Location and Installation, System Size Determinations, Alternative Systems

DEPARTMENT OF HEALTH
Division of Environmental Health

RULE NO: RULE TITLE
64E-6.005: Location and Installation
64E-6.008: System Size Determinations
64E-6.009: Alternative Systems

NOTICE OF CHANGE

Notice is hereby given that the following changes have been made to the proposed rule in accordance with subparagraph 120.54(3)(d)1., F.S., published in Vol. 35 No. 9, March 6, 2009 issue of the Florida Administrative Weekly.

64E-6.005 Location and Installation

(1) through (3) No change.

(4) Suitable, unobstructed land shall be available for the installation and proper functioning of the system. At least 75 percent of the unobstructed area must meet minimum setback requirements of subsections (1) and (3) above to allow for drainfield repair or system expansion. The minimum unobstructed area shall:

(a) Be at least 1.5 2 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 300 400 square feet. Unobstructed soil area between drain trenches shall be included in the unobstructed area calculation.

(b) Be contiguous to the drainfield.

(c) Be in addition to the setbacks required in subsections (1), (2), and (3) above.

(5) through (9) No change.

Rulemaking Specific Authority 381.0065(3)(a), 489.553, 489.557(1) FS. Law Implemented 381.0065, 489.553 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,________.

 

64E-6.008 System Size Determinations.

(1) through (4) No change.

(5) The minimum absorption area for standard subsurface drainfield systems, graywater drainfield systems, and filled systems shall be based on estimated sewage flows and Table III so long as estimated sewage flows are 200 gallons per day or higher. When estimated sewage flows are less than 200 gallons per day, system size shall be based on a minimum of 200 gallons per day.

 

TABLE III For Sizing of Drainfields Other Than Mounds
U.S. DEPARTMENT OF AGRICULTURE SOIL TEXTURAL CLASSIFICATION	SOIL TEXTURE LIMITATION (PERCOLATION RATE)	MAXIMUM SEWAGE LOADING RATE TO TRENCH & BED ABSORPTION SURFACE IN GALLONS PER SQUARE FOOT PER DAY
		TRENCH	BED
Sand; Coarse Sand not	Slightly limited	0.80 1.20	0.60 0.80
associated with a	(Less than 2 min/inch)
seasonal water table
of less than 48 inches;
and Loamy Coarse Sand
Loamy Sand; Sandy Loam;	Slightly limited
Coarse Sandy Loam;	(2-4 min/inch)	0.80 0.90	0.60 0.70
Fine Sand Loam; Fine Sandy Loam;	Moderately limited
Silt Loam; Very Fine	(5-10 min/inch)	0.65	0.35
Sand; Very Fine Sandy
Loam; Loamy Fine Sand;
Loamy Very Fine Sand;
Sandy clay loam;
Clay Loam; Silty Clay	Moderately limited	0.35	0.20
Loam; Sandy Clay;	(Greater than 15
Silty Clay, Silt	min/inch but not
	exceeding 30 min/inch)
Clay; Organic Soils;	Severely limited	Unsatisfactory for standard subsurface system Unsatisfactory for standard subsurface system
Hardpan; Bedrock	(Greater than 30
	min/inch)
Coarse Sand with	Severely limited
an estimated wet season	(Less than 1
high water table within	min/inch and a
48 inches of the bottom	water table less
of the proposed	than 4 feet below
drainfield; Gravel or	the drainfield)
Fractured Rock or
Oolitic Limestone
Footnotes to Table III

 

1. through 2. No change.

3. When all other site conditions are favorable, horizons or strata of moderately or severely limited soil may be replaced with slightly limited soil or soil of the same texture as the satisfactory slightly limited permeable layer lying below the replaced layer. The slightly limited permeable layer below the replaced layer shall be identified within the soil profile which was submitted as part of the permit application. The resulting soil profile must show complete removal of the moderately or severely limited soil layer being replaced and must be satisfactory to a minimum depth of 54 inches beneath the bottom surface of the proposed drainfield. The width of the replacement area shall be at least 2 feet wider and longer than the drain trench and for absorption beds shall include an area at least 2 feet wider and longer than the proposed bed. Drainfields shall be centered in the replaced area. Where at least 33 percent of the moderately limited soils at depths greater than 54 inches below the bottom of the drainfield have been removed to the depth of slightly limited soil, drainfield sizing shall be based on the following sewage loading rates. Where severely limited soils are being removed at depths greater than 54 inches below the bottom of the drainfield, 100 percent of the severely limited soils at depths greater than 54 inches shall be removed down to the depth of an underlying slightly limited soil. Maximum sewage loading rates for standard subsurface systems installed in replacement areas shall be 0.80 0.90 gallons per square foot per day for trench systems and 0.60 0.70 gallon per square foot per day for absorption beds in slightly limited soil textures. Where moderately limited soil materials are found beneath the proposed drainfield, and where system sizing is based on that moderately limited soil, soil replacements of less than 33% may be permitted.

4. Where coarse sand, gravel, or oolitic limestone directly underlies the drainfield area, the site shall be approved provided a minimum depth of 42 inches of the rapidly percolating soil beneath the bottom absorption surface of the drainfield and a minimum 12 inches of rapidly percolating soil contiguous to the drainfield sidewall absorption surfaces, is replaced with slightly limited soil material. Where such replacement method is utilized, the drainfield size shall be determined using a maximum sewage application rate of 0.80 gallons per square foot per day of drainfield in trenches and 0.60 0.70 gallon per square foot per day for drainfield absorption beds.

5. No change.

(6) No change.

Rulemaking Specific Authority 381.0065(3)(a) FS. Law Implemented 381.0065 FS. History–New 12-22-82, Amended 2-5-85, Formerly 10D-6.48, Amended 3-17-92, 1-3-95, Formerly 10D-6.048, Amended 11-19-97, Amended 3-22-00, 9-5-00, 11-26-06,________.

 

64E-6.009 Alternative Systems.

Unnumbered introductory paragraph – No change.

(1) through (2) No change.

(3) Mound systems – are used to overcome certain limiting site conditions such as an elevated seasonal high water table, shallow permeable soil overlying slowly permeable soil and shallow permeable soil located over creviced or porous bedrock. Special installation instructions or design techniques to suit a particular site shall, using the criteria in subsection 64E-6.004(4), F.A.C., be specified on the construction permit in addition to the following general requirements.

(a) through (c) No change.

(d) Where the soil material underlying a mound system is of a similar slightly limited textural material as that used in system construction, the mound drainfield size shall be based on estimated sewage flows as specified in Rule 64E-6.008, F.A.C., Table I and upon the quality of fill material utilized in the mound system. When estimated sewage flows are calculated to be less than 200 gallons per day, specifications for system design shall be based on a minimum flow of 200 gallons per day. Maximum sewage loading rates for soils used in mound construction shall be in compliance with the following:

 

Fill Material	Maximum Sewage Loading	Maximum Sewage Loading
	Rate to Mound Drain	Rate to Mound Absorption
	Trench Bottom Surface	Bed Bottom Surface in
	in gallons per square	gallons per square foot
	foot per day	per day
Sand; Coarse Sand;	0.80 1.00	0.600.75
Loamy Coarse Sand;
Fine Sand;	0.80	0.600.65
Sandy Loam; Coarse	0.65	0.40
Sandy Loam; Loamy Sand
Fine Sandy Loam;	0.35	0.25
Very Fine Sand; Loamy Fine Sand;
Loamy Very Fine Sand

 

(e) through (i) No change.

(4) through (10) No change.

Rulemaking Specific Authority 381.0065(3)(a) FS. Law Implemented 381.0065 FS. History–New 12-22-82, Amended 2-5-85, Formerly 10D-6.49, Amended 3-17-92, 1-3-95, Formerly 10D-6.049, Amended 11-19-97, 2-3-98, 3-22-00, 4-21-02, 06-18-03, 11-26-06,________.