(A) Treatment required. Sewage discharged from a dwelling or other establishment that is not served by a system issued a permit containing effluent and discharge limits or specific monitoring requirements by the Department or Agency must be treated according to applicable requirements.
(B) Compliance criteria for new construction. An SSTS regulated under a current permit is considered compliant if it meets the applicable requirements of § 52.16(U).
(C) Compliance criteria for existing systems. To be in compliance, an existing SSTS must meet the provisions of this subpart.
(1) The SSTS must be protective of public health and safety. A system that is not protective is considered an imminent threat to public health or safety. At a minimum, a system that is an imminent threat to public health or safety is a cesspool, seepage pit, drywell or leaching pit, a system with discharge of sewage or sewage effluent to the ground surface, drainage systems, ditches, or storm water drains or directly to surface water; systems that cause a reoccurring sewage backup into a dwelling or other establishment; systems with electrical hazards; or sewage tanks with unsecured, damaged, or weak maintenance hole covers. A determination of protectiveness ft other conditions must be made by a qualified employee of the Department or licensed inspection business.
(2) The SSTS must be protective of groundwater. A system that is not protective is considered a system failing to protect groundwater. At a minimum, a system that is failing to protect groundwater is a system that is a seepage pit, cesspool, drywell, leaching pit, or other pit; a system with less than the required vertical separation distance described in divisions (C)(4) and (5) of this section; and a system not abandoned in accordance with § 52.23. A determination of the threat to groundwater quality for other conditions must be made by a qualified employee of the department or local unit of government or licensed inspection business.
(3) The SSTS must be operated, meet performance standards, and be managed according to its operating permit.
(4) SSTS built after March 31,1996, or in an SWF area as defined in § 52.02, shall have a three foot vertical separation. No more than a 15% reduction in the vertical separation distance is allowed to account for settling of sand or soil, normal variation of measurements, and interpretations of the limiting layer conditions.
(5) SSTS built before April 1, 1996, in areas that are not SWF areas as defined in § 52.02, must have at least two feet of vertical separation.
(6) The vertical separation measurement for divisions (C)(4) and (5) of this section shall be measured outside of the area of system influence in an area of similar soil and on the same contour elevation.
(7) An existing system which is found to be an imminent threat to public health and safety by either a qualified employees of the Department, local unit of government, or a licensed inspection business is hereby declared to be a public health nuisance and shall be repaired, upgraded, replaced or its use discontinued within 30 days of notice and order to comply by the Department. Any further discharge of effluent must be stopped immediately (by such methods as reducing or stopping all water use or pumping the tank as necessary) until such time as the system is corrected.
(8) Any existing system which is found to be failing to protect groundwater shall be replaced or otherwise brought into compliance within 90 days of notice and order to comply by the Department.
(9) An existing system that is not otherwise considered an imminent threat to public health and safety and which was constructed under a permit issued by the Department, or other local unit of government that verified that the required vertical separation existed at the time of installation, need not be upgraded, repaired, replaced, or its use discontinued notwithstanding the fact that at the time of a compliance inspection, there appears to be less than the required vertical separation between the system bottom and any limiting layer.
(D) Compliance criteria for systems with a flow of greater than 2,500 gallons per day. In addition to the requirements under division (C) of this section, systems designed under § 52.16(D) must demonstrate that the additional nutrient reduction component required under those items is in place and functioning.
(E) Compliance criteria for systems receiving replacement components. Components of an existing system that result in the system being in noncompliance must be repaired or replaced according to this chapter. The repaired or replacement components must meet technical standards and criteria of this chapter. The remaining components of the existing system must result in the system being in compliance with division (C) of this section. If a compliant existing sewage tank is to be used with the design of the new soil dispersal system, the tank must also be baffled and be watertight.
(F) New construction, replacement, or existing MSTS designed under this chapter are considered conforming if they meet the requirements of this chapter. Existing MSTS constructed before the effective date of this chapter are considered conforming if they meet the requirements of this section, except for divisions(I)(4) and (5) of this section.
(G) To be in compliance, all MSTS must:
(1) Have treatment processes and devices that do not allow sewage or sewage effluent contact with humans, insects, or vermin;
(2) Disperse sewage effluent into our soil or sand below final grade, with the effluent remaining below final grade;
(3) Not discharge to drainage tile, the ground surface, or surface water or back up sewage into dwellings or other establishments;
(4) Treat and disperse sewage effluent in a safe manner, including protection from physical injury and harm; and
(5) Not have received hazardous material.
(H) MSTS must be considered an imminent threat to public health and safety for noncompliance with division (G) of this section and any other condition that poses an imminent threat as determined by a qualified employee of the Department or licensed MSTS inspection business.
(I) To be in compliance, all MSTS must:
(1) Maintain a zone of unsaturated soil between the bottom of the soil treatment and dispersal system and the periodically saturated soil or bedrock during loading of effluent, as described in Section § 52.16(E)(9).
(2) Not be seepage pits, cesspools, drywells, leaching pits, sewage tanks, and treatment vessels that observably leak below the designated operating depth;
(3) Not allow viable fecal organisms to contaminate underground waters or zones of seasonal saturation;
(4) Employ nitrogen reduction processes that reduce nitrogen contribution to groundwater as determined:
(a) If the discharge from an MSTS will impact water quality of an aquifer, as defined Minn. Rules Chapter 4725.0100, subpart 21, the effluent from an MSTS, combination with the effective recharge to the groundwater, must not exceed concentration of total nitrogen of 10 mg/L or greater at the property boundary or nearest receptor, which is closest; or
(b) If the discharge from an MSTS will not impact water quality of an aquifer, as defined Minn. Rules Chapter 4725.0100, subpart 21, best management practices developed by the Commissioner to mitigate water quality impacts to groundwater must be employed; and
(5) Not exceed a groundwater discharge of phosphorus to a surface water that exceeds the phosphorus standard to the receiving water.
(J) To be in compliance, all MSTS must meet the following requirements:
(1) All methods and devices used to treat and disperse sewage must be designed to conform to all applicable federal, state and local regulations.
(2) Systems no longer in use must be abandoned according to § 52.23.
(K) To be in compliance, MSTS must meet performance standards and be operated and managed according to its operating permit and management plan, as described in § 52.22(A). To be in compliance, an MSTS designed before the effective date of this chapter must be operated according to applicable requirements in § 52.22.
(L) Components of existing MSTS that cause non-compliance must be repaired or replaced. The repaired or replaced components must meet technical standards and criteria of this chapter. The remaining components must comply with divisions (A) to (J) of this section, including division (I)(4) of this section, if constructed after the effective date of this chapter.
(M) MSTS in compliance with this chapter shall be issued a certificate of compliance. MSTS found not in compliance with this chapter shall be issued a notice of noncompliance.
(N) MSTS issued a notice of noncompliance based on the criteria in divisions (G) and (H) of this section shall be repaired or replaced within 30 days or as directed by M.S. Chapter 145A. whichever is more restrictive.
(O) MSTS issued a notice of noncompliance based on criteria in divisions (I) and (J) of this section shall be repaired replaced according to this chapter.
(P) Systems issued a notice of non-compliance based on criteria in division (K) of this section must immediately be maintained, monitored, or managed according to the operating permit.
(Ord. 2010-162, passed 5-17-2010)