in-20260311-IR-410260064FNA: RESIDENTIAL ON-SITE SEWAGE SYSTEMS

TITLE 410 INDIANA DEPARTMENT OF HEALTH Notice of First Public Comment Period LSA Document #26-64 RESIDENTIAL ON-SITE SEWAGE SYSTEMS PURPOSE OF NOTICE The Indiana Department of Health (IDOH) is soliciting public comment on adding, amending, and repealing rules at 140 IAC 6-8.3, regarding residential on-site sewage systems, to: (1) update and add definitions; (2) bring the rule into conformance with statutory updates; (3) update matters incorporated by reference; and (4) update onsite sewage system regulations. ADDITIONAL DOCUMENTS Regulatory Analysis: 20260311-IR-410260064RAA Notice of Public Hearing: 20260311-IR-410260064PHA CITATIONS AFFECTED: 410 IAC 6-8.3 AUTHORITY: IC 16-19-3-1; IC 16-19-3-4; IC 16-19-3-27; IC 16-41-25-1 OVERVIEW Basic Purpose -and Background Under IC 16-19-3-4, the executive board of IDOH has the authority to adopt rules to protect or improve public health in the state, including rules concerning the disposition of excremental and sewage matter through the design, installation, construction, maintenance, and operation of residential on-site sewage systems. Under IC 16-19-3-1, IDOH possesses all powers necessary to fulfill the duties prescribed in statute and for the enforcement of any of the provisions of health laws and rules. During the 2025 legislative session, Section 4 of House Enrolled Act 1052 added IC 16-19-3-34, requiring IDOH to update these rules by July 1, 2026. The parties impacted by the rule changes are homeowners who utilize on-site sewage systems, on-site sewage system installers, on-site sewage system designers, soil scientists, and local health department staff. For purposes of IC 4-22-2-28.1, small businesses affected by this rulemaking may contact the Small Business Regulatory Coordinator: For purposes of IC 4-22-2-28.1, the Small Business Ombudsman designated by IC 5-28-17-6 is: Resources available to regulated entities through the small business ombudsman include the ombudsman's duties stated in IC 5-28-17-6, specifically IC 5-28-17-6(9), investigating and attempting to resolve any matter regarding compliance by a small business with a law, rule, or policy administered by a state agency, either as a party to a proceeding or as a mediator. REQUEST FOR PUBLIC COMMENT IDOH is soliciting public comment on the proposed rule. Comments may be submitted in one of the following ways: COMMENT PERIOD DEADLINE All comments must be postmarked or time stamped not later than April 10, 2026. The rule, Regulatory Analysis, appendices referenced in the Regulatory Analysis, and materials incorporated by reference (if applicable) are on file at the Indiana Department of Health, Office of Legal Affairs, 2 North Meridian Street, Indianapolis, Indiana and are available for public inspection. Copies of the rule, Regulatory Analysis, and appendices referenced in the Regulatory Analysis are available at the Indiana Department of Health office. If IDOH does not receive substantive comments during the public comment period or public hearing, the rule may be adopted with text that is the same as or does not substantially differ from the text of the proposed rule published in this notice. PROPOSED RULE Sec. 5.1. "Base flood elevation" or "BFE" means the elevation of surface water resulting from a flood for which there is a one percent (1%) probability of equaling or exceeding that level in any given year, as calculated by a method and procedure approved by the natural resources commission. The base flood elevation is also referred to as the regulatory or one hundred (100) year flood elevation. Sec. 7.1. “Best judgment” means the process by which a local health department reviews the site and soil evaluation report and site characteristics in a situation where a residential on-site sewage system has failed, and a replacement soil absorption system cannot meet the requirements of this rule for new construction. The local health department uses their best judgment to determine the optimal approach to soil absorption system replacement that comes as close to meeting the requirements of this rule as possible. Sec. 7.2. “Cesspool” means a relatively shallow underground reservoir from which effluent seeps out of the sidewalls. A cesspool is typically not preceded by a septic tank. Sec. 8.1. “Construction, new” means either: Best judgment, as described in this rule for replacement of failed soil absorption systems, may not be used for new construction. Sec. 8.2. “Construction, repair or replacement” means either: In accordance with this rule, the best judgment of the local health department may be used, when necessary and appropriate, for the repair or replacement of a soil absorption system in a failing residential on-site sewage system. Sec. 12. (a) "Design daily flow" or "DDF" means the calculated peak daily sewage flow from a residence used to design a residential on-site sewage system. It is one hundred fifty (150) gallons per day times the number of bedrooms and bedroom equivalents. (b) For dwellings that are not tiny houses or recreational vehicles, the DDF is one hundred fifty (150) gallons per day times the number of bedrooms and bedroom equivalents. (c) For tiny houses, the DDF is at least three hundred (300) gallons per day. (d) For recreational vehicles used as dwellings, the DDF is seventy-five (75) gallons per day times the maximum occupancy number indicated by the recreational vehicle manufacturer. Sec. 12.1. “Designer” means an individual who designs and submits detailed on-site sewage system construction plans to the local health department for review as part of a construction permit application. Sec. 14. "Drainageway" means the channel portion of the landscape in which surface water or rainwater runoff gathers intermittently to flow flows to a lower elevation. Sec. 14.1. “Drywell” means a subsurface excavation, typically reinforced along the outer walls with brick, blocks, metal, or precast concrete, and may contain aggregate in the interior of the lining. A drywell is often bottomless. A drywell may or may not be preceded by a septic tank and is usually deeper than thirty-six (36) inches. Sewage seeps out of the sidewalls and bottom of a drywell. Sec. 16.1. “Fixed reference point” means a location that is readily identifiable, from which measurements can be taken to describe the location of soil borings, soil pits, and system components, and in place until the project is completed. Sec. 17.1. “Fragic soil properties” means a diagnostic soil characteristic associated with some soil aggregates in subsoil horizons of mineral soils. Aggregates with fragic properties are firm or firmer and brittle when the moisture content is at or near field capacity. Air-dry fragments slake when submerged in water, but are weakly cemented or not cemented. In addition, the aggregates show evidence of pedogenesis and are restrictive to roots. In effect, fragic soil properties are recognized in materials exhibiting all the characteristics of a fragipan except for continuity or thickness. Fragic soil properties are diagnostic for fragic subgroups (intergrades to other soil classes having a fragipan). Soil horizons that exhibit fragic properties, including those that qualify as fragipans, are designated by the suffix “x” (e.g., Bx or Btx). Sec. 17.2. “Fragipan” means a natural, diagnostic subsurface horizon with very low organic matter, high bulk density, or high mechanical strength relative to overlying and underlying horizons, and has a hard or very hard consistence (seemingly cemented) when dry, but showing a moderate to weak brittleness when moist. The layer typically has redoximorphic features, is slowly or very slowly permeable to water, is considered root restricting, and usually has few to many bleached, roughly vertical planes that are faces of coarse or very coarse polyhedrons or prisms, as classified in the U.S. Department of Agriculture's Soil Taxonomy. Sec. 18. "Health officer" means the health officer of a local board of health department. Sec. 18.1. “High strength waste” means either of the following: Sec. 18.2. “IAPMO” means the International Association of Plumbing and Mechanical Officials. Sec. 19.1. “Inspector” means an individual who performs inspections of existing on-site sewage systems in compliance with section 54.1 of this rule to determine system compliance with this rule. Sec. 19.2. “Installer” means an individual who performs any work in furtherance of the: of a residential on-site sewage system subject to the provisions of this rule. (Department of Health; 410 IAC 6-8.3-19.2) Sec. 20. "Interceptor drain" means a subsurface drainage system constructed only on the upslope side or sides of a soil absorption system for the purpose of lowering a seasonal high water table and diverting subsurface water around the soil absorption system site. Sec. 20.1. “Involuntary” means a need to modify or improve a dwelling or residential outbuilding due to factors outside the owner's control, such as destruction by wind, fire, flood, or other natural disaster, or condemnation of a dwelling. Sec. 20.2. (a) “Limiting layer” means a soil horizon that restricts the suitability of a site for a soil absorption system or the depth of installation of a soil absorption system. A limiting layer can be a restrictive soil horizon or poor filter. (b) A restrictive limiting layer is a soil horizon with: (c) A poor filter limiting layer is a soil horizon with: Sec. 27. "Perimeter drain" means a subsurface drainage system that completely surrounds a soil absorption system for the purpose of lowering a seasonal high water table or and preventing movement of subsurface water into a soil absorption system site. Sec. 30.1. “Recreational vehicle” means a travel trailer, park model, collapsible trailer, truck-mounted camper, or motor home. Sec. 32. "Residential on-site sewage system" or "on-site sewage system" means all equipment and devices necessary for proper conduction, collection, storage, treatment, and on-site disposal of sewage from: The term includes, but is not limited to, residential sewers, grease traps, septic tanks, secondary treatment units, dosing tanks, effluent pumps, distribution boxes, soil absorption systems, temporary subsurface drainage systems, dispersal areas, sewage holding tanks, and sanitary vault privies. The term also includes any miscellaneous components that may be required to ensure proper operation and function of the system as described in this rule. Sec. 32.1. “Residential on-site sewage system expansion” means the addition of any system component or components, or an increase in the size of a soil absorption system intended to expand the system's capacity to treat an increased DDF or prevent, stop, or abate a residential on-site sewage system failure. 410 IAC 6-8.3-33 "Residential on-site sewage system failure" defined Sec. 33. "Residential on-site sewage system failure" means a residential on-site sewage system that exhibits at least one (1) or more of the following: A failed residential on-site sewage system is a public and an environmental health hazard. Sec. 33.1. "Residential on-site sewage system malfunction" or “malfunction” means a residential on-site sewage system component that is not functioning in accordance with this rule or the manufacturers' requirements. Residential on-site sewage system malfunction does not have to meet the definition of residential on-site sewage system failure, but there may also be failure. Malfunction may include, but is not limited to, at least one (1) of the following: Sec. 33.2. “Residential on-site sewage system repair” means an activity undertaken to replace or modify any existing component or components of an existing on-site sewage system, including a component of the existing soil absorption system, such as a pipe, chamber, or distribution box. Residential on-site sewage system repair does not include routine maintenance of the system. Sec. 33.3. “Residential on-site sewage system replacement” means an activity undertaken to replace a soil absorption system. Residential on-site sewage system replacement may also include adding, replacing, or repairing any other system component or components. Sec. 35.1. “Responsible charge of installers” means the direct control and personal supervision by a registered installer of the work being performed at a job site for the installation of an on-site sewage system, including, but not limited to, site preparation work, tilling, construction, finish grading, and soil stabilization for all components of the on-site sewage system being installed. Sec. 39. "Segment drain" means a subsurface drainage system constructed between two (2) soil absorption fields in the same on-site sewage system for the purpose of lowering a seasonal high water table and intercepting and diverting subsurface water away from the downslope soil absorption field. Sec. 41.1. “Sewage holding tank” means a septic tank or tanks, or a combination of septic and dosing tanks, for which the outlet of the last tank in the series has been sealed off to prevent sewage or effluent discharge from the tank or tanks. Sec. 43. "Soil absorption system" or "soil absorption field" means pipes or chambers laid in a system of subsurface trenches, or pipes laid in elevated beds, into which the effluent from the septic tank is discharged into the soil for treatment and dispersal. The soil absorption system also includes the distribution box and effluent sewers after the distribution box, or the pressure manifold. Sec. 43.1. “Soil boring” means an excavation made by a soil auger, a probe, or similar small diameter soil sampling equipment used to pull soil samples out of the ground that are used to provide a description and characterization of the soil. Sec. 44. "Soil horizon" means a layer of soil or soil material approximately parallel to the land surface and differing from adjacent genetically related layers in physical, chemical, and biological properties or characteristics, such as: Sec. 45. "Soil loading rate" means the allowable rate of application of septic tank effluent to the soil. It is expressed in gallons per day, per square foot. Sec. 45.1. “Soil pit” means an excavation that is wide, deep, and long enough for the soil scientist to enter safely, according to the federal Occupational Safety and Health Administration and any other federal, state, or local requirements, to directly observe, characterize, and describe the soil profile. Sec. 46. "Soil profile analysis" means the observation and evaluation of the physical, chemical, and biological characteristics of the soil horizons or layers to: Sec. 49. "Subsurface drainage system" means any pipe with or without a layer of gravel, stone, or coarse sand, placed below the surface of the ground and designed or constructed in such a manner as to: way that: Interceptor, drains, perimeter, drains, and segment drains are types of subsurface drainage systems. Sec. 50. "Technology new to Indiana" or "TNI" means on-site sewage treatment or disposal methods, processes, or equipment not described in this rule that have been approved by the department in accordance with section 52(h) of this rule IC 16-19-3-27.5. Sec. 50.1. “Temporary benchmark” means an object whose actual elevation, or an arbitrarily assumed elevation of that object, is used as a point of reference until the project is completed. Sec. 50.2. “Tiny house” means a structure used as a dwelling that is not more than four hundred (400) square feet in floor area, not including lofts. Sec. 50.3. “Upgraded piping” means: Sec. 50.4. “Voluntary” means an owner's intentional or deliberate action to modify or improve a dwelling or residential outbuilding. Sec. 50.5. “Watertight” means that water or effluent cannot leak into or out of the structure except through piping in the designated pipe penetration ports or connectors. Pipe penetrations or connections must result in a connection that does not allow liquid to flow around the pipe penetration. Results of watertightness testing, as specified in IAPMO/ANSI Z1000-2019 9.1, may be provided to confirm watertightness of new tanks. For existing tanks, the water test procedure outlined in IAPMO/ANSI Z1000-2019 9.1.3 may be used for watertightness testing. For new or existing distribution boxes, a visual examination should be completed. Sec. 51. (a) This rule shall be administered by the a local boards of health department through their health officer and the health officer's authorized representatives. (b) Each local health department residential on-site sewage system permit program is subject to review by the department. A review may include, but not be limited to, a review of the permits issued, supporting documentation, and a review of on-site sewage system installations. (c) In accordance with IC 16-41-25-10 and IC 16-41-25-11, the department or its agent, or the health officer or the health officer's their agent, shall be permitted to enter upon all properties at the proper time for the following purposes necessary to achieve compliance with this rule: (d) A local ordinance is not considered more stringent than this rule if it is in accordance with IC 16-19-3-27.8. Sec. 52. (a) No person shall throw, run, drain, seep, or otherwise dispose into any of the surface waters or groundwaters of this state, or cause or permit or suffer to be thrown, run, drained, allowed to seep, or otherwise disposed into those waters, organic or inorganic matter from a dwelling or residential on-site sewage system that would cause or contribute to a health hazard or water pollution. (b) If a residential on-site sewage system failure occurs, the local health officer may require the residence and residential outbuilding, if applicable, to make a direct connection to a sanitary sewer, if the sanitary sewer is available within three hundred (300) feet of the affected property line and available for connection at a construction cost and connection fee estimated not to exceed one hundred fifty percent (150%) of the cost estimated for installing an on-site sewage system to serve the residence or residential outbuilding. (b) (c) The: of residential on-site sewage systems shall must comply with the provisions of this rule. (c) All (d) Residential on-site sewage systems utilizing using sanitary privies shall must conform to department bulletin S.E. 11, "The Sanitary Vault Privy", 2021 edition. (d) (e) A dwelling that is not connected, or cannot be connected, to a sanitary sewerage system shall must be provided with a residential on-site sewage system that includes a septic tank and a soil absorption system that has not failed. the following: (e) A temporary sewage holding tank is an alternative method of sewage disposal subject to the written approval of the department, except as provided in subsection (f). A temporary sewage holding tank shall not be used as a primary means of residential sewage disposal except: (f) A temporary sewage holding tank may be approved by the local health department: (f) A cesspool or drywell, with or without a septic tank, is not a suitable means of residential sewage disposal. (g) If any conditions preclude the installation of a residential on-site sewage system as described in this rule, the local board of health department may not approve the use of other residential on-site sewage system technology unless written approval from the department is: (h) In order To permit development of new or more efficient sewage treatment or disposal processes, the department may approve the installation of experimental and TNI equipment, facilities, or pollution control devices for which extensive experience or records of use have not been developed in Indiana. The applicant for the approval must submit evidence of sufficient clarity and conclusiveness to convince the department that the proposal has a reasonable and substantial probability of satisfactory operation without failure TNI may be approved in accordance with IC 16-19-3-27.5. (i) No portion of the a residential on-site sewage system or its associated drainage system, shall sewage holding tank, or sanitary vault privy may be constructed upon on property other than that from which the sewage originates unless easements an easement or a declaration of an on-site sewage system easement, if both properties are owned by the same person, which grant grants permission for the construction and access for system maintenance, have has been obtained for that property and have has been legally approved and recorded by the proper authority or commission. (j) Residential on-site sewage systems shall not be used for the disposal of water from: These sewage systems shall also not be used for the disposal of chemical wastes in quantities that would pollute groundwater or inhibit solids settling or digestion in the septic tank. (k) A jetted bathtub with a capacity of greater than one hundred twenty-five (125) gallons shall must be treated as an extra bedroom for the on-site sewage system sizing requirements of this rule. (l) An existing residential on-site sewage system may be considered for connection or reconnection to a new or replacement dwelling or residential outbuilding if the following apply: Sec. 52.1. (a) On-site sewage system installers shall abide by all associated requirements in state statutes, rules, and local ordinances regarding on-site sewage systems. (b) An installer shall register with the local health department if they wish to install, expand, replace, alter, repair, or abandon a residential on-site sewage system. Registration requires: (c) A registered installer has responsible charge for the work being performed on the on-site sewage system. (d) An installer who only abandons on-site sewage systems is exempt from competency testing. (e) A lapse of certification or registration, or repeated violation of any state statute, rule, or ordinance regarding on-site sewage systems, may result in the revocation or denial of registration renewal by the local health officer. Sec. 53. (a) For a dwelling or place of residence that will not be connected to a sanitary sewerage system, the owner, or agent of the owner, shall obtain a written construction permit, signed by the health officer, for construction of a residential on-site sewage system prior to before the: (b) A local health department shall not issue a construction permit for a new on-site sewage system, the repair of an on-site sewage system, or the replacement of a soil absorption system using TNI without the written approval of the department, except for the provisions of section 52(g) of this rule. (c) The approval of a site by the local plan commission or the county recorder does not constitute approval by the local health officer. (d) The application for Before a permit is issued, an application for a construction permit shall must be made to on a form provided by the local health department. The A complete application shall must contain, or include as attachments, the following: (e) When site limitations and soil information for the site have been determined, the owner is responsible for the residential on-site sewage system design that: (f) The local health department may require scaled drawings of the site and residential on-site sewage system as part of the application process. (g) In accordance with IC 16-41-25-1(a), the local health department shall issue or deny, in writing to the owner, a residential on-site sewage system construction permit within thirty (30) days of receipt of after receiving an application and plan submittal. (h) No construction on the residential on-site sewage system may take place if the residential on-site sewage system site is disturbed or altered after the on-site evaluation by the addition of fill material, other than construction necessary for the residential on-site sewage system, or by cutting, scraping, compaction compacting, or the removal of removing soil, until a new on-site evaluation has been conducted and a modified construction permit has been issued. (i) A soil absorption system replacement for a residential on-site sewage system shall must meet or exceed the minimum provisions of this rule. When a replacement soil absorption field is necessary due to on-site sewage system failure, and if the replacement soil absorption system cannot meet all of the provisions of this rule, deviations to this rule for a soil absorption system replacement may be made in accordance with the best judgment of the local department of health based on the following: department as follows: (k) If it is determined that the proposed on-site sewage system design does not meet the minimum requirements of this rule, the permit may be denied in accordance with section 55(e) of this rule. (l) The permittee shall notify the health officer or the health officer's designee when the work is ready for final inspection: (m) The construction permit for a residential on-site sewage system in violation of this section may be revoked by the health officer in accordance with section 55(e) of this rule. Requirements of permits issued for the construction of residential on-site sewage systems shall not be considered fulfilled until the installation is completed, to the satisfaction of in compliance with this rule and the approved construction plan, and approved by the health officer or the health officer's duly authorized representative. (n) Individual lots in subdivisions designed to utilize use residential on-site sewage systems, for which the plats were approved by the local plan commission, county health department, or county recorder and recorded prior to before December 21, 1990, are exempt from the provisions of sections 70(b)(8) 70(b)(7) and 72(b)(7) 72(b)(6) of this rule if the soils on the individual lot have characteristics that would allow the soil to be rated as slight or moderate in accordance with guidelines as set forth in the soils manuals and handbooks of the NRCS. The soil absorption system to serve each lot that is exempted by this section shall must meet the sizing criteria as follows: (o) Individual lots in subdivisions designed to utilize use residential on-site sewage systems, the plats for which were approved by the local plan commission and recorded prior to before December 21, 1990, will be granted an exemption by the department from the provisions of section 70(b)(8) 70(b)(7) of this rule if the health officer of the county in which where the development is located certifies to the department, in writing, that: The certification must be accompanied by a brief description of the on-site sewage system approved for each lot for which exemption is requested, including information on the design of the on-site sewage system, as well as information on the type of soil on the site. An affirmative response to subdivisions (1) and (2) must be included in the certification for the exemption to the provisions of section 70(b)(8) 70(b)(7) of this rule to be granted. Sec. 54. (a) Local health departments may require written operating permits in accordance with IC 16-19-3-27(b)(2) for on-site sewage systems, where best judgment of the local health department was used for permit issuance, sewage holding tanks, and sanitary vault privies, as follows: (b) An operating permit shall must identify all components of an on-site sewage system requiring inspection and maintenance. (c) The records for an operating permit requiring scheduled inspection and maintenance shall must contain the following: (d) The An owner shall provide the local health department with the following: (e) The local health department may require a system to be inspected, as described in section 54.1 of this rule, detailing the functionality of the system components and maintenance concerns before operating permit renewal. (f) If a service contract is discontinued for any reason, the owner or service provider shall contact the local health department and a new service contract for operation and maintenance must be provided to the local health department within one (1) month of the lapse in contract. (e) (g) The operating permit for a residential on-site sewage system in violation of subsection (d) may be revoked by the health officer in accordance with section 55(e) of this rule. Sec. 54.1. (a) When an on-site sewage system is to be inspected for determinations made in section 52(l) of this rule for: the requirements of this section apply. (b) Before an existing on-site sewage system is inspected, the inspector shall obtain a copy of the on-site sewage system construction permit and operating permit files, if available, including, but not limited to, the permit or permits, construction plan, final inspection documentation, and any complaint information related to the on-site sewage system being inspected from the local health department. (c) The system must minimally include a residential on-site sewage system as defined in this rule as follows: (d) Each component of the on-site sewage system must be thoroughly inspected and documented, including, but not limited to the following: (e) Within thirty (30) days of a completed inspection, a written report of the system evaluation shall be submitted to the local health department, including, but not limited to the following: Sec. 55. (a) Should If a residential on-site sewage system fail, fails, the failure shall must be corrected by the owner within the time limit set by the health officer. (b) If any component of a residential on-site sewage system is found to be: the health officer may require the repair, replacement, or service of that component. The repair, replacement, or service shall must be conducted within the time limit set by the health officer. (c) Any A person found to be violating this rule may be served by the health officer with a written order stating the nature of the violation and providing a time limit for satisfactory correction thereof. (d) After receiving an order in writing from the local board of health department or the health officer, the owner of the property shall comply with the provisions of this rule, as set forth in the order, and within the time limit specified therein. The order shall must be served on the owner or the agent of the owner, but may be served on any person who, by contract with the owner, has assumed the duty of complying with the provisions of an order. (e) The health officer may deny an application for a construction or an operating permit, or may revoke a permit previously issued, for reasons including, but not limited to, any of the following: (f) The written denial or revocation shall must state the following: (g) The parties involved may agree to use the appeal procedures set forth in IC 4-21.5, the Administrative Orders and Procedures Act. Sec. 56. (a) Before issuance of any a permit for construction of a residential on-site sewage system or the replacement or alteration of a soil absorption system, an on-site evaluation, which shall include includes a description of the soil profile, shall must be conducted. (b) Properties of the soil at each site shall must be described by a registered professional soil scientist using the guidelines set forth in the soil manuals, technical bulletins, and handbooks of the NRCS. (c) At least three (3) soil profile descriptions must be completed in the area of the soil absorption field and provide good coverage of the entire soil absorption field area. (c) (d) Soil profile information shall must be recorded: whichever is shallower. (d) (e) The on-site evaluation shall must be conducted before application and plan submittal. (e) (f) The information in the written on-site soils evaluation report shall must include the following: (f) (g) When soil characteristics are to be used for calculations for the depth of a subsurface drainage system, the following information shall must be recorded to a depth of eighty (80) inches: (h) On-site soil evaluation reports created from the evaluation of the soil profiles to be used for obtaining an on-site sewage system construction permit must be signed by the registered professional soil scientist and submitted directly to the local health department by the soil scientist. Sec. 57. (a) All Septic tanks, dosing tanks, lift stations, and soil absorption systems shall must be located in accordance with Table I as follows: Table I Separation Distances Minimum Distance in Feet from Septic Tank and Other Treatment Units, Dosing Tank, Lift Station, Sewage Holding Tank Soil Absorption System Private water supply well1,2, subsurface cistern1 50 50 Private geothermal well1,2 50 50 Commercial water supply well1 100 100 Commercial geothermal well1 100 100 Public water supply well, lake,1, 3, 4 or reservoir1, 3, 4 200 200 Other pond, retention pond, lake, or reservoir3 50 50 Stormwater detention area3, 5 25 25 River, stream, ditch, or drainage tile6 25 25 Buildings, foundations, slabs, garages, patios, barns, aboveground and belowground swimming pools, retaining walls, closed loop geothermal systems, roads, driveways, parking areas, or paved sidewalks 107 108 Front, side, or rear lot lines 5 5 Water lines continually under pressure 10 10 Suction water lines 50 50 Sinkhole 25 25 1 The distances enumerated shall must be doubled for soil absorption systems constructed where there exist horizons, layers, or strata exist within thirty-four (34) inches of the ground surface, with a soil loading rate greater than seventy-five hundredths (0.75) gallons per day, per square foot, as determined from Table IV of section 70(b)(8) 70(b)(7) of this rule, unless that hazard can be overcome through on-site sewage system design. 2 The separation distance to a private water supply well abandoned in accordance with 312 IAC 13-10-2(e) may be reduced to ten (10) feet. 3 Measured from the normal or ordinary high water mark. 4 See subsections (b) and (c). 5 Stormwater detention area: area designated for the temporary detention of stormwater, with the outlet located at the lowest elevation of the depression. 6 See section 59(f) of this rule for subsurface drainage system separation. 7 Patios without footers, aboveground swimming pools, and sidewalks may be located within ten (10) feet of a septic tank, as long as no required access points are obstructed. 8 A minimum separation of ten (10) feet is required on all sites. (b) A residential on-site sewage system shall may not be located within two hundred (200) feet of a public water supply lake or reservoir. However, a residential on-site sewage system that includes secondary treatment may be less than two hundred (200) feet, but not less than fifty (50) feet, from the normal or ordinary high water mark of the lake or reservoir if it: (c) A residential on-site sewage system approved under the provisions of subsection (b) must be maintained for the life of the system through an operating permit issued under the provisions of section 54 of this rule. (d) Sewers shall may not be located within fifty (50) feet of a water supply well or subsurface pump suction line, except as follows: (e) Water lines and sewers shall may not be laid in the same trench, as follows: Sec. 58. (a) A dispersal area is required for a soil absorption system when: (b) When the conditions in subsection (a) apply, the following requirements shall must be met: (c) For sites that do not meet the conditions of subsection (a), the minimum dispersal area shall must be ten (10) feet. For sites that meet the conditions of subsection (a), the dispersal area shall must be as indicated in Table II as follows: Table II - Minimum Dispersal Areas1 for Soil Absorption Systems Slope < ½ %2: On-site sewage system without perimeter drain One-fourth (¼) width of soil absorption system5 Slope ½ %3: On-site sewage system without perimeter drain One-half (½) width of soil absorption system5 Any slope: On-site sewage system with perimeter drain4 Ten (10) feet or the distance to the perimeter drain 1No buildings, foundations, slabs, garages, patios, barns, aboveground and belowground swimming pools, retaining walls, roads, driveways, parking areas, or paved sidewalks are allowed in the dispersal area. 2Dispersal area is located on each side of the outside edge of the outer trench parallel to the length of the trench, or on each side of the outside edge of the sand area and parallel to the long axis of an elevated sand mound. 3Dispersal area is located on the downslope side of the soil absorption system. 4For on-site sewage systems with a subsurface perimeter drain without a seasonal high water table, the design and construction of the drain shall must meet the requirements of section 59 of this rule. 5Dispersal area width shall must not be less than ten (10) feet. A dispersal area width of more than twenty-five (25) feet is not required. (d) Any A disturbance within a dispersal area shall must not create compacted soil material. (e) The location of the dispersal area shall must meet the following requirements: Sec. 59. (a) A surface diversion: (b) When a subsurface drainage system is constructed, it shall must be sufficiently deep to lower a seasonal high water table as required in subsection (d) or (e). (c) If the site has a slope of equal to or less than two percent (2%), the subsurface drain shall must surround the on-site sewage system. If the site slope exceeds two percent (2%), the subsurface drain may be constructed only on the upslope side of the on-site sewage system. (d) If the seasonal high water table is perched, the subsurface drain trench shall must be constructed at least two (2) inches into structureless massive compact clay with firm or very firm consistence, glacial till, or fragipan whenever site and soil conditions permit. When the drain cannot be constructed at least two (2) inches into the structureless massive compact clay with firm or very firm consistence, glacial till, or fragipan, the depth of the drain shall must be the following unless calculations are used to determine drain depth: (e) If drainage calculations are used to determine drain depth, drainage formulas and calculations shall must be submitted to the local health department as part of the plan submittal, showing a lowering of the seasonal high water table: (f) Subsurface drainage systems shall must be located at soil absorption system sites as follows: (g) The A subsurface drain pipe shall must be: (h) The subsurface drain trench shall: must: (i) A subsurface drain trench installed upslope from a residential on-site sewage system shall must be: (j) A subsurface drain trench installed on sides or downslope, and segment drain trenches may be: (k) The aggregate backfill for subsurface drain trenches shall must meet the minimum requirements of: (l) When INDOT Specification 23 sand is used for backfill, the drainpipe shall must be wrapped with a geotextile fabric. (m) The aggregate used as backfill in the perimeter, interceptor, or segment drain trenches described in subsections (i)(2) and (j)(2) shall must be covered with a geotextile fabric barrier that meets the minimum requirements in section 69 of this rule in such a manner as to prevent way that prevents the aggregate from becoming clogged with the earth fill. (n) The subsurface drain trench and the associated discharge piping shall must be constructed to permit water to flow by gravity throughout its length. No pumps or siphons shall must be utilized used to effect the movement of the collected water. (o) Tile outlets shall must be provided with rodent guards. Sec. 60. (a) Septic tanks shall must be: (b) Cast in place, concrete block, wood, or metal septic tanks are prohibited. (c) Every septic tank shall must have a minimum capacity below the water line as specified in Table III as follows: Table III - Required Minimum Capacities for Septic Tanks Number of Bedrooms in Dwelling Capacity of Septic Tank in Gallons 2 or less 750 3 1,000 4 1,250 5 1,500 5+ 1,500 plus 300 multiplied by the number of bedrooms over 5 (d) All Septic tank effluent, including effluent from tanks fitted with aeration units for aerobic digestion, shall must discharge into a soil absorption system or other treatment system as approved in accordance with section 52(h) of this rule. (e) Two-compartment tanks shall must meet the following requirements: (f) When multiple tanks are used in series, no single tank may be less than seven hundred fifty (750) gallons. The larger of the two (2) tanks must be upstream of the other. (g) When sewage is pumped into a septic tank using a grinder pump: (h) Tanks fitted with aeration units for aerobic digestion shall: must: (i) Water softener backwash shall must be discharged to: Sec. 61. (a) The minimum water depth in any compartment shall must be thirty (30) inches. (b) The maximum water depth for calculating septic tank capacity shall must not exceed six and one-half (6 ½) feet. (c) The inlet baffle or sanitary tee shall must extend at least: (d) All New septic tanks must be provided with an outlet filter that meets or exceeds the requirements of section 64 of this rule. (e) Any A septic tank not provided with an outlet filter in the interior of the tank shall must be provided with: (f) There shall must be at least one (1) inch clear space between the underside of the septic tank lid and the top of the inlet and outlet baffles or tees. (g) Scum storage capacity (space between the liquid level and the top of the outlet baffle or tees) shall must be not less than twelve and one-half percent (12.5%) (12 ½%) of the liquid depth of the septic tank. (h) The inlet baffle shall must not be more than twelve (12) inches nor less than four (4) inches from the inside of the inlet end of the tank. The outlet baffle shall must not be more than twelve (12) inches nor less than four (4) inches from the outlet end of the septic tank. Baffles shall must be constructed of durable materials not subject to corrosion or decay. (i) The bottom of the septic tank inlet shall must not be less than two (2) inches nor more than four (4) inches above the liquid level. (j) Reinforced concrete septic tanks shall must be constructed of concrete designed to withstand all structural, hydraulic, hydrostatic, earth loads, and any anticipated traffic loads, and with a compressive strength of four thousand (4,000) pounds per square inch or greater. (k) Concrete septic tank walls shall must be at least two and one-half (2 ½) inches or greater in thickness. The design must allow at least one (1) inch cover over reinforcing steel or welded wire fabric. (l) Concrete septic tank bottoms shall must conform to the specifications set forth for septic tank walls. (m) Concrete septic tank tops shall must be a minimum of at least four (4) inches in thickness and reinforced with three-eighths (3/8) inch reinforcing rods in a twelve (12) inch grid or equivalent. (n) Type III fibers, meeting ASTM C 1116-10a(2015), are permitted only as a secondary reinforcing material. Fiber additions will be considered only for the purpose of resisting temperature and shrinkage efforts, and not as primary reinforcing material. (o) All Access openings shall must meet the following requirements: (p) All Risers shall must meet the following requirements: (q) Pipe connectors shall must be provided that meet the following requirements: Sec. 62. (a) Dosing tanks must be: (b) Cast in place, concrete block, wood, or metal dosing tanks are prohibited. (c) Reinforced concrete dosing tanks shall must be constructed of concrete designed to withstand all structural, hydraulic, hydrostatic, earth loads, and any anticipated traffic loads, and with a minimum compressive strength of four thousand (4,000) pounds per square inch or greater. (d) Concrete dosing tank walls shall must be at least two and one-half (2 ½) inches or greater in thickness. The design shall must allow at least one (1) inch cover over reinforcing steel or welded wire fabric. (e) The required liquid holding capacity of the dosing tank shall must not be considered as any portion of the required liquid volume of the septic tank. (f) The liquid holding capacity of a dosing tank must equal the dose volume required by this rule for each type of soil absorption system, in addition to the volume of liquid that will drain back from any effluent force main when pumping ceases. stops. Additional capacity must be provided to: (g) Dosing tanks shall must be provided with pipe connectors that meet the following requirements: (h) Each dosing tank shall must be fitted with an effluent pump sized in conformance with section 65 of this rule and section 76(b), 78(d), 78(q), 82(b), or 82(j) of this rule, whichever is applicable, with controls and with a high water alarm switch set at a level above the design high water mark. The alarm shall: must: (i) Switches or sensors that are comparable to mercury float level switches shall must be used for dosing tank effluent pump start and stop controls and for high water alarms. Sec. 62.1. (a) A sewage holding tank is an alternative method of sewage disposal in accordance with IC 16-41-25-9. (b) Sewage holding tanks must be: (c) A temporary sewage holding tank may be used: (d) Sewage holding tanks must have the minimum capacity of: (e) Reinforced concrete sewage holding tanks must be constructed of concrete designed to withstand all structural, hydraulic, hydrostatic, earth loads, and any anticipated traffic loads, and with a compressive strength of four thousand (4,000) pounds per square inch or greater. (f) Concrete sewage holding tank walls and bottoms must be at least two and one-half (2 ½) inches or greater in thickness. The design must allow at least one (1) inch cover over reinforcing steel or welded wire fabric. (g) Concrete sewage holding tank tops must be at least four (4) inches in thickness and reinforced with three-eighths (⅜) inch reinforcing rods in a twelve (12) inch grid or equivalent. (h) ASTM C 1116-10a(2015) type III fibers are permitted only as a secondary reinforcing material. Fiber additions will be considered only for the purpose of resisting temperature and shrinkage efforts, and not as primary reinforcing material. (i) Sewage holding tanks must have at least one (1) opening eighteen (18) inches in minimum diameter for pumping access positioned in a way that allows for maintenance, cleaning, and servicing. (j) Holding tanks are required to have an operating permit issued by the local health department. (k) Receipts from pumping and maintenance of a sewage holding tank, and other documents for repair or modification of a sewage holding tank, must be submitted to the local health department within thirty (30) days of the service provided or a time frame approved by the local health department. (l) If a sewage holding tank is not operated in a safe and sanitary way and in accordance with IC 16-41-25-9 and this rule, the local health department may require the residence or residential outbuilding to: Sec. 63. (a) Septic, tanks, and dosing, tanks shall and sewage holding tanks must be installed level on: (b) All Drain holes in septic, tanks, and dosing, tanks shall and sewage holding tanks must be: (c) When the top of the septic, tank, or dosing, tank or sewage holding tank is installed at or above grade, all access openings shall must be fitted with watertight, securely fastened covers. (d) When the top of the septic, tank, or dosing, tank or sewage holding tank is installed below grade, risers shall: must: (e) Septic tanks, and dosing tanks shall not be installed with the top of the riser below the RFE. (f) All (e) The joints in the sewer connecting septic tanks in series or septic tanks to dosing tanks shall must be sealed in accordance with the manufacturer's instructions in order to be watertight and to withstand the pressures exerted on them. Sec. 64. (a) An outlet filter shall must be installed in the septic tank of new on-site sewage systems and existing on-site sewage systems requiring a new septic tank. (b) For on-site sewage systems requiring repair, or soil absorption systems requiring replacement, the local health department may require an outlet filter. The outlet filter, if required by the local health department, must meet the requirements of this section. (c) Outlet filters shall must be located in the outlet end of: (d) An access opening of eighteen (18) inches in minimum dimension shall must be: (e) Outlet filters shall: must: (f) The outlet filter housing shall: must: (g) A filter alarm may be installed in the septic tank to indicate when the outlet filter is in need of service. (h) An outlet filter with cartridge shall must remain in service for the life of the septic tank. (i) Outlet filter manufacturers shall provide installation and maintenance instructions with each outlet filter. Outlet filters shall must be: (j) Outlet filters shall must be serviced according to the manufacturer's service recommendations, but no not less frequently than each time the septic tank is cleaned, as follows: Sec. 65. (a) All Effluent pumps shall must be: (b) Effluent pumps shall must be provided with a suitable means of quick, convenient disconnection from the discharge piping, as follows: (c) All Floats for pump operation shall must be mounted according to manufacturer's specifications using fasteners manufactured for that purpose. (d) Controls other than liquid level sensors shall must not be located within the dosing tank. (e) Junction boxes shall must be rated as a NEMA 4X, National Electrical Manufacturers Association, NEMA 250-2008 All 250-2020. The connectors to the junction box shall must form a watertight seal: (f) Any A connector not used for wiring shall must be fitted with a watertight plug. Sec. 66. (a) Concrete distribution boxes shall must be constructed of concrete with a compressive strength of four thousand (4,000) pounds per square inch or greater. Other materials may be considered on a case-by-case basis. All materials must: (b) The distribution box material must: (b) (c) The minimum interior dimension of a distribution box shall must be twelve (12) inches. (c) (d) The distribution box shall or top of the distribution box riser must be fitted with a watertight, securely fastened removable lid for access. The distribution box may be fitted with a riser to the ground surface. The riser joints and the lid connection to the riser must be watertight When the top of the distribution box is installed below final grade, a riser must be installed over the box and extend to or above final grade. The joints between riser sections must be watertight. (e) Distribution boxes must be stabilized to prevent movement during installation and operation. (d) (f) The interior bottom of the distribution box shall must be at least four (4) inches below the invert elevation of the effluent ports. A minimum of At least eight (8) inches freeboard above the invert elevation of the effluent port shall must be provided. (e) (g) The influent port shall must be located or baffled to prevent unequal distribution of effluent to the distribution system as follows: (g) (h) Each distribution box shall must be designed to split the effluent flow equally among the effluent ports. All The effluent ports shall must be: Sec. 67. (a) Piping used in a residential on-site sewage system shall must meet or exceed the following applicable standards: (b) Gasketed compression-type joints Upgraded piping must be used on pressure sewers when they are located ten (10) feet or less from a water line do not meet the required horizontal and vertical separations required in section 57(e) of this rule. (c) Soil absorption system gravity distribution laterals shall must meet one (1) of the following standards: (d) Gravity distribution laterals shall must have two (2) or three (3) rows of holes separated by one hundred twenty (120) degrees, with a five-eighths (⅝) inch or three-quarters (¾) inch hole diameter with holes spaced at five (5) inches or less. (e) Pipe for subsurface drainage systems shall must meet the following standards for polyethylene pipe: Sec. 68. (a) Aggregate to be used in soil absorption systems shall must be gravel, stone, or other materials listed by the department. Crushed limestone aggregate, if used, shall must be rated as forty percent (40%) or less on the Los Angeles abrasion quality requirement of the INDOT 2012 2024 Standard Specifications, Section 904, Aggregates. (b) Aggregate must be: (c) Tire chips may be used in place of stone for soil absorption systems on a one-for-one basis, volumetrically. Tire chips used for soil absorption systems must have a nominal size of two (2) inches, with chip dimensions being not less than one-half (½) inch and not greater than four (4) inches. (d) Fines, sand, and clay shall must be removed from the aggregate prior to before its placement in the trench. Sec. 69. (a) The physical characteristics of barrier materials shall must have the following minimum average roll values: (b) The chemical characteristics of barrier materials shall must be: Sec. 70. (a) On-site sewage system feasibility, location, and selection shall must be based on the: If site conditions are acceptable, subsurface trench soil absorption systems are the systems of choice. (b) All of The following site conditions in this section must be met if subsurface trench on-site sewage systems are to be constructed: Table IV - Soil Loading Rates for Subsurface Trench On-Site Sewage Systems (in gpd/ft2) SOIL STRUCTURE CLASSES SOIL TEXTURE CLASSES Single Grain Granular Strong: Angular, Sub-Angular Blocky, Prismatic Moderate: Angular, Sub-Angular Blocky, Prismatic Weak: Angular, Sub-Angular Blocky, Prismatic; Platy1 Fragic Characteristics: Very Coarse Prismatic Structureless, Massive, Friable, V. Friable Structureless, Massive, Compact, Firm, V. Firm; Platy2 Gravel, Coarse Sand 1.20 N/A N/A N/A N/A N/A N/A N/A Loamy Coarse Sand, Medium Sand 1.20 1.20 N/A N/A 1.20 N/A N/A N/A Fine Sand, Loamy Sand, Loamy Fine Sand 0.75 0.60 N/A 0.75 0.75 N/A 0.75 N/A Very Fine Sand, Loamy V. Fine Sand 0.50 0.50 N/A 0.75 0.60 N/A 0.60 N/A Sandy Loam, Coarse Sandy Loam N/A 0.75 N/A 0.60 0.60 0.00 0.60 0.00 Fine Sandy Loam, V. Fine Sandy Loam N/A 0.75 N/A 0.60 0.60 0.00 0.60 0.00 Loam N/A 0.75 0.75 0.50 0.50 0.00 0.50 0.00 Silt Loam, Silt N/A 0.75 0.75 0.50 0.30 0.00 0.30 0.00 Sandy Clay Loam N/A 0.60 0.60 0.50 0.30 0.00 0.30 0.00 Silty Clay Loam, Clay Loam, Sandy Clay N/A 0.60 0.60 0.30 0.25 0.00 0.25 0.00 Silty Clay, Clay N/A 0.60 0.50 0.30 0.25 N/A 0.25 0.00 Organic Soil Materials N/A N/A N/A N/A N/A N/A 0.00 N/A Limnic Soil Materials N/A N/A N/A N/A N/A N/A N/A 0.00 Bedrock N/A N/A N/A N/A N/A N/A N/A N/A N/A NOT APPLICABLE 1Naturally occurring platy structure. 2Platy structure caused by mechanical compaction has a soil loading rate of 0.00 gpd/ft2 unless broken up by methods approved by the department. (c) Subsurface trench soil absorption systems shall must not be constructed as follows: Sec. 71. (a) On-site sewage system feasibility, location, and selection shall must be based on the: (b) A subsurface trench gravity system may be constructed if the: (c) A subsurface trench gravity on-site sewage system may also be constructed if the: (d) A subsurface trench on-site sewage system that utilizes uses alternating fields or is dosed using pump assisted distribution may be constructed if the: (e) If any a soil absorption system, including either half of an alternating field on-site sewage system, is designed with a total absorption trench length greater than five hundred (500) lineal feet, the absorption system shall must be dosed using pump assisted distribution. (f) If any a soil horizon within twenty-four (24) inches of the proposed trench bottom has a soil loading rate of one and twenty-hundredths (1.20) gallons per day, per square foot, as determined from Table IV in section 70(b)(8) 70(b)(7) of this rule, the on-site sewage system shall utilize must use pressure distribution. Sec. 72. (a) On-site sewage system feasibility, location, selection, and design shall must be based on the: (b) Elevated sand mound on-site sewage systems may be constructed if the following site conditions are met: Table V - Soil Loading Rates for Elevated Sand Mound On-Site Sewage Systems (in gpd/ft2) SOIL STRUCTURE CLASSES SOIL TEXTURE CLASSES Single Grain Granular Strong: Angular, Sub- Angular Blocky, Prismatic Moderate: Angular, Sub-Angular Blocky, Prismatic Weak: Angular, Sub-Angular Blocky, Prismatic; Platy1 Fragic Characteristics: Very Coarse Prismatic Structureless, Massive, Friable, V. Friable Structureless, Massive, Compact, Firm, V. Firm; Platy2 Gravel, Coarse Sand >1.20 N/A N/A N/A N/A N/A N/A N/A Loamy Coarse Sand, Medium Sand 1.20 1.20 N/A N/A 1.20 N/A N/A N/A Fine Sand, Loamy Sand, Loamy Fine Sand 0.60 0.60 N/A 0.60 0.60 N/A 0.60 N/A Very Fine Sand, Loamy V. Fine Sand 0.50 0.50 N/A 0.50 0.50 N/A 0.50 N/A Sandy Loam, Coarse Sandy Loam N/A 0.60 N/A 0.60 0.60 0.00 0.60 0.00 Fine Sandy Loam, V. Fine Sandy Loam N/A 0.60 N/A 0.60 0.60 0.00 0.60 0.00 Loam N/A 0.50 0.50 0.50 0.50 0.00 0.50 0.00 Silt Loam, Silt N/A 0.50 0.50 0.50 0.50 0.00 0.50 0.00 Sandy Clay Loam N/A 0.50 0.50 0.50 0.50 0.00 0.50 0.00 Silty Clay Loam, Clay Loam, Sandy Clay N/A 0.25 0.25 0.25 0.25 0.00 0.25 0.00 Silty Clay, Clay N/A 0.25 0.25 0.25 0.25 N/A 0.25 0.00 Organic Soil Materials N/A N/A N/A N/A N/A N/A 0.00 N/A Limnic Soil Materials N/A N/A N/A N/A N/A N/A N/A 0.00 Bedrock N/A N/A N/A N/A N/A N/A N/A N/A N/A NOT APPLICABLE 1 Naturally occurring platy structure. 2 Platy structure caused by compaction has a soil loading rate of 0.00 gpd/ft2 unless broken up by methods approved by the department. (c) Elevated sand mound soil absorption systems shall must not be constructed as follows: Sec. 73. On-site sewage system selection may be summarized in Table VI as follows: Table VI - Table for On-Site Sewage System Selection Based on Requirements of 410 IAC 6-8.3 Site Requirements Subsurface Trench On-Site Sewage Systems Elevated Sand Mound On-Site Sewage Systems (Sec. 72) Gravity Flow1 (Sec. 70, 71) Flood Dosing or Alt. Fields1 (Sec. 70, 71) Flood Dosing1 (Sec. 70, 71) Pressure Dist. (Sec. 70, 71) Slope < 15% < 15% <15% <15% < 6% Design Daily Flow > 450 > 450 Any Any Any Any Acceptable Loading Rate Range for Determining System Size > 0.25 > 0.25 > 0.25 > 0.25 > 0.25 > 0.25 < 0.75 < 0.75 < 0.75 < 0.75 < 1.20 < 1.20 Distance from Trench Bottom (Ground Surface for Mounds) to Layer with a Soil Loading Rate > 0.25 gpd/ft2 > 30 > 24 > 24 > 24 > 24 > 20 Distance from Trench Bottom (Ground Surface for Mounds) to Layer with a Soil Loading Rate 1.20 gpd/ft2 > 24 > 30 > 24 > 24 > 24 > 24 > 20 Distance from Trench Bottom (Ground Surface for Mounds) to Layer with a Soil Loading Rate = 1.20 gpd/ft2 > 24 > 30 > 24 > 24 > 24 Press. Dist. required for SLR = 1.20 > 0 Distance from Trench Bottom (Ground Surface for Mounds) to a Soil Horizon Developed from Wisconsin Glacial Till That Shows Effervescence3 > 30 > 24 > 24 > 24 > 24 > 20 Distance from Trench Bottom (Ground Surface for Mounds) to Soil Horizon with > 20% Clay and 35% Coarse Fragments by Volume > 30 > 24 > 24 > 24 > 24 > 20 Distance from Trench Bottom (Ground Surface for Mounds) to Soil Horizon with 20% Clay and 60% Coarse Fragments by Volume > 30 > 24 > 24 > 24 > 24 > 20 Distance from Trench Bottom (Ground Surface for Mounds) to Seasonal High Water Table2 > 24 > 24 > 24 > 24 > 24 > 20 Total Lineal Feet of Trench < 500 < 500 < 500 for Alt. Fields Any Any N/A 1These conditions are also suitable for subsurface trench pressure distribution on-site sewage systems. 2For subsurface trench systems, if the distance from trench bottom to seasonal high water table is less than twenty-four (24) inches, drainage must be installed in accordance with section 59 of this rule. For elevated sand mound systems, if the depth of the seasonal high water table is less than twenty (20) inches below the ground surface, drainage must be installed in accordance with section 59 of this rule. 3See Sections 58(a)(2)(E), 58(a)(2), 70(b)(6), 71(b)(3)(B), 71(c)(3)(B), 71(d)(2)(B) 71(b)(3), 71(c)(3), 71(d)(2), and 72(b)(5). This chart does not include considerations such as the specific landscape features that must be met, the size of the soil absorption system, the size of the area necessary for construction of the soil absorption system on the contour, with necessary setback and separation distances, dispersal area, the diversion of surface drainage, the feasibility of subsurface drainage, the ability to obtain easements, etc. This chart does not take into consideration the necessity to pump the effluent to overcome differences in elevation (when a subsurface trench gravity system might otherwise be constructed). Sec. 74. (a) The minimum absorption area, in square feet, required for each subsurface trench soil absorption system shall must be based on the following: Area = 150 g × number of bedrooms and bedroom equivalents Design Daily Flow (in gpd) Soil loading rate in gpd/sq. ft. gpd/sq. ft2 (b) The area of the on-site sewage system and dispersal area must be protected from disturbance before, during, and after construction of the system. The local health department may require: (b) (c) Subsurface trench soil absorption systems shall must be as long and narrow as the site permits while not exceeding maximum trench length. (c) All (d) Subsurface trench on-site sewage systems shall must be located in accordance with the separation distances shown in Table I in section 57(a) of this rule. (d) (e) Special caution shall must be taken to prevent wheeled and tracked vehicles from compacting the area selected for placement of the soil absorption system before, during, and after construction of the trenches, especially during wet weather. Alteration of soil structure by movement of vehicles may be grounds for rejection of the site or the soil absorption system, or both. (e) (f) Subsurface soil absorption systems shall must not be constructed during periods of wet weather when the soil is sufficiently wet at the depth of installation to exceed its plastic limit, as follows: (f) (g) Vegetation at the soil absorption system site that would interfere with the soils evaluation, system layout, or system construction shall must be cut and removed prior to before installation without causing compacted soil material. (g) (h) If trees are present within the proposed soil absorption system: (h) (i) Excessive smearing of the usable absorption trench sidewalls or bottom during construction may: (i) The (j) A residential sewer shall must be a minimum of at least four (4) inches in diameter. Four (4) inch sewers shall must be installed with a positive slope of: (j) (k) A six (6) inch residential sewer, if utilized, shall used, must be installed with a positive slope of: (k) (l) A vertical drop may be installed in a residential sewer. Each vertical drop shall must have a cleanout located immediately upslope. (l) (m) Effluent sewers shall must meet the following requirements: (m) All (n) Sewer and effluent sewer joints shall must be sealed according to the manufacturer's recommendations in order to be watertight and to withstand the pressures exerted on them. (n) (o) The absorption trenches of a subsurface trench soil absorption system shall must be constructed along the contour. (o) (p) The minimum depth from original grade to the bottom of a trench of a subsurface trench soil absorption system shall must not be less than ten (10) inches, and the maximum depth from final grade to the bottom of a trench of a subsurface trench soil absorption system shall must not be more than thirty-six (36) inches. (p) All (q) Subsurface trench soil absorption systems shall must be designed to utilize use trenches with a minimum width of eighteen (18) inches and a maximum trench width of thirty-six (36) inches. (q) (r) There shall must be a minimum separation of seven and one-half (7½) feet, on center, between soil absorption system trenches, measured perpendicular to the trenches. (r) (s) No single absorption trench in a subsurface trench soil absorption system shall may exceed one hundred (100) feet in length, except for subsurface trench pressure distribution on-site sewage systems. (s) (t) Each trench and distribution lateral in a subsurface trench soil absorption system shall must be uniformly level throughout its length and width. (t) (u) The distal ends of distribution laterals and trenches shall must not be tied together. (u) (v) The distal end of each distribution lateral shall must be capped, with the cap joint sealed according to the manufacturer's recommendations, in order to be watertight and to withstand the pressures exerted on it. (v) (w) Perforated pipe distribution laterals in the absorption trench of a subsurface trench soil absorption system shall must be completely surrounded by aggregate that meets the specifications in section 68 of this rule. There shall must be at least six (6) inches of aggregate below the pipe. (w) (x) The minimum depth of aggregate above the distribution laterals shall must be: (x) (y) The aggregate used in a subsurface trench soil absorption system shall must be covered with a geotextile fabric barrier in such a manner as to prevent way that prevents the aggregate from becoming clogged with the earth fill. The barrier material shall: must: (y) A minimum of (z) At least twelve (12) inches of cover shall must be provided over the aggregate in the trenches, and any fill required to provide cover shall must be crowned over the entire soil absorption system to promote surface runoff. (z) (aa) Tire chips, if used for aggregate, will have protruding wires and shall must be removed from the ground surface during site cleanup. Sec. 79. (a) The size of the aggregate bed shall must be determined from the following: minimum aggregate bed area (ft2) (AB) = DDF (150 gal. x number of bedrooms and bedroom equivalents)(in gpd) Design Daily Flow (in gpd) DDF (gpd) n < 1500 3 1501-3000 4 3001-4000 5 Minimum length of the aggregate bed (ABL) = Minimum aggregate bed area (AB) Maximum aggregate bed width (ABW) (b) The aggregate bed shall must be installed on the INDOT Specification 23 sand in the basal area, as listed in Table XV in section 80(j) of this rule. (c) The location of the aggregate bed shall must be: (d) The design of the aggregate bed shall must comply with the following: Figure 1, as follows, presents a visual depiction of the location of the aggregate bed within the basal area: Sec. 80. (a) The dimensions of the basal area shall must be as long and narrow as the site allows, in compliance with the requirements of subsection (c). (b) Numerical dimensions provided in this section for basal area and elevated sand mound size are rounded up to the nearest whole number. (c) The size of the basal area shall must be determined from the following: Minimum basal area (ft2)(BA) = DDF (150 gal. × number of bedrooms and bedroom equivalents)(in gpd) Design Daily Flow soil loading rate (SLR) (A) Minimum basal area width = minimum basal area (ft.2) (BA) ; or length of aggregate bed (ft) (ABL) (B) Slope Minimum Basal Area Width (BAW) 0% < slope < ½% Aggregate bed width + 14 ft. ½% > slope < 6% Aggregate bed width + 9 ft. (C) The dimensions determined from clause (A) or (B) for the INDOT Specification 23 sand shall must maintain a minimum sideslope grade of three-to-one (3:1). (d) The location of the basal area within the elevated sand mound shall must be: (e) The design of the basal area shall must be for: (f) The basal area shall must be constructed on the tilled surface of the soil absorption system site in accordance with the provisions of section 87 of this rule. (g) The long axis of the basal area and elevated sand mound shall must be constructed along the contour of the soil absorption system site. (h) The minimum depth of the INDOT Specification 23 sand under the aggregate bed shall must be twelve (12) inches. (i) The INDOT Specification 23 sand shall must have a minimum final grade on all sides of three-to-one (3:1). (j) The INDOT Specification 23 sand used in the elevated sand mound shall must meet the following standard: Table XV - INDOT Specification 23 Sand* Sieve Sizes Percent (%) Passing Sieve (by Weight) 3/8 in (9.50 mm) 100 No. 4 (4.75 mm) 95 - 100 No. 8 (2.36 mm) 80 - 100 No. 16 (1.18 mm) 50 - 85 No. 30 (600 μm) 25 - 60 No. 50 (300 μm) 5 - 30 No. 100 (150 μm) 0 - 10 No. 200 (75 μm) 0 - 3 *The sand shall must not have more than forty-five percent (45%) retained between any two (2) consecutive sieves. (k) Figure 1 in section 79(d) of this rule presents a visual depiction of the location of the basal area within the elevated sand mound. Sec. 81. (a) Numerical dimensions for the soil material cover from the edge of the basal area to the edge of the elevated sand mound are based on a final grade of three-to-one (3:1) (on level sites). The plan views and numerical dimensions are for a simple slope (a slope that forms a plane). Elevated sand mounds sited on complex slopes are more difficult to design and construct on contour. (b) The minimum length of an elevated sand mound shall must be the sum of the following: (c) The minimum width of the elevated sand mound shall must be determined from the following: Sec. 90. (a) The local health department shall issue a permit and require an inspection for the abandonment of an on-site sewage system in accordance with section 53(a)(9) of this rule. (a) (b) When the use of an on-site sewage system is discontinued, the following procedure must be followed for all tanks and electrical service: (b) (c) If there are no plans to use the area for other purposes, the components of the soil absorption system may be left intact. if there are no plans to use the area for other purposes. Vegetative cover must be maintained. (c) (d) If effluent has surfaced, those areas must be covered with hydrated lime followed by top soil and a vegetative cover. (d) (e) If components of the soil absorption system are to be removed, the following procedure must be used: (e) (f) Written documentation of tank pumping and system abandonment must be provided to the local health department by the homeowner in the form of a receipt from the contractor and landfill, if used. Sec. 91. (a) Bulletin S.E. 11, "The Sanitary Vault Privy", 2021 edition, is incorporated by reference as part of this rule. It is available at the Indiana Department at of Health, 2 North Meridian Street, Indianapolis, IN 46204. (b) NSF/ANSI Standard 40-2010 Standards 40-2023 and Standard 46-2010a 46-2020 are incorporated by reference as part of this rule. Two (2) copies of each standard are available for reference in the files of the department. Copies of the standards may be obtained by mailing a request to the National Sanitation Foundation, 789 North Dixboro Road, P.O. Box 130140, Ann Arbor, MI 48113-0140, or at www.techstreet.com/cgi-bin/joint.cgi/nsf. (c) ASTM Standards C 923-08, C 990-09, C 1644-06, C 923-20, C 990-24, C 1116-10a(2015), C 1644-24, D 1785-21a, D 2241-2020, D 2661-2021, D 2665-2020, D 2680-2020, D 2729-2021, D 3034-2021, D 2241-24, D 2661-24, D 2665-24, D 3034-24, D 4355-21, D 4491-2022, D 4533-15, D 4533-15(2023), D 4632-2023, D 4751-21a, D 6241-22a, F 405-05, F 480-14 (2022), F 667-16 (2021), and F 810-12 (2018), F 810-12(2024) are incorporated by reference as part of this rule. Two (2) copies of each standard are available for reference in the files of the department. ASTM standards may be obtained at http://www.astm.org/Standard/index.shtml. (d) AASHTO Standard M252-23 is incorporated by reference as part of this rule. Two (2) copies of the standard are available for reference in the files of the department. This standard may be obtained at https://store.transportation.org/Item/PublicationDetail?ID=5093. (e) NRCS Standard 606, July 2022, is incorporated by reference as part of this rule. Two (2) copies of the standard are available for reference in the files of the department. This standard may be obtained at https://www.nrcs.usda.gov/resources/guides-and-instructions/subsurface-drain-ft-606-conservation-practice-standard. (f) INDOT 2012 2024 Standard Specifications, Section 904, Aggregates, is incorporated by reference as part of this rule. Two (2) copies of the standard are available for reference in the files of the department. The standard may be obtained at https://www.in.gov/dot/div/contracts/standards/book/sep23/2024%20Standard%20Specifications.pdf. (g) NEMA 250-2008 250-2020 is incorporated by reference as part of this rule. Two (2) copies of the standard are available for reference in the files of the department. The standard may be obtained at https://www.nema.org/docs/default-source/standards-document-library/ansi_nema_250-2020-contents-and-scope76f809d7-afad-4aa1-80cd-e1d09b60f2e5.pdf?sfvrsn=cb4086bd_3. (h) IAPMO Z1000-2019, Prefabricated Septic Tanks, is incorporated by reference as part of this rule. Two (2) copies of the standard are available for reference in the files of the department. The standard may be obtained at https://webstore.ansi.org/SDO/IAPMO?gclid=EAIaIQobChMI-8P-vZLJ-QIVn8mUCR2xTQxTEAAYASAAEgJ9K_D_BwE. (i) Soil Taxonomy: A Basic System of Soil Classification for Making and Interpreting Soil Surveys, Second Edition, USDA, 1999 is incorporated by reference as part of this rule. This document may be obtained at https://nrcspad.sc.egov.usda.gov/DistributionCenter/pdf.aspx?productID=703. LSA Document #26-64 Last Hearing Held: April 15, 2026 Documents Incorporated by Reference: NSF/ANSI Standards 40-2023 and 46-2020; ASTM Standards C 923-20, C 990-24, C 1116-10a(2015), C 1644-24, D 2241-24, D 2661-24, D 2665-24, D 3034-24, D 4533-15(2023), and F 810-12(2024); INDOT 2024 Standard Specifications, Section 904, Aggregates; NEMA 250-2020; IAPMO Z1000-2019, Prefabricated Septic Tanks; Soil Taxonomy: A Basic System of Soil Classification for Making and Interpreting Soil Surveys, Second Edition, USDA, 1999 Small Business Regulatory Coordinator: Z. Claire Dyer, Advisory Chief, Indiana Department of Health, 2 North Meridian Street, Indianapolis, IN 46204, (317) 454-0040, ZDyer@health.in.gov