[Ord. No. 11-0248 §1, 8-9-2011]
A.
Scope. The provisions of this Article shall govern the evaluation
of, and requirements for, on-site sewage treatment system sites on
existing lots and the creation of new lots or parcels of land. The
site evaluation shall have the signature of an engineer, geologist,
or sanitarian.
B.
Site Evaluation. Site evaluation shall include soil conditions, properties and permeability, depth to zones of soil saturation, depth to bedrock, slope, landscape position, all setback requirements and the potential for flooding. Soil test data shall relate to the undisturbed elevations, and a vertical elevation reference point or benchmark shall be established. Soil test data shall be conducted in accordance with Section 705.330.
C.
Replacement System Area. On each parcel of land being initially
developed, sufficient area of suitable soils based on the soil tests,
system location and site requirements of this code for one (1) replacement
system shall be established. Where borehole test data in the replacement
system area are equivalent to data in the proposed system area, a
separate soil morphology pit is not required. An access easement encompassing
the replacement system area shall be recorded with the Jefferson County
Department of the County Recorder prior issuance of the building permit.
1.
Non-conforming site conditions. Where site conditions do not permit replacement systems in accordance with this code and an alternative system is utilized, the alternative system shall be approved in accordance with Section 705.050.
2.
Undisturbed site. The replacement system area shall
not be disturbed to the extent that the site area is no longer suitable.
The replacement system area shall not be used for construction of
buildings, parking lots or parking areas, below ground swimming pools
or any other use that will adversely affect the replacement area.
[Ord. No. 11-0248 §1, 8-9-2011]
General. A conventional soil absorption system shall not be located on land with a slope greater than twenty percent (20%). A conventional soil absorption system shall be located a minimum of twenty (20) feet from the crown of a land with a slope greater than twenty percent (20%), except where the top of the aggregate of a system is at or below the bottom of an adjacent roadside ditch. Where a more restrictive land slope is to be observed for a soil absorption system, other than a conventional soil absorption system, the more restrictive land slope specified in the design Sections of this code shall apply, see Section 705.470.
[Ord. No. 11-0248 §1, 8-9-2011]
A.
Soil Borings And Profile Descriptions. Soil borings shall be conducted on all sites, regardless of the type of on-site sewage treatment system planned to serve the parcel. Borings shall extend at least three (3) feet below the bottom of the proposed system. Borings shall be of sufficient size and extent to determine the soil characteristics important to an on-site sewage treatment system. Soil borings shall be conducted and reported in accordance with Subsections (A)(1 — 5). Where it is not practical to have borings made with a backhoe, such borings shall be dug by hand.
1.
Number. There shall be a minimum of four (4) borings
with one (1) being made with backhoe for new construction and three
(3) borings, with one (1) being made from backhoe on replacement,
repairs, or existing systems. On a case-by-case basis lots less than
two (2) acres in size may have three (3) borings but must first be
approved by the Code Official.
2.
Location. Each morphology pit and borehole location
shall be accurately located and referenced to the vertical elevation
and horizontal reference points on a detailed drawing. Designs, including
morphology pits and boring locations, shall either be drawn to scale
or have the horizontal dimensions clearly indicated between the boring
and the horizontal reference points. Pits shall be dug in or within
twenty (20) feet to the proposed drainfield area. There shall be a
minimum of two (2) additional borings in reserve area on new systems.
3.
Soil description. Soil profile descriptions shall be written for all morphology pits and borings. The thickness in inches of the different soil horizons observed shall be indicated. Horizons shall be differentiated on the basis of color, texture, soil mottles or bedrock. Depths shall be measured from the ground surface. Soil morphology reports shall follow the provisions listed in Article VII.
4.
Soil mottles. Seasonal or periodic soil saturation
zones shall be estimated at the highest level of soil mottles. A detailed
description of the soil mottling shall be required.
B.
Bedrock. The depth of the bedrock, except sandstone, shall
be established at the depth in a soil boring where greater than fifty
percent (50%) of the weathered-in-place material is consolidated.
Sandstone bedrock shall be established at the depth where an increase
in resistance to penetration of a knife blade occurs.
C.
Alluvial And Colluvial Deposits. Subsurface soil absorption
systems shall not be placed in alluvial and colluvial deposits with
shallow depths, extended periods of saturation or possible flooding.
[Ord. No. 11-0248 §1, 8-9-2011]
General. The permeability of the soil in the proposed absorption system shall be determined by conducting a soil evaluation in accordance with Section 705.480.
[Ord. No. 11-0248 §1, 8-9-2011]
Verification. Depth to soil mottles, depth
to high ground water, soil textures, depth to bedrock and land slope
shall be verified by an on-site soil evaluator. The Code Official
shall require, where necessary, backhoe pits to be provided for verification
of soil boring data. The results of soil test and permeability evaluation
shall be subject to verification by the Code Official.
[Ord. No. 11-0248 §1, 8-9-2011]
A.
Ground Water, Bedrock Or Slowly Permeable Soils. There shall
be a minimum of three (3) feet of soil between the bottom of the soil
absorption system and high ground water or bedrock. Soil with a loading
rate of four-tenths (0.4) gallon/square foot or faster shall exist
for the depth of the proposed soil absorption system. There shall
be forty-eight (48) inches of suitable soil for a conventional soil
absorption system.
B.
Loading Rate, Trench Or Bed. A subsurface soil absorption system of the trench or bed type shall not be installed where the loading rate is slower than two-tenths (0.2) gallon/square foot without installing a holding tank and/or a sewer system with provision for pumping and a pumping agreement by owner and registered hauler. Also see Section 705.420 Alternative Systems.
C.
Filled Area. 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. 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 existing soil, the following procedures are required.
1.
Placement of fill. The approval of a conventional
soil absorption system shall be based on evidence indicating its conformance
to code requirements for area, morphology and elevation. The fill
material shall be of a sandy loam, or silt loam texture, as defined
in Soil Group II. The fill material shall not be hauled or worked
wet. The area is to be filled shall have proper erosion control, and
be protected from traffic, small brush and trees removed prior to
placement.
2.
Bedrock. Sites with less than thirty-six (36) inches
of soil over bedrock are permitted to be filled with sandy loam soil
or coarser material up to and including medium sand to overcome the
site limitations. If the area to be filled has less than six (6) inches
of existing soil between bedrock and the fill material, a minimum
of six (6) inches of Group I soil shall be filled above the bedrock
before placing Group II soil. The area to be filled shall extend twenty
(20) feet minimum beyond the edge of the drainfield trenches in all
directions.
4.
Monitoring. Sites that will have thirty-six (36)
inches or less of soil above high ground water after the topsoil is
removed shall be monitored for high ground water levels in the filled
area.
5.
Inspection of fill. Placement of the fill material
shall be inspected by the Code Official.
6.
Design requirements. Any filled area shall be large enough to accommodate a shallow trench system and a replacement system. The site of the area to be filled shall be determined by an analysis of the natural soil and use of the building. Where any portion of a trench system or its replacement is in the fill, the fill shall extend twenty (20) feet beyond all sides of both systems before the slope begins. Where any portion of a drip system or its replacement is in the fill, the fill shall extend ten (10) feet beyond all sides of both systems before the slope begins. Soil morphology tests shall be conducted before filling to determine soil textures and depth to high ground water or bedrock. Vegetation and topsoil shall be removed prior to filling. Slopes at the edge of the filled areas shall have a maximum ratio of three (3) units horizontal to one (1) unit vertical 3:1 provided the twenty (20) feet separating distance is maintained (see Figure A-2, Appendix A).
D.
Altering Slopes. Areas with slopes exceeding the slopes specified in Section 705.170 shall not be utilized unless graded and reshaped as follows:
1.
Site investigation. Soil test data shall show that
a sufficient depth of suitable soil material is present to provide
the required amount of soil over bedrock and ground water after alteration.
A complete site evaluation shall be performed after alteration of
the site; and
2.
System location. A soil absorption (conventional
type) system shall be installed in the cut area of an altered site.
A soil absorption system shall not be installed in the fill area of
an altered site. The area of fill on an altered site is permitted
to be used as a portion of the required twenty (20) feet separating
distance from the crown of a critical slope. There shall be a minimum
of six (6) feet of natural soil between the edge of a system area
and the down slope side of the altered area; and
3.
Site protection. All altered slope areas shall be altered so surface water drainage will be diverted away from the system areas. All disturbed areas shall be seeded or sodded with grass, and appropriate steps shall be taken to control erosion (see Figure A-1, Appendix A).
E.
Lot Area Requirements. All newly created lots with on-site
sewage treatment systems shall have a minimum of eighty-seven thousand
one hundred twenty (87,120) square feet (two (2) acres). There shall
be only one (1) on-site system per recorded lot.
1.
On-site evaluation report. A report shall be submitted to the Code Official for approval of all newly created lots having on-site sewage treatment systems. Site evaluation report information required shall be as outlined in Article IV of this code.
2.
Pre-existing lots.
|
Table 406.7. Minimum Lot Size
| ||||
|---|---|---|---|---|
|
Served by:
|
Prior to May 1996
|
May 1996 to
March 31, 2004
|
Since March 31, 2004
| |
|
Public water supply
|
20,000 sq ft.
|
60,000 sq ft.
|
2 acres
| |
|
Well
|
40,000 sq ft.
|
60,000 sq ft.
|
2 acres
| |
a.
If a lot becomes defined as unbuildable due to the adoption of this
code, the owner may request a variance to the Board of Building Appeals.
A variance may be considered for the following conditions only.
(2)
Reserve area requirements.
(3)
Setbacks as specified in Table 602.1.
(4)
Drainfield quantity requirements with provision of holding tank minimum area for infiltrative surface, shown in Tables 613(a),(b), Tables 614(a),(b), and Tables 614.5(a),(b) requires detailed soil evaluation as outlined in Article VII. All holding tanks require an operating permit. Variances requests shall comply with information required in Section 705.090.
b.
In instances where an owner proposes to consolidate pre-existing
lots to create a larger lot in order to accommodate an on-site sewage
treatment system, the consolidation of the lots shall not be considered
a new lot and is not required to meet the two (2) acre minimum described
above.
[Ord. No. 11-0248 §1, 8-9-2011]
A.
General Requirements. These regulations set forth requirements
for the developer of any subdivision or the creation of any parcel
of land to determine the method of wastewater disposal from either
an engineering report, or a geological evaluation with a soil morphology
report submitted with a wastewater report, recommending the type of
on-site sewage treatment system to be used within the subdivision
prior to sale or lease of any lots.
1.
Definitions as set forth in this code.
2.
Unless specifically provided otherwise in this code, the regulation
shall apply to any developer who subdivides, owns or controls land:
a.
Develops or divides land into a subdivision;
b.
Resubdivides land into more lots, adds additional lots to an existing
subdivision; or
c.
Resubdivides land into more lots, adds additional lots to which when added to an existing group of lots which are contiguous, or which are known, designated or advertised as a common unit or by a common name, in accordance with Subsection (A)(3) of this code, will in total constitute a subdivision.
4.
If the Code Official determines that there is a violation of the
Missouri Clean Water Law and Regulations, any developer(s), owner(s)
or person(s) controlling any on-site sewage treatment system on or
after the effective date of this code, whether then in existence or
installed after the effective date of this code, shall eliminate the
system or bring the system in compliance with this code. Elimination
shall be accomplished by connection to an available centralized sewer
system or a sewer system regulated and certificated by the Missouri
Public Service Commission and which is in compliance with the Missouri
Clean Water Law and regulations. A sewer system shall be deemed available
when any part of the sewer system is located within four hundred (400)
feet of the property line of the residence. Connection(s) to the sewer
system shall be made in accordance with the provisions and requirements
of local ordinances, laws or Public Service Commission regulations
governing the available sewer systems.
5.
Any subdivision located adjacent to or within the designated wastewater
facilities planning area of a municipality or sewer district, or within
the service area of a Public Service Commission regulated sewer utility,
which has an approved plan for wastewater disposal within its designated
planning area, shall demonstrate to the satisfaction of the Code Official
that the proposed method of wastewater disposal within the subdivision
will ultimately conform with the approved municipality, sewer district
or Public Service Commission regulated sewer utility wastewater facilities
plan.
6.
Prior to the sale or lease or offer to sell or lease of any land
or any lot or residence located in a subdivision to any person(s)
or the commencement of construction on any lot by the developer(s)
or any person(s), whichever occurs sooner, the developer(s) of any
subdivision(s):
a.
Shall submit to the Code Official an engineering report and a soils morphology reports on each lot (including a geological evaluation with seven (7) lots or more). The engineering report shall outline plans for the method(s) of wastewater disposal within the subdivision(s). The engineering report shall meet the requirements of Subsection (B) and must be approved in writing by the Code Official in accordance with Subsection (E); or
b.
May choose to determine the method of wastewater treatment from the results of a geological evaluation in accordance with Subsection (C).
c.
Subdivisions with seven (7) lots or more, all engineering reports
and geological evaluations shall be submitted to the Department of
Natural Resources (DNR) for their approval.
B.
Engineering Reports.
1.
Where a developer proposes centralized sewage collection and treatment
systems to satisfy the requirements of this code, the engineering
report shall be considered acceptable, provided that all other requirements
of the Missouri Clean Water Law and regulations can be satisfied and
continuing authority in accordance with 10 CSR 20-6.010 Construction
and Operating Permits will be established prior to the sale or lease
of lots or the commencement of construction of residence.
2.
For subdivisions with lots of two (2) acres (eighty-seven thousand
one hundred twenty (87,120) square feet) or more, on which construction
of on-site sewage treatment systems may be used, provided that the
engineering report demonstrates to the satisfaction of the Code Official
that the lot sizes, topography, soils and geology in the subdivision
are such that on-site sewage treatment systems may be utilized without
causing a violation of the Missouri Clean Water Law and Regulations.
a.
All on-site sewage treatment systems shall be located in accordance
with Table 602.1.
b.
The on-site sewage treatment systems shall be designed in accordance
with the Missouri Department of Natural Resources latest revision
of 19 CSR 20-3.060 and this code. The designs shall provide for all
wastewater to be contained on the lot and handled in a manner that
there will be no violation of the Missouri Clean Water Law and regulations.
3.
If the Code Official determines that the engineering report does
not adequately meet the previous requirements, the engineering report
shall be disapproved and then must be revised and resubmitted for
approval.
4.
For subdivisions on which construction of single-family residences
are proposed, submittal of an engineering report is not required where:
C.
Geological Evaluation.
1.
A geological evaluation of a subdivision pertaining to the use of
on-site sewage treatment systems shall be obtained in accordance with
10 CSR 20-6.030.
a.
The request for the geological evaluation shall include a plat of
the subdivision or several plats with a drawing showing the location
of the individual plats in relation to each other. The number of lots,
lot sizes, and type of water supply shall also be provided with the
request.
2.
If the geological evaluation indicates that there exist severe geologic
limitations for ground water contamination or surfacing effluents
crossing property lines from the use of on-site sewage treatment systems,
centralized sewage collection and treatment systems shall be provided.
3.
If the geological evaluation indicates that there exists moderate,
slight or no geologic limitations of ground water contamination or
surfacing effluents crossing property lines from the use of on-site
sewage treatment systems, centralized sewage collection and treatment
systems need not be provided and the following shall be submitted
to the Code Official for approval:
a.
Soil morphology report shall be submitted with on-site sewage treatment
system recommendations for Code Official approval.
4.
If at any time after a geological evaluation has been performed and
the results have been received by the developer, any changes are made
as to lot sizes, number of lots or types of water supply, another
geological evaluation shall be obtained. If the new geological evaluation
indicates severe geologic limitations are caused by the proposed changes,
a centralized sewage collection and treatment system shall be provided,
for which a construction permit shall be obtained. In addition, a
continuing authority in accordance with 10 CSR 20-6.010 Construction
and Operating Permits must be established prior to the sale of lots,
lease of lots, or construction of residences.
D.
Interim Facilities.
1.
Where centralized sewage collection and treatment systems are proposed
or required, on-site sewage treatment systems may be used as an interim
measure for a maximum of thirty percent (30%) of the planned lots,
area or residences within the subdivision, provided that:
a.
The engineering report clearly demonstrates to the satisfaction of
the Missouri Department of Natural Resources and the Code Official
the necessity for interim use as opposed to immediate development
of the centralized system and a continuing authority is established
in accordance with 10 CSR 20-6.010 Construction and Operating Permits,
prior to the sale or lease of lots or the commencement of construction
of residences on lots.
b.
Geological evaluation is obtained in accordance with Subsection (C) and the results indicate there does not exist severe geological limitations for ground water contamination or surfacing effluents crossing property lines from the use of on-site sewage treatment systems.
c.
The on-site sewage treatment systems shall be designed in compliance
with this code.
E.
Review.
1.
The developer of any subdivision or the creation of additional parcel
of land shall be required to submit an engineered report, or to obtain
the alternative geological evaluation with a soil morphological report
on each lot and shall obtain written approval of the report, or the
geological evaluation, from the Code Official prior to the sale or
commencement of any work on a lot.
2.
There shall be no deviation or change that may adversely affect the
geological evaluation, lot sizes, or number of lots on the proposed
methods of wastewater disposal for a subdivision following approval
of the engineering report or alternative geological evaluation without
first securing written approval of the proposed changes from the Code
Official.
3.
Within fifteen (15) days of receipt of the completed engineering
report and any other documents or information required in this code,
the Code Official will approve or disapprove the subdivision wastewater
disposal plans and attach any conditions to an approval, which it
deems necessary to protect waters of the State.
F.
Compliance With Other Laws. Nothing in this code shall excuse
any person from complying with or from liability for violations of
the Missouri Clean Water Law and Regulations or any other laws of
the State of Missouri.
