[Ord. No. 26-03, 2-4-2026]
The following words and terms, when used, shall have the following meaning, unless the context clearly indicates otherwise.
ABSORPTION SYSTEM
The final treatment and disposal of the septic tank effluent. The absorption system includes the distribution box, the perforated pipe and gravel or other gravelless distribution pipe, the filter materials and the trenches.
AERATION UNIT
Any sewage tank which utilizes the principle of oxidation in the decomposition of sewage by the introduction of air into the sewage.
ALTERNATIVE SYSTEM
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.
BAFFLE
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.
BEDROCK
That layer of parent material which is consolidated and unweathered.
BEDROOM
Any room within a dwelling that is used as a sleeping room.
BLACK WATER
Liquid waste from a dwelling or other establishment produced by toilet waste, or culinary operations and specifically excluding laundry.
BUILDING SEWER
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.
BUSINESS
Any building used for any purpose other than as a single-family dwelling.
CAPACITY
The liquid volume of a sewage tank using inside dimensions below the outlet.
COMMERCIAL SYSTEM
An on-site sewage disposal system used for disposing of wastewater from a commercial establishment or subdivision.
DEPARTMENT WITH ADMINISTRATIVE AUTHORITY
The governing body, Cass County Environmental Health Department.
DISTRIBUTION BOX
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.
DISTRIBUTION PIPES
Perforated pipes or agricultural drain tiles used to distribute sewage tank effluent in soil treatment systems.
DOSING CHAMBER (OR PUMP PIT OR WET WELL)
A tank or separate compartment following the sewage tank which serves as a reservoir for the dosing device.
DOSING DEVICE
A pump, siphon or other device that discharges sewage tank effluent from the dosing chamber to the soil treatment system.
DWELLING
Any building or place used or intended to be used by human occupants as a single family or two (2) family unit.
GEOLOGIST
A person that meets the requirements of Chapter 256 of the Missouri State Statutes.
GRAVELLESS SYSTEM
An absorption system comprised of large diameter, eight (8)- and ten (10)-inch corrugated plastic pipe, perforated with holes on a one hundred twenty degree (120°) are centered on the bottom, wrapped in a sheath of spun bonded nylon filter wrap and installed level in a trench without gravel bedding.
GRAY WATER
Liquid waste from a dwelling produced by bathing, laundry, culinary operations, from floor drains and specifically excluding toilet waste.
GREASE INTERCEPTOR OR GREASE TRAP
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.
HOLDING TANK
A watertight tank for storage of sewage until it can be transported to a point of approved treatment and disposal.
IMPERMEABLE
With regard to bedrock, a bedrock having very few cracks or crevices and having a vertical permeability less than one (1) inch in twenty-four (24) hours shall be considered impermeable. Regarding soils, a soil horizon or layer having a vertical permeability less than one (1) inch in twenty-four (24) hours shall be considered impermeable.
INDIVIDUAL SEWAGE TREATMENT SYSTEM
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
Intermittent Sand filters are beds of granular materials twenty-four (24) to thirty-six inches (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.
LIMITING CONDITION
A flow restrictive soil layer, bedrock, a water table, seasonal water table, groundwater or highly permeable material that limits or precludes the treatment of or dispersal of effluent in the soil of a property where an onsite wastewater treatment system will be/is located.
MANUFACTURED HOME PARK
Any single parcel of land with more than two (2) manufactured homes used as full-time residences.
MOTTLING
A zone of chemical oxidation and reduction activity appearing as splotchy patches of red, brown, orange and gray in the soil.
MOUND SYSTEM
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.
OTHER ESTABLISHMENT
Any public or private structure other than a dwelling which generates sewage.
PLASTIC LIMIT
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.
PROFESSIONAL ENGINEER
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.
ROCK FRAGMENTS
The percentage of rock fragments in 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 soil is of concern in areas of residual soils overlying highly permeable bedrock.
SANITARIAN
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.
SEPTAGE
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.
SEPTIC 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.
SETBACK
A separation distance measured horizontally.
SEWAGE
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.
SEWAGE FLOW
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.
SEWAGE TANK
A watertight tank used in the treatment of sewage which includes, but is not limited to septic tanks and aeration units.
SEWAGE TANK EFFLUENT
That liquid which flows from a septic or aeration unit under normal operation.
SINGLE FAMILY DWELLING WASTEWATER STABILIZATION POND
A sealed earthen basin which uses natural unaided biological processes to stabilize wastewater and used on large lots.
SINKHOLE
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 come into contact with 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.
SITE
The area bounded by the dimensions required for the proper location of the soil treatment system.
SLOPE
The ratio of vertical rise or fall to horizontal distance.
SOIL CHARACTERISTICS-LIMITING.
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.
SOIL MORPHOLOGY
The method of testing absorption qualities of the soil by physical examination of the soils' color, mottling, texture, structure, topography and hillslope position.
SOIL SCIENTIST
A person who is qualified by the Missouri Department of Health as a soil scientist.
SOIL TEXTURAL CLASSIFICATION
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.
SOIL TREATMENT AREA
That area of trench or bed bottom which is in direct contact with the trench rock of the soil treatment system.
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.
STANDARD SYSTEM
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.
TOILET WASTE
Fecal matter, urine, toilet paper and any water used for flushing.
TRENCH ROCK
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 (3) inch.
VALVE BOX
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.
WATER TABLE
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.
WATERTIGHT
Constructed so that no water can get in or out below the level of the outlet.
[Ord. No. 26-03, 2-4-2026]
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. Not included within the scope of this definition are building sewers, septic tanks subsurface absorption systems, mound systems, intermittent sand filters, gravelless systems, or aeration unit wastewater treatment systems that serve any facility serving more than the equivalent of fifteen (15) persons or more than three thousand (3,000) gallons per day or any commercial or industrial wastewater stabilization ponds or any community collection or treatment system. For systems of this nature contact the Missouri Department of Natural Resources, the Missouri Department of Health and Senior Services and or the Missouri Public Service Commission accordingly.
[Ord. No. 26-03, 2-4-2026]
All on-site wastewater treatment and disposal systems shall be located in accordance with the distances shown below.
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 or public right-of-way
10
10
100
Building foundation (including slab on grade and pole/post frame)
5
15
50
Basement
15
25
50
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
50
50
50
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)
Setback 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. 26-03, 2-4-2026]
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 twenty (120) 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 twenty (120) 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 1,500 gallons per day.
B. 
Other residential dwellings.
1. 
Duplexes: one hundred twenty (120) gallons per day per bedroom, minimum three hundred (300) gallons per day per unit, maximum three thousand (3,000) gallons per day for two (2) units.
2. 
Apartments and condominiums: one hundred twenty (120) 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 eight (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
Food or Drink Establishments (wastes per patron) (1)
Tavern or bar (not serving food)
Fast-food (paper service)
Cafe or restaurant
Restaurant serving alcoholic beverages
Restaurant grinding garbage
 
0.01
0.02
0.03
0.04
0.07
 
2
3
5
5
6
Schools (waste per student)
Day school, no cafeteria, gym or showers with cafeteria - ADD
With garbage grinding - ADD
With gym and showers - ADD
Boarding schools
0.02
0.02
0.02
0.01
0.17
10
4
1
10
75
Institutions
Hospitals (per bed)
Institutions other than hospitals nursing homes
0.22
0.17
0.17
125-200
100-150
100-125
Commercial and Recreational
Public parks (toilets only) (2)
Public parks with bath house, showers, toilets (2)
Swimming pools and beaches
Country clubs (per resident member)
Country clubs (per member present)
Service stations (waste per customer)(1)
Laundromats (per machine)
Hotels
Motels (without restaurants)
Luxury resorts
Camper trailer
Work or construction camps
Churches (per seat)
Stores, malls or shopping centers (per one thousand (1,000) square feet of floor area)
Office buildings (per employee) (3)
Drive-in theaters (2)
Stadiums, auditoriums, theaters or drive-ins (per seat)
 
0.02
0.06
0.06
0.17
0.06
0.01
1.25
0.15
0.1
0.17
0.08
0.15
0.01
 
0.34
0.05
0.01
0.01
 
5
15-25
15-25
75-100
15-25
5
580
50
40
 75
30
60
5
 
200
15
5
5
TABLE II 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 three (3) times the number of parking spaces.
(3)
Office buildings are assumed to have one (1) employee per three hundred (300) square foot of gross floor area.
D. 
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. Minimum size for gray water tank shall be one thousand (1,000) gallons.
[Ord. No. 26-03, 2-4-2026]
A. 
The site evaluation is to be performed by a soil scientist registered with the State of Missouri when the results are intended for use in determining the location, design or installation of an OWTS.
1. 
Procedures for soil morphology.
a. 
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.
b. 
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.
c. 
Site evaluation. An investigation of a proposed soil absorption site shall consider the following factors:
(1) 
Topography and landscape position.
(2) 
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;
(3) 
Soil drainage, which includes both external (surface) and internal (soil); D soil depth;
(4) 
Restrictive horizons; and
(5) 
Available space.
d. 
Site evaluations shall be made in accordance with the following. Based on this evaluation, each of the factors listed above shall be classified as suitable, provisionally suitable or unsuitable.
e. 
Topography and landscape position. Uniform slopes under fifteen percent (15%) shall be considered suitable with respect to topography. 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 lines shall follow the contour of the ground.
(1) 
Uniform slopes between fifteen percent (15%) and thirty percent (30%) shall be considered provisionally suitable with respect to topography, if the soils are thirty-six (36) inches or thicker. 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 period. Usable areas larger than minimum are ordinarily required in this slope range.
(2) 
Slopes greater than thirty percent (30%) shall be considered unsuitable except when a thorough study of the soil characteristics indicates that a soil absorption system will function satisfactorily and sufficient ground area is available to properly install such a system. Slopes greater than thirty percent (30%) may be classified as provisionally suitable when all of the following conditions are met:
(a) 
The slope can be terraced or otherwise graded or the absorption lines located in naturally occurring soil to maintain a minimum ten-foot horizontal distance from the absorption trench and the top edge of the fill embankment;
(b) 
The soil characteristics can be classified as suitable or provisionally suitable to a depth of at least one (1) foot below the bottom of the absorption trench;
(c) 
Surface water runoff is diverted around the absorption field so that three (3) will be no scouring or erosion of the soil over the field;
(d) 
If necessary, groundwater flow is intercepted and diverted to prevent the water from running into or saturating the soil absorption system; and
(e) 
There is sufficient ground area available to install the septic tank system with these modifications.
(3) 
Complex slope patterns and slopes dissected by gullies and ravines shall be considered unsuitable to topography.
(4) 
Areas subject to frequent flooding shall be considered unsuitable to landscape positions.
(5) 
Depressions shall be considered unsuitable with respect to landscape positions except when the site complies essentially with the requirements of this Section and is specifically approved by the administrative authority.
(6) 
If directed by the administrative authority, the surface area on or around a ground absorption system sewage treatment and disposal system shall be landscaped to provide adequate drainage. The interception of perched or lateral groundwater movement shall be provided where necessary to prevent soil saturation on or around the ground absorption sewage treatment and disposal system.
f. 
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:
(1) 
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 flour when pressed between the fingers, five hundredths (0.005) 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.
(a) 
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.
(i) 
Sand. Sand has a gritty feel, does not stain the fingers and does not form a ribbon or ball when wet or moist.
(ii) 
Loamy sand. Loamy sand has a gritty feel, stains the fingers (silt and clay), forms a weak ball and cannot be handled without breaking.
(b) 
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.
(i) 
Sandy loam. Sandy loam feels gritty and forms a ball that can be picked up with the fingers and handled with or without breaking.
(ii) 
Loam. Loam may feel slightly gritty but does not show a fingerprint and forms only short ribbons ranging from twenty-five (0.25) hundredths to fifty hundredths (0.50) inch in length. Loam will form a ball that can be handled without breaking.
(c) 
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.
(i) 
Silt loam. Silty loam feels floury when moist and will show a fingerprint but will not ribbon and forms only a weak ball.
(ii) 
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.
(iii) 
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 (1) inch pieces.
(iv) 
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.
(v) 
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.
(d) 
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 IVa) 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.
(i) 
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.
(ii) 
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.
(iii) 
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.
(e) 
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.
g. 
Soil drainage. Soils with seasonally high-water tables are of major concern in evaluating sites for sewage effluent disposal. These are the soil areas that give good sewage absorption rates during dry seasons of the year but force sewage effluent to the surface during the wetter seasons.
(1) 
Any soil profile that has the grayish colors of chroma 2 or less (Munsell color chart) indicative of high-water tables, or is either subject to periodic high water, within twenty-four (24) inches of the surface, or is less than twelve (12) inches above the proposed trench bottom and the high-water table, shall be considered unsuitable as to drainage. Soils where the seasonally high-water table is less than forty-eight (48) inches and more than twenty-four (24) inches below the naturally occurring surface shall be considered provisionally suitable for soil drainage, provided there remains at least twelve (12) inches vertical of soil between the proposed trench bottom and the seasonally high-water table. Soils where the seasonally high-water table is greater than forty-eight (48) inches below the naturally occurring surface shall be considered suitable for soil drainage. Drainage systems installed for groundwater lowering shall be maintained so that a minimum vertical separation of one (1) foot occurs between the absorption trench bottom and the seasonally high-water table.
h. 
Soil thickness. The thickness of soils to rock which are classified as suitable or provisionally suitable in texture and structure shall be at least forty-eight (48) inches when conventional soil absorption systems at conventional depths are to be utilized. Soil thickness greater than forty-eight (48) inches shall be considered as suitable as to soil thickness. Soil thickness less than forty-eight (48) inches and greater than thirty-six (36) inches shall be considered provisionally suitable. Where special design and installation modifications can be made to provide at least two (2) feet of naturally occurring soil below the bottom of the absorption trench, these soils may be reclassified as provisionally suitable in thickness.
i. 
Restrictive horizons. Restrictive horizons in soils are recognized by their apparent resistance in excavation or in the use of a soil auger. Restrictive horizons may occur as fragipans or claypans. The fragipan is a layer that owes its hardness mainly to extreme density or compactness as opposed to high clay content or cementation. The layer is typically dense and brittle. Although fragments are friable when removed, when in place the material is so dense that water moves through it very slowly. Unlike fragipans, the claypan is a compact, slowly permeable layer in the subsoil having a much higher clay content than the overlying material. A sharply defined boundary exists between the claypan and the overlying material. Claypans are typically hard when dry and plastic and sticky when wet.
(1) 
Restrictive horizons that are greater than six (6) inches thick severely restrict the movement of water and sewage effluent and do not adequately respond to groundwater lowering drainage systems. Where these horizons are less than six (6) inches thick, they do not severely restrict the movement of water and sewage effluent but rather indicate the presence of a seasonally high-water table and may be modified after special investigation.
(2) 
Soils in which restrictive horizons are six (6) inches or more in thickness and at depths greater than forty-eight (48) inches below the ground surface shall be considered suitable as to depth to restrictive horizons. Restrictive horizons six (6) inches or more in thickness and at depths between forty-eight (48) inches and twenty-four (24) inches shall be considered provisionally suitable as to depth to restrictive horizons. Restrictive horizons six (6) inches or more in thickness encountered at depths less than twenty-four (24) inches below the ground surface shall be considered unsuitable as to depth to restrictive horizons.
2. 
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 - aeration and chlorination, drip irrigation, lagoon with synthetic liner.
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 (4) inch perforated pipe and gravel, gravelless pipe, or chamber system.
3. 
A site evaluation may be required on a repair as determined by the Department.
[Ord. No. 26-03, 2-4-2026]
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 (4) 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 and within fifty (50) feet of a change in direction and 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 the 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) inch 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. 26-03, 2-4-2026]
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.
2. 
All tanks must be constructed of concrete, or materials otherwise approved by the Department.
3. 
No metal or site built tanks will be considered.
4. 
All tanks shall be watertight and designed and constructed to withstand all lateral earth pressures under saturated soil conditions with the tank empty.
5. 
All tanks shall be designed and constructed to withstand a minimum of two (2) feet of saturated earth cover above the tank top.
6. 
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.
7. 
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. 
Electrical Wiring Requirements.
a. 
Electrical box shall be on the outside of pump tank with an electrical disconnect.
b. 
Plugs with electrical tape will not be approved.
c. 
Wiring shall be a minimum of 12-2 UF or manufactures recommendations, whichever is greater on all lift stations.
d. 
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.
e. 
Wiring on all alarms shall be a minimum of 14-2 UF or manufactures recommendation whichever is greater.
5. 
All discharge lines shall have a one-eighth (1/8) inch weep hole drilled to prevent siphoning and air lock in discharge line.
6. 
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. 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 these regulations and with the following:
1. 
Limitations. Special conditions where aeration units should not be used may include, but not be limited to, the following:
a. 
Where intermittent use will adversely affect performance.
b. 
Where dependable maintenance service is not available.
c. 
Where electrical service is unreliable.
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.
a. 
The aeration unit shall have a minimum treatment capacity of one hundred twenty (120) gallons per bedroom per day or four hundred (400) gallons whichever is greater.
4. 
Effluent disposal. Effluent from an aeration unit shall be discharged into a soil absorption system or other final treatment system in accordance with Section 700.200, 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.
5. 
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 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 provide proof of certification upon request of the Administrative 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 with 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.
[Ord. No. 26-03, 2-4-2026]
A. 
General. The common design of absorption systems is one (1) 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. 
Interceptor drains can be used to improve soil drainage in areas having seasonally high-water tables or perched groundwater.
a. 
Interceptor drains shall consist of a perforated drainpipe meeting the same specification as set forth in Section 700.170 of these standards.
b. 
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.
c. 
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.
d. 
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.
e. 
Diversion berms may be used to keep surface water from contributing to high soil moisture levels in the absorption field areas.
f. 
Diversion berms shall be located transversely in the direction of the ground slope.
g. 
The area where the berm is constructed shall be stripped of vegetation prior to placing fill for the berm.
h. 
The fill shall be good quality topsoil reasonably free of stones, roots and other debris.
i. 
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. 26-03, 2-4-2026]
A. 
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.
1. 
Standard trenches shall be constructed in accordance with Section (5) of 19 CSR 20- 3.060.
2. 
Absorption trenches shall not be constructed in unstabilized fill or ground which has become severely compacted due to construction equipment.
3. 
Absorption trenches shall not be constructed in soils which are wet.
4. 
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.
5. 
Blasting of the rock in the area of the lateral lines is not allowed.
6. 
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.
7. 
Absorption trenches shall be at least eighteen (18) inches wide and no more than thirty-six (36) inches wide.
8. 
The bottom of standard absorption trenches shall be at least eighteen (18) inches and not more than thirty (30) inches below the finished grade.
9. 
The pipe used between the sewage tank and the absorption system shall be a minimum of four (4) inch inside diameter equivalent to the pipe used for the building sewer as set forth in Section 700.150 of these standards.
10. 
The pipe shall have a minimum fall of not less than one-eighth (1/8) inch per foot.
11. 
All joints shall be of watertight construction.
12. 
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.
13. 
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.
14. 
Fittings used in the absorption field shall be compatible with the materials used in the distribution lines.
15. 
When four (4) or six (6) 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-degree (120°) centers. Coiled tubing shall not be used.
16. 
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.
17. 
All systems shall have a minimum of a twelve (12) inch vertical separation between any limiting condition or restrictive horizon.
18. 
The ends of distribution lines should be capped or plugged, or when they are at equal elevations, they shall be connected.
19. 
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 (1) 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.
20. 
Complex slope patterns and slopes dissected by gullies shall not be considered for installation of absorption trenches.
21. 
Uniform slopes under fifteen percent (15%) shall be considered suitable for installation of absorption trenches.
22. 
When slopes are less than two percent (2%), provisions shall be made to insure adequate surface drainage.
23. 
When slopes are greater than four percent (4%), the absorption trenches shall follow the contour of the ground.
24. 
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.
25. 
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 (10) 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.
26. 
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.
27. 
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 (0.5) gallon per lineal foot of four (4) inch pipe).
28. 
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.
29. 
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.
30. 
Gravelless subsurface absorption systems may be used as an alternative to conventional four (4) 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.
(1) 
The eight (8) inch pipe may be considered equal to an eighteen (18) inches wide standard absorption trench.
(2) 
The ten (10) inch pipe may be considered equal to a twenty-five-inch (25) wide absorption trench.
(3) 
Two 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.
(4) 
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.
(5) 
The tubing shall be visibly marked to indicate the top of the pipe.
(6) 
All gravelless drain field pipe shall be encased at the point of manufacture with a spun bonded nylon filter wrap.
(7) 
The trench for the gravelless system shall be dug with a level bottom.
(8) 
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.
(9) 
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.
(10) 
In cohesive soils, the minimum width of excavation should be twenty-four (24) inches.
(11) 
In clay soils it is recommended that the trench be backfilled with sandy material or good topsoil.
(12) 
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 inches (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 (0.5) 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 (0.3) gpd/sq. ft. 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.
31. 
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 (3) 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. 26-03, 2-4-2026]
A. 
Modifications to standard absorption systems may be utilized to overcome selected soil and site limitations, must be approved by the Department. All systems shall have a minimum of a twelve (12) inch vertical separation between any limiting factor or restrictive horizon. Modifications must be approved by the Department and may 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 percent (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 (2). 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, percolation rates slower than sixty (60) minutes per inch 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.
a. 
For a maximum loading rate of forty-five hundredths (0.45) gallons 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.
b. 
The material must be natural or manufactured sand and have no more than fifteen percent (15%) clay content.
c. 
Clean "creek sand" that is screened to one fourth (1/4) inch and smaller may be used.
d. 
Manufactured sand shall be chat sand produced from flint chat in the Joplin area or fines manufactured from igneous rocks or chert gravel may be used.
e. 
The sand used for the liner shall contain less than twenty-five percent (25%) material retained on a No. 10 sieve.
f. 
Finely crushed limestone is not acceptable. For high loading rates, the sand must meet the requirements for an intermittent sand filter.
g. 
In standard four (4) inch pipe and grave 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.
h. 
To place sand on the sides of the trenches, the trench walls may be excavated on a slope instead of vertically.
(1) 
The side slopes should be two to one (2:1) and in no case steeper than one to one (1:1).
(2) 
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.
(3) 
In gravelless pipe systems the minimum thickness of liner material is six (6) inches around the pipe.
(4) 
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.
(5) 
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.
(6) 
For sand-lined trenches to function properly, the permeability of the natural material should be like the permeability of the liner material.
(7) 
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.
[Ord. No. 26-03, 2-4-2026]
A. 
Single residence wastewater stabilization ponds are NOT permitted with lots less than three (3) acres in size. Lagoon construction will not be allowed on lots less than three (3) acres in size except under certain circumstances with an approved variance from the County Commission and signed off on by a licensed engineer.
1. 
A properly sized and constructed Class I NSF Standard 40 listed aerobic treatment unit may precede any lagoon.
2. 
All lagoons with an aerobic treatment unit shall be designed to operate at a minimum depth of three (3) feet.
3. 
All lagoons without an aerobic treatment unit shall be designed to operate at a minimum depth of four (4) feet.
4. 
All lagoons shall be preceded by a tank that is properly sized per this Chapter.
5. 
The pond shall be located a minimum of one hundred (100) feet from the residence in which it serves.
6. 
Lagoon sizing requirements as follows:
3 Bedroom
4 Bedroom
5 Bedroom
Surface Area
(sq. ft.)
Square Pond Dimen- sions
Round Pond Diameter
Surface Area
(sq. ft.)
Square Pond Dimen- sions
Round Pond Diameter
Surface Area
(sq. ft.)
Square Pond Dimen- sions
Round Pond Diameter
With ATU
1,225
35' X 35'
40'
1,600
40' X 40'
45'
2,000
45' X 45'
50'
W/O ATU
2,000
45' X 45'
50'
2,500
50'X50'
55'
3,000
55'X55'
60'
7. 
The following minimum separation distances may be modified as necessary to accommodate site requirements or local codes:
a. 
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.
b. 
The pond shall be located a minimum of two hundred (200) feet from the nearest foundation of an existing neighboring residence.
c. 
The pond shall be located at least one hundred (100) feet from a potable water supply or pump suction line; and
d. 
The pond shall be located at least fifty (50) feet from a stream, watercourse, lake or impoundment.
8. 
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 such as percolation rates slower than one hundred twenty (120) minutes per inch. 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.
9. 
Steeply sloping areas should be avoided.
10. 
Selection of the pond site should consider a clear sweep of the surrounding area by prevailing winds. Heavy timber is to be removed for a distance of fifty (50) feet from the water's edge to enhance wind action and prevent shading.
11. 
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.
12. 
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.
13. 
The freeboard shall be a minimum of twenty-four (24) inches without the use of an aerobic treatment unit or eighteen (18) inches with the use of an aerobic treatment unit. Additional freeboard may be provided.
14. 
To minimize erosion and facilitate weed control, embankments shall be seeded with a locally hardy grass from the outside toe 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.
15. 
The influent line shall be of a sound durable material of watertight construction of Schedule 40 or greater. 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.
16. 
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 no exceeding three (3) times the width. No islands, peninsulas, or coves shall be permitted. Embankments should be rounded at corners to minimize accumulation of floating materials.
17. 
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.
18. 
Embankments shall be constructed of impervious materials and compacted sufficiently to form a stable structure with very little settlement.
19. 
The pond area shall be enclosed with a fence conforming to the following conditions:
a. 
The fence shall be at least four (4) feet in height;
b. 
The fence shall be welded, woven or chain link material with no smaller than fourteen (14)-gauge wire. Cattle or hog panels can be substituted with a tee post being used for a line post;
c. 
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 at least twenty-four (24) inches deep and properly braced;
d. 
The fence shall be of sound construction with no gaps or openings along the bottom;
e. 
The fence shall be no closer than the center of the berm to the water's edge at the operating level. Fence setbacks should not exceed thirty (30) feet from the water's edge;
f. 
A properly hinged four (4) foot high gate or comparable materials shall be installed and provided with an effective latching device. If using cattle or hog panels the end of one (1) panel may be wired in such a manner to easily pivot open for access for maintenance and mowing purposes provided that at all other times it is properly tied closed to restrict access to the pond area. The gate should be minimum of thirty-six (36) inches in width to accommodate maintenance and mowing equipment; and
g. 
The fence must be completed prior to final inspection of the system.
h. 
The fence shall remain in place and maintained properly until one (1) of the following occurs, at which time the pond shall be decommissioned as required by the authority having jurisdiction.
(1) 
Connection to a sewer utility is obtained.
(2) 
Another treatment system is installed.
(3) 
The structure in which it serves is removed without any future plans of reconstruction.
20. 
Effluent from a pond must be disposed of on the property from which it originated. This may be accomplished by locating an 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.
21. 
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 nay source of rainwater to the wastewater stabilization pond.
22. 
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.
23. 
The pond area shall be properly maintained at all times to prevent the growth or overgrowth of vegetation, cattails, trees etc., that may hinder the clear sweep of the area of prevailing winds.
24. 
The maintenance of the encroachment area (fifty (50) feet) of water's edge shall be maintained in such a matter to not allow the growth of timber.
25. 
At no time shall the pond be abandoned for more than one (1) year without proper decommissioning.
[Ord. No. 26-03, 2-4-2026]
A. 
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 or 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.
[Ord. No. 26-03, 2-4-2026]
A. 
The use of holding tanks is generally discouraged and should be limited to situations where construction of satisfactory sewage treatment with onsite disposal systems do not meet minimum standards. And where a centralized collection system is not available. Use of a holding tank must be specifically approved by the administrative authority on a case-by-case basis which require stipulations in a signed agreement regarding the use and the length of time for use of the holding tank.
1. 
Should a centralized collection system become available the holding tank shall be voided and connection to the centralized system be made.
2. 
A holding tank shall be constructed of the materials and by the same procedures as those specified for watertight septic tanks.
3. 
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
4. 
Warning Device: A high-water alarm device shall be installed on holding tanks so that it activates one (1) foot below the inlet pipe. This device shall either be an audible or illuminated alarm. If the latter, it shall be conspicuously mounted. The tank shall be regularly visually inspected to minimize the chance of accidental sewage overflows.
5. 
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. The tank shall be protected against flotation under high water table conditions. This shall be achieved by weight of the tank, earth anchors or shallow bury depths.
6. 
The tank shall be located in an area readily accessible to the pump truck under all weather conditions and where accidental spillage during pumping will not create a nuisance.
7. 
The tank shall be located no closer than twenty-five (25) feet to a property line, open ditch, waterway, crawlspace or basement or no closer than ten (10) feet to slab on grade foundations.
8. 
Holding Tank Agreement: A contract for disposal and treatment of the sewage wastes shall be maintained by the owner with a pumper, agency or firm which possesses a current and valid permit issued by the Department of Natural Resources for such activity. 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.