shall be at the sole discretion of the department.