South Carolina Code of Regulations › Chapter 61 - DEPARTMENT OF HEALTH AND ENVIRONMENTAL CONTROL › Subchapter 61-56 - ONSITE WASTEWATER SYSTEMS › Section 61-56.400 - Appendices of Standards for Permitted Systems › Appendix 61-56.400.B - System Standard 150 - Large (greater than 1500 gpd) and Community Systems

Current through Register Vol. 48, No. 6, June 28, 2024
(1) Site/Permitting Requirements
(a) Designs for large and community onsite wastewater systems
				  shall be prepared by a Registered Professional Engineer licensed in South
				  Carolina. Further, the Department may require whatever engineering and soils
				  based submittals are deemed necessary to determine the feasibility and
				  acceptability of any site for such a system.
(b) No part of the system, with the exception of solid pipe,
				  may be located within one hundred (100) linear feet of a receptor.
(c) The depth to the zone of saturation (ZOS) shall be at
				  least thirty-six (36) inches below the naturally occurring soil surface and at
				  least six (6) inches below the deepest point of effluent application.
(d) The depth to any restrictive horizon must be greater than
				  twelve (12) inches below the bottom of the proposed wastewater infiltration
				  trenches.
(e) The long-term acceptance rate for system sizing shall be
				  based upon the most hydraulically limiting, naturally occurring soil texture
				  from the ground surface to twelve (12) inches below the bottom of the proposed
				  wastewater infiltration trenches.
(f) There shall be at least fifty (50) percent reserved
				  subsurface wastewater infiltration area repair or replacement area available
				  consisting of soils suitable for a large onsite wastewater system, except where
				  public (community) systems are utilized, in which case there must be at least
				  one hundred (100) percent repair or replacement area.
(g) Large (greater than 1500 gpd) and community onsite
				  wastewater systems incorporating advanced treatment methods, including but not
				  limited to aerobic pre-treatment, lagoons, surface or subsurface drip
				  irrigation, low pressure pipe distribution, and other maintenance intensive
				  methods, shall be required to obtain a Land Application Permit under
				  R.61-9.505.
(h) Efforts to circumvent the requirements of this standard
				  by configuring remote, individually deeded, adjacently located subsurface
				  wastewater infiltration areas in lieu of a community onsite wastewater system
				  shall not be permitted. On a very limited basis, a few of these individual
				  systems may be considered for mass installation where the wastewater
				  infiltration trenches will be adjacent to each other in a defined area,
				  provided that the combined peak wastewater loading is less than fifteen hundred
				  (1500) gpd. In such cases:
(i) Each subsurface wastewater infiltration area plot shall
				  be sized such that there is sufficient area for one hundred (100) percent
				  subsurface wastewater infiltration area replacement.
(ii) Each plot shall be deeded with all appropriate easements
				  as a lot in conjunction with the specific unit that it serves, and required
				  protective offsets, as described in Section 200.6, shall apply to each
				  individual remote subsurface wastewater infiltration area.
(iii) A plan shall be prepared by a Registered Professional
				  Engineer licensed in South Carolina that illustrates the overall plan;
				  specifies the route and identification of effluent sewers and force mains;
				  specifies the entity responsible for perpetual maintenance of the sewer lines
				  and mass subsurface wastewater infiltration area; specifies the configuration
				  and identification of the individual subsurface wastewater infiltration area
				  parcels; and specifies the manner in which ingress and egress will be provided
				  to the individual subsurface wastewater infiltration area parcels.
(iv) When the combined peak wastewater loading of the
				  adjacently located subsurface wastewater infiltration areas from the entire
				  project will exceed fifteen hundred (1500) gpd, the project shall be considered
				  as a public (community) collection and treatment system, and all requirements
				  described in Section 103.1(5) and this standard shall apply.
(2) Installation Requirements
(a) Large (greater than 1500 gpd) and community onsite
				  wastewater systems shall not be constructed in fill material and shall not be
				  placed any closer to receptors than one hundred (100) feet.
(b) Conventional wastewater infiltration trenches installed
				  in the naturally occurring soil and having a width of thirty-six (36) inches
				  shall be utilized.
(c) Wherever possible, designs that favor long wastewater
				  infiltration trenches, convex landscape positions, and rectangular subsurface
				  wastewater infiltration area configurations shall be required.
(d) All tree/brush removal shall be done in a manner that
				  minimizes the disturbance or loss of naturally occurring soil.
(3) Community or Cluster Collection and Treatment Onsite
				  Wastewater Systems
(a) An onsite wastewater system serving more than one (1)
				  piece of deeded property shall be considered as a public (community) collection
				  and treatment system.
(b) A permit activity will not occur that is inconsistent
				  with a plan or plan amendment approved under Section 208(b) of the Clean Water
				  Act, unless the Department finds such variance necessary to protect the
				  public's health, safety, and welfare.
(c) A public entity shall own the system and shall be
				  responsible for the operation, maintenance, and replacement of all components
				  unless otherwise approved by the Department. The Department may consider a
				  request from a private entity or person; however, such proposals must be
				  evaluated on a case-by-case basis. The Department will evaluate the capability
				  of long-term, reliable system operation in its evaluation of a permit
				  request.
(d) If the project is owned by a private entity or person,
				  the Department shall require financial assurances for the operation,
				  maintenance, and replacement of the tank(s) and subsurface wastewater
				  infiltration area system and relevant collection/pumping components.
(e) There shall be an area equivalent to one hundred (100)
				  percent in size of the original primary subsurface wastewater infiltration area
				  held in reserve for system repair or replacement. This area shall have a
				  suitable configuration and shall meet all minimum requirements for large onsite
				  wastewater systems.
(f) The collection sewer and pumping portions of a community
				  onsite wastewater system shall receive a separate Construction Permit under
				  R.61-67.300.
(g) The responsible party(s) on record shall be required to
				  properly operate and maintain in good working order all system(s) parts which
				  are installed pursuant to the permit and to comply with all terms and
				  conditions of the permit. System parts include, but are not limited to, sealed
				  watertight tanks, lid(s), piping, aggregate, pump, and pump
				  components.