(1) Approval by Other Agencies - No proposed
subdivision shall be approved by the State Planning Office, a local or regional
planning commission or other agency authorized to approve subdivisions until
the plans for such subdivisions have been approved by the
(2) Lot Size - Lots
shall be large enough to construct the original subsurface sewage disposal
system and to provide an area for duplication of that system. The area(s) for
both original and duplicate systems shall meet the provisions of these rules
and be of sufficient size to accommodate a conventional subsurface sewage
disposal system with thirty-six (36) inch wide trenches except where
alternative subsurface sewage disposal systems are utilized.
Evaluation and Lot Design - Either a
High-Intensity or a General Soil Evaluation shall be conducted as described
(i) A high-intensity soil evaluation shall be
made of the entire subdivision, the entire lot or a minimum of twenty thousand
(20,000) square feet (contiguous to usable soil area, if any) per lot. Each
soil delineation shall be drawn and plotted using a scale of one (1) inch to
one hundred (100) feet. The soil mapping shall be done by a soil consultant
approved by the Department pursuant to the requirements of Rule 0400-48-01-.18.
Two (2) copies of such map shall be submitted to the Commissioner.
(ii) A general soil evaluation map shall be
made of the entire subdivision using a standard mapping legend provided by the
Department and each soil delineation shall be drawn and plotted using a scale
of one (1) inch to one hundred (100) feet. The soil mapping shall be done by a
soil consultant approved by the Department pursuant to the requirements of
Rule0400-48-01-.18. Two (2) copies of such map shall be submitted to the
Commissioner. Soil delineations based on slopes, soil depth to rock and water
problems shall be identified on the map. Each delineation appearing on the plat
through soil evaluation shall be interpreted by the soil consultants in terms
of eligibility for percolation tests.
When the services of a soil consultant are
provided by the Department, three (3) copies of a plat of the site drawn to a
scale of one (1) inch equals one hundred (100) feet shall be submitted to the
Commissioner. The site shall be either grid staked or lots staked as follows:
(i) A one hundred (100) feet master-grid
system with surveyed control stakes numbered at not more than five hundred
(500) feet intervals and the location of the same on the plat. The ratio of
precision of the unadjusted survey shall be a minimum of 1:1000. The plat shall
show the seal and signature of the surveyor and show a bar scale. Intermediate
grid stakes with numbers at not more than one hundred (100) feet intervals
shall be numbered and shown on the plat. The intermediate stakes may be set by
rough chaining or other methods to a lesser degree of accuracy, however, said
intermediate stakes shall be within two (2) feet of the distance shown. The
Commissioner may require the removal of vegetative growth such as weeds, vines
and briars to permit access to all parts of the property. In wooded areas
cut/flagged lines shall be maintained until the property is
(ii) Staked lots must
have a numbered surveyed stake at each corner. The ratio of precision of the
unadjusted survey shall be a minimum of 1:1000. The plat shall show the seal
and signature of the surveyor and show a bar scale. Intermediate ground control
stakes shall be numbered and set in areas where lot corners are not visible
from any point on the lot. The intermediate stakes must be set no more than two
hundred (200) feet apart, and said intermediate stakes may be set by rough
chaining or other methods to a lesser degree of accuracy, however, said stakes
shall be within two (2) feet of the distance shown on the plat. The
Commissioner may require the removal of vegetative growth such as weeds, vines,
and briars to permit access to all parts of the property. In wooded areas
cut/flagged lines shall be maintained until property is mapped.
3. When the service of a private
soil consultant is utilized, then the requirements in subparts 2(i) or (ii) of
this subparagraph shall apply.
Under authority of T.C.A. §
after a general or high intensity soil evaluation has been conducted by an
approved soil consultant and the soils are found to have the following
characteristics, then a percolation test may be conducted pursuant to
(i) There shall be a
minimum depth of twenty-four (24) inches of undisturbed soil.
(ii) Slopes of more than thirty (30) percent
do not qualify for percolation tests unless provisions of subparagraph (4)(d)
of Rule0400-48-01-.04 are met.
(iii) No water problem shall exist. A water
problem shall be considered to exist if any of the conditions are present as
listed in the "Soils Handbook of Tennessee."
Where a percolation test is required to
determine the percolation rate for a conventional system, the percolation holes
used to determine this rate must be located at the intersection of lines in a
grid pattern with maximum perpendicular distances of fifty (50) feet between
the lines of the grid. Each hole shall be considered reasonably representative
of a square area of two thousand five hundred (2,500) square feet which
includes that hole in the approximate center of the square; or
percolation test is required to determine the percolation rate for an
alternative system, the percolation holes used to determine this rate must be
located at the intersection of lines in a grid pattern with maximum
perpendicular distances of twenty-five (25) feet between the lines of the grid.
Each hole shall be considered reasonably representative of a square area of six
hundred twenty-five (625) square feet, which includes that hole in the
approximate center of the square.
Where percolation tests are used
to determine the rate at which water moves through the soil, the minimum lot
size shall be twenty thousand (20,000) square feet where a public water supply
is used or a minimum of twenty-five thousand (25,000) square feet where a
private water supply is used. The Department shall be notified at least three
(3) days prior to the day that the percolation test will be conducted.
Percolation test procedures may be monitored when deemed necessary.
(i) Two (2) copies of the subdivision plat at
a scale of one (1) inch equals one hundred (100) feet shall be submitted to the
Commissioner. Such plat shall show percolation test holes iden tified by number
and plotted to scale, subdivision boundaries and other perti nent topographic
features. All lot and grid lines shall be drawn with appropriate numbers shown
on the plat corresponding with survey stakes on the ground.
(ii) Tabulated results of percolation test
holes shall be reported on a form provided by the Department.
(iii) The actual average percolation rate
shall be determined by averaging only the test results from the area actually
to be covered by the permit, which includes both initial and duplicate area.
Areas in which percolation test results were unfavorable shall be excluded. The
average percolation rate shall be calculated on a weighted basis.
(iv) Percolation test results shall not be
conclusive evidence as to the suitability of an area. Such tests shall be
considered and analyzed as one of the many criteria in determining site
percolation test locations shall adhere to the requirements of paragraph (1) of
(a) Each lot shall be accurately surveyed and
lot boundaries designated by survey stakes with lot numbers shown on said
Three (3) copies of a
subdivision plat at a scale of one (1) inch equals one hundred (100) feet shall
be submitted to the Commissioner, which shall indicate:
1. Lot dimensions with all lots
2. Easements for any
3. Surface and underground
drainage designed so as not to interfere with subsurface sewage disposal
4. Positive drainage plan,
where needed. A positive drainage outlet must be available for each lot
requiring soil improvement practices before the final plat is signed. If
construction of a positive outlet is necessary, all construction shall be done
before final plat approval is given. Off property easements may be
5. Seal and signature of
registered surveyor. (In order to survey and plat subdivisions an engineer, by
law, must be a registered surveyor).
6. Precision of the unadjusted survey. A
minimum ratio of precision of the unadjusted survey of 1:7,500 is
8. North arrow indicating
magnetic north or otherwise and indicate the scale of the plat.
9. All final plats shall have distances on
all lines and shall indicate the identity of all corners such as steel post,
concrete or iron pin.
(c) The submittals required by paragraphs (3)
and (4) of this rule may be combined into one (1) submittal to the
After review of
the site and information submitted, the Commissioner shall:
1. Approve in writing the subdivision as
2. Recommend in
writing the corrections needed to receive approval, or
3. Indicate in writing that the proposed
subdivision or areas therein are not suitable with reasons therefore.
(e) Where revisions are made to
the construction design, revised plats shall be submitted to the
Whenever the data required in these rules are
insufficient to determine suitability of an individual lot or subdivision, the
Commissioner may require additional data.
(a) Two (2) copies of the final plat shall be
submitted to the Commissioner with permanent lot lines drawn and the
information required by subparagraph (3)(a), subparagraph (3)(b), and paragraph
(4) of this rule. Additional plats for recording purposes without soil
delineation, contour lines and percolation test hole locations may be submitted
(b) The estimated
wastewater flow or number of bedrooms for each lot shall be shown on the
(c) Any subdivision plat may
be subject to restrictions as determined by the Commissioner and such
restrictions shall be recorded on the plat. This may include designation of
primary and duplicate areas or soil area to be reserved for subsurface sewage
Commissioner may approve a plat by attaching an appropriate signature after all
provisions of these rules are met.
(e) Before any changes or restrictions can be
made or removed, a revised plat must be submitted to the Commissioner in order
to maintain plat approval.
(7) Individually owned lots in unapproved
subdivisions shall meet the requirements of this rule with the exception that
only one copy of each plat shall be submitted to the Commissioner, with the
plat representing only the individual lot. Where a plat of the unapproved
subdivision has been recorded, this rule shall only apply to those subdivisions
recorded after June 30, 1995.