[Ord. No. 23-04, 7-5-2023]
The following words and terms, when used, shall have the following
meaning, unless the context clearly indicates otherwise.
The final treatment and disposal of the septic tank effluent.
The absorption system includes the distribution box, the perforated
pipe and gravel or other gravel less distribution pipe, the filter
materials and the trenches.
A subordinate building or use which customarily is incidental
to that of the main building or use of the premises.
Any sewage tank which utilizes the principle of oxidation
in the decomposition of sewage by the introduction of air into the
sewage.
A high water alarm device shall be installed so that it activates
when levels reach one (1) foot below the inlet pipe. This device shall
be an audible and illuminated signal to alert.
A means by which septic tank effluent is disposed of other
than the conventional absorption system. Examples of alternative systems
are wetlands, intermittent sand filters, and low-pressure pipe.
A device installed in a septic tank for proper operation
of the tank and to provide maximum retention of solids. This includes
vented sanitary tees and submerged pipes in addition to those devices
normally called baffles.
That layer of parent material which is consolidated and unweathered.
Any room within a dwelling that is used as a sleeping room.
Liquid waste from a dwelling or other establishment produced
by toilet waste, or culinary operations and specifically excluding
laundry.
That part of the drainage system which extends from the end
of the building drain and conveys its discharge to an individual sewage
treatment system.
Any building used for any purpose other than as a single-family
dwelling.
The liquid volume of a sewage tank using inside dimensions
below the outlet.
An on-site sewage disposal system used for disposing of wastewater
from a commercial establishment or subdivision.
The governing body, Cass County Environmental Health Department.
A water-tight box that receives the discharge or effluent
from the septic tank and equalizes the flow of sewage to each individual
line of the absorption system. All gravity fed outlets are required
to have flow equalization devices.
Perforated pipes or agricultural drain tiles are used to
distribute sewage tank effluent in soil treatment systems.
A tank or separate compartment following the sewage tank
which serves as a reservoir for the dosing device.
A pump, siphon or other device that discharges sewage tank
effluent from the dosing chamber to the soil treatment system.
Any building or place used or intended to be used by human
occupants as a single-family or two-family units.
A person that meets the requirements of Chapter 256 of the
Missouri State Statutes.
An absorption system comprised of large diameter, eight-
and ten-inch corrugated plastic pipe, perforated with holes on a one
hundred twenty degrees (120°) arc centered on the bottom, wrapped
in a sheath of spun bonded nylon filter wrap and installed level in
a trench without gravel bedding.
Liquid waste from a dwelling produced by bathing, laundry,
culinary operations, from floor drains and specifically excluding
toilet waste.
A device to catch or trap grease that is in suspension or
solution in liquid waste and to retain the grease solids separated
in the trap receptacle.
A watertight tank for storage of sewage until it can be transported
to a point of approved treatment and disposal.
With regard to bedrock, a bedrock having very few cracks
or crevices and having a vertical permeability less than one-inch
in twenty-four (24) hours shall be considered impermeable. Regarding
soils, a soil horizon or layer having a vertical permeability less
than one-inch in twenty-four (24) hours shall be considered impermeable.
A sewage treatment system, or part of a system, serving a
dwelling(s) or other establishment(s), which utilizes subsurface soil
treatment and disposal.
Intermittent Sand filters are beds of granular materials
twenty-four (24) to thirty-six (36) inches deep underlain by graded
gravel and collecting tile. Wastewater is applied intermittently to
the surface of the bed through distribution pipes or troughs and the
bed is under-drained to collect and discharge the final effluent.
Uniform distribution is normally obtained by dosing so as to flood
the entire surface of the bed. Filters may be designed to provide
free access (open filters) or may be buried in the ground (buried
filters) shall be discharged to a soil absorption system.
Any single parcel of land with more than two (2) manufactured
homes used as full-time residences.
A zone of chemical oxidation and reduction activity appearing
as splotchy patches of red, brown, orange and gray in the soil.
A system where the soil treatment area is built above the
ground to overcome limits imposed by proximity to water table or bedrock
or by rapidly or slowly permeable soils.
Any public or private structure other than a dwelling which
generates sewage.
A soil moisture content below which the soil may be manipulated
for purposes of installing a soil treatment system and above which
manipulation will cause compaction and puddling.
An engineer holding a current license to practice from the
Missouri Board for Architects, Professional Engineer, and Land Surveyors,
having a background in soils, wastewater, and geology.
The percentage of rock fragments in a soil that are greater
than two (2) millimeters in diameter or retained on a No. 10 sieve
which may include chert, sandstone, shale, limestone, or dolomite.
The amount of rock fragments in a soil is of a concern in areas of
residual soils overlying highly permeable bedrock.
A person registered as a sanitarian by the National Environmental
Health Association or employed as a sanitarian by the State or local
health department. Also known as Environmental Public Health Specialist
or Public Health Specialist or Inspector.
Those solids and liquids removed during periodic maintenance
of a septic or aeration unit tank, or those solids and liquids removed
from a holding tank.
Any watertight, covered receptacle designed and constructed
to receive the discharge of sewage from a building sewer, separate
solids from liquid, digest organic matter, store liquids through a
period of detention and allow the clarified liquids to discharge to
a soil treatment system.
A separation distance measured horizontally.
Any water carried domestic waste, exclusive of footings and
roof drainage, from any industrial, agricultural, or commercial establishment
or any other structure. Domestic waste, includes, but is not limited
to, liquid waste produced by bathing, laundry, culinary operations,
liquid wastes from toilets and floor drains and specifically excludes
animal waste and commercial process water.
Flow as determined by measurement of actual water use or,
if actual measurements are unavailable, as estimated by the best available
data provided by 19 CSR 20-3.060, Small Sewage Works Design Guide.
A watertight tank used in the treatment of sewage, which
includes, but is not limited to, septic tanks and aeration units.
That liquid which flows from a septic or aeration unit under
normal operation.
A sealed earthen basin which uses natural unaided biological
processes to stabilize wastewater and used on large lots.
Any natural depression in the surface of the ground with
or without collapse of adjacent rock, that provides a means through
which surface water can encounter subsurface water. Sinkhole depression
may be gradual or abrupt; they may or may not have a well-defined
eye. While most sinkholes can be defined as the area with a "closed
contour," some sinkholes, such as those located on the sides of hills
and in stream valleys, may not. All sinkholes provide discreet points
of recharge to groundwater.
The area bounded by the dimensions required for the proper
location of the soil treatment system.
The ratio of vertical rise or fall to horizontal distance.
Those soil characteristics which preclude the installation
of a standard system, including, but not limited to, evidence of water
table or bedrock closer than three (3) feet to the ground surface
and percolation rates slower than one hundred twenty (120) minutes
per inch. Also, the amount of rock fragments in areas of significant
potential for groundwater contamination.
The method of testing absorption qualities of the soil by
physical examination of the soils' color, mottling, texture,
structure, topography, and hillslope position.
A person who is qualified by the Missouri Department of Health
as a soil scientist.
Soil particle sizes or textures specified in this rule refer
to the soil textural classification in the Soil Survey Manual Handbook
No. 18, U.S. Department of Agriculture, 1951.
That area of trench or bed bottom which is in direct contact
with the trench rock of the soil treatment system.
A system where sewage tank effluent is treated and disposed
of below ground surface by filtration and percolation through the
soil. It includes those systems commonly known as seepage bed, trench,
drain field, disposal field and includes mound arid low pressure pipe
systems.
An individual sewage treatment system employing a building
sewer, sewage tank and the soil treatment system commonly known as
seepage bed or trenches, drain field or leach field.
Fecal matter, urine, toilet paper and any water used for
flushing.
Clean rock washed creek gravel or similar insoluble, durable
and decay-resistant material free from dust, sand, silt or clay. The
size shall range from one and one-half (1 1/2) inches to three-inch
rock.
Any device which can stop sewage tank effluent from flowing
to a portion of the soil treatment area. This includes, but is not
limited to, caps or plugs on distribution or drop box outlets, divider
boards, butterfly valves, gate valves or other mechanisms.
The highest elevation in the soil where all voids are filled
with water, as evidenced by presence of water or soil mottling or
other information. This includes perched and zones of saturation for
long periods of time.
Constructed so that no water can get in or out below the
level of the outlet.
[Ord. No. 23-04, 7-5-2023]
For these standards, on-site wastewater treatment and disposal
system means all equipment and devices necessary for proper conduction,
collection, storage, treatment and disposal of wastewater from a dwelling
or other facility serving the equivalent of fifteen (15) persons,
three thousand (3,000) gallons per day, or less. Included within the
scope of this definition are building sewers, septic tanks, subsurface
absorption systems, mound systems, intermittent sand filters, gravelless
systems, single-family wastewater stabilization ponds and aeration
unit wastewater treatment systems.
[Ord. No. 23-04, 7-5-2023]
All on-site wastewater treatment and disposal systems shall
be located in accordance with the distances shown in Table I.
|
Table I
| |||
|---|---|---|---|
|
Sewage
|
Disposal
|
Lagoons
| |
|
Minimum Distance in Feet From
|
Tanks (1)
|
Area (2)
| |
|
Private water supply well
|
50
|
100
|
100
|
|
Public water supply well (3) community or non-community
|
300
|
300
|
300
|
|
Classified stream, lake or impoundment
|
50
|
50
|
50
|
|
Stream or open ditch
|
25
|
25
|
25
|
|
Property lines
|
10
|
10
|
100
|
|
Building foundation (including slab on grade)
|
5
|
15
|
50
|
|
Basement
|
15
|
25
|
100
|
|
Water line under pressure
|
10
|
10
|
10
|
|
Suction water line
|
50
|
100
|
100
|
|
Upslope interceptor drains
|
—
|
10
|
10
|
|
Downslope interceptor drains
|
—
|
25
|
25
|
|
Top of slope of embankments or cuts of 2 feet or more vertical
height
|
—
|
20
|
20
|
|
Other soil absorption system except repair area
|
—
|
20
|
20
|
|
Swimming pools
|
15
|
15
|
15
|
|
Springs and caves
|
50
|
100
|
100
|
|
Sinkhole rim (4)
|
50
|
100
|
500
|
|
Flood Zone A & AE
|
50
|
50
|
100
|
|
FOOTNOTES TO TABLE I
| ||
|
(1)
|
Includes sewage tanks, intermittent sand filters and dosing
chambers.
| |
|
(2)
|
Includes subsurface absorption systems. Does not include wastewater
stabilization ponds.
| |
|
(3)
|
State regulations require a minimum of one hundred (100) feet
but recommend three hundred (300) feet. For newly developed areas,
three hundred (300) feet will be the required minimum. Where there
are existing lots which were subdivided in accordance with Cass County
Planning and Zoning Regulations in effect at the time of subdivision
and which cannot attain the three hundred (300) feet setback, the
setback can be reduced to the one hundred (100) feet minimum. The
maximum attainable setback will be required.
| |
|
(4)
|
Set back distance from sinkholes refers to the horizontal distance
from the rim of the sinkhole, which is defined as the perimeter of
the sinkhole depression. Where the required setback distance from
the sinkhole rim cannot be reasonably met on an existing tract of
land which is in conformity with the Cass County Zoning Regulations
the following shall apply:
| |
|
a.
|
The absorption field shall be located a minimum of one hundred
(100) feet from the sinkhole flooding area. The sinkhole flooding
area is defined as the area below the elevation of the lowest point
on the sinkhole rim OR the areas inundated by runoff from a storm
with an annual exceedance probability of one percent (1%) (100-year
storm and a duration of twenty-four (24) hours. Volume of runoff shall
be calculated according to the methods set forth in USDA Soil Conservation
Service Technical Release No. 55 Urban Hydrology for Small Watersheds.
| |
|
b.
|
A soil morphology evaluation shall be performed.
| |
|
c.
|
The size of the absorption field shall be based upon the minimum
wastewater application rate of two-tenths (0.2) gallons per day per
square foot of absorption area.
| |
|
d.
|
An alternative system may be required depending upon soil conditions.
| |
|
e.
|
The Department may require that absorption trenches be sand
lined.
| |
[Ord. No. 23-04, 7-5-2023]
A.
Single-Family Dwelling (Including Manufactured Homes).
1.
In determining the volume of sewage from single-family dwellings,
the minimum flow rate shall be one hundred fifty (150) gallons per
day per bedroom. The minimum volume of sewage from each single-family
dwelling shall be three hundred (300) gallons per day and each additional
bedroom above two (2) bedrooms shall increase the volume of sewage
by one hundred fifty (150) gallons per day. When the occupancy of
a single-family dwelling exceeds two (2) persons per bedroom, the
volume of sewage shall be determined by the maximum occupancy at a
rate of seventy-five (75) gallons per person per day.
2.
The maximum wastewater flow for on-site wastewater systems serving
single-family dwellings is one thousand five hundred (1,500) gallons
per day.
B.
Other Residential Dwellings.
1.
Duplexes: one hundred fifty (150) gallons per day per bedroom,
minimum (300) gallons per day per unit, maximum three thousand (3,000)
gallons per day for two (2) units.
2.
Apartments and condominiums: one hundred fifty (150) gallons
per day per bedroom, minimum three hundred (300) gallons per day per
unit, maximum three thousand (3,000) gallons per day per building.
C.
Other Establishments.
For establishments or housing developments other than a single-family
residence 19 CSR 20-3.060-Subsection (2)(E) shall be used to estimate
the sewage flow rate. Values for estimated sewage flow derived from
19 CSR 20-3.060 for establishments having food service operations
shall be increased by a factor of one and one-half (1.5) to compensate
for the high organic strength. A portion of 19 CSR 20-3.060(2)(E)
is shown in Table II for convenience.
|
Table II
| ||
|---|---|---|
|
Type of Establishment
|
Pounds BOD per person (unless otherwise noted)
|
Gallons* per day per person
|
|
Employee Sanitary Waste
(Generally, means 8-hour shift employees at institutions, commercial
establishments, factories and similar establishments. Total employee
waste figure, if applicable, must be added to the appropriate patron
or residential total from the following table)
|
0.05
|
15
|
|
Residential (See previous page)
| ||
|
Food or Drink Establishments (Wastes per patron) (1)
| ||
|
Tavern or bar (not serving food)
|
0.01
|
2
|
|
Fast-food (paper service)
|
0.02
|
3
|
|
Cafe or restaurant
|
0.03
|
5
|
|
Restaurant serving alcoholic beverages
|
0.04
|
5
|
|
Restaurant grinding garbage.
|
0.07
|
6
|
|
Schools (Waste per student)
| ||
|
Day school, no cafeteria, gym or showers
|
0.02
|
10
|
|
With cafeteria - ADD
|
0.02
|
4
|
|
With garbage grinding - ADD
|
0.02
|
1
|
|
With gym and showers - ADD
|
0.01
|
10
|
|
Boarding schools
|
0.17
|
75
|
|
Institutions
| ||
|
Hospitals (per bed)
|
0.22
|
125-200
|
|
Institutions other than hospitals
|
0.17
|
100-150
|
|
Nursing homes
|
0.17
|
100-125
|
|
Commercial and Recreational
| ||
|
Public parks (toilets only) (2)
|
0.02
|
5
|
|
Public parks with bath house, showers, toilets (2)
|
0.02
|
5
|
|
Swimming Pools and Beaches
|
0.06
|
15-25
|
|
Country clubs (per resident member)
|
0.06
|
15-25
|
|
Country clubs (per member present)
|
0.17
|
75-100
|
|
Service stations (waste per customer) (1)
|
0.06
|
15-25
|
|
Laundromats (per machine)
|
0.01
|
5
|
|
Hotels
|
1.25
|
580
|
|
Motels (without restaurants)
|
0.15
|
50
|
|
Luxury resorts
|
0.10
|
40
|
|
Camper trailer
|
0.17
|
75
|
|
Work or construction camps
|
0.08
|
30
|
|
Churches (per seat)
|
0.15
|
60
|
|
Stores, malls or shopping centers
|
0.01
|
5
|
|
(Per 1,000 square feet of floor area)
|
0.34
|
200
|
|
Office buildings (per employee) (3)
|
0.05
|
15
|
|
Drive-in theaters (2)
|
0.01
|
5
|
|
Stadiums, auditoriums, theaters or drive-ins (per seat)
|
0.01
|
5
|
|
NOTES:
| |
|
(1)
|
Number of customers or patrons assumed in determining the daily
wastewater flow will be subject to verification by the Department
from use at similar facilities.
|
|
(2)
|
Number of persons is assumed to be 3 times the number of parking
spaces.
|
|
(3)
|
Office buildings are assumed to have 1 employee per 300 square
foot of gross floor area.
|
|
(4)
|
Maximum wastewater flow is limited to 1,500 gallons per day
unless otherwise approved by the Department.
|
|
(5)
|
Gallons per person per day includes normal infiltration for
residential systems.
|
|
(6)
|
Population to be served. Unless satisfactory justification can
be given for using lower per-unit occupancies, the following numbers
shall be used in determining the population for which to design the
sewage works:
|
|
Type of Unit
|
Persons/Unit
|
|---|---|
|
Residences
|
3.7
|
|
Apartments or Condominiums
| |
|
(1 bedroom)
|
2.0
|
|
(2 bedroom)
|
3.0
|
|
(3 bedroom)
|
3.7
|
|
Mobile Homes
|
3.0-3.7
|
|
Camper trailer without sewer hookup
|
2.5
|
|
Camper trailer with sewer hookup
|
3.0
|
|
Motels
|
3.0
|
D.
Reduction In Sewage Flow. Reductions in design sewage flow rates
may be allowed by the Department on a case-by-case basis depending
upon water conservation plans.
E.
Gray Water — Black Water Systems. Separate systems may be used for gray water and black water systems. Forty percent (40%) of the average daily waste flow shall be considered black water. The remaining sixty-percent (60%) of the average waste daily the flow shall be considered gray water. Septic tank size for black water will be as required as in Section 700.160.
F.
Minimum
size for gray water tank shall be one thousand (1,000) gallons.
[Ord. No. 23-04, 7-5-2023]
A.
The Site Evaluation is to be performed by a registered soil scientist
in accordance with 19 CSR 20-3.060, Subsection (2)(A) - (D) to determine
the best location for the on-site system and the type and amount of
lateral field to be used.
B.
Procedures For Soil Morphology
1.
General. The intent of this Section is to provide minimum standards
for site evaluations based upon evaluation of the soil characteristics,
namely texture, color, structure, drainage, and depth. Criteria are
also given for sizing standard systems and some alternative systems.
2.
Adoption And Use. Where this rule is administered by an administrative
authority, those administrative authorities may adopt this Section
in whole or in part, as part of a local code or ordinance. Nothing
in this rule or Section shall require any administrative authority
to allow an installation based upon the criteria contained in this
Section. The administrative authority may require percolation tests
in addition to evaluation of soil characteristics. Whenever percolation
tests and these criteria are used, the size of the proposed system
or suitability of a site should be based upon which criteria produce
the most conservative system. This type of evaluation should be conducted
by a professional soil scientist, engineer, sanitarian or registered
geologist with special training in determining soil morphological
characteristics in the field.
3.
Site Evaluation. An investigation of a proposed soil absorption
site shall consider the following factors:
a.
Topography and landscape position;
b.
Soil characteristics (morphology) which include texture, structure,
porosity, consistence, color and other physical, mineral and biological
properties of various horizons, and the thickness and arrangement
of the horizons in the soil profile;
c.
Soil drainage, which includes both external (surface) and internal
(soil); D Soil depth;
d.
Restrictive horizons; and
e.
Available space.
4.
Soil Characteristics (Morphology). Soil borings or pits shall
be taken at the site to be used for soil absorption systems. These
borings shall be taken to a depth of forty-eight (48) inches or as
required to determine the soil characteristics. Soil borings or pits
and core samples shall be evaluated, and a determination made on the
suitability of the soil to treat and absorb septic tank effluent.
The important soil characteristics, which shall be reviewed by the
administrative authority, are as follows:
a.
The relative amounts of the different sizes of mineral particles
in a soil are referred to as soil texture. All mineral soils are composed
of sand, two (2) to five-hundredths (0.05) millimeters in size; silt,
which includes intermediate-sized particles that cannot be seen with
the naked eye but feel like four (4) when pressed between the fingers,
five-hundredths (0.05) to two-thousands (0.002) millimeter in size;
or clay, which is extremely small in size and is the mineral particle
that gives cohesion to a soil, less than two-thousandths (0.002) millimeters
in size or a combination of these. The texture of the different horizons
of soils may be classified into five (5) general groups and shall
be used for determining the application rates.
(1)
Soil Group I. Sandy texture soils contain more
than seventy percent (70%) sand-sized particles in the soil mass.
These soils do not have enough clay to be cohesive. Sandy soils have
favorable sewage application rates but may have a low filtering capacity
leading to malfunction due to contamination of groundwater. The sandy
group includes the sand and loamy sand soil textural classes and shall
generally be considered suitable in texture.
(2)
Soil Group II. Course loamy texture soils contain
more than thirty percent (30%) sand-sized particles and fewer than
twenty percent (20%) clay-sized particles in the soil mass. They exhibit
slight or no stickiness. The coarse loamy group includes sandy loam
and loam soil textural classes and shall generally be considered suitable
in texture.
(a)
Sandy Loam. Sandy loam feels gritty and forms a
ball that can be picked up with the fingers and handled with or without
breaking.
(b)
Loam. Loam may feel slightly gritty but does not
show a fingerprint and forms only short ribbons ranging from twenty-five-hundredths
(0.25) to fifty-hundredths (0.50) inch in length. Loam will form a
ball that can be handled without breaking.
(3)
Soil Group III. These fine loamy texture soils
contain fewer than forty percent (40%) clay-sized particles and not
more than thirty percent (30%) sand-sized particles in a soil mass.
This group is limited to less than thirty-five percent (35%) clay
when the clay minerals exhibit high shrink/swell characteristic and
exhibit slight to moderate stickiness. The fine loamy group includes
sandy clay loam; silt loam; clay loam and silty clay loam textural
classes and shall generally be considered provisionally suitable in
texture.
(a)
Silt Loam. Silty loam feels floury when moist and
will show a fingerprint but will not ribbon and forms only a weak
ball.
(b)
Silt. Silt has a floury feel when moist and sticky
when wet but will not ribbon and forms a ball that will tolerate some
handling.
(c)
Sandy Clay Loam. Sandy clay loam feels gritty but
contains enough clay to form a firm ball and may ribbon to form seventy-five-hundredths
(0.75) to one-inch pieces.
(d)
Silty Clay Loam. Silty clay loam is sticky when
moist and will ribbon from one (1) to two (2) inches. Rubbing silty-clay
loam with the thumbnail produces a moderate sheen. Silty clay loam
produces a distinct fingerprint.
(e)
Clay Loam. Clay loam is sticky when moist. Clay
loam forms a thin ribbon of one (1) to two (2) inches in length and
produces a slight sheen when rubbed with the thumbnail. Clay loam
produces a non-distinct fingerprint.
(4)
Soil Group IV. These clay texture soils contain
forty percent (40%) or more clay-sized particles and include sandy
clay, silty clay and clay. This group may also include clay loam and
silty clay loam when the clay fraction is greater than thirty-five
percent (35%) and of a high shrink/swell nature. There are two (2)
major types of clays: non-expandable and expandable. The non-expandable
clays, when wet are slightly sticky to sticky; when most, are friable
to firm; and when dry, they are slightly hard to hard. The non-expandable
clays (Group IV a) shall generally be considered provisionally suitable
in texture. The expandable clays, when wet are very sticky and very
plastic and when moist, these clays are very firm to extremely firm
and when dry, are very hard to extremely hard. The expandable clays
(Group IV b) shall be considered unsuitable in texture.
(a)
Sandy Clay. Sandy clay is plastic, gritty and sticky
when moist and forms a firm ball and produces a thin ribbon to over
two (2) inches in length.
(b)
Silty Clay. Silty clay is both plastic and sticky
when moist and lacks any gritty feeling. Silty clay forms a firm ball
and readily ribbons to over two (2) inches in length.
(c)
Clay. Clay is both sticky and plastic when moist,
produces a thin ribbon over two (2) inches in length, produces a high
sheen when rubbed with the thumbnail and forms a strong ball resistant
to breaking.
(5)
Soil Group V. This soil group may be of any texture;
however, the most predominant are cherty and very cherty clays, silt
loams and silty clay loams. The amount of rock fragments in these
soils is of a concern in areas of residual soils overlying highly
permeable bedrock where groundwater could become contaminated. In
general soils with less than fifty percent (50%) rock fragments will
be considered suitable. In general, soils with greater than fifty
percent (50%) rock fragments will be considered provisionally suitable
if geological limitations are not severe.
(6)
Recommendations may be made as follows:
(a)
Type A is a parcel of land which is
determined by the site evaluation to be unsuitable for conventional
type systems, or the required distances from wells cannot be met,
greater than forty-five percent (45%) slope or as determined by the
Department.
(b)
Type A Systems include intermittent
and recirculating sand filters, aeration and chlorination, drip irrigation,
wetland.
(c)
Type B is a parcel of land which is
provisionally suitable or can be made, provisionally suitable for
on-site systems as determined by the site evaluation.
(d)
Type B Systems include sand lined
trenches, shallow placement and LPP or dosing systems.
(e)
Type C is a parcel of land which is
suitable for conventional on-site systems as determined by a site
evaluation.
(f)
Type C Systems include conventional
systems using four-inch perforated pipe and gravel, gravelless pipe,
or chamber system.
(7)
A site evaluation may be required on a repair as
determined by the Department.
[Ord. No. 23-04, 7-5-2023]
A.
Building sewers used to convey wastewater from a building to an on-site
wastewater treatment and disposal system shall be constructed of plastic
pipe meeting the minimum requirements of American Society for Testing
and Materials (ASTM) Standards F789-85 and D3034-81, Schedule 40 PVC,
cast iron or vitrified clay and all with approved type joints.
1.
Size. Building sewers shall not be less than four (4) inches)
in diameter.
2.
Slope. Building sewers shall be laid to the following minimum
slope: four-inch sewer — twelve (12) inches per one hundred
(100) feet six-inch sewer — eight (8) inches per one hundred
(100) feet.
3.
Cleanouts. A cleanout shall be provided at least every one hundred
(100) feet or within fifty (50) feet of a change in direction or slope
if the change exceeds ninety degrees (90°).
4.
Connection To Sewage Tank. The pipe going into and out of the
sewage tank shall be Schedule 40 PVC, cast iron or equivalent and
shall extend a minimum of two (2) feet beyond the hole of excavation
for the sewage tank.
5.
Building sewers may be located in a common trench with a water
line with a minimum separation of two (2) feet.
6.
Building sewers shall have a minimum of twelve (12) inches of
cover from the top of the pipe to finished grade.
7.
Building sewers laid under drives or paved traffic areas shall
either be encased in metal conduit or shall be Schedule 40 PVC with
a minimum of four (4) inches of cleaned crushed rock bedding (nominal
size not less than one-half (1/2) inches or greater than one (1) inch)
on all sides of the pipe; or shall be cast iron, ductile iron, or
galvanized steel pipe.
[Ord. No. 23-04, 7-5-2023]
A.
General.
1.
All liquid waste and wash water shall be discharged into the
sewage tank. Roof, garage, footing, surface water, drainage and cooling
shall be excluded from the sewage tank. All sewage tank effluent shall
be discharged to a soil absorption system or an evaporation pond that
is designed to retain the effluent upon the property from which it
originated.
All tanks must be constructed of concrete, or materials otherwise
approved by the Department and meet criteria as set forth in 19 CSR
20-3.060.
2.
Blasting for the tank will be allowed if not in violation of
any subdivision regulation and will not cause damage to existing property
including homes, roads, or water lines.
3.
No metal or site-built tanks will be considered.
4.
Inspection ports shall be raised to grade.
B.
Location. Location of the sewage tank shall consider the following:
1.
The sewage tank shall be placed so that it is accessible for
the removal of liquids and accumulated solids.
2.
The sewage tank shall be placed on three (3) inches of gravel
in firm and settled soil or rock subgrade capable of bearing the weight
of the tank and its contents.
3.
The sewage tanks shall be set back as specified in Table I.
4.
Tops and sides of sewage tanks shall be covered with earth backfill
or other approved material. The top of the tank shall be covered with
a minimum of twelve (12) inches of earth. Where it is impractical
to completely bury the tank, the sides shall be covered with a minimum
of three (3) feet of earth graded to a slope not steeper than two
and one-half (2 1/2) horizontal to one (1) vertical, or enclosed in
a retaining wall, and insulated as required to provide the same R-value
as three (3) feet of earth cover.
C.
Lift Station.
1.
Sizing requirements for lift stations shall be based upon two
(2) full day storage of residence plus dosing requirements.
2.
Site plan shall specify pump type, horsepower required, total
system head (dynamic and static) and flow rate.
3.
All pump inlets shall be set eight (8) to twelve (12) inches
above the bottom of the lift station.
4.
Lift stations shall be equipped with an audible and visual alarm.
5.
Electrical Wiring Requirements.
a.
Electrical box shall be on the outside of pump tank with an
electrical disconnect.
6.
Plugs with electrical tape will not be approved.
7.
Wiring shall be a minimum of 12-2 UF or manufactures recommendations,
whichever is greater on all lift stations.
8.
Wiring longer than two hundred fifty (250) feet shall be a minimum
of 10-2 UF or manufactures recommendation whichever is greater and
shall be sized appropriately for voltage drop.
9.
Wiring on all alarms shall be a minimum of 14-2 UF or manufactures
recommendation whichever is greater.
10.
All discharge lines shall have a one-eight (1/8) inch weep hole
drilled to prevent siphoning and air lock in discharge line.
11.
Administrative authority shall require pump test for final approval.
D.
Solids Removal. It is recommended that the owner of any septic tank
or his/her agent shall regularly inspect and arrange for the removal
and sanitary disposal of septage from the tank whenever the top of
the sludge layer is less than twelve (12) inches below the bottom
of the outlet baffle or whenever the bottom of the scum layer is less
than three (3) inches above the bottom of the outlet baffle. Yearly
inspections of septic tanks are recommended.
E.
Liquid Capacity. The liquid capacity of a septic tank serving a dwelling
shall be based upon the number of bedrooms contemplated in the dwelling
served and shall be at least as large as the capacities given below:
|
Number of Bedrooms
|
Minimum Liquid Capacity Gallons
|
|---|---|
|
1 to 3
|
1,200
|
|
4
|
1,500
|
|
5
|
2,000
|
|
For individual residences with more than five (5) bedrooms,
multiple-family residences, or any place of business or public assembly,
the liquid capacity of the septic tank shall be designed in accordance
with the following:
|
|
V = 0.75Q + 1125; where,
|
|
V is the liquid capacity of the septic tank; and Q is the design
daily sewage flow.
|
F.
Aeration Units. An aeration unit wastewater treatment plant utilizes
the principle of oxidation in the decomposition of sewage by the introduction
of air into the sewage. An aeration unit may be used as the primary
treatment unit instead of a septic tank except where special local
conditions may limit their use. All aeration type treatment systems
shall comply with the general requirements for sewage tanks set forth
in Subsection (4)(E) of 19 CSR 20-3.060 and with the following:
2.
General. The aeration unit shall be located where it is readily
accessible for inspection and maintenance. Setback distances for aeration
units shall be in accordance with Table I.
3.
Design. All aeration units shall comply with National Sanitation
Foundation Standard No. 40 or as required by the Department. In addition,
all aeration unit treatment plants shall comply with the requirements
stipulated in this Section.
4.
The aeration unit shall have a minimum treatment capacity of
one hundred fifty (150) gallons per bedroom per day or five hundred
(500) gallons whichever is greater.
G.
Effluent Disposal. Effluent from an aeration unit or other septic tank shall be discharged into a soil absorption system or other final treatment system in accordance with Section 700.190, Alternative Systems of these standards. NO reduction in the area of soil absorption systems or other final treatment systems shall be permitted because of the use of an aeration unit instead of a septic tank. Direct surface discharge from an aeration unit treatment plant shall not be permitted.
1.
Operation And Maintenance.
a.
All aerobic treatment units, pump tanks, or any other serviceable
equipment identified by the regulatory authority shall have a service
contract maintained in accordance with the manufacturer's specifications.
b.
Any individual or company providing a service in accordance with Subsection (A) shall be certified by the manufacturer of the equipment, or one (1) of its certified agents, when such certification is offered.
c.
All individuals or a company providing services in accordance with Subsection (A) shall be registered with the regulatory authority.
d.
All aerobic treatment units shall have a total suspended solids
test performed annually. This test must be performed in the mixed
liquor compartment (in accordance to manufacture specification) with
sample taken immediately after the method of agitation has stopped.
The sample must be allowed to settle undisturbed for thirty (30) minutes.
If the settleable solids exceed seventy-five percent (75%), the results
must be reported to the regulatory authority and a licensed wastewater
pump service must pump the tank.
2.
Wastewater Stabilization Ponds. Single residence wastewater
stabilization ponds are NOT permitted with lots less than five (5)
acres in size. Lagoon construction will not be allowed on lots less
than five (5) acres in size except under certain circumstances with
an approved variance from the County Commission or Department and
Department. Waste stabilization ponds will be constructed according
to Department of Health Chapter 3 of 19 CSR 20-3.060, Section 6(D).
a.
The administrative authority shall require a properly sized
and constructed Class-1 NSF Standard 40 listed aerobic treatment unit
to precede any lagoon.
b.
All lagoons shall be designed to operate at a minimum depth
of four (4) feet.
c.
Lagoon design criteria (see Lagoon Sizing Requirements).
|
Lagoon Sizing Requirements
| ||||||||
|---|---|---|---|---|---|---|---|---|
|
3 BEDROOM
|
4 BEDROOM
|
5 BEDROOM
| ||||||
|
Surface Area Requirement fltz
|
Square Pond Dimension, feet x feet
|
Round Pound Dimension, dia. (feet)
|
Surface Area Requirement feet2
|
Square Pond Dimension, feet x feet
|
Round Pond Dimension, dia. (feet)
|
Surface Area Requirement feet2
|
Square Pond Dimension, feet x feet
|
Round Pond Dimension, dia
(feet)
|
|
2500
|
50 x 50
|
56
|
3250
|
57x57
|
64
|
3970
|
63 x 63
|
71
|
d.
The following minimum separation distances may be modified as
necessary to accommodate site requirements or local codes:
(1)
The pond shall be located a minimum of one hundred
(100) feet from property lines as measured from the adjoining pond
shoreline. However, this distance must be increased where necessary
to be sure that all effluent is disposed upon the property from which
it originated;
(2)
The pond shall be located a minimum of two hundred
(200) feet from the nearest foundation of an existing neighboring
residence;
(3)
The pond shall be located at least one hundred
(100) feet from a potable water supply or pump suction line; and
(4)
The pond shall be located at least fifty (50) feet
from a stream, watercourse, lake or impoundment.
e.
Ponds may be utilized when there are no significant limitations
related to groundwater from their use and the soils have been demonstrated
to be very slowly permeable. There shall be either a minimum separation
distance between the pond bottom and creviced bedrock of three (3)
feet or installation of a clay liner with a minimum thickness of one
(1) foot or a synthetic liner, either of which must be acceptable
to the administrative authority. Percolation losses from the pond
shall not exceed one-eighth (1/8) inch per day to prevent groundwater
contamination or nuisance conditions. Site modifications may be accomplished
to provide these soil requirements. In areas of severe geological
limitations, restrictive layers such as fragipans shall be a minimum
of twelve (12) inches thick and shall not be breached during construction.
f.
Steeply sloping areas should be avoided.
g.
Selection of the pond site should consider a clear sweep of
the surrounding area by prevailing winds. Heavy timber should be removed
for a distance of fifty (50) feet from the water's edge to enhance
wind action and prevent shading.
h.
A single cell is generally acceptable for single residence pond
systems. If multiple cells are used for further polishing or storing
of the effluent, the secondary cell should be one-half (1/2) the size
of the primary cell.
i.
The minimum embankment top width shall be four (4) feet. The
embankment slope shall not be steeper than three to one (3:1) on the
inner and outer slopes. Inner embankment slopes shall not be flatter
than four to one (4:1). Outer embankment slopes shall be sufficient
to prevent the entrance of surface water into the pond. The freeboard
shall be at least eighteen (18) inches and preferably twenty-four
(24) inches. Additional freeboard may be provided.
j.
To minimize erosion and facilitate weed control, embankments
shall be seeded with a locally hardy grass from the outside tow to
one (1) foot above the water line. Alfalfa or similar long-rooted
crops which might interfere with the structure of the embankment,
shall not be used. Rip rap may be necessary under unusual conditions
to provide protection of embankments from erosion.
k.
The influent line shall be of a sound durable material or watertight
construction of the line shall have a minimum diameter of four (4)
inches and be laid on a firm foundation at a minimum grade of one-eighth
(1/8) inch per foot from the point of entry into the pond. The influent
line shall discharge as far as practical from the possible outlet
side of the pond. A cleanout or manhole should be provided in the
influent line near the pond embankment. From this point the line shall
either be laid to the inner toe of the embankment and then on the
bottom of the pond to the terminus point or the line shall be supported
and secured every five (5) feet. A concrete splash pad three (3) feet
square should be placed under the terminus of the pipe. The elevation
of the cleanout or manhole bottom should be a minimum of six (6) inches
above the high-water level in the pond.
l.
The pond shall be shaped so there are no narrow or elongated
portions. Round, square or rectangular cells are considered most desirable.
Rectangular cells shall have a length not exceeding three (3) times
the width. No islands, peninsulas, or coves shall be permitted. Embankments
should be rounded at comers to minimize accumulation of floating materials.
m.
The floor of the pond shall be stripped of vegetation and leveled
to the proper elevation. Organic material removed from the pond area
shall not be used in embankment construction. The wetted area of the
pond must be sealed to prevent excessive exfiltration. Seals consisting
of soils must be adequately compacted by the construction equipment.
n.
Embankments shall be constructed of impervious materials and
compacted sufficiently to form a stable structure with very little
settlement.
o.
The pond area shall be enclosed with a fence conforming to the
following conditions:
(1)
The fence shall be at least four (4) feet in height;
(2)
The fence shall be welded, woven or chain link
material with no smaller than fourteen-gauge (14 ga) wire. Cattle
or hog panels can be substituted with a tee post being used for a
line post;
(3)
Fence posts shall be pressure-treated wood, galvanized
and/or painted steel. Fence posts shall be driven, tamped or set in
concrete. Line posts should be at least eighteen (18) inches deep
and shall be spaced no more than ten (10) feet apart. Corner posts
should be properly braced;
(4)
The fence shall be of sound construction with no
gaps or openings along the bottom;
(5)
The fence shall be no closer than the center of
the berm to the water's edge at the four-foot operating level.
Fence set-backs should not exceed thirty (30) feet from the water's
edge;
(6)
A properly hinged four-foot high gate or comparable
materials shall be installed and provided with an effective latching
device. The gate should be thirty-six (36) to forty-eight (48) inches
in width to accommodate maintenance and mowing equipment; and
(7)
The fence must be completed prior to occupancy
of the dwelling.
p.
Effluent from a pond must be disposed of on the property from
which it originated. This may be accomplished by locating the outlet
as far as practical from the property line and out of any natural
drainage ditches or swales. The minimum distance from the outlet to
a property line shall be one hundred (100) feet. Another method is
to construct a terraced swale with a minimum length of one hundred
fifty (150) feet. If these methods are unsuccessful, or whenever there
is less than twelve (12) inches of permeable soil over a restrictive
layer, controlled surface irrigation must be used. To utilize controlled
surface irrigation, the pond must be capable of operating up to five
(5) feet deep with one (1) foot of freeboard or have a second cell
for storage. The administrative authority shall approve the method
of effluent disposal.
q.
It may be necessary to introduce water into the pond to facilitate
start-up of the biological processes; however, there shall be no permanent
connection of any roof drain, footing drain or any source of rainwater
to the wastewater stabilization pond.
r.
Odor problems caused by spring turnover of water, temporary
overloading, ice cover; atmospheric conditions or anaerobic conditions
may be controlled by broadcasting sodium or ammonium nitrate over
the surface of the pond. In general, the amount of sodium or ammonium
nitrate should not exceed two (2) pounds per day until the odor dissipates.
[Ord. No. 23-04, 7-5-2023]
A.
The common design of absorption systems is one using absorption trenches,
each separate from the other and each containing a distribution pipe.
This type of system should be used whenever practical. Other types
of absorption systems may be used as alternatives where the site conditions
meet the specific design requirements of the alternative systems.
1.
Standard Absorption Trenches. The absorption trench gives additional
treatment to the sewage from the treatment tank. Regardless of its
appearance of clarity or transparency, the outflow or effluent from
a sewage tank is a dangerous source of contamination. The satisfactory
operation of the sewage disposal system is largely dependent upon
the proper site selection, design and construction of the absorption
trench.
2.
Standard trenches shall be constructed in accordance with Section
(5) of 19 CSR 20-3.060.
3.
Absorption trenches shall not be constructed in unstabilized
fill or ground which has become severely compacted due to construction
equipment.
4.
Absorption trenches shall not be constructed in soils which
are wet.
5.
The minimum area in any absorption trench system shall be based
on daily wastewater flow and loading rate. The minimum size system
shall be four hundred (400) square feet.
6.
Blasting of the rock in the area of the lateral lines is not
allowed.
7.
Each absorption trench system shall have a minimum of two (2)
trenches with no one (1) trench longer than one hundred (100) feet.
The absorption trenches shall be separated with a minimum spacing
of ten (10) feet of undisturbed earth between trenches.
8.
Absorption trenches shall be at least eighteen (18) inches wide
and no more than thirty-six (36) inches wide. Thirty-six-inch wide
trenches should not be utilized in soils with loading rates of less
than three-tenths (0.3). The bottom of standard absorption trenches
shall be at least eighteen (18) inches and not more than thirty (30)
inches below the finished grade except as approved by the Department.
9.
The pipe used between the sewage tank and the absorption system shall be a minimum of four-inch inside diameter equivalent to the pipe used for the building sewer as set forth in Section 700.130 of these standards. The pipe shall have a minimum fall of not less than one-eighth (1/8) inch per foot. All joints shall be of watertight construction.
10.
Gravity-fed absorption field distribution lines should be at
least four (4) inches in diameter. If perforated distribution lines
are used, the perforation shall be at least one-half (1/2) inch and
no more than three-fourths (3/4) inch in diameter.
a.
All pipe used for distribution lines shall meet ASTM standard
D2729 or those of an equivalent testing laboratory. ASTM 2729 is a
minimum of two thousand five hundred (2,500) lb. crushproof. Fittings
used in the absorption field shall be compatible with the materials
used in the distribution lines.
b.
When four- or six-inch diameter corrugated plastic tubing is
used for distribution lines, it shall be certified as complying with
applicable ASTM standards. The corrugated tubing shall have three
(3) rows of holes, each hole between one-half (1/2) inch and three-fourths
(3/4) inch in diameter and spaced longitudinally approximately four
(4) inches on centers. The rows of holes may be equally spaced one
hundred twenty degrees (120°) on centers around the periphery
or three (3) rows may be located in the lower portion of the tubing,
the outside rows being approximately on one hundred twenty degrees
(120°) centers. Coiled tubing shall not be used.
11.
The absorption trenches shall be constructed as level as possible
but in no case shall the fall in a single trench bottom exceed one-fourth
(1/4) inch in ten (10) feet as determined by an engineer's level.
The ends of distribution lines should be capped or plugged, or when
they are at equal elevations, they shall be connected.
12.
Rock used in soil absorption systems shall be clean, washed
gravel or crushed stone and graded or sized between one and one-half
(1 1/2) to three (3) inches. The rock shall be placed a minimum
of one-foot deep with at least six (6) inches below the pipe and two
(2) inches over the pipe and distributed uniformly across the trench
bottom and over the pipe. Before placing soil backfill over the trenches,
the gravel shall be covered with:
a.
Unbacked, rolled three and one-half (3 1/2) inch thick
fiberglass insulation;
b.
Untreated building paper;
c.
Synthetic drainage fabric;
d.
A minimum of eight (8) inches of straw for a compacted thickness
of two (2) inches;
e.
Other material approved by the Department may be used to separate
the gravel from the backfill.
13.
Complex slope patterns and slopes dissected by gullies shall
not be considered for installation of absorption trenches. Uniform
slopes under fifteen percent (15%) shall be considered suitable for
installation of absorption trenches. When slopes are less than two
percent (2%), provisions shall be made to insure adequate surface
drainage. When slopes are greater than four percent (4%), the absorption
trenches shall follow the contour of the ground. Uniform slopes between
fifteen percent (15%) and thirty percent (30%) should not be used
for installation of absorption trenches unless the soils are three
(3) feet or more below the trench bottom. Slopes within this range
may require installation of interceptor drains upslope from the soil
absorption system to remove all excess water that might be moving
laterally through the soil during wet periods. Usable areas larger
than minimum are ordinarily required in this slope range. Slopes greater
than thirty percent (30%) shall not be utilized for installation of
absorption trenches unless the following requirements can be met and
approval is first obtained from the Department:
a.
The slope can be terraced, graded, or the absorption trenches
can be located in naturally occurring soil so as to maintain a minimum
ten-foot horizontal distance from the absorption trench and the top
edge of the fill embankment;
b.
The soil is permeable and no restrictive layers or water tables
occur at a depth within two (2) feet of the trench bottom;
c.
Surface water runoff is diverted around the absorption trench
field so that there will be no scouring or erosion of the soil over
the field;
d.
If necessary, groundwater flow from heavy rainfall is intercepted
and diverted to prevent that water from running into or saturating
the soil absorption system; and
e.
There is sufficient ground area available to install the absorption
trench system with these modifications.
14.
Effluent distribution devices, including distribution boxes,
flow dividers and flow diversion devices, shall be of sound construction,
watertight, not subject to excessive corrosion and of adequate design
as approved by the Department. Effluent distribution devices shall
be separated from the sewage tank and absorption trenches by a minimum
of two (2) feet of undisturbed or compacted soil and shall be placed
level on a solid foundation of soil or concrete to prevent differential
settlement of the device.
a.
Each distribution line shall connect individually to the distribution
box.
b.
The pipe connecting the distribution box to the distribution
line shall be of a tight joint construction laid on undisturbed earth
or properly bedded throughout its length.
c.
No more than four (4) distribution lines should be connected
to a distribution box receiving gravity flow unless the ground surface
elevation of the lowest trench is below the flow line elevation of
the distribution box.
d.
All distribution boxes should be marked or raised to grade.
15.
Step-downs or drop boxes may be used where topography prohibits
the placement of absorption trenches on level grade. Serial distribution
systems should be limited to where there is at least three (3) feet
separation between the bottom of the absorption trenches and the limiting
condition such as slow permeability or zone of seasonal.
16.
Dosing is recommended for all systems except serial distribution
systems and shall be provided when the design sewage flow requires
more than five hundred (500) lineal feet of distribution line. When
the design sewage flow requires more than one thousand (1,000) lineal
feet of distribution line, the absorption field shall be divided into
two (2) equal portions and each half dosed alternatively, not more
than four (4) times per day. Dosing may be accomplished by the use
of a pump. Each side of the system shall be dosed not more than four
(4) times per day. The volume of each dose shall be the greater of
the daily sewage value divided by the daily dosing frequency, or an
amount equal to approximately three-fourths (3/4) of the internal
volume of the distribution lines being dosed (approximately one-half
(1/2) gallon per lineal foot of four-inch pipe).
17.
Whenever dosed distribution box systems are utilized, the separation
distance between the absorption trench bottom and limiting condition
should be at least two (2) feet.
18.
For all serial distribution systems where design sewage flow
requires more than five hundred (500) lineal feet of distribution
line, the absorption field shall be divided into two (2) equal portions
and each half dosed alternatively by means of flow diverted devices.
19.
Gravelless subsurface absorption systems may be used as an alternative
to conventional four-inch pipe placed in gravel filled trenches, however
cannot be used in areas where conventional systems would not be allowed
due to poor permeability, high groundwater or insufficient depth to
bedrock. Design approval for these systems is required from the Department
prior to installation and all manufacturing specifications and installation
procedures shall be closely adhered to.
a.
The four (4) inch (inner diameter) corrugated polyethylene tubing
used in gravelless systems shall meet the requirements of ASTM F667,
Standard Specification for Large Diameter Corrugated Polyethylene
Tubing. The eight-inch pipe may be considered equal to an eighteen
(18) inches wide standard absorption trench. The ten-inch pipe may
be considered equal to a twenty-five (35) inch wide absorption trench.
Two (2) rows of perforations shall be provided located one hundred
twenty degrees (120°) apart along the bottom half of the tubing,
each sixty degrees (60°) from the bottom centerline. Perforations
shall be cleanly cut and uniformly spaced along the length of the
tubing and should be staggered so that there is only one (1) hole
in each corrugation. The tubing shall be visibly marked to indicate
the top of the pipe. All gravelless drainfield pipe shall be encased
at the point of manufacture with a spun bonded nylon filter wrap.
The trench for the gravelless system shall be dug with a level bottom.
On sloping ground, the trench should follow the contour of the ground
to maintain a level trench bottom and to ensure a minimum backfill
of six (6) inches. It is recommended that minimum trench width for
the gravelless system be eighteen (18) inches in friable soils to
ensure proper backfill around the bottom half of the pipe. In cohesive
soils, the minimum width of excavation should be twenty-four (24)
inches. In clay soils it is recommended that the trench be backfilled
with sandy material or good topsoil. The gravelless system may be
installed at a trench bottom depth of eighteen (18) inches minimum
to thirty (30) inches maximum, but a shallower trench bottom depth
of eighteen (18) to twenty-four (24) inches is recommended. To promote
equal effluent and suspended solids distribution, the slope of the
drainpipe should be from zero (0) to one-half (1/2) inch per one hundred
(100) feet.
b.
The Department may permit the use of chamber leach systems on
sites where the minimum soil-loading rate is three-tenths (3/10) gpd/square
feet. The other requirements of these standards relative to depth
to restrictive horizons, maximum depth of trenches, etc. shall also
be met and installed according to manufacture specifications. The
Department allows a reduction in square footage if indicated by the
soil morphology results. Chambers must have a minimum of twelve (12)
inches cover.
20.
Bed systems may be used on sites where the minimum soil-loading
rate is four-tenths (0.4) and essentially meets the other requirements
of this Section, and only on lots which are limited by topography,
space or other site planning considerations. In these cases, the number
of square feet of bottom area needed shall be increased by fifty percent
(50%) over what would be required for a trench system. Distribution
lines shall be at least eighteen (18) inches from the side of the
bed and shall have lines on three-foot centers. When the design volume
of sewage exceeds six hundred (600) gallons per day, adequate space
shall be provided to accommodate a trench system for the absorption
field.
[Ord. No. 23-04, 7-5-2023]
A.
Modifications
to standard absorption systems which may be utilized to overcome selected
soil and site limitations and must be approved by the Department include
the following:
1.
Shallow placement of absorption trenches shall be utilized where
insufficient depth to seasonally high or perched water table or where
insufficient soil thickness prevents the placement of conventional
distribution lines in accordance with this Section. Shallow trenches
shall be designed and constructed to provide a minimum of two (2)
feet of natural soil separation between the trench bottom and the
uppermost elevation of the seasonally high or perched water table
and rock. In areas of thin soils and potential for groundwater contamination
the vertical separation between the trench bottom and bedrock shall
be four (4) feet or more. Shallow trenches may be constructed by placing
the top of the gravel at original ground level and covering the absorption
field with loamy soil or good topsoil to a depth of twelve (12) to
eighteen (18) inches at the center. The cover over the absorption
field shall extend at least five (5) feet beyond the edge of any trench
and have a turf grass cover established immediately after construction.
If an area is to be filled and the trenches constructed in the fill
with the bottom of the trenches in at least six (6) inches of natural
soil, the following procedures must be followed:
a.
The fill material should be of sandy texture with a maximum
clay content of fifteen (15%). The fill material should not be hauled
or worked wet. The area to be filled must be protected from traffic
and small brush and trees removed prior to placement;
b.
The soil surface must be loosened with a cultivator or garden
plow. This work must be done when the soil is dry;
c.
The fill is moved onto the site without driving on the loosened
soil. The fill material is then tilled into the natural soil to create
a gradual boundary between the two. The remaining fill is then added
in layers until the desired height is obtained with each layer being
tilled into the preceding layer.
d.
The site is then shaped to shed water and fill all low spots
before the absorption system is installed. After installation of the
absorption system the site must have a turf grass cover established
as soon as possible.
2.
Alternating dual field absorption systems may be utilized where
soils are limited by high clogging potentials or high shrink/swell
potential soils and where the potential for malfunction and need for
immediate repair is required. Alternating dual field absorption systems
shall be designed with two (2) complete absorption fields, each sized
a minimum of seventy-five percent (75%) of the total area required
for a single field and separated by an effluent flow diversion valve.
The diversion valve shall be constructed to resist five hundred (500)
pounds crushing strength, structurally sound and shall be resistant
to corrosion. Valves placed below ground level shall be installed
so that it may be operated from the ground surface.
3.
Sand-lined trenches may be used in areas where the soil has
greater than fifty percent (50%) rock fragments and there is a potential
for groundwater contamination due to bedrock conditions. For a maximum
loading rate of forty-five-hundredths gallons (0.45 gals.) per day
per square foot or a minimum of two hundred sixty-five (265) square
feet per bedroom the sand is not required to meet the requirements
for intermittent sand filters. The material must be natural or manufactured
sand and have no more than fifteen percent (15%) clay content. Clean
"creek sand" that is screened to one-quarter (1/4) and smaller may
be used. Manufactured sand shall be chat sand produced from flint
chat or fines manufactured from igneous rocks or chert gravel may
be used. The sand used for the liner shall contain less than twenty-five
percent (25%) material retained on a No. 10-sieve. Finely crushed
limestone is not acceptable. For high loading rates, the sand must
meet the requirements for an intermittent sand filter.
a.
In standard four-inch pipe and gravel trenches the depth of
liner material must be twelve (12) inches below the gravel and at
least six (6) inches on the sides of the gravel up to the top of the
gravel. To place sand on the sides of the trenches, the trench walls
may be excavated on a slope instead of vertically. The side slopes
should be two to one (2:1) and in no case steeper than one to one
(1:1). When it is impossible to excavate the trenches on a slope the
sand may be placed on the sides of trenches by digging the trench
twelve (12) inches deeper than the recommended trench depth. The sand
is placed eighteen (18) inches deep in the bottom of the trench and
a V-shaped form is dragged through the sand to push the sand at least
six (6) inches up on the sides of the gravel.
b.
In gravelless pipe systems the minimum thickness of liner material
is six (6) inches around the pipe.
c.
The effluent to sand-lined systems in areas of potential groundwater
contamination should be equally distributed as much as practically
possible. Serial and drop box systems shall not be used. As a minimum,
a distribution box shall be used to evenly distribute the effluent
to the trenches. Dosing is recommended to assure even more positive
distribution.
d.
Sand-lined trenches may be used with the approval of the Department
where the percentage of rock fragments is less than seventy percent
(70%) for at least four (4) feet below the trench bottom. For sand-lined
trenches to function properly, the permeability of the natural material
should be like the permeability of the liner material. Sand-lined
trenches must not be used over fragipans or other restrictive layers
which have perched water tables and could cause saturation of the
liner material.
4.
Interceptor drains can be used to improve soil drainage in areas having seasonally high-water tables or perched groundwater. Interceptor drains shall consist of a perforated drainpipe. Coiled piping may be used for interceptor drains. The pipe shall be bedded in rock meeting the specifications set forth in Section 700.170 of these standards. There shall be a minimum of four (4) inches of gravel below the pipe, and two (2) inches of gravel above the pipe. The gravel shall be covered with a barrier material as set forth in Section 700.170 of these standards and the remainder of the trench backfilled with earth. Trenches for interceptor drains shall be excavated to a minimum width of twelve (12) inches and a maximum width of twenty-four (24) inches. The depth of the interceptor drains shall be set such that the top of the gravel is no higher than the bottom of the absorption trench at any point in the absorption field.
a.
Vertical drains are not allowed unless there are no other means
to improve soil drainage; no alternative sites are available on the
property; and the property has been zoned and subdivided in accordance
with Cass County regulations.
b.
Diversion berms may be used to keep surface water from contributing
to high soil moisture levels in the absorption field areas. Diversion
berms shall be located transversely in the direction of the ground
slope. The area where the berm is constructed shall be stripped of
vegetation prior to placing fill for the berm. The fill shall be good
quality topsoil reasonably free of stones, roots and other debris.
Berms shall be a minimum of six (6) inches and a maximum of twelve
(12) inches high and shall be sloped no greater than three (3) horizontal
to one (1) vertical.
[Ord. No. 23-04, 7-5-2023]
A.
Drip Soil Absorption. Shall be designed and sealed by a Missouri
Registered Engineer.
B.
Low Pressure Pipe. Shall be designed and sealed by a Missouri Registered
Engineer
C.
Holding Tanks. The use of holding tanks is generally discouraged
and should be limited to situations where construction of satisfactory
sewage treatment with on-site disposal systems do not meet minimum
standards. And where a centralized collection system is not available.
Should a Centralized collection system become available the Holding
Tank shall be voided and connection to the Centralized system be made.
1.
Sizing. The minimum liquid capacity of a holding tank shall
be provided for a single-family residence per the following table:
|
Minimum Holding Tank Capacities
| |
|---|---|
|
No of Bedrooms
|
Gallons
|
|
1 — 3
|
2,000
|
|
4
|
2,500
|
|
5
|
3,000
|
|
6
|
3,500
|
|
7
|
4,000
|
|
8
|
4,500
|
2.
Warning Device. A high water alarm device shall be installed
in/on holding tanks so that it activates one (1) foot below the inlet
pipe. This device shall be an audible and illuminated alarm.
3.
Access. An access riser shall extend up to the finish grade
with a properly secured or locked lid. The access riser shall be of
sufficient size to permit access to the warning device controls and
for pumping of the tank.
4.
Holding Tank Agreement. The property owner agrees to keep records
of dates when the holding tank was pumped, who pumped the tank, and
the name and address of an approved site where the septage was disposed.
|
All other construction standards in 19 CSR 20-3.060 apply to
holding tanks.
|
D.
Sand Filters; Bed Systems. Shall be designed and sealed by a Missouri
Registered Engineer and plans shall include all calculations. The
Department must specifically approve these systems.
2.
Sand filters must be designed and constructed in accordance
with 19 CSR 20-3.060(6)(0).
3.
Use of these facilities with mechanical equipment and sand filters
should be limited to where continued maintenance can be performed
by an entity such as a sewer district, municipality or private firm
established for that purpose. A contract for continued maintenance
should be always maintained by the owner.
E.
Other Systems. Where unusual conditions exist, special systems of
treatment and disposal, other than those specifically mentioned in
this standard, may be employed, provided:
1.
Reasonable assurance of performance of the system is presented
to the Department;
2.
The engineering design of the system is first approved by the
Department;
3.
There is no discharge to the ground surface of surface waters;
4.
Adequate substantiating data to indicate that the effluent will
not contaminate any drinking water or any surface water;
5.
Treatment and disposal of the waste protects public health and
general welfare; and
6.
These systems comply with all applicable requirements of these
standards and with all local codes and ordinances and all applicable
requirements of Chapter 701 of the Missouri Statutes.
