When approved by the Department, alternative systems may,
at the discretion of the applicant, be utilized in circumstances where standard
subsurface systems are not suitable or where alternative systems are more
feasible. Unless otherwise noted, all rules pertaining to siting, construction,
and maintenance of standard subsurface systems must apply to alternative
systems. In addition, the Department may, using the criteria in subsection
62-6.004(4),
F.A.C., require the submission of plans prepared by an engineer licensed in the
State of Florida, prior to considering the use of any alternative
system.
(1) Waterless, incinerating or
organic waste composting toilets - may be approved for use if found in
compliance with standards for Wastewater Recycle/Reuse and Water Conservation
Systems as defined by ANSI/NSF International Standard Number 41-2018
"Non-liquid Saturated Treatment Systems" (September 2018) or NSF International
Protocol P157-2019 "Incinerating Toilet Systems-Health and Sanitation" (January
2019) hereby adopted and incorporated by reference, and provided that graywater
and any other liquid and solid waste is properly collected and disposed of in
accordance with standards established in this chapter. These standards have
been deemed copyright protected and are available from the publisher at NSF
International, 789 North Dixboro Road Ann Arbor, Michigan 48105, or at
publisher's website at
www.nsf.org, and are
available for inspection as provided in subsection (11) below. For residences,
the required drainfield absorption surface and unobstructed area of the system
treating the remaining sewage flow must be reduced by 25% when waterless,
incinerating or organic waste composting toilets are used exclusively for all
toilet wastes. Solids removed from waterless, incinerating or organic waste
composting toilets must be mixed with lime, containerized, and disposed of with
the solid waste from the establishment. Liquids discharging from waterless,
incinerating or organic waste composting toilets must be plumbed into the
onsite system serving the establishment.
(2) Sanitary pit privy - shall not be
permitted except at remote locations where electrical service is unavailable.
In no case shall such installations be permitted for permanent
residences.
(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
62-6.004(4),
F.A.C., be specified on the construction permit in addition to the following
general requirements.
(a) Site preparation
must render the site in compliance with requirements of subsections
62-6.006(1)
-(6), F.A.C.
(b) Prior to the
construction of a mound system, the applicant may fill all or a portion of a
lot utilizing slightly limited soil.
(c) The O horizon of original topsoil and
vegetation must be removed from beneath the drainfield, shoulder and slope area
and the exposed underlying soil plowed or roughened to prevent formation of an
impervious barrier between the fill and natural soil. Moderately limited soil
material may be used in the construction of mound systems, but shall only be
used in the construction of mound slopes and the soil cap. If moderately or
severely limited soil is to be replaced beneath the mound, Rule
62-6.008, F.A.C., Table III,
footnote 3. shall be followed.
(d)
Where the soil material underlying a mound system is of a similar textural
material as that used in system construction, the mound drainfield size shall
be based on estimated sewage flows as specified in Rule
62-6.008, 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 Rate to
Mound Drain Trench Bottom Surface in gallons per square foot per
day
|
Maximum Sewage Loading Rate to
Mound Absorption Bed Bottom Surface in gallons per square foot per
day
|
|
Sand; Coarse Sand; and Loamy Coarse Sand
|
0.80
|
0.60
|
|
Fine Sand;
|
0.80
|
0.60
|
|
Sandy Loam; Coarse Sandy Loam; and Loamy
Sand
|
0.65
|
0.40
|
|
Fine Sandy Loam; Very Fine Sand; Loamy Fine Sand;
and Loamy Very Fine Sand
|
0.35
|
0.25
|
(e)
Where moderately limited soils underlie the mound within 36'' inches of the
bottom of the drainfield, drainfield sizing shall be based on the most
restrictive soil texture existing in the profile to a depth of 36'' inches
below the bottom of the drainfield, using Table III for soil loading
rates.
(f) There shall be a minimum
4' feet separation between the shoulder of the fill and the nearest trench or
absorption bed sidewall. Where a portion of the mound slope will be placed
adjacent to building foundations, pilings or supports for elevated structures,
mobile home walls, swimming pool walls, retaining walls, or similar
obstructions there shall be a minimum 5' foot separation between the sidewall
of the absorption area and the obstruction. Such obstructions shall impact the
slope on no more than 50 percent of the shoulder perimeter. Retaining walls
must be designed by a professional engineer licensed in the State of Florida to
withstand the lateral earth forces under saturated conditions and to prevent
seepage. Where mounds are placed on slopes exceeding 2 percent, the toe of the
slope on the downslope side of the mound shall extend an additional 4'' inches
for each additional 1 percent of slope. To taper the maximum elevation of the
mound at the outer perimeter of the shoulder down to the toe of the slope,
additional moderately or slightly limited fill shall be placed at a minimum 2'
foot horizontal to 1' foot vertical grade where mound height does not exceed
36'' inches. Mound heights which exceed 36'' inches shall have a slope not
steeper than 3' foot horizontal to 1' foot vertical. The entire mound including
slopes, shoulders and the soil cap shall be stabilized with vegetation. Slopes
steeper than 5:1 shall be sodded or hydroseeded. Soil caps and unsodded slopes
must, at a minimum, be hydroseeded or seeded with grass and a layer of hay or
similar cover. Where fill material is present in the amount so as to provide a
level surface from the top of the required cover over the system over the area
where the slopes would normally be located, no slopes shall be required. For
example, if the neighboring lot has been permanently filled to the same level
as the applicant's lot, a five-foot separation from the property line to the
system will be required, as opposed to requiring the slope area. Stabilization
of a mound shall be the responsibility of the septic tank contractor who
constructed the mound system unless the written agreement for system
construction clearly states the system owner is responsible. Mound slopes which
do not conform to permit requirements shall at a minimum be restored to permit
specifications prior to stabilizing. Other synthetic or vegetative covers
providing protection from mound erosion equal to or better than sod shall be
approved by the Department. Final installation approval shall not be granted
until sodding, hydroseeding, seeding and haying or other approved stabilization
of the mound has occurred. No portion of the drainfield or shoulder area shall
be covered with asphalt or a concrete driveway or be subject to vehicular
traffic. Landscaping features such as boulders or trees which obstruct
drainfield or fill shoulder area shall not be used. Hydroseeding shall be
performed in accordance with the product manufacturer's instructions and
Section 7.5, Permanent Seeding, of the Florida Erosion and Sedimentation
Control Inspector's Manual, July 2008, herein incorporated by
reference.
(g) There shall be a
soil cap of slightly or moderately limited soil material over the drainfield
and shoulder area. The soil cap shall be no less than 6'' inches thick at the
outer perimeter of the shoulder. Additional soil cap material shall be placed
over the mound and graded to provide drainage off and away from the mound. The
maximum depth from the bottom of the drainfield to the finished ground surface
shall not exceed 30 inches after natural settling.
(h) The site shall be landscaped according to
permit specifications and shall be protected from automotive traffic or other
activity that could damage the system. Swales or other surface drainage
structures shall be utilized to prevent water shed from mounds draining onto
neighboring property.
(i) All fill
material used in the construction of systems shall be free of extraneous
non-soil material such as grass, roots and any other debris. Shell fragments
less than 2.0 mm in diameter are excluded from the classification of extraneous
non-soil materials and are considered to be soil particles. Severely limited
soil material shall not be used in system construction. Fill material
consisting of mechanically crushed and sieved rock shall not be used in system
construction.
(j) Where moderately
limited soil is used to construct a mound system, a low pressure distribution
network is required.
(4)
Filled systems - filled systems shall be constructed in accordance with the
minimum requirements for mounds, except as provided for in footnote 5., Table
III, and that sewage loading rates to trench or absorption bed bottom areas
shall be based on values found in Table III.
(5) Drip irrigation systems - Drip irrigation
systems may, at the option of the applicant, be used in lieu of a mineral
aggregate drainfield. Drip irrigation systems must meet all requirements of
this chapter except as noted below.
(a) Drip
irrigation systems must receive effluent from an approved aerobic treatment
unit or a performance-based treatment system designed to meet at least
secondary treatment standards for CBOD
5 and TSS, and
must meet the following requirements:
1. Drip
irrigation systems shall be designed by an engineer licensed in the State of
Florida.
2. The infiltrative area
required shall be the same as the area required for a mineral aggregate
drainfield with reductions allowed for the reduction of
CBOD5 and TSS as noted in this chapter for aerobic
treatment units.
3. In an
absorption bed configuration, the drainfield area shall be calculated as
extending one foot beyond the sides of the outermost emitter lines.
Notwithstanding the provision of paragraph
62-6.014(5)(b),
F.A.C., the individual bed size limitation of 1500 square feet does not apply
to drip emitter systems.
4. In a
trench containing a single emitter line, the drainfield area shall be
calculated as 2' feet multiplied by the emitter spacing in feet multiplied by
the number of emitters.
5. Drip
effluent disposal systems shall be considered pressure distribution systems.
Head loss calculations shall be provided to insure proper hydraulic pressure at
the emitter. Pump selection shall be indicated in the design specifications.
Pump performance curves shall be included in the permit application.
6. Recirculation rates shall be in the design
specifications.
7. Check valves,
petcocks, inline filters, and vacuum breaking device locations shall be shown
on the design drawings.
8. Drip
irrigation systems shall be time-dosed over the 24-hour period. Demand control
dosing shall override timed-dosing in periods of flow where timed dosing cannot
accommodate the excessive flow.
9.
Emitter lines shall be designed as a continuous loop circuit with no
dead-ends.
10. Emitter lines shall
be drawn to scale and emitter spacing shall be indicated on the
drawings.
11. Vacuum release valves
shall be installed at the highpoint of the emitter lines.
12. The maximum emitter longitudinal spacing
on an emitter line shall be 2' feet. The maximum spacing between adjacent
emitter lines in an absorption bed configuration shall be 2' feet. The
24''-inch separation from the seasonal high water table shall be measured from
the emitter orifice. Setbacks shall be measured from the drip emitter
lines.
13. The setback from drip
emitter lines to building foundations and property lines shall be no less than
two feet.
14. The definition of a
filled system in Rule
62-6.002, F.A.C., is not
applicable to drip effluent disposal systems. A drip effluent disposal system
is considered to be a mound system when any part of the bottom surface of any
drip emitter line is located at or above the elevation of undisturbed native
soil in the drainfield area. A drip effluent disposal system is considered a
standard subsurface drainfield system when the entire bottom surface of every
drip emitter line is installed below the elevation of undisturbed native soil
in the drainfield area.
15. For
mound systems there shall be a minimum 18''-inch separation between the
shoulder of the fill and the nearest drip emitter line. Mound system slopes
shall be in accordance with paragraph
62-6.009(3)(f),
F.A.C., except that a minimum 2' foot separation is required between the
nearest drip emitter line and a building foundation, retaining wall, or similar
obstruction. Mound systems shall be stabilized in accordance with paragraph
62-6.009(3)(f),
F.A.C.
16. For standard subsurface
systems, the elevation of any fill covering the drainfield shall extend no less
than 18 inches away from all emitter lines before tapering down to natural
grade.
17. Minimum cover on the
emitter lines shall be 6'' inches for all drip irrigation systems. The maximum
cover for all drip irrigation systems shall be no greater than 12''
inches.
18. The system shall
include a petcock on the dosing pump discharge line for effluent
sampling.
19. All systems shall
incorporate an automatic mechanism for backwashing or flushing the drip lines
and filters.
20. All onsite sewage
treatment and disposal systems that include a drip effluent disposal system and
aerobic treatment unit or performance-based treatment system shall have a
biennial operating permit, a maintenance contract with an approved maintenance
entity, and shall be inspected in accordance with the requirements of this
chapter.
21. Drip irrigation
systems shall be designed to have a minimum operating pressure at the emitter
head of 10 PSI, a maximum operating pressure at the emitter head of 45 PSI, a
maximum system operating pressure of 60 PSI, and a maximum discharge rate per
emitter of 1.5 gallons per hour.
22. The hydraulic surge storage requirement
of Rule
62-6.028, F.A.C., does not apply
to drip irrigation systems.
23.
Drip irrigation systems must only use components approved by the Onsite Sewage
Program.
24. Unobstructed area for
drip irrigation systems may be located anywhere on the establishment property
that meets the setbacks for unobstructed area and can be accessed via
transmission lines, supply lines and return lines installed in accordance with
this chapter. The land containing only transmission lines, supply lines and
return lines shall not be included in the calculation of unobstructed
area.
25. Supply lines and return
lines shall be considered as transmission lines for determining setbacks not
specified in this section.
26.
Except for slopes required to meet the stabilization requirements of paragraph
62-6.009(3)(f),
F.A.C., the area over the drip irrigation drainfield shall be stabilized in the
same way or vegetated with plant species specified by the design engineer. The
species specified shall not include trees.
27. For drip emitter lines using
non-pressure-compensating emitters, the maximum elevation difference shall be
four inches between the highest and the lowest emitter in any individual line
segment between the supply and the return line. For drip emitter lines using
pressure-compensating emitters, there shall be no more than 18'' inches of
elevation difference between the highest and lowest emitter in any line.
Neither property slope nor drip emitter line slope shall result in the depth of
cover over the drip emitter lines to be outside of the range permitted in
subparagraph
62-6.009(5)(a)
17., F.A.C.
28. The minimum
effective soil depth below drip emitter lines shall be 42'' inches; however,
spodic layers greater than 24'' inches below the drip emitter lines may remain
in place at the discretion of the design engineer.
(b) Drip irrigation systems shall be
monitored during required maintenance visits by visual inspection of the ground
surface above the emitter lines for evidence of soil saturation at the ground
surface.
(6) Tire chip
aggregate systems - tire chip aggregate may be used as a substitute for mineral
aggregate in onsite sewage treatment and disposal system drainfields under the
following conditions:
(a) The tire chips meet
the specifications for mineral aggregate found in this chapter: Mixed tire and
mineral aggregate shall be approved where each type of aggregate meets its
respective standard and the combined mixture meets the gradation requirements
in paragraph
62-6.014(5)(c),
F.A.C.
(b) Exposed wire protrudes
no more than one-half (1/2) inch from 90% of the chips.
(c) At least 80% of the bead wire has been
removed from the tires to be chipped.
(d) The system receives domestic wastewater
only.
(e) Tire chip aggregate shall
not be used where the seasonal high water table is less than 12'' inches below
the bottom of the drainfield at the wettest season of the year.
(f) In all other respects tire chip
aggregates and mixed tire-mineral aggregates shall be installed with identical
site restrictions and construction requirements as approved mineral
aggregates.
(7) In-ground
Nitrogen-reducing Biofilters (INRB) - As described in this subsection, are
defined as an arrangement of materials installed in layers underneath a
drainfield for the purpose of reducing the mean total nitrogen (TN) by acting
as a biological filter. INRB layers, also referred to as media layers, may be
placed beneath the drainfield provided the resulting system meets all
requirements of this chapter except as noted in this subsection. All repairs or
modifications to existing INRB systems will be required to meet the standards
of this subsection. The target removal effectiveness for mean TN is a minimum
of 65% for all INRB.
(a) Where a liner is used
as part of the INRB design, the INRB must be designed by a professional
engineer, and must be installed per paragraph (c) or (d) below. For INRBs using
liners, the engineer must inspect the liner and Media Layer 2 of the system
prior to the Department's construction inspection. Final system approval will
not be granted until the engineer has supplied the following in a report to the
Department: liner and Media Layer 2 inspection report; an as-built cross
section with elevations; a dimensioned plan view of the installed INRB system;
and a statement indicating that the system has been installed in conformance
with permitting requirements. The engineer's liner and Media Layer 2 inspection
report satisfy the Media Layer 2 inspection requirements of paragraph (e)
below. Where paragraph (c) or (d) does not modify a standard found in paragraph
(b), the standard found in paragraph (b) will apply.
(b) INRB layers must be installed as follows:
1. The drainfield must be installed centered
over sand fill material (Media Layer 1) that is at least 18'' inches thick and
conforms to the textures and colors in subparagraph 10. below. Media Layer 1
must extend beneath the entire drainfield absorption surface and to a point at
least one foot beyond the perimeter of any portion of the drainfield absorption
surface.
2. Below Media Layer 1
there must be a layer of nitrogen-reducing media and fine aggregate mix (Media
Layer 2) that is at least 12 inches thick and extends beneath the entire
drainfield absorption surface and extends at least 24'' inches beyond the
perimeter of any portion of the drainfield absorption surface. Media Layer 2
must also extend upward along the boundary of Media Layer 1 to a point four to
six inches below the bottom of the drainfield. Media Layer 1 must be centered
above Media Layer 2. Media Layer 2 must conform with subparagraphs 8. and 11.
below.
3. The bottom of Media Layer
2 must be at least 6'' inches above the wet-season water table.
Click here to view
image
Figure 1. In-ground Nitrogen-reducing Biofilter media layer
system
4. Media longevity
and nutrient reduction may be enhanced by the use of low-pressure distribution.
Any Department-approved drainfield effluent distribution method may be
used.
5. The existing soil profile
throughout the area of the drainfield and the area where the INRB will be
placed must indicate slightly limited soils extending from the existing ground
surface to at least 36'' inches below existing ground surface in addition to
compliance with the effective soil depth requirements of subsection
62-6.006(1),
F.A.C., for the installation of the drainfield.
6. Only drainfield materials approved per
Rule
62-6.014 or
62-6.009, F.A.C., can be
used.
7. As measured vertically, no
portion of Media Layer 2 can be within 18'' inches of the absorption surface of
the drainfield.
8. An example of
nitrogen-reducing media is lignocellulosic material such as chips or shavings
of lumber, wood mulch, yellow pine sawdust, or 2''-inch to 3''-inch wood chips.
All sources of lignocellulosic material must be untreated by preservatives.
Lignocellulosic material must be free of extraneous non-woody materials such as
plastic, metal, grass, leaves, and any other debris. The nitrogen-reducing
media must be demonstrated in Florida-based domestic wastewater studies as
innovative systems to be effective at providing a substrate for
denitrification.
9. The
nitrogen-reducing media must comply with the provisions of Rule
62-6.0151, F.A.C.
10. Media Layer 1 must consist of fine
aggregate having a texture of sand or fine sand but excluding:
a. Those having color values less than or
equal to 4 with chromas less than or equal to 3; or
b. Those with colors on the gley
charts.
11. Media Layer 2
must be composed of 40-60% nitrogen-reducing media by volume, with the
remainder to be fine aggregate and must not be installed when the observed
water table at time of construction is at or above the lowest depth of Media
Layer 2. The fine aggregate to be mixed with the nitrogen-reducing media must
be one or more of the following textures: sand, fine sand, coarse sandy loam,
sandy loam, loamy sand, fine sandy loam, very fine sand, loamy fine sand, and
loamy very fine sand; and must conform to the colors in subparagraph 10.,
above. Media Layer 2 must shall be thoroughly mixed while the soil is in a
non-plastic state, with the constituents uniformly distributed when
installed.
12. Where the system has
a total required drainfield size over 1, 500' square feet, the design engineer
must address the potential for mounding of the effluent between the drainfield
and the bottom of Media Layer 2 at the estimated sewage flow and will increase
the separation between the drainfield and Media Layer 2, to ensure Media Layer
1 maintains no less than 18 inches of unsaturated soil beneath the drainfield.
A four-inch diameter observation port in the center of the drainfield must be
installed to monitor this parameter. The observation port must be capped and
lockable and installed within a protective surface cover. A toilet flange must
be securely attached to the bottom of the observation port to prevent the port
from being inadvertently raised from its installed position. The observation
port, including the flange, must be perforated at the lowest elevation possible
to allow accurate measurements. If installed within three feet of the sidewall
of a bed or trench, the port must be grouted to prevent effluent from flowing
down the outer surface of the port to the media.
13. Drainfield repair will not necessitate
Media Layer 2 replacement provided the media has been in use for less than 10
years or if sampling within the previous 12 months shows denitrification at or
above the target level for mean TN removal effectiveness which must be a
minimum 65%.
14. Setback distances
to the Media Layers 1 and 2 extending to the absorption surface of the
drainfield will be reduced as follows:
a.
Except for building foundations, vertical obstructions and pilings for elevated
structures, where the required setback is <=5 feet, the setback must be
reduced to one foot.
b. Where the
required setback is >=10 feet, the setback must be reduced by five
feet.
c. Setbacks to all other
parts of the system must comply with the requirements in this chapter and
Section 381.0065,
F.S.
(c) INRB
layers with liner, no underdrain, must be installed in accordance with
paragraph (b) above with the following variations:
1. The system drainfield must be low-pressure
dosed unless the professional engineer chooses another method to provide
nitrification. Lift-dosing may be used provided the design calculations show
that the entire distribution network will be charged with each dose.
2. Media Layer 2 must be enclosed beneath,
and on the lower 6-8'' inches of all sides, by an impermeable liner composed of
polyvinyl chloride (PVC), high-density polyethylene (HDPE), ethylene propylene
diene methylene (EPDM) or other material having a thickness of at least 30 mils
and being certified by the manufacturer for a minimum lifetime of 30 years
buried in contact with sewage. If a manufacturer will not certify the liner for
a minimum of 30 years, the engineer of record must choose a liner based on the
manufacturer's product information regarding resistance to physical and
chemical substances to which it will be subject over the thirty-year period.
EPA-approved landfill liners may be considered by the engineer of
record.
3. No portion of the liner
or Media Layer 2 can be within 18'' inches of the absorption surface of the
drainfield.
4. The lowest point of
the liner or Media Layer 2 must be no less than 6'' inches above the wet-season
water table. There must be at least 6'' inches of unsaturated slightly limited
soil between the bottom of the liner and the wet-season water table.
5. Media Layers 1 and 2 must extend beneath
the entire drainfield absorption surface to a point at least 3.5' feet beyond
the perimeter of any portion of the drainfield absorption surface. For repairs,
the 3.5' feet dimension may be reduced incrementally to not less than 1.0' feet
if necessary, to comply with a setback or if physical room is unavailable.
Maintaining the 3.5 feet dimension will have a protection factor of 5 in
determining the relative priority of competing factors in the application of
Rule
62-6.015, F.A.C., Table V. No
part of the liner can be placed within 12'' inches of the pump or treatment
tank.
6. Media Layer 1 must comply
with subparagraph (b)10. above.
7.
Media Layer 2 must comply with subparagraph (b)11. above, be at least 12''
inches thick, and extend beneath the entire area below Media Layer 1.
8. The Department will not require sampling.
Sampling may be required by the professional engineer, municipality or other
state agency as necessary to comply with applicable regulatory
requirements.
9. Where the system
has a total required drainfield size over 1, 500' square feet, the design
engineer must address the potential for mounding of the effluent between the
drainfield and the liner at the estimated sewage flow and will increase the
separation between the drainfield and Media Layer 2 to ensure Media Layer 1
maintains no less than 18 inches of unsaturated soil beneath the drainfield. A
four-inch diameter observation port must be installed in the center of the
liner to allow the liquid level of effluent contained within the bottom of the
media liner to be monitored. The observation port must be capped and lockable
and installed within a protective surface cover. A toilet flange must be
securely attached to the bottom of the observation port to prevent the port
from being inadvertently raised from its installed position. The observation
port, including the flange, must be perforated at the lowest elevation possible
to allow accurate measurements. If installed within three feet of the sidewall
of a bed or trench, the port must be grouted to prevent effluent from flowing
down the outer surface of the port to the media.
10. The perimeter of the liner, in linear
feet, multiplied by the perimeter loading rate must not be less than the
estimated daily sewage flow for the system. The most restrictive soil texture
between the elevation of the bottom of the drainfield and the elevation six
inches below the bottom of the liner throughout the area of the installation
and 24'' inches beyond the perimeter of the liner will be used to determine the
media layer perimeter loading rate.
|
PERIMETER LOADING
RATE
|
|
|
Soil Texture
|
Gallons/Linear Feet/Day
|
|
Coarse sand; sand; and loamy coarse sand
|
5
|
|
Fine sand
|
4
|
|
Loamy sand; coarse sandy loam; and sandy
loam
|
3
|
11.
The professional engineer may specify methods to replenish media and remove
spent media if the continued presence of such spent media reduces the efficacy
of the process and the methods do not compromise the efficacy of the
system.
12. Any seams or
penetrations through the liner must be sealed in accordance with the liner
manufacturer's instructions to prevent leakage for the life of the
liner.
13. Setback distances to the
liner, or to Media Layers 1 and 2 extending to the absorption surface of the
drainfield will be reduced as follows:
a.
Except for building foundations, vertical obstructions and pilings for elevated
structures, where the required setback is <=5 feet, the setback will be
reduced to one foot.
b. Where the
required setback is >=10 feet, the setback will be reduced by five
feet.
c. Setbacks to all other
parts of the system will comply with the requirements in this chapter and
Section
381.0065, FS.
Click here to view
image
Figure 2. INRB with Liner without
underdrain
(d) INRB layers with liner and underdrain,
must be installed in accordance with paragraphs (a) and (b) above with the
following variations:
1. The system
drainfield must be low-pressure dosed unless the professional engineer chooses
another method to provide nitrification. Lift-dosing may be used provided the
design calculations show that the entire distribution network will be charged
with each dose.
2. The drainfield
must be installed and centered over Media Layer 1 which conforms to the
textures and colors in subparagraph (b)10. Media Layer 1 must extend at least
18'' inches past the perimeter of the drainfield.
3. Below Media Layer 1, Media Layer 2 must be
installed and must extend at least 18 inches past the perimeter of the
drainfield. Media Layer 2 must conform with subparagraphs (b)8., 9. and 11.
above.
4. An impermeable liner
meeting the construction standards of subparagraphs (c)2.-4., (c)9., and
(c)12.-13. above, must be installed below Media Layer 2. The liner's interior
surface must extend to a point at least 18'' inches past the perimeter of the
drainfield, at which point the liner must be directed upwards toward the ground
surface maintaining contact with Media Layers 1 and 2, stopping at a point four
to six inches below the level of the bottom of the drainfield. No portion of
Media Layer 2 can be less than 18'' inches below the absorption surface of the
drainfield. Media Layer 2 with liner will extend beneath the entire drainfield
absorption surface and extend at least 18'' inches beyond the perimeter of any
portion of the drainfield absorption surface. No part of the liner can be
placed within 12'' inches of the pump or treatment tank.
5. An underdrain must be installed on top of
and in contact with the interior surface of the bottom of the liner within
Media Layer 2 and must disperse to a separately sized, located and installed
drainfield. The underdrain must be designed to maximize effluent movement
through Media Layer 2 into the underdrain. The transmission line from the
underdrain to the separate drainfield must be set to maintain saturation to the
top of Media Layer 2. For gravity flow, in order to maintain distribution as
high as possible above the wet-season water table and to maintain the
shallowest depth to finished grade, the transmission line must have a slope
between zero and 1/8'' inch per foot when distributing the effluent to the
separate drainfield.
6. Provided
the effluent has passed vertically without pressure through Media Layer 1, the
professional engineer may specify the separate drainfield that is separated
from the wet-season water table by no less than 6'' inches and the separate
drainfield may be installed no more than 48'' inches below final grade,
provided there is slightly limited soils to a depth of 12'' inches below the
separate drainfield's absorption surface.
7. The minimum thickness of Media Layer 2
must be 12'' inches from the top of the liner to the bottom of Media Layer 1.
Media Layer 2 thickness, as measured between the top of the underdrain and the
top of Media Layer 2, must be 7 inches.
8. Compliance with subparagraph
62-6.009(7)(b)
8.-14., F.A.C., is required.
9. The
department will not require sampling. Sampling may be required by the
professional engineer, municipality or other state agency as necessary to
comply with applicable regulatory requirements.
10. The lowest point of the liner or media
layer must be no less than 6 inches above the wet-season water table. There
must be at least 6 inches of unsaturated slightly limited soil between the
bottom of the liner and the wet-season water table.
11. Where the system has a total required
drainfield size over 1, 500' square feet, the design engineer must address the
potential for mounding of the effluent between the drainfield and the liner at
the estimated sewage flow and will increase the separation between the
drainfield and Media Layer 2 to ensure Media Layer 1 maintains no less than
18'' inches of unsaturated soil beneath the drainfield. A four-inch diameter
observation port must be installed in the center of the liner to allow the
liquid level of effluent contained within the bottom of the media liner to be
monitored. The observation port must be capped and lockable and installed
within a protective surface cover. A toilet flange must be securely attached to
the bottom of the observation port to prevent the port from being inadvertently
raised from its installed position. The observation port, including the flange,
must be perforated at the lowest elevation possible to allow accurate
measurements. If installed within three feet of the sidewall of a bed or
trench, the port must be grouted to prevent effluent from flowing down the
outer surface of the port to the media.
12. The professional engineer may specify
methods to replenish media and remove spent media if the continued presence of
such spent media reduces the efficacy of the process and the methods do not
compromise the efficacy of the system.
13. Setback distances to the liner, or Media
Layers 1 and 2 extending to the absorption surface of the drainfield will be
reduced as follows:
a. Except for building
foundations, vertical obstructions, and pilings for elevated structures, where
the required setback is <=5 feet, the setback will be reduced to one
foot.
b. Where the required setback
is >=10 feet, the setback will be reduced by five feet.
c. Setbacks to all other parts of the system
will comply with the requirements in this chapter and Section
381.0065, F.S.
Click here to view
image
Figure 3 - INRB with liner and
underdrain
(e) Prior to covering Media Layer 2, in
addition to the inspections required in Rule
62-6.003, F.A.C., upon
completion of the installation of Media Layer 2, a person installing or
constructing the system must notify the Department that Media Layer 2 has been
installed and must have that portion of the system inspected by the Department.
If the inspection of Media Layer 2 is the initial inspection of the system, the
initial inspection fee in paragraph
62-6.030(1)(i),
F.A.C., must be paid. If an initial inspection occurred before the Media Layer
2 inspection, the reinspection fee in paragraph
62-6.030(1)(j),
F.A.C., must be paid.
(f) Repairs
of systems incorporating media layers must meet the current standard for
nitrogen reduction. The provisions of subsection
62-6.003(3),
F.A.C., do not apply to repair of systems that include media layers, nor will
repairs be allowed per subsection
62-6.015(3),
F.A.C.
(g) Final installation
approval must not be granted until the Department has confirmed that the
property owner has executed and recorded in the public property records at the
county courthouse, a written notice that informs all subsequent property owners
of the use of the nitrogen-reducing media onsite system that may require
special repair or maintenance procedures. The notice must include the
Department's construction permit number for the system, and that additional
information may be obtained by contacting the Department.
(8) Alternative system component and design
approval - After innovative system testing is completed, requests for approval
of system components and designs which are not specifically addressed in this
chapter shall be submitted to the Department's Onsite Sewage Program.
(a) Requests for alternative system component
material and design approval shall include:
1.
Detailed system design and construction plans by an engineer licensed in the
State of Florida,
2. Certification
of the performance capabilities of the product submitted by an engineer
licensed in the State of Florida,
3. Research supporting the proposed system
materials,
4. Empirical data
showing results of innovative system testing in the State of Florida; and,
5. A design, installation and
maintenance manual showing how to design and install the system in accordance
with this chapter for standard, filled, mounded, gravity-fed, dosed, bed and
trench configurations.
(b) In addition to those items listed in
paragraph
62-6.009(7)(a),
F.A.C., manufacturers of drip effluent disposal system distribution lines,
emitters, and components shall apply for and obtain approval from the
Department's Onsite Sewage Program for specific model numbers or part numbers
prior to inclusion of the components on any site specific permit application.
Manufacturer's of drip effluent disposal system components shall provide design
and installation manuals for engineering and construction guidance. Design
manuals shall include tables that detail flow rates vs. pressure and pressure
loss per length(s) of distribution pipe.
(c) The detailed plans and information
submitted with the approval request shall be reviewed by the Department's
Onsite Sewage Program to determine whether or not there is a reasonable
certainty of the effectiveness and reliability of the proposed alternative
system component. If the Department is not satisfied that the information
provided provides reasonable evidence of the effectiveness and reliability of
the alternative system component and designs, the Department shall deny the
approval. Department approval of any alternative system component does not
guarantee or imply that any individual system installation will perform
satisfactorily for a specific period of time. Upon Department approval of the
material and design, the manufacturer shall list the Department approval date
in the installation and design manual. Proposals to amend the approved
installation and design manual shall be submitted to the Department for
approval. The date of amendment approval shall be included in the
manual.
(d) Except as provided for
in Part IV of this chapter, alternative drainfield materials and designs shall
not be approved which would result in a reduction in drainfield size using the
mineral aggregate drainfield system as described in Rule
62-6.014, F.A.C., and the total
surface area of soil at the bottom of the drainfield as the criteria for
drainfield sizing comparisons. Alternative system component and design
approvals shall not be granted for the following items:
1. Those which, in whole or in part, are used
to achieve a more advanced level of treatment than the baseline treatment level
specified in Part IV of this chapter,
2. Aerobic treatment units,
3. Septic tank designs, filters, seals, and
sealants,
4. Additives,
5. Header and drainfield pipe, including
their layout; and,
6. Water table
separation and setback requirements.
(e) Unless determined unnecessary or
impractical by the Department at the time of component approval, effective
January 1, 2010, all components shall be labeled with the name of the
manufacturer and the model identification of the component. The design,
installation and maintenance manual shall show the location of the label and
shall include an illustration of a typical label. The label shall be in a
location where it will be visible or easily exposed at the time of system
inspection. All identifying marks shall be inscribed or affixed at the point of
manufacture.
(9) Other
alternative systems - systems such as low pressure distribution networks, small
diameter gravity sewers, low pressure sewer systems, alternating absorption
fields, and sand filters designed and submitted by an engineer who is licensed
in the State of Florida, meeting the general requirements of this chapter,
shall be approved by the Department where evidence exists that use of such
systems will not create sanitary nuisance conditions, health hazards or pollute
receiving waters. Use of an alternative system may require the establishment of
procedures for routine maintenance, operational surveillance, and environmental
monitoring to assure the system continues to function properly.
(10) Use of a system to serve more than one
residence or commercial building under separate ownership and when located on
separate lots shall require the establishment of a local sewer district,
maintenance franchise, or other legally binding arrangement for the operation
and maintenance of such system.
(11) All materials incorporated herein may be
obtained from the Department of Environmental Protection, Onsite Sewage Program
at
www.floridadep.gov or 2600 Blair
Stone Road, MS #3596, Tallahassee, Florida 32399-2400 or Florida Department of
State, Florida Administrative Code and Register, R.A. Gray Building, 500 South
Bronough Street, Tallahassee, Florida 32399-0250. Reference materials deemed
copyright protected are available for inspection at the same
address.