R317-5-2. Definitions

  2.1. Definitions found in Rules R317-1 and R317-4 apply to large underground wastewater disposal systems except where specifically replaced by the following definitions:

  "Alternative system" means a LUWD system that is not a conventional system.

  "Building sewer" means the pipe that carries wastewater from the building to a public sewer, a LUWD system, or other point of dispersal. It sometimes is synonymous with "house sewer".

  "Conventional system" means a LUWD system typically consisting of a building sewer, septic tank, and an absorption system utilizing absorption trenches, absorption beds, or deep wall trenches.

  "Curtain drain" means any ground water interceptor or drainage system that is backfilled with gravel or other suitable material and is intended to interrupt or divert the course of shallow ground water or surface water away from the LUWD system.

  "Malfunctioning or failing system" means a LUWD system that is not functioning in compliance with the requirements of this rule and may include:

  1. absorption systems that seep or flow to the surface of the ground or into waters of the state;

  2. systems that overflow from any of their components;

  3. systems that cause backflow into any portion of a building drainage system;

  4. systems discharging effluent that does not comply with applicable effluent discharge standards of its operating permit;

  5. leaking septic tanks; or

  6. noncompliance with standards stipulated in or by the construction permit, operating permit, or both.

  "Maximum ground water table" means the highest elevation that the top of the "ground water table" or "ground water table, perched" is expected to reach for any reason over the full operating life of a LUWD system at that site.

  "Mound system" means an alternative LUWD system where the bottom of the absorption system is placed above the elevation of the original site, and the absorption system is contained in a mounded fill body above that grade.

  "Packed bed media system" means an alternative LUWD system that uses natural or synthetic media to treat wastewater. Biological treatment is facilitated via microbial growth on the surface of the media. The system may include a pump tank, a recirculation tank, or both.

  "Public health hazard" means, for the purpose of this rule, a condition whereby there are sufficient types and amounts of biological, chemical, or physical agents relating to water or sewage that are likely to cause human illness, disorders or disability. These may include pathogenic viruses and bacteria, parasites, toxic chemicals and radioactive isotopes. A malfunctioning LUWD system constitutes a public health hazard.

  "Sand lined trench system" means an alternative LUWD system consisting of a series of narrow excavated trenches utilizing sand media and pressure distribution.

  "Unapproved LUWD system" means any LUWD system that is deemed by the division to be any of the following:

  1. installation without the required division oversight, permits, or inspections;

  2. repairs to an existing system without the required division oversight, permits, or inspections; or

  3. alteration to an existing system without the required division oversight, permits, or inspections.

  "Waiver" means an acceptable deviation from the requirements established within this rule or referenced rules. The waiver must be acceptable to division staff based on the engineer providing adequate design justification to demonstrate that the deviation proposed will not override the safeguarding of public health, the protection of water quality, or the protection of the receiving environment. Waiver requests should be based on acceptable engineering practice and standards.