62-660.801. General Permit for a Wastewater Disposal System for a Laundromat

(1) General Requirements.

(a) This rule authorizes a general permit for any person constructing or operating a wastewater disposal system for a laundromat designed and operated in accordance with this rule, provided that all the conditions of this rule are met.

(b) This general permit shall be subject to the general conditions of Rule 62-4.540, F.A.C.

(c) The permittee shall complete and submit DEP Form 62-660.900(4), Laundromat General Permit Notification Form, effective 1-2-91, which is adopted and incorporated herein by reference, and required information 30 days before use of this general permit. This form may be obtained by contacting the appropriate district office or by writing the Department of Environmental Protection, Bureau of Water Facilities Planning and Regulation, 2600 Blair Stone Road, MS3535, Tallahassee, Florida 32399-2400.

(d) Within 30 days after construction is complete, the engineer of record or another registered professional engineer shall certify to the Department, using DEP Form 62-660.900(2), Industrial Wastewater Facilities Certificate of Completion of Construction, that the permitted construction is complete and usable and that it was done in accordance with the plans submitted to the Department except when minor deviations were necessary. These deviations and the reasons for them shall be described in detail.

(e) There shall be no discharge of dry cleaning materials.

(f) This general permit does not relieve the permittee of the responsibility for obtaining any other permits required by the Department or any other federal, state, or local agency.

(g) The design volume of flow shall be less than 10,000 gallons per day. The design flow shall be determined by multiplying the maximum hourly rate by 12. The maximum hourly rate shall be based on the number of washing machines, the water used per cycle, and the maximum expected number of cycles per machine per hour.

(2) Treatment System Design Requirements. All design calculations and drawings shall be submitted with the notification form, DEP Form 62-660.900(4), Laundromat General Permit Notification Form. Either a trickling filter or a sand filter system shall be constructed using all of the components and the design criteria listed below. The chlorination and disposal system components and design criteria listed in subsections (3) and (4) of this rule are required of all systems.

(a) Trickling filter systems shall include, at a minimum, the following components:

1. A screen chamber that contains at least four non-corrosive screens: two 1/4-inch screens followed by two 1/8-inch screens.

2. A primary settling tank that provides a minimum of four hours’ detention based on the maximum hourly rate.

3. A sump pump with an effective capacity equal to, or greater than, the maximum hourly rate.

4. A recirculation pump that provides a minimum recirculation ratio of 2:1, and that is piped to provide continuous dosing of the filter 24 hours per day.

5. The following design criteria, if the trickling filter uses rock media:

a. Crushed rock, slag, or an inert manufactured material that will pass through a 3 1/2-inch square screen and that will be retained on a 2-inch screen.

b. A filter depth of at least 6 feet.

c. A hydraulic loading not to exceed 460 gallons per square foot per day.

d. An organic loading not to exceed 1.24 pounds of BOD per cubic yard per day.

6. The following design criteria, if the trickling filter uses plastic filter media:

a. A filter depth based on expected performance.

b. A hydraulic loading not to exceed 1840 gallons per square foot per day.

c. An organic loading not to exceed 5 pounds of BOD per cubic yard per day.

7. A distribution system, such as a reaction type distributor, to provide uniform application of waste influent over the filter.

8. Underdrains sloped to prevent ponding and designed to provide adequate ventilation to allow a free flow of air through the filter.

9. A secondary settling tank that provides a minimum detention of one hour at the maximum hourly rate.

(b) Open sand filter systems shall include, at a minimum, the following components:

1. A screen chamber that contains at least four non-corrosive screens: two 1/4-inch screens followed by two 1/8-inch screens.

2. A primary settling tank that provides a minimum detention of four hours based on the maximum hourly rate.

3. At least two filter beds, allowing alternate loading and resting of the beds, with a maximum filter loading of 4.5 gallons per day per square foot.

4. A gravel base, placed in three layers, each at least six inches thick, over the underdrains. Suggested gradings for the three layers are: 1 1/2-inch to 3/4-inch; 3/4-inch to 1/4-inch; and 1/4-inch to 1/8-inch. Underdrains shall be sloped to the outlet, and spaced 10 feet on center. Alternate thicknesses and gradings for the gravel base may be used, provided the gravel base adequately supports the filter material, prevents the sand from entering the underdrains, and provides uniform flow over the gravel base and underdrains.

5. At least 30 inches of clean sand placed over the gravel base. The effective size of the sand shall be between 0.31 and 0.45 millimeters and the uniformity coefficient shall not be greater than 3.5.

(3) Chlorination Requirements.

(a) A chlorination tank shall be provided, designed for a minimum thirty minute contact time.

(b) A chlorine residual of at least 0.5 mg/l shall be maintained at all times.

(4) Disposal System Requirements.

(a) The disposal of wastewater shall be to either an absorption field designed in accordance with Rule 62-610.550, F.A.C., or to a percolation pond designed in accordance with Rule 62-610.500, F.A.C. The design of the absorption field or percolation pond shall be based on the results of soil testing and mounding analysis as required in paragraphs (b) and (c) below.

(b) At a minimum, the following soil tests shall be conducted at the disposal site to simulate actual loading conditions during the design life of the absorption field or percolation pond and to determine the horizontal and vertical permeabilities of the underlying strata. These tests shall be conducted at a frequency of one test per 1000 square feet of disposal area.

1. Double-ring infiltrometer tests.

2. Soil borings to a depth of at least ten feet below the disposal site. Lithologic logs of each boring shall be provided, along with permeability test results from each distinct soil stratum encountered.

(c) Based on test results in paragraph (b) above, the applicant shall perform a mounding analysis as described in subparagraph 62-610.310(3)(c)8., F.A.C.

Specific Authority 403.051, 403.814 FS. Law Implemented 120.55, 403.051, 403.061, 403.087, 403.088, 403.814 FS. History–New 11-27-89, Amended 1-2-91, 4-22-93, Formerly 17-660.801, Amended 12-24-96.