64E-6.018. System Location, Design and Maintenance Criteria

Table III of Chapter 64E-6, Part I, F.A.C., and other subsections of Part I pertaining to soil texture, soil depth, and maximum sewage loading rates for specific soils shall not apply to areas subject to the provisions of this Part except for Table III, Footnote 2., as it relates to the falling head percolation test procedure. However, approved system design criteria, system location, operation, maintenance and monitoring requirements of subsections 64E-6.018(1), (2), (3), and (4), F.A.C., shall apply. A minimum of one soil profile and one percolation test per application shall be required for site evaluations performed in the Florida Keys. However, a soil profile and percolation test is not required when the system design engineer chooses the use of an injection well for effluent disposal. All new onsite sewage treatment and disposal systems shall be performance-based treatment systems designed by an engineer licensed in the State of Florida and shall meet the minimum level of waste treatment as defined in Rule 64E-6.017, F.A.C. All receptacles subject to a positive buoyancy exposure shall be anchored or otherwise weighted to prevent flotation during flooding periods. The receptacles shall be evaluated for buoyancy while in their normal operating condition.

(1) An onsite sewage treatment and disposal system which meets the location, construction, maintenance and operational requirements of paragraphs 64E-6.018(1)(a) or (b), F.A.C., shall be approved, provided that if an aerobic treatment unit is a component of the system design, the certification, construction, operational and maintenance requirements of Rule 64E-6.012, F.A.C., shall also be met.

(a) When final effluent disposal is into a nutrient reducing material-lined drainfield system, the following general requirements shall apply:

1. The county health department shall require the installer of a nutrient reducing material lined drainfield system to provide certification from the installer’s nutrient reducing material supplier that the material supplied for such type of installations meets the requirements of this subsection.

2. No part of the system shall be within 25 feet of the boundaries of surface water bodies or salt marsh and Buttonwood Association habitat areas where the dominant vegetation species are those typical of salt marsh communities.

3. The bottom surface of the nutrient reducing material layer shall be at least 12 inches above mean high water.

4. Appropriate shallow root vegetative cover shall be established over drainfield systems to maximize the beneficial effects of evapotranspiration.

5. Nutrient reducing material has a finite life span. The nutrient reducing material shall be replaced as necessary to ensure that the system continues to meet the minimum level of waste treatment.

(b) An injection well shall be approved for final effluent disposal provided setbacks from salt marsh/buttonwood habitats and other surface water bodies cannot be met by another effluent disposal system noted above, and provided the installation is in compliance with the following:

1. An injection well shall not be permitted or installed under the provisions of this part in any area designated by the United States Environmental Protection Agency or the Florida Department of Environmental Protection as having a single or sole source aquifer. Single source aquifer is defined in subsection 62-520.200(14), F.A.C.

2. In areas where injection wells are approved for use, the DOH Monroe County Health Department shall be the permitting authority for the engineer designed onsite sewage treatment unit and the injection well, where the estimated daily domestic sewage flow will not exceed 2000 gallons per day. For establishments having a total daily sewage flow greater than 2000 gallons per day but not greater than 10,000 gallons per day, the Monroe County Health Department shall be the permitting authority for the engineer designed treatment unit and DEP is the permitting authority for the injection well and any additional associated effluent treatment device.

3. The ground surface within a distance of at least 10 feet in all directions around the injection well and any portion of the onsite sewage treatment and disposal system shall not be subject to surface or ground water flooding. In addition, the invert of the effluent inlet pipe to the injection well shall be a minimum 18 inches above the estimated seasonal high water level.

4. If there is adequate vertical and horizontal clearance to allow for proper maintenance, repair or replacement of the treatment unit and injection well, such components of the onsite sewage treatment and disposal system shall be allowed to be placed beneath an elevated building.

5. Prior to discharge into an injection well, effluent shall be disinfected by chlorination or other disinfection method approved by the State Health Office. A minimum disinfection level equivalent to a free chlorine residual of 0.5 milligrams per liter measured at the point of effluent discharge after a minimum chlorine contact time of 15 minutes into the injection well, shall be maintained in the effluent at all times.

6. An injection well to receive an estimated daily domestic sewage flow not exceeding 2000 gallons per day shall meet minimum construction criteria a., b. and c. of this sub-paragraph. The Monroe County Health Department shall be notified by the well driller the time when the well will be drilled so the county health department can schedule observation of well construction. The DOH Monroe County Health Department shall not approve an injection well for use until the well driller has certified, in writing to the DOH Monroe County Health Department, that the well has been installed in compliance with the provisions of this sub-paragraph. The inspection fee for the construction of an injection well shall be $125.00.

a. An injection well as defined in subsection 64E-6.017(3), F.A.C., shall be constructed, in part, utilizing a casing of polyvinyl chloride, commonly referred to as PVC. The minimum PVC casing weight and strength classification shall be schedule 40 and the minimum outside diameter of the casing shall be 4 inches. Other casing materials having strength and corrosion resistance properties equal to or greater than PVC schedule 40 pipe shall also be approved.

b. An open hole having a minimum diameter of 6 inches shall extend to a depth of not less than 30 feet below the bottom of the casing.

c. The annular space between the casing and the natural rock wall of the borehole shall be grouted the full length of the casing.

7. A minimum of one maintenance visit every four months shall be made to those systems using injection wells for effluent disposal. The visit shall include an inspection of the chlorination unit and any filter units. When an aerobic treatment unit is a component of the onsite sewage treatment and disposal system, documents and reports required in Rule 64E-6.012, F.A.C., shall also include the results of aerobic treatment unit inspections and shall include information on chlorine residuals to assess compliance with the disinfection requirements of this rule.

8. If an injection well is discontinued for effluent disposal the injection well shall be properly abandoned and plugged by filling the injection well from bottom to top with cement grout.

(2) For an aerobic treatment unit treating domestic sewage flows in excess of 1500 gallons per day but not exceeding 10,000 gallons per day, where effluent from the treatment unit will be discharged to an engineer designed soil absorption drainfield system, the following requirements shall be met:

(a) The soil absorption drainfield system shall be set back from surface water bodies by the greatest distance attainable, but shall meet at least minimum setback and elevation requirements specified in subsection 64E-6.018(1), F.A.C.

(b) The owner or lessee of a system shall comply with the general maintenance and operational requirements of subsections 64E-6.012(2) and (3), F.A.C., and any additional operation and maintenance requirements specified by the system design engineer.

(3) The owner or lessee of a performance-based treatment system shall obtain and maintain a maintenance contract with an approved maintenance entity.

(a) All new onsite sewage treatment and disposal systems shall be inspected by an approved maintenance entity at least two times each year.

(b) A maintenance report shall be kept by the maintenance entity. A copy of all maintenance reports shall be provided to the county health department. The report shall include the following information:

1. The address of the system.

2. Date and time of inspection.

3. Sample collection time and date, and person who collected sample.

4. Results of all sampling.

5. Volume of effluent treated, to include total monthly and daily average.

6. Maintenance performed.

7. Problems noted with the treatment system and actions taken or proposed to overcome them.

(4) In conjunction with the systems specified in subsections 64E-6.018(1) and (2), F.A.C., an applicant may use the alternative systems described in subsection 64E-6.009(1), (3), (4), (5) or (6), F.A.C. An alternative system shall meet the general intent of Part I and Part II of this rule.

Rulemaking Authority 381.0011(4), (13), 381.006, 381.0065(3)(a) FS., Ch. 99-395, LOF. Law Implemented 381.0065, 381.00655 FS., Ch. 99-395, LOF. History–New 7-15-86, Amended 3-17-92, 1-3-95, Formerly 10D-6.063, Amended 3-3-98, 3-22-00, 4-21-02, 11-26-06.