RELATES TO: KRS 211.350-211.380,
211.990(2)
NECESSITY, FUNCTION, AND CONFORMITY:
KRS
211.350 to
211.380
directs the cabinet to regulate the construction, installation, or alteration
of on-site sewage disposal systems except for systems with a surface discharge.
The purpose of this administrative regulation is to establish minimum component
standards including design, construction, and materials specifications for
on-site sewage disposal systems in Kentucky in order to protect the public
health.
Section 1. Citation of
Administrative Regulation. This administrative regulation may be cited as the
"Construction standards for components of on-site sewage disposal
systems."
Section 2. Definitions.
As used in this administrative regulation the following terms shall have the
meanings set forth below:
(1) "Approved" means
that which has been considered acceptable to the cabinet.
(2) "Cabinet" means the Cabinet for Human
Resources and includes its authorized agents.
(3) "Component" means any device used in the
construction, installation or alteration of an on-site sewage disposal system
which forms an integral part of that system, and is necessary to its proper
operation and maintenance. It includes, but is not limited to:
(a) Sewage pretreatment units, holding tanks,
grease traps, pump or dosing tanks, and necessary equipment and
appurtenances;
(b) Distribution
boxes, alternating valves, filters, and similar devices; and
(c) Piping, fittings, valves, and leaching
chambers.
(4) "Effluent"
means the liquid discharge of a septic tank or other sewage pretreatment
unit.
(5) "Gravelless pipe" means
large diameter perforated piping designed for use in lateral field trenches
without the use of trench rock or gravel fill material. Such pipe includes a
mandatory overwrap or encasing of synthetic filter material meeting specific
criteria.
(6) "Grease" means fats
or oils of animal, vegetable, or mineral origin, separately or in colloidal or
dissolved states in combination with soaps, detergents, and/or food
particles.
(7) "Grease trap" means
a component designed to separate grease and its constituents from the
wastewater stream, provide for storage of separated grease, and discharge the
remaining wastewater for treatment.
(8) "Lateral field" means the area in which
the subsurface soil absorption system is installed and is a general term for
the system itself.
(9) "Low
pressure pipe system" means an on-site sewage disposal system consisting of a
sewage pretreatment unit, a dosing tank with pump(s) or siphon(s), a
pressurized supply line, manifold, and lateral lines, and necessary control
devices and appurtenances.
(10)
"Leaching chamber" means a specially designed component for use in lateral
field trenches or beds, with or without the use of trench rock or gravel fill
material, which forms an open bottomed chamber or cavern over the subsurface
soil absorption surface, and which interlocks with other such chambers to
obtain the necessary absorption surface area.
(11) "On-site sewage disposal system" means a
complete system installed on a parcel of land, under the control or ownership
of any person, which accepts sewage for treatment and ultimate disposal under
the surface of the ground. The common terms "on-site sewage system" or "on-site
system" also have the same meaning. This definition includes, but is not
limited to, the following:
(a) A conventional
system consisting of a sewage pretreatment unit(s), distribution box(es), and
lateral piping within rock-filled trenches or beds;
(b) A modified system consisting of a
conventional system enhanced by shallower trench or bed placement, artificial
drainage systems, dosing, alternating lateral fields, fill soil over the
lateral field, or other necessary modifications to the site, system or
wasteload to overcome site limitations;
(c) An alternative system consisting of a
sewage pretreatment unit(s), necessary site modifications, wasteload
modifications, and a subsurface soil absorption system using other methods and
technologies than a conventional or modified system to overcome site
limitations;
(d) Cluster systems
which accept effluent from more than one (1) structure's or facility's sewage
pretreatment unit(s) and transport the collected effluent through a sewer
system to one (1) or more common subsurface soil absorption system(s) of
conventional, modified or alternative design; and
(e) A holding tank which provides limited
pretreatment and storage for off-site disposal where site limitations preclude
immediate installation of a subsurface soil absorption system, or connection to
a municipal sewer.
(12)
"Person" means any individual, firm, association, organization, partnership,
business trust, corporation, company or governmental unit.
(13) "Secretary" means the Secretary for the
Cabinet for Human Resources.
(14)
"Sewage pretreatment unit" means a watertight sewage treatment structure
designed and constructed to receive raw sewage, separate solids from liquids,
digest organic matter through a period of retention, and allow clarified
effluent to discharge to a subsurface soil absorption system. Such pretreatment
units fall into three (3) basic categories:
(a) Septic tanks - which rely predominantly
on anaerobic bacterial action for treatment;
(b) Aerobic units - which introduce
atmospheric air into the sewage to promote treatment by aerobic bacteria;
and
(c) Combination units - which
provide treatment through both anaerobic and aerobic bacterial action and/or
mechanical filtering, ozonation or ultraviolet irradiation.
(15) "Subsurface soil absorption
system" means that portion of an on-site sewage disposal system which accepts
effluent from a sewage pretreatment unit(s) for further treatment by microbial,
plant and animal life within the soil, as well as treatment by filtration,
chemical decomposition and bonding within the soil itself, and consists of:
(a) Devices, components, and piping to
transport effluent under pressure or by gravity flow, and distribute the
effluent to the soil absorption surfaces;
(b) Trenches, beds, chambers, mounds,
lagoons, artificial marshes, etc., separately or in combination, which form or
enclose the soil absorption surfaces;
(c) Rock, gravel, or other fill materials
required within the system, including barrier materials, and fill soil within
or over the system; and
(d)
Artificial drainage systems, and other necessary site or soil
modifications.
Section
3. Approval Procedures.
(1) All
commercial manufacturers and suppliers of materials, components, and equipment
designed or intended for use in the construction of on-site sewage disposal
systems shall obtain approval of such materials, components, and equipment from
the cabinet prior to their sale or use in Kentucky. Such approval shall be
based upon conformance to recognized design, materials, construction, and
performance standards of the National Sanitation Foundation (NSF), the American
Society for Testing and Materials (ASTM), and the standards set forth in this
administrative regulation.
(2)
Manufacturers, purveyors and suppliers of materials, components, and equipment
shall submit the following information, as applicable, to the cabinet in review
and consideration in the approval process:
(a)
All applicable plans, specifications, process descriptions, and other relevant
data.
(b) Supportive test data from
independent laboratories, testing firms, NSF, ASTM, and other approved
organizations.
(c) Other pertinent
information as requested by the cabinet.
(3) New or experimental materials,
components, or equipment shall be submitted for approval as outlined in
subsection (2) of this section and the following additional requirements and
restrictions shall apply:
(a) Those materials,
components, or equipment which consist of modifications to existing approved
products shall be considered for approval after demonstration, through
independent testing of the modifications, that improved performance, service
life, or ease of maintenance and operation results.
(b) Those materials, components, or equipment
which involve new or experimental technologies relating to design,
construction, or operational process shall be considered for approval on a
probationary basis. During the probationary period, it shall be the
responsibility of the person seeking approval of such product to contract with
an independent testing firm to provide monitoring of the performance of the
product in its intended usage. Such monitoring of the product shall include
documentation of the site conditions where the product is installed, the waste
load generated by the user and its constitution, and other parameters deemed
necessary by the cabinet. In the event that the product fails to perform in an
acceptable manner, it shall be the responsibility of the person seeking its
approval to replace the product with another product which is approved by the
cabinet for that particular use.
(c) Any materials, components, or equipment
which, in the opinion of the cabinet, meet the requirements for approval after
careful study and testing, as required, shall be considered to be approved for
use in Kentucky for the specific purpose(s) intended. Such approval shall be
made in writing to the person requesting same and shall set forth any
conditions or restrictions for the use of the product when deemed necessary by
the cabinet. Each product, so approved, shall be listed by the cabinet on an
"approved listing of materials, components, and equipment," which shall be
updated on a timely basis and distributed to local health departments and other
interested parties on request.
Section 4. Septic Tank Pretreatment Units.
(1) Precast concrete.
(a) All precast concrete septic tanks shall
be designed and constructed so as to provide sufficient rigidity and structural
strength to prevent damage due to hydrostatic water pressure and support
vertical uniform loading of 150 lb./sq. ft. on the top of the tank.
(b) A minimum and product strength of 4,000
pound per square inch shall be used in the construction of the tank.
(c) The top, bottom, ends and sides of the
tank shall have a minimum thickness of two and one-half (2 1/2)
inches.
(d) The tank shall be
reinforced by using a minimum reinforcing of six (6) inch No. 10 gauge welded
steel reinforcing wire lapped at least six (6) inches. Other reinforcing
methods may be used provided that such other methods can be demonstrated to the
satisfaction of the cabinet to be equal, or superior, to the method described
herein.
(e) The tank shall be so
designed and constructed that all joints, seams, or other openings shall be
watertight in use. Asphalt compounds, neoprene gaskets, or other acceptable
sealant materials shall be used to insure watertightness.
(f) At least two (2) manholes shall be
provided to permit access for maintenance of the tank. Manholes shall have a
minimum dimension of ten (10) inches and a maximum of twenty-four (24) inches
measured on the bottom edge of the manhole opening into the tank. Manholes
shall be located on each end of the tank over the inlet and outlet structures
(baffles or tees). The manhole openings shall be beveled so as to adequately
seal and support the manhole cover. The manhole cover shall possess sufficient
strength to support a uniform load of 150 lb./sq. ft. without damage to the
cover or tank and provide a means for removal (handles).
(g) Cast-in-place baffles, at inlet and
outlet ends of the tank have a minimum thickness of two (2) inches and be
reinforced in the same manner as the tank. For cast-in-place baffles
reinforcing wire into and along the tank side walls a minimum of (6) inches for
proper anchorage. For tanks using drop-in baffles, a molded in slot or groove
with a minimum one (1) inch penetration into the tank side wall shall be
provided to retain the baffle. Such slot or groove shall be slightly tapered to
produce a secured "wedge fit" baffle. For bolt-on tee-type baffle structures,
stainless steel bolts, washers and nuts shall be used for anchorage. Such bolts
shall be cast-in-place in the baffle or tank end wall and securely anchored by
attachment to tank or baffle reinforcing material. On those tanks where baffle
attachment bolts penetrate through the tank endwall suitable bushings or seals
shall be used to render bolt holes watertight. Suitable sealants shall also be
used on all baffle edges which contact the tank end wall to prevent
short-circuiting of tank contents.
(h) In lieu of concrete baffles, sanitary
tees or other baffle devices of corrosion resistant materials (fiberglass,
plastic) may be used as long as joints are properly sealed, acceptable
attachment methods are used, and the specified dimensions above and below the
liquid level of the tank are maintained.
(i) Internal dimensions of the tank shall
fall within plus or minus one (1) foot of the proportional ratios of 2:1 to
3:1, the length being approximately two (2) to three (3) times the width. The
minimum liquid depth shall be thirty-four (34) inches with maximum depth of
fifty-four (54) inches. The inlet and outlet pipe knockouts or holes shall be
of sufficient diameter to accept a minimum four (4) inch diameter pipe and
shall be so designed as to provide a minimum height difference of three (3)
inches for the inlet pipe invert above the outlet pipe invert. Inlet and outlet
holes shall be so located on the ends of the tank as to provide a minimum
freeboard space of ten (10) inches to one (1) foot between the liquid level and
the inside top surface of the tank for scum storage. Both inlet and outlet
baffles or tees shall extend above the liquid level of the tank to within at
least two (2) inches but not less than one (1) inch of the inside top surface
of the tank to contain scum and provide venting space for gases. Baffle designs
which extend to the inside top of the tank may be used provided that a slotted
vent space of a minimum height of one (1) inch by four (4) inches in width is
located at the juncture of the baffle and tank top in the center of the baffle.
The inlet tee or baffle shall extend below the liquid level between eight (8)
to ten (10) inches, and the outlet baffle or tee shall extend downward to
thirty-five (35) to forty (40) percent of the total liquid depth of the tank.
When baffles are used, the distance between the outlet baffle and tank end wall
shall be between four (4) to six (6) inches, and the distance between the inlet
baffle and end wall shall be between six (6) to ten (10) inches.
(j) All tanks offered for sale or use in
Kentucky shall bear, by imprint, stencil, or other acceptable means of marking,
the manufacturer's name, the serial number assigned to the manufacturer's plans
and specifications approved by the cabinet, and the liquid or working capacity
of the tank. This imprint, stencil, or other marking shall be located to the
right of the knockout or hole made for the outlet pipe on the outlet end of the
tank.
(2) Constructed on
site. Septic tanks constructed on site of cast-in-place concrete, or concrete
block shall be constructed to conform with the requirements in subsection (1)
of this section except as follows:
(a)
Cast-in-place concrete septic tanks shall have a minimum wall thickness of four
(4) inches.
(b) Concrete block
septic tanks shall have a minimum wall thickness of at least eight (8) inches
when the design volume is less than 1,000 gallons and a minimum wall thickness
of at least ten (10) inches when the design volume is 1,000 gallons or more.
All septic tanks constructed of block shall be plastered on the inside with a
1:3 mix (one (1) part cement, three (3) parts sand) of portland cement at least
three-eighths (3/8) inch thick or the equivalent using other approved
waterproofing material, and provided with acceptable reinforcing within all
walls.
(c) The bottom and top of
the constructed on site septic tank shall be poured reinforced concrete with a
minimum thickness of four (4) inches.
(d) For large capacity (5,000 gallons or
more) cast-in-place concrete tanks, maximum liquid depth shall be sixty-six
(66) inches.
(3)
Prefabricated steel. Prefabricated steel septic tanks shall conform to the
requirements listed under subsection (1)(a), (e), (f), (h), (i) and (j) of this
section, in addition to the following:
(a) All
prefabricated steel tanks shall be thoroughly coated on all surfaces with a
minimum one-eighth (1/8) inch thick coating of liquid asphalt, mastic compound,
plastic waterproofing compound, or liquid cured vinyl. Each such septic tank
shall be accompanied on site delivery by a one-half (1/2) pint container of the
coating material for use in touchup coating of steel surfaces of the tank
exposed through damage in shipping and handling. If such volume is insufficient
to repair all damaged areas, additional coating material shall be secured by
the installer.
(b) Coated steel
baffles shall not be used in prefabricated steel tanks. Sanitary tees of
approved plastic, fiberglass, or cast iron shall be required.
(4) Molded plastic, fiberglass.
Septic tanks of molded plastic, fiberglass, or other such type of materials
shall conform to the requirements listed under subsection (1)(a), (e), (f),
(h), (i) and (j) of this section, in addition to the following: baffles, if
used in lieu of sanitary tees, shall be molded or formed in place so as to be
an integral part of the tank. Glued, riveted, or otherwise mechanically
attached baffles are not permitted (solvent welding on plastic tanks and resin
bonding on fiberglass are acceptable). Such baffles shall be formed of material
equal in thickness and rigidity to the tank wall material.
Section 5. Aerobic Pretreatment Units.
(1) Precast concrete tank. All precast
concrete tank aerobic pretreatment units shall comply with the construction
requirements of Section 4(1)(a), (b), (c), (d), (e), (f) and (j) of this
administrative regulation, in addition to the following:
(a) All cast-in-place baffles, compartment
walls, dividers, weirs, and other devices or structural forms shall be a
minimum thickness of two (2) inches and be reinforced in the same manner as the
tank. Such reinforcing material shall extend into and along the tank side wall
a minimum of six (6) inches.
(b)
Baffles, compartment walls, dividers, weirs, and other such devices or
structural forms that are not cast-in-place or may be of dissimilar materials
to the tank shall be of corrosion resistant materials, of sufficient structural
strength and anchorage to the tank to prevent damage or dislodgment in normal
operation, and where requiring routine maintenance, readily accessible through
tank access manholes.
(c) All
manholes providing access to mechanical or electrical components, chlorinating
or other treatment devices or filters shall be provided with risers extending
to grade to allow ready access for maintenance. Covers for such manholes or
risers shall be provided with locks or other devices to prevent entry by
unauthorized persons. On units which are intended to be installed flush with
grade or above grade, which are designed to have an open top, suitable
gridding, decking, or other such barriers to entry to the tank shall meet the
150 lb./sq. ft. support strength requirements and shall be so designed and
installed to prevent entry to the tank or contact with its contents by
unauthorized persons.
(2) Prefabricated steel. All prefabricated
steel tank aerobic pretreatment units shall comply with the construction
requirements listed in Section 4(1)(a), (e), (f), (j), and (3)(a) of this
administrative regulation, subsection (1)(b) and (c) of this section, in
addition to the following: coated steel, welded-in-place or mechanically
attached baffles, compartment walls, dividers, weirs, and other devices or
structural forms shall receive additional corrosion protection materials or
coatings when they are exposed directly through splash or immersion on two (2)
or more surfaces or sides to tank liquid contents.
(3) Molded plastic, fiberglass. All molded
plastic or fiberglass tank aerobic pretreatment units shall comply with the
construction requirements listed in Section 4(1)(a), (e), (f) and (j) of this
administrative regulation, and subsection (1)(b) and (c) of this section, in
addition to the following: baffles, compartment walls, dividers, weirs, and
other such devices or structural forms, if cast or molded in place, shall be
formed of material equal in thickness and rigidity to the tank
material.
(4) Piping, mechanical
devices and electrical equipment, filtration devices, and other appurtenances.
(a) All internal or external piping or
conduits and fittings necessary to the transport of tank sewage contents
between tank compartments, mechanical equipment, or other components of the
treatment process involved shall be of Schedule 40 PVC or ABS plastic pipe.
Mixing of PVC and ABS or other dissimilar plastic pipe or fittings is
prohibited.
(b) Mechanical fittings
and connections where used to connect PVC or ABS piping to equipment or
components shall be corrosion resistant and of a type, design, and construction
compatible for use with the type of pipe involved.
(c) Mechanical aerators, stirrers, diffusers,
rotating disks, and other devices used to provide direct exposure of
atmospheric air to tank sewage contents shall be constructed of corrosion
resistant materials and of sufficient structural strength to withstand normal
operating stresses without damage or deformation resulting in system
malfunction for the designed service life of the device.
(d) Pumps, electrical motors, or other such
devices shall be of sealed or submersible design and construction when subject
to submersion, splash, or corrosive atmosphere within the aerobic pre-treatment
unit. Such pumps, motors, or other such devices shall be properly sized and
designed for the intended use and duty cycle.
(e) Filters, chemical feeders, and other such
devices shall be constructed of corrosion resistant materials and possess
sufficient strength to withstand normal operational stresses without damage or
deformation resulting in system malfunction.
(f) Electrical controls, switches, ozone
generators, ultraviolet generators, and other such devices relying upon
electrical current for operation shall be designed and constructed as to be
water and corrosive vapor proof in all portions of the device where electrical
current carrying components are located. All such devices shall be properly
grounded and otherwise designed, constructed, installed, and operated in
accordance with National Electrical Code requirements.
(g) All fasteners, brackets, clips, hangers,
or other such devices used in the anchorage, installation, mounting, or
attachment of unit components and equipment both internal or external to the
aerobic pretreatment tank shall be designed and constructed of materials
possessing sufficient strength and corrosion resistance to withstand normal
operational stresses without damage or deformation resulting in system
malfunction.
(h) All components of
aerobic pretreatment units which require routine maintenance shall be installed
and located within the unit as to be readily accessible. Such components which
require replacement, removal, or dismantling for routine maintenance shall be
designed, constructed, and installed so as to facilitate their replacement,
removal, or dismantling with simple tools. A maintenance instruction manual
using pictures and simple language for identification of unit components,
maintenance to be performed, components needing routine replacement, removal or
dismantling procedures, maintenance interval, and simple troubleshooting
procedures shall be included with all units. Such manual shall be provided to
the ultimate operator or user of the unit. When aerobic pretreat-ment units are
to be installed by other persons, rather than the manufacturer or his agents, a
detailed installation manual shall be supplied outlining proper installation
procedures including hookup to an electrical power source, unit start-up
procedures, and necessary adjustments or calibrations to be made to meet
manufacturer's operating specifications for effluent quality.
Section 6. Dosing and
Holding Tanks.
(1) All dosing and holding
tanks shall comply with the general construction requirements listed in Section
4 of this administrative regulation for septic tanks, based upon the type of
material used in their construction, in addition to the following:
(a) Access manholes for dosing or holding
tanks shall be extended to grade through the use of suitable risers to permit
ease of access for maintenance and pumping.
(b) Such manholes in dosing and holding tanks
shall provide a minimum opening of eighteen (18) inches by eighteen (18) inches
into the tank. Manhole riser lids or covers shall be designed and constructed
so as to be watertight and, through the use of locks, locking devices, or other
means, prevent access to the tank by unauthorized persons.
(c) All dosing or holding tanks, due to their
frequently empty or partially filled condition, shall be designed or installed
(using suitable anchoring devices or antiflotation devices) to prevent
flotation or vertical shifting due to ground water pressure.
(2) All dosing and holding tank
equipment, controls, and appurtenances shall comply, where applicable, with the
requirements of Section 5(4)(a), (b), (d), (f), (g) and (h) of this
administrative regulation, in addition to the following:
(a) High water alarms, including an audible
or visible alarm system within the structure served by the dosing or holding
tank, shall be installed in such tanks and calibrated to activate an alarm
whenever the tank liquid level reaches eighty-five (85) percent of capacity.
Such alarms shall be connected to a separate electrical circuit, and visible
systems shall be located in an area of high pedestrian traffic.
(b) When pumps are used for dosing effluent
into the lateral field or are used for lifting effluent to a lateral field
above the elevation of the dosing tank, electrically operated mercury float
switch controls shall be provided to permit automatic operation of such pumps.
Manually operated pump controls are not permitted. When pumps are used, they
shall be installed in an elevated position in respect to the tank bottom, by
placement on stands designed for such purpose, concrete blocks, or through the
use of suitable hangers to allow for sludge storage space and prolong service
life of the pumps. Elevation distance from the tank bottom shall be a minimum
of eight (8) inches.
(c) In lieu of
pumps, automatic dosing siphons may be used for lateral field dosing where a
suitable downhill gradient exists from the elevation of the siphon to the
lateral field.
Section
7. Grease Traps. All grease traps shall comply with the general
construction requirements listed in Section 4 of this administrative regulation
for septic tanks, based upon the type of material used in their construction,
in addition to the following:
(1) Inlet
baffle, sanitary tee or baffle device shall extend two (2) to no more than four
(4) inches below the liquid level of the trap;
(2) Outlet baffle, sanitary tee or baffle
device shall extend downward to eighty (80) percent of the total liquid depth
of the trap;
(3) The minimum liquid
depth shall be twenty-four (24) inches with a maximum depth of forty-eight (48)
inches;
(4) Grease traps are
exempted from the 2:1 to 3:1 length to width ratio requirements in Section 4 of
this administrative regulation; and
(5) A manhole or manholes shall be provided
on each grease trap to allow free access for servicing all areas of the trap.
Such manhole(s) shall have a minimum dimension of eighteen (18) inches measured
at the bottom edge of the manhole opening into the trap, and manhole risers
shall be used to extend the manhole(s) to grade.
Section 8. Distribution Devices.
(1) Precast concrete.
(a) All precast concrete distribution boxes
shall be designed and constructed to provide sufficient strength and structural
integrity to withstand a vertical uniform load of 150 lb./sq. ft. on the top of
the box.
(b) A minimum end product
strength of 4,000 pounds per square inch shall be used in the construction of
the box and lid.
(c) A minimum wall
thickness of one and one-half (1 1/2) inches shall be used in the construction
of distribution box bottoms, side walls, and lids and shall be reinforced by a
minimum No. 10 gauge six (6) inch by six (6) inch welded steel reinforcing
wire, or equivalents, as approved by the cabinet.
(d) Distribution box lids or covers shall
meet the requirements of paragraph (a) of this subsection and shall be provided
with suitable handles for removal.
(e) Knockouts or holes for inlet and outlet
piping shall be of sufficient diameter to accept four (4) inch diameter piping
but no more than five (5) inches in diameter at the inside surface of the
box.
(f) All distribution devices
offered for sale or use in Kentucky shall bear, by imprint, stencil, or other
acceptable means of marking, the manufacturer's name and the serial number
assigned to the manufacturer's plans and specifications approved by the
cabinet. This imprint, stencil, or other marking shall be located on the inlet
end of the device. Low pressure pipe manifolds shall meet the identification
requirements for plastic piping in Section 9 of this administrative
regulation.
(2) Molded
plastic and fiberglass. Molded plastic or fiberglass distribution boxes shall
be designed and constructed to meet the requirements listed in subsection
(1)(a), (d), (e) and (f) of this section.
(3) Equal flow and level type design
standards.
(a) Outlet holes or knockouts in
equal flow and level boxes shall be spaced a minimum of seven (7) inches on
centers to permit access for application of waterproofing sealants around
lateral piping and the external surface of the box side wall or endwall. When
plastic or neoprene connectors are cast into the box, this requirement may be
waived. Outlet holes or knockouts shall be located a minimum distance of six
(6) inches on centers, on a single plane, above the inside bottom surface of
the box and a minimum of three (3) inches on centers from adjacent side walls
in the outlet portion of the box. At the inlet portion of equal flow boxes a
minimum distance of eight (8) inches on centers shall be maintained between
outlet holes and the side wall or endwall to allow for the placement of a
baffle to retard incoming effluent velocity.
(b) Centerline of the inlet hole or knockout
shall be a minimum distance of one and one-half (1 1/2) inches to a maximum of
three (3) inches above the centerline of the outlets.
(c) All equal flow boxes shall be provided
with a baffle on the inlet end of the box. A double flange, molded or cast-in
slot, or other acceptable means to retain the baffle in place shall be
provided. Baffle material and construction shall be equal to that used in the
box itself. Baffles and their mounts or retainers shall be so designed as to
provide a passageway for effluent between the box bottom and bottom edge of the
baffle of no more than two (2) inches in height. The baffle shall extend to one
(1) inch above the top of the inlet.
(d) Equal flow boxes shall be designed so as
to provide unobstructed access, on removal of the lid or top, for direct,
simultaneous viewing of all outlets to facilitate the performance of "water
leveling" procedures during installation.
(4) Hillside or drop box type design
standards.
(a) Lateral outlet holes or
knockouts shall be located a minimum of two and one-half (2 1/2) inches on
centers, on a single plane above the inside bottom surface of the box, and a
minimum of three (3) inches on centers from adjacent side walls.
(b) Centerline of the inlet hole or knockout
shall be a minimum of five (5) inches above the center-line of the lateral
outlets and a minimum of one (1) inch above the centerline of the supply line
outlet going to the next box in series.
(c) Hillside or drop boxes shall be designed
so as to provide sufficient separation distance (twelve (12) inches or greater
recommended) between the inlet side wall and supply line outlet side wall to
minimize the risk of short-circuiting of effluent under heavy flow conditions
or on steep hillsides where gradient induced flow velocity is created. In lieu
of this requirement, box designs offsetting the vertical centerlines of inlets
and supply line outlets or other acceptable means, may be employed.
(5) Plastic low pressure pipe
manifolds. All plastic pipe, fittings, and connectors used in low pressure pipe
supply lines and manifolds shall be of Schedule 40 PVC or ABS construction and
materials.
(6) Alternating valves
and devices design standards.
(a) Alternating
valves and devices shall meet the general design and construction standards
listed in subsection (1)(a) and (d) of this section, and if constructed of
precast concrete, subsection (1)(b) and (c) of this section as well.
(b) All alternating valves and devices shall
be designed and constructed to provide a positive seal to each outlet when in a
closed position. The valving device shall be constructed of corrosion resistant
materials and of sufficient strength to withstand normal operational stresses
without damage or deformation resulting in valve malfunction.
(c) All alternating valves and devices shall
be fitted with risers and watertight lids or covers, extending to grade, which
will permit unobstructed access for maintenance, inspection, and
operation.
Section
9. Piping, Fittings, and Connectors.
(1) Nonperforated pipe - gravity flow usage.
(a) All nonperforated piping used for gravity
flow carriage of effluent between septic tanks in series, septic tanks or other
pretreatment units and distribution or alternating devices, and for two (2)
feet into lateral trenches or beds from distribution devices shall be at least
SDR 35 ASTM-D3034 and D3033 for PVC and ASTM-D2751 for ABS. 1,500 lb. crush
ASTM-F810 for polyethylene may be used between distribution devices and lateral
trenches or beds.
(b) All such
nonperforated piping shall be of a minimum internal diameter of four (4)
inches, except that such piping used between distribution devices and lateral
trenches or beds may be reduced to a minimum internal diameter of two (2)
inches with the use of approved reducer coupler fittings.
(c) Each standard section of pipe as supplied
by the manufacturer shall be plainly marked, embossed, or engraved showing the
manufacturer's name or hallmark, the SDR 35 ASTM D3034, D3033, or D2751, 1,500
lb. crush ASTM-F810 designation, and the type of pipe material (PVC, ABS, or
polyethylene).
(2)
Nonperforated pipe - pressure usage.
(a) All
nonperforated piping used for pressurized carriage of effluent between dosing
or pumping and distribution or alternating devices shall be of at least 160 psi
PVC or ABS.
(b) 160 psi
polyethylene pipe or equivalent may be used in all applications listed above in
lieu of PVC or ABS piping, except in the construction of any portion of a low
pressure pipe (LPP) system where PVC or ABS pipe shall be required.
(c) Each standard section of pipe as supplied
by the manufacturer, or in the case of polyethylene or equivalent piping rolls
at not greater than ten (10) foot intervals, shall be plainly marked, embossed,
or engraved showing the manufacturer's name or hallmark, the 160 psi
designation, and the type of pipe material.
(d) All such pipe used on an individual low
pressure pipe (LPP) system installation shall be of the same type of material
mixing of PVC, ABS, polyethylene, or other equivalent piping is
prohibited.
(3)
Perforated pipe - gravity flow usage.
(a) All
perforated pipe used for gravity flow carriage and distribution of effluent
within lateral trenches, beds, mounds, or other such applications shall meet
1,500 lb. crush ASTM-F810 standards for rigid piping and ASTM-F405 for
corrugated semirigid piping.
(b)
Each standard section of pipe as supplied by the manufacturer shall be plainly
marked, embossed, or engraved showing the manufacturer's name or hallmark, the
type of pipe material, and showing the product meets applicable ASTM standards
and a bearing load of 1,500 lbs., per foot. In addition, a painted or other
clearly marked line or spot shall be marked on each section to denote the top
of the pipe.
(c) All such gravity
flow usage perforated pipe shall have a minimum internal diameter of two (2)
inches.
(d) On two (2) inch or
three (3) inch diameter pipe: if one (1) row of holes is use, it shall be
located directly opposite the top marking on the pipe and holes shall be a
minimum one-fourth (1/4) inch in diameter; if two (2) rows of holes are used,
they shall be one-quarter (1/4) inch to five-sixteenths (5/16) inch in
diameter, and evenly spaced and placed within an arc of 120 degrees on the
bottom of the pipe. Spacing of holes longitudinally shall be between twelve
(12) inches to five (5) feet on centers.
(e) All four (4) inch diameter or greater
pipe shall have at least two (2) rows of holes five-sixteenths (5/16) to
one-half (1/2) inch in diameter, evenly spaced and placed within an arc of 120
degrees on the bottom of the pipe. If three (3) holes are used, the center row
shall be directly opposite the top marking. Spacing of holes longitudinally
shall be between three (3) to twelve (12) inches on centers.
(4) Perforated pipe - gravelless
pipe design.
(a) All eight (8) and ten (10)
inch I.D. corrugated polyethylene pipe used in gravelless pipe lateral fields
shall meet the requirements of ASTM F667.
(b) Each standard section of pipe as supplied
by the manufacturer shall be plainly marked, embossed, or engraved showing the
manufacturer's name or hallmark, the type of pipe material, and showing the
product meets ASTM F667. In addition, a painted or other clearly marked line
shall be placed on each section to denote the top of the pipe.
(c) All gravelless piping shall be encased,
at the point of manufacturer, with a spun bonded nylon filter wrap, or
equivalent, meeting or exceeding the performance criteria below:
Physical Properties
|
Nominal Values
|
Minimum Values
|
Weight, oz./sq.yd. (ASTM D3776-79)
|
0.85
|
0.75
|
Thickness, Mils (ASTM D1777-64/1975)
|
5.4
|
4.4
|
Fiber size, denier per filament (dpf)
|
4.7
|
4.1
|
Grab Strength, lbs. (ASTM
D1682-64/1975) Machine direction Transverse
direction
|
26 18
|
19 11
|
Burst strength, psi (ASTM D231-62/1975)
|
36
|
26
|
Air permeability,cfm/sq.ft. (ASTM
D737-75/1980)
|
700
|
500
|
Water flow rate
|
500 gpm/sq.ft. @ 3" Head
|
Specific gravity
|
1.0- 1.3
|
Temperature resistance (ASTM D648)
|
425°F
|
Surface reaction to water
|
Hydrophilic
|
Fiber length
|
Continuous
|
(d)
Gravelless pipe hole placement and diameter shall be as follows: holes shall be
cleanly drilled and be placed in two (2) rows spaced 120 degrees apart along
the bottom half of the pipe and 120 degrees from the top stripe to either row.
Hole size shall be between five-sixteenths (5/16) inch to one-half (1/2) inch
in diameter, and holes shall be placed only in corrugation "valleys," not on
the crown or in the corrugation sidewall.
(e) All gravelless piping and encasing filter
wrap shall be further encased, at the point of manufacture, within a plastic
shipping and storage bag of sufficient burst strength, tear resistance and
opacity, to prevent physical damage and ultraviolet radiation deterioration of
the filter wrap.
(f) The
manufacturer shall also make available suitable wide-width plastic tape for
sealing of pipe section and fitting joints.
(5) Perforated pipe - pressure usage, low
pressure pipe systems (LPP).
(a) Pipe used for
pressure carriage and distribution of effluent within lateral trenches, beds,
mounds, or other low pressure pipe (LPP) applications shall be of at least 160
psi PVC or ABS construction. Deep hub water line type pipe shall be
used.
(b) Pipe shall meet the
requirements listed under subsection (2)(c) and (d) of this section.
(c) Minimum pipe internal diameter shall be
determined on a case-by-case basis, based upon system size, configuration, and
other factors necessary in the design of a low pressure pipe system. In no case
shall the internal diameter be less than one (1) inch.
(d) Pipe perforations shall run in a straight
line along the bottom of the pipe. Where preperforated pipe is unavailable,
perforations shall be hand-drilled, and deburred. Hole diameters and hole
spacing shall be determined on a case-by-case basis relative to design
requirements of the low pressure pipe system. Hole sizes may range from 5/32 to
one-fourth (1/4) inch in diameter, and hole spacing form three (3) to eight (8)
feet depending on design requirements.
(6) Fittings and connectors.
(a) Piping elbows, tees, wyes, reducers, end
caps, plugs, connectors, and other such fittings shall be designed and
constructed for the intended use.
(b) Fittings and connectors shall be formed
of materials compatible with the piping to which they are joined and meet the
same standards as that piping. Mixing of different pipe and fitting materials
except when expressly designed and constructed for such purpose is
prohibited.
(c) Joints formed
between fittings, connectors, and/or piping shall be rigid and watertight and
shall be made by the methods (solvent welding, chemical fusion, mechanical
compression, etc.) applicable to the materials joined.
Section 10. Leaching Chambers. All
leaching chambers shall comply with the general construction requirements
listed in Section 4 of this administrative regulation for septic tanks, based
upon the type of material used in their construction, in addition to the
following:
(1) Metal leaching chambers are
prohibited;
(2) All leaching
chambers shall be designed and constructed to support vertical uniform loading
of 600 lb./sq.ft. on the top of the chamber without damage or permanent
deformation;
(3) All leaching
chambers shall be designed and constructed to provide ports, slots, holes or
other similar openings on sidewalls to allow air movement and effluent access
to lateral field trench or bed sidewall absorption surfaces;
(4) All leaching chambers shall be designed
and constructed to be interlocking to allow serial installation of chambers,
and be provided with acceptable end plates, caps or other necessary fittings
and connectors;
(5) All leaching
chambers shall be provided with at least one (1) inspection port of a minimum
internal dimension of six (6) inches centrally located in the top of the
chamber; and
(6) All such chambers
offered for sale or use in Kentucky shall bear, by imprint, stencil, or other
acceptable means of marking, the manufacturer's name and the serial number
assigned to the manufacturer's plans and specifications approved by the
cabinet. This imprint, stencil, or other marking shall be located beside the
observation port.
Section
11. Trench Fill and Barrier Material.
(1) Trench fill material.
(a) River gravel or crushed dolomitic
limestone shall be used for bedding and trench fill material for conventional
gravity flow lateral lines. Foreign matter, dust, and fines shall be removed.
Such material shall be of sufficient hardness to attain a three (3) on the
Moh's Scale (material hard enough to scratch a copper penny without crumbling
or powdering shall be considered acceptable). Such material shall conform to
the sizing standards and specifications of the Kentucky Transportation Cabinet
for No. 2, No. 23, and No. 4 coarse aggregates, except that other grades may be
used if they are in conformance with the general requirements of this paragraph
and are acceptable to the cabinet. A size range of three-quarters (3/4) inch to
two and one-half (2 1/2) inches in rough diameter shall be used, and material
shall be graded for uniformity in size.
(b) Other materials such as blast furnace
slag may be considered for usage if such materials can meet or exceed all of
the requirements of paragraph (a) of this subsection.
(c) Pea gravel of a minimum one-fourth (1/4)
inch diameter shall be used for bedding and trench fill material for low
pressure pipe systems. River gravel or crushed limestone may also be used if
washed and screened to a uniform size range of three-fourths (3/4) inch to one
and one-half (1 1/2) inch.
(d)
Graded sands used for the construction of mound systems or filter units shall
be sized according to the design requirements of the system or unit
involved.
(e) Crushed rock, gravel,
pea gravel, sand, or other such materials meeting the requirements of this
section for use as trench fill, lateral bedding material, mound fill, or filter
material may be used, as applicable, in the construction of curtain, vertical,
and underdrain ground water drainage systems.
(2) Trench barrier material.
(a) Straw or synthetic filter fabrics shall
be used in all lateral trenches, beds, mounds, subsurface sand filters, or
ground water drainage systems to provide a barrier to the entrance of soil
backfill into the rock, gravel, pea gravel, or sand fill in such trenches,
beds, mounds, filters, or drainage systems.
(b) Other similar materials may be considered
for such usage provided that they can be demonstrated to perform in an
equivalent manner with the above and do not restrict air movement within the
trench, bed, mound, filter, or drainage system.