All onsite sewage treatment and disposal systems must be located and installed so that with proper maintenance the onsite sewage treatment and disposal systems function in a sanitary manner, do not create sanitary nuisances or health hazards and do not endanger the safety of any domestic water supply, groundwater or surface water. Sewage waste and effluent from onsite sewage treatment and disposal systems must not be discharged onto the ground surface or directly or indirectly discharged into ditches, drainage structures, ground waters, surface waters, or aquifers. To prevent such discharge or health hazards:

1. (1) Onsite sewage treatment and disposal systems established after the effective date of the rule must be placed no closer than the minimum distances indicated for the following:

   1. (a) Seventy-five feet from a private potable well as defined in Rule 62-6.002, F.A.C., or a multi-family water well as defined in Rule 62-6.002, F.A.C.
   2. (b) One-hundred feet from a public drinking water well as defined in Rule 62-6.002, F.A.C., if such a well serves a facility with an estimated sewage flow of 2,000 gallons or less per day.
   3. (c) Two-hundred feet from a public drinking water well as defined in Rule 62-6.002, F.A.C., if such a well serves a facility with an estimated sewage flow of more than 2,000 gallons per day.
   4. (d) Fifty feet from a non-potable water well as defined in Rule 62-6.002, F.A.C.
   5. (e) Ten feet from any storm sewer pipe, to the maximum extent possible, but in every instance the setback must not be less than 5 feet.
   6. (f) Fifteen feet from the design high-water line of retention areas, detention areas, or swales designed to contain standing or flowing water for less than 72 hours after a rainfall or the design high-water level of normally dry drainage ditches or normally dry individual-lot stormwater retention areas.

2. (2) Onsite sewage treatment and disposal systems must not be located under buildings or within 5 feet of building foundations, including pilings for elevated structures, or within 5 feet of mobile home walls, swimming pool walls, or within 5 feet of property lines except where property lines abut utility easements which do not contain underground utilities, or where recorded easements are specifically provided for the installation of onsite sewage treatment and disposal systems for service to more than one lot or property owner.

   1. (a) Sidewalks, decks and patios are not subject to the 5 foot setback, however, drainfields must not be installed beneath such structures. Any tank located beneath a driveway must have traffic lids as specified in paragraph 62-6.013(1)(f), F.A.C. Concrete structures, which are intended to be placed over a septic tank, must have a barrier of soil or plastic material placed between the structure and the tank so as to preclude adhesion of the structure to the tank.
   2. (b) Onsite sewage treatment and disposal systems must not be located within 10 feet of water storage tanks in contact with the ground or potable water lines unless such lines are sealed with a water proof sealant within a sleeve of similar material pipe to a distance of at least 10 feet from the nearest portion of the onsite sewage treatment and disposal system or the water lines themselves consist of schedule 40 PVC or stronger. The water line must not be located within 24 inches of the onsite sewage treatment and disposal system. Potable water lines within 5 feet of the drainfield must not be located at an elevation lower than the drainfield absorption surface. Irrigation lines as referred to in Section 381.0065(2)(o), F.S., and water lines connected to a non-potable water supply must not be located within 24 inches of the onsite sewage treatment and disposal system without backflow devices per Section 381.0065(2)(o)1. and 2., F.S., being installed on the water line to preclude contamination of the water system.
   3. (c) Onsite sewage treatment and disposal systems must be setback a minimum of 15 feet from groundwater interceptor drains.
3. (3) Except for the provisions of Sections 381.0065(4)(g)1. and 2., F.S., onsite sewage treatment and disposal systems must not be located laterally within 75 feet of the boundaries of surface water bodies. Onsite sewage treatment and disposal systems must be located a minimum of 15 feet from the design high water line of a swale, retention or detention area designed to contain standing or flowing water for less than 72 hours after a rainfall, or the design high water level of normally dry drainage ditches or normally dry individual lot storm water retention areas.

4. (4) Suitable, unobstructed land must be available for the installation and proper functioning of the onsite sewage treatment and disposal system. The minimum unobstructed area must:

   1. (a) Be at least 1.5 times as large as the drainfield absorption area required by rule. For example, if a 200 square feet drainfield is required, the total unobstructed area required, inclusive of the 200 square feet drainfield area, would be 300 square feet. Unobstructed soil area between drain trenches is included in the unobstructed area calculation.
   2. (b) Be contiguous to the drainfield.
   3. (c) Be in addition to the setbacks required in subsections (1), (2), and (3) above.
5. (5) Onsite sewage treatment and disposal systems if installed in fill material, the fill must be required to settle for a period of at least 6 months, or has been compacted to a density comparable to the surrounding natural soil. The fill material must be of a suitable, slightly limited soil material.
6. (6) To prevent soil smear and excessive soil compaction, drainfields must not be installed in soils with textures finer than sand, loamy sand, or sandy loam when the soil moisture content is above the point at which the soil changes from semi-solid to plastic.

7. (7) Onsite sewage treatment and disposal systems must be installed where a sewerage system is not available and when conditions in Section 381.0065(4), F.S., are met. Onsite graywater tank and drainfield systems may, at the homeowners’ discretion, be utilized provided blackwater is disposed into a sanitary sewerage system when such sewerage system is available. Graywater systems may, at the homeowners’ discretion, be utilized in conjunction with an onsite blackwater system where a sewerage system is not available for blackwater disposal. To establish compliance with Sections 381.0065(4)(a)-(g), F.S., the following are required:

   1. (a) The lot area under Section 381.0065(4)(a), F.S., must consist of at least 1/2 acre (21,780 square feet). Contiguous area outside of the lot must not be included in the determination of the lot area. Residential lots platted and recorded or approved on or after January 1, 1972, but before January 1, 1983, that do not meet the lot area or dimension requirements of Section 381.0065(4)(a), F.S., must install one of the following to address this deficiency and comply with current rules to the maximum extent possible as required pursuant to Section 381.0065(4)(g)1., F.S.:

      1. An enhanced nutrient-reducing onsite sewage treatment and disposal system defined in Section 381.0065(2)(f), F.S., provided the authorized daily sewage flow allowance pursuant to paragraph 62-6.005(7)(c), F.A.C., and all required setbacks are met, or

      2. A performance-based treatment system that is designed to meet, at minimum, Advanced Secondary Treatment Standards pursuant to Table IXb, found in paragraph 62-6.025(11)(d), F.A.C., and will maintain a 24-inch separation between the bottom of the drainfield and the water table elevation during the wettest season pursuant to subsection 62-6.006(2), F.A.C., provided that:

      a. The estimated daily sewage flow does not exceed what is allowed by subsection 62-6.028(2), F.A.C.,

      b. The system must maintain the maximum practicable setback, up to the setback in accordance with paragraph 62-6.005(1)(a), F.A.C., to private potable wells, and in no case will the setback to a private potable well be reduced below 50 feet, and

      c. All other setback reductions must comply with paragraph 62-6.028(1)(b), F.A.C.

   2. (b) The determination of lot densities under Section 381.0065(4)(b), F.S., must be made on the basis of the net acreage of the subdivision which must exclude from the gross acreage all paved areas and prepared road beds within public or private rights-of-way or easements and must also exclude surface water bodies. Residential lots platted and recorded or approved on or after January 1, 1972, but before January 1, 1983, that do not meet the lot density requirements of Section 381.0065(4)(b), F.S., must install one of the following to comply with current rules to the maximum extent possible as required pursuant to Section 381.0065(4)(g)1., F.S.:

      1. An enhanced nutrient-reducing onsite sewage treatment and disposal system defined in Section 381.0065(2)(f), F.S., provided the authorized daily sewage flow allowance pursuant to paragraph 62-6.005(7)(c), F.A.C., is met, and all required setbacks are met, or

      2. A performance-based treatment system that is designed to meet, at minimum, Advanced Secondary Treatment Standards pursuant to Table IXb, found in paragraph 62-6.025(11)(d), F.A.C., and will maintain a 24-inch separation between the bottom of the drainfield and the water table elevation during the wettest season pursuant to subsection 62-6.006(2), F.A.C., provided that:

      a. The estimated daily sewage flow does not exceed what is allowed by subsection 62-6.028(2), F.A.C.,

      b. The system must maintain the maximum practicable setback, up to the setback in accordance with paragraph 62-6.005(1)(a), F.A.C., to private potable wells, and in no case will the setback to a private potable well be reduced below 50 feet, and

      c. All other setback reductions comply with paragraph 62-6.028(1)(b), F.A.C.

   3. (c) Authorized daily sewage flow allowances specified in Sections 381.0065(4)(a), (b) and (g), F.S., are calculated on an individual lot by lot or parcel of land basis based on its net usable area in acres. The net usable area of each lot or parcel of land does not include paved areas and prepared road beds within public rights-of-way or easements and does not include surface water bodies. At the option of the permit applicant and with approval of the Department, contiguous unpaved and non-compacted road rights-of-way and easements with no subsurface obstructions that would affect the operation of drainfield systems may be included in determining the net usable area. Where an unobstructed easement is contiguous to two or more lots, each lot will receive a pro rata share of the area contained in the easement. The authorized daily sewage flow allowed equals the net usable area multiplied by 2,500 gallons per acre per day if a public drinking water system as defined in subparagraphs 62-6.002(47)(b)1., 2., or 3., F.A.C., is utilized, or multiplied by 1,500 gallons per acre per day if a limited use public water system as defined in subparagraph 62-6.002(47)(b)4., F.A.C., or a private potable well, multi-family water well, cistern, or other private or certain public water systems regulated under Section 381.0062, F.S., is utilized. Subsection 62-6.008(1), F.A.C., must be used for determining estimated daily sewage flows.
   4. (d) Platted residential lots are subject to the requirements set forth in Sections 381.0065(4)(g)1. and 2., F.S.
   5. (e) When portions of a lot or lots which were platted prior to January 1, 1972, are combined in such a manner that will decrease the total density of the subdivision, pre-1972 lot provisions apply. However, the maximum setback possible to surface water bodies must be maintained with a minimum setback of 50 feet.

8. (8) Notwithstanding the requirements of this section, where an effluent transmission line consists of schedule 40 PVC, the transmission line must be set back from private potable wells, irrigation wells or surface water bodies by not less than 25 feet when installed. Effluent transmission lines constructed of schedule 40 PVC must be set back from property lines and building foundations by not less than 2 feet. Schedule 40 PVC effluent transmission lines must be set back from potable water lines and storm water lines by no less than 5 feet unless all portions of the potable water line or storm water line within 5 feet of the effluent transmission line are:

   1. (a) A minimum of 12 inches above the top of the effluent transmission line; and,
   2. (b) Sealed with a waterproof sealant within a sleeve of schedule 40 PVC or stronger pipe or the water line itself consists of schedule 40 PVC or stronger pipe.

9. (9) Onsite sewage treatment and disposal systems for estimated establishment domestic sewage flows exceeding 5,000 gallons per day but not exceeding 10,000 gallons per day must be located and installed under the following conditions.

   1. (a) The estimated daily sewage flow from the establishment will be divided by the net usable area associated with the establishment. The resulting number must not exceed 2,500 gallons per acre per day for establishments which use a public water system, as defined in subparagraphs 62-6.002(47)(b)1., 2. and 3., F.A.C.
   2. (b) No more than 5,000 gallons of wastewater will be discharged into any single onsite sewage treatment and disposal system serving the establishment.

Rulemaking Authority 381.0065(3)(a), 381.0065(4)(e) FS. Law Implemented 381.0065 FS. History–New 12-22-82, Amended 2-5-85, Formerly 10D-6.46, Amended 3-17-92, 1-3-95, Formerly 10D-6.046, Amended 11-19-97, 2-3-98, 3-22-00, 5-24-04, 6-25-09, Formerly 64E-6.005, Amended 6-21-22, 6-8-26.