City of Estell Manor, NJ Appendices

USDA soil textural triangle.

$330 USDA Soil Tex Triangle.tif$

Definitions. For the purposes of this article, the following terms shall have the meanings herein ascribed to them.

The uppermost mineral horizon in a normal soil profile. The upper part of the A-horizon is characterized by maximum accumulation of finely divided, dark-colored organic residues, known as "humus," which are intimately mixed with the mineral particles of the soil.

ARTESIAN ZONE OF SATURATION

A zone of saturation which exists immediately below a hydraulically restrictive horizon, and which has an upper surface that is at a pressure greater than atmospheric, either seasonally or throughout the year.

CHROMA

The relative purity or strength of a color, a quantity which decreases with increasing grayness. Chroma is one of the three variables of soil color as defined in the Munsell system of classification.

CLAY

A particle size category consisting of mineral particles which are smaller than 0.002 millimeter in equivalent spherical diameter. Also, a soil textural class having more than 40% clay, less than 45% sand, and less than 40% silt, as shown in § 330-35A, USDA soil textural triangle.

CLAY LOAM

A soil textural class having 27% to 40% clay and 20% to 45% sand, as shown in § 330-35A, USDA soil textural triangle.

COARSE FRAGMENT

A rock fragment contained within the soil which is greater than two millimeters in equivalent spherical diameter or which is retained on a two-millimeter sieve.

COUNTY SOIL SURVEY REPORT

A report prepared by the U.S. Department of Agriculture, Natural Resources Conservation Service, which includes maps showing the distribution of soil mapping units throughout a particular county together with narrative descriptions of the soil series shown and other information relating to the uses and properties of the various soil series.

DIRECT SUPERVISION

Control over and direction of work carried out by others with full knowledge of and responsibility for such work.

EQUIVALENT SPHERICAL DIAMETER OF A PARTICLE

The diameter of a sphere which has a volume equal to the volume of the particle.

EXCESSIVELY COARSE HORIZON

A horizon of limited thickness within the soil profile which provides inadequate removal of pollutants from stormwater due to a high coarse fragment content, excessively coarse texture and/or excessively rapid permeability.

EXCESSIVELY COARSE SUBSTRATUM

A substratum below the soil profile which extends beyond the depth of soil profile pits and borings and which provides inadequate removal of pollutants from stormwater due to a high coarse fragment content, excessively coarse texture and/or excessively rapid permeability.

EXTREMELY FIRM CONSISTENCE

A type of soil material whose moist aggregated mass crushes only under very strong pressure; cannot be crushed between the thumb and forefinger and shall be broken apart bit by bit.

FIRM CONSISTENCE

A type of soil material whose moist aggregated mass crushes under moderate pressure between the thumb and forefinger but resistance is distinctly noticeable.

HARD CONSISTENCE

A type of soil material whose dry aggregated mass is moderately resistant to pressure; can be broken in the hands without difficulty but is barely breakable between the thumb and forefinger.

HUE

The dominant spectral color; one of the three variables of soil color defined within the Munsell system of classification.

HYDRAULICALLY RESTRICTIVE HORIZON

A horizon within the soil profile which slows or prevents the downward or lateral movement of water and which is underlain by permeable soil horizons or substrata. Any soil horizon which has a saturated permeability less than one inch per hour is hydraulically restrictive.

HYDRAULICALLY RESTRICTIVE SUBSTRATUM

A substratum below the soil profile which slows or prevents the downward or lateral movement of water and which extends beyond the depth of profile pits or borings or to a massive substratum. A substratum which has a saturated permeability less than one inch per hour is hydraulically restrictive.

LOAMY SAND

A soil textural class, as shown in § 330-35A, USDA soil textural triangle, that has a maximum of 85% to 90% sand with a percentage of silt plus 1.5 times the percentage of clay not in excess of 15%; or a minimum of 70% to 85% sand with a percentage of silt plus 1.5 times the percentage of clay not in excess of 30%.

LOWER PLASTIC LIMIT

The moisture content corresponding to the transition between the plastic and semisolid states of soil consistency. This corresponds to the lowest soil moisture content at which the soil can be molded in the fingers to form a rod or wire, 1/8 inch in thickness, without crumbling.

MOTTLING

A color pattern observed in soil consisting of blotches or spots of contrasting color. The term "mottle" refers to an individual blotch or spot. The terms "color variegation," "iron depletion" and "iron concentration" are equivalent to the term "mottling." Mottling due to redoximorphic reactions is an indication of seasonal or periodic and recurrent saturation.

MUNSELL SYSTEM

A system of classifying soil color consisting of an alphanumeric designation for hue, value and chroma, such as "7.5 YR 6/2," together with a descriptive color name, such as "strong brown."

O-HORIZON

A surface horizon, occurring above the A-horizon in some soils, which is composed primarily of undecomposed or partially decomposed plant remains which have not been incorporated into the mineral soil.

PERCHED ZONE OF SATURATION

A zone of saturation which occurs immediately above a hydraulically restrictive horizon and which is underlain by permeable horizons or substrata which are not permanently or seasonally saturated.

PIEZOMETER

A device consisting of a length of metal or plastic pipe, open at the bottom or perforated within a specified interval, and used for the determination of depth to water, permeability or hydraulic head within a specific soil horizon or substratum.

PLATY STRUCTURE

Characterized by a soil aggregate which has one axis distinctly shorter than the other two and is oriented with the short axis vertical.

REGIONAL ZONE OF SATURATION

A zone of saturation which extends vertically without interruption below the depth of soil borings and profile pits.

SANDY CLAY

A soil textural class having 35% or more of clay and 45% or more of sand, as shown in § 330-35A, USDA soil textural triangle.

SANDY LOAM

A soil textural class, as shown in § 330-35A, USDA soil textural triangle, that has a maximum of 20% clay, and the percentage of silt plus twice the percentage of clay exceeds 30%, and contains 52% or more sand; or less than 7% clay, less than 50% silt, and between 43% and 52% sand.

SILT

A particle size category consisting of mineral particles which are between 0.002 millimeter and 0.05 millimeter in equivalent spherical diameter. It also means a soil textural class having 80% or more of silt and 12% or less of clay, as shown in § 330-35A, USDA soil textural triangle.

SILT LOAM

A soil textural class having 50% or more of silt and 12% to 27% of clay; or 50% to 80% of silt and less than 12% of clay, as shown in § 330-35A, USDA soil textural triangle.

SILTY CLAY

A soil textural class having 40% or more of clay and 40% or more of silt, as shown in § 330-35A, USDA soil textural triangle.

SILTY CLAY LOAM

A soil textural class having 27% to 40% of clay and less than 20% of sand, as shown in § 330-35A, USDA soil textural triangle.

SOIL AGGREGATE

A naturally occurring unit of soil structure consisting of particles of sand, silt, clay, organic matter, and coarse fragments held together by the natural cohesion of the soil.

SOIL COLOR

The soil color name and Munsell color designation determined by comparison of the moist soil with color chips contained in a Munsell soil color book.

SOIL CONSISTENCE

The resistance of a soil aggregate or clod to being crushed between the fingers or broken by the hands. Terms for describing soil consistence described are in N.J.A.C. 7:9A-5.3(h).

SOIL HORIZON

A layer within a soil profile differing from layers of soil above and below it in one or more of the soil morphological characteristics, including color, texture, coarse fragment content, structure, consistence and mottling.

SOIL LOG

A description of the soil profile which includes the depth, thickness, color, texture, coarse fragment content, mottling, structure and consistence of each soil horizon or substratum.

SOIL MAPPING UNIT

An area outlined on a map in a County Soil Survey Report and marked with a letter symbol designating a soil phase, a complex of two or more soil phases, or some other descriptive term where no soil type has been identified.

SOIL PHASE

A specific type of soil which is mapped by the Natural Resources Conservation Service and which belongs to a soil series described within the County Soil Survey Report.

SOIL PROFILE

A vertical cross section of undisturbed soil showing the characteristic horizontal layers or horizons of the soil which have formed as a result of the combined effects of parent material, topography, climate, biological activity and time.

SOIL SERIES

A grouping of soil types possessing a specific range of soil profile characteristics which are described within the County Soil Survey Report. Each soil series may consist of several soil phases which may differ in slope, texture of the surface horizon or stoniness.

SOIL STRUCTURAL CLASS

One of the shape classes of soil structure described in N.J.A.C. 7:9A-5.3(g).

SOIL STRUCTURE

The naturally occurring arrangement, within a soil horizon, of sand, silt and clay particles, coarse fragments and organic matter, which are held together in clusters or aggregates of similar shape and size.

SOIL TEST PIT

An excavation made for the purpose of exposing a soil profile which is to be described.

SOIL TEXTURAL CLASS

One of the classes of soil texture defined within the USDA system of classification (Soil Survey Manual, Agricultural Handbook No. 18, USDA Soil Conservation Service 1962).

SOIL TEXTURE

The relative proportions of sand, silt and clay in that portion of the soil which passes through a sieve with two-millimeter openings.

STATIC WATER LEVEL

The depth below the ground surface or the elevation with respect to some reference level, of the water level observed within a soil profile pit or boring, or within a piezometer, after this level has stabilized or become relatively constant with the passage of time.

SUBSTRATUM

A layer of soil or rock material present below the soil profile and extending beyond the depth of soil borings or profile pits.

UNSUITABLE SOIL

All soil other than suitable soil.

USDA SYSTEM OF CLASSIFICATION

The system of classifying soil texture used by the United States Department of Agriculture which defines 12 soil textural classes based upon the weight percentages of sand, silt and clay in that portion of the soil which passes through a sieve with two-millimeter openings. The soil textural classes are shown graphically on the USDA Soil Textural Triangle, as shown in § 330-35A.

VALUE

The relative lightness or intensity of a color; one of the three variables of soil color defined within the Munsell system of classification.

VERY FIRM CONSISTENCE

Characterized by a moist soil which crushes under strong pressure; barely crushable between thumb and forefinger.

VERY HARD CONSISTENCE

Characterized by a dry soil which is resistant to pressure, can be broken in the hands only with difficulty; not breakable between the thumb and forefinger.

ZONE OF SATURATION

A layer within or below the soil profile which is saturated with groundwater, either seasonally or throughout the year. This includes both regional and perched zones.

Methods for assessing soil suitability for infiltration stormwater management BMPs. The results of a subsurface investigation shall serve as the basis for the site selection and design of stormwater infiltration BMPs. The subsurface investigation shall include, but not be limited to, a series of soil test pits and soil permeability tests conducted in accordance with the following:

(1)

All soil test pits and soil permeability results shall be performed under the direct supervision of a professional engineer. All soil logs and permeability test data shall be accompanied by a certification by a professional engineer. The results and location (horizontal and vertical) of all soil test pits and soil permeability tests, both passing and failing, shall be reported to the City.

(2)

During all subsurface investigations and soil test procedures, adequate safety measures shall be taken to prohibit unauthorized access to the excavations at all times. It is the responsibility of persons performing or witnessing subsurface investigations and soil permeability tests to comply with all applicable federal, state and local laws and regulations governing occupational safety.

(3)

A minimum of two soil test pits shall be excavated within the footprint of any proposed infiltration BMP to determine the suitability and distribution of soil types present at the site. Placement of the test pits shall be within 20 feet of the basin perimeter, located along the longest axis bisecting the BMP. For BMPs larger than 10,000 square feet in area, a minimum of one additional soil test pit shall be conducted within each additional area of 10,000 square feet. The additional test pit(s) shall be placed approximately equidistant to other test pits, so as to provide adequate characterization of the subsurface material. In all cases, where soil and or groundwater properties vary significantly, additional test pits shall be excavated in order to accurately characterize the subsurface conditions below the proposed infiltration BMP. Soil test pits shall extend to a minimum depth of eight feet below the lowest elevation of the basin bottom or to a depth that is at least two times the maximum potential water depth in the proposed infiltration BMP, whichever is greater.

(4)

A soil test pit log shall be prepared for each soil test pit. The test pit log shall, at a minimum, provide the elevation of the existing ground surface, the depth and thickness (in inches) of each soil horizon or substratum, the dominant matrix or background and mottle colors using the Munsell system of classification for hue, value and chroma, the appropriate textural class as shown on the USDA textural triangle, the volume percentage of coarse fragments (larger than two millimeters in diameter), the abundance, size, and contrast of mottles, the soil structure, soil consistence, and soil moisture condition, using standard USDA classification terminology for each of these soil properties. Soil test pit logs shall identify the presence of any soil horizon, substratum or other feature that exhibits an in-place permeability rate less than one inch per hour.

(5)

Each soil test pit log shall report the depth to seasonally high water level, either perched or regional, and the static water level based upon the presence of soil mottles or other redoximorphic features, and observed seepage or saturation. Where redoximorphic features, including soil mottles resulting from soil saturation are present, they shall be interpreted to represent the depth to the seasonal high water table unless soil saturation or seepage is observed at a higher level. When the determination of the seasonally high water table shall be made in ground previously disturbed by excavation, direct observation of the state water table during the months of January through April shall be the only method permitted.

(6)

Any soil horizon or substratum which exists immediately below a perched zone of saturation shall be deemed by rule to exhibit unacceptable permeability (less than one inch per hour). The perched zone of saturation may be observed directly, inferred based upon soil morphology, or confirmed by performance of an hydraulic head test as defined at N.J.A.C. 7:9A-5.9.

(7)

Stormwater infiltration BMPs shall not be installed in soils that exhibit artesian groundwater conditions. A permeability test shall be conducted in all soils that immediately underlie a perched zone of saturation. Any zone of saturation which is present below a soil horizon which exhibits an in-place permeability of less than 0.2 inch per hour shall be considered an artesian zone of saturation unless a minimum one-foot-thick zone of unsaturated soil, free of mottling or other redoximorphic features and possessing a chroma of four or higher, exists immediately below the unsuitable soil.

(8)

A minimum of one permeability test shall be performed at each soil test pit location. The soil permeability rate shall be determined using test methodology as prescribed in N.J.A.C. 7:9A-6.2 (tube permeameter test), 6.5 (pit bailing test) or 6.6 (piezometer test). When the tube permeameter test is used, a minimum of two replicate samples shall be taken and tested. Alternative permeability test procedures may be accepted by the approving authority, provided the test procedure attains saturation of surrounding soils, accounts for hydraulic head effects on infiltration rates, provides a permeability rate with units expressed in inches per hour and is accompanied by a published source reference. Examples of suitable sources include hydrogeology, geotechnical or engineering text and design manuals, proceedings of American Society for Testing and Materials (ASTM) symposia, or peer-review journals. Neither a soil permeability class rating test, as described in N.J.A.C. 7:9A-6.3, nor a percolation test, as described in N.J.A.C. 7:9A-6.4, are acceptable tests for establishing permeability values for the purpose of complying with this Part 1.

(9)

Soil permeability tests shall be conducted on the most hydraulically restrictive horizon or substratum to be left in place below the basin as follows. Where no soil replacement is proposed, the permeability tests shall be conducted on the most hydraulically restrictive horizon or substratum within four feet of the lowest elevation of the basin bottom or to a depth equal to two times the maximum potential water depth within the basin, whichever is greater. Where soil replacement is proposed, the permeability tests shall be conducted within the soil immediately below the depth of proposed soil replacement or within the most hydraulically restrictive horizon or substratum to a depth equal to two times the maximum potential water depth within the basin, whichever is greater. Permeability tests may be performed on the most hydraulically restrictive soil horizons or substrate at depths greater than those identified above based upon the discretion of the design or testing engineer. The tested infiltration rate should then be divided by two to establish the soil's design permeability rate. Such division will provide a safety factor of 100% to the tested rate.

(10)

The minimum acceptable tested permeability rate of any soil horizon or substratum shall be one inch per hour. Soil materials that exhibit tested permeability rates slower than one inch per hour shall be considered unsuitable for stormwater infiltration. The maximum reportable tested permeability rate of any soil horizon or substratum shall be no greater than 20 inches per hour regardless of the rate attained in the test procedure.

(11)

After all construction activities have been completed on the development site and the finished grade has been established in the infiltration BMP, a minimum of one permeability test shall be conducted within the most hydraulically restrictive soil horizon or substratum below the as-built BMP to ensure the performance of the infiltration BMP is as designed. Hand tools and manual permeability test procedures shall be used for the purpose of confirming BMP performance. In addition, the infiltration BMP shall be flooded with water sufficient to demonstrate the performance of the BMP. Test results shall be certified to the City's designated engineer.

(12)

A groundwater mounding analysis shall be provided for each stormwater infiltration BMP. The groundwater mounding analysis shall calculate the maximum height of the groundwater mound based upon the volume of the maximum design storm. The professional engineer conducting the analysis shall provide the City's designated engineer with the methodology and supporting documentation for the mounding analysis used and shall certify to the City, based upon the analysis, that the groundwater mound will not cause stormwater or groundwater to breakout to the land surface or cause adverse impact to adjacent surface water bodies, wetlands or subsurface structures, including, but not limited to, basements and septic systems. If there is more than one infiltration BMP proposed, the model shall indicate if and how the mounds will interact. The mounding analysis shall be calculated using the most restrictive soil horizon that will remain in place within the explored aquifer thickness unless alternative analyses is authorized by the City's designated engineer. The mounding analysis shall be accompanied by a cross section of the infiltration BMP and surrounding topography and the mound analysis shall extend out to the point(s) at which the mound intersects with the preexisting maximum water table elevation.

(13)

The applicant shall demonstrate that stormwater infiltration BMPs meet the seventy-two-hour drain time requirement established in § 330-21A of this Part 1.

Bicycle-safe inlet grates. Site development plans that incorporate site design features that help to prevent discharge of trash and debris from drainage systems shall comply with the following standard to control passage of solid and floatable materials through storm drain inlets. For purposes of this subsection, "solid and floatable materials" means sediment, debris, trash, and other floating, suspended, or settleable solids.

(1)

Design engineers shall use either of the following grates whenever they use a grate in pavement or another ground surface to collect stormwater from that surface into a storm drain or surface water body under that grate:

(a)

The New Jersey Department of Transportation (NJDOT) bicycle-safe grate, which is described in Chapter 2.4 of the NJDOT Bicycle Compatible Roadways and Bikeways Planning and Design Guidelines (April 1996); or

(b)

A different grate, if each individual clear space in that grate has an area of no more than seven square inches, or is no greater than 0.5 inch across the smallest dimension. Examples of grates subject to this standard include grates in grate inlets, the grate portion (non-curb-opening portion) of combination inlets, grates on storm sewer manholes, ditch grates, trench grates, and grates of spacer bars in slotted drains. Examples of ground surfaces include surfaces of roads (including bridges), driveways, parking areas, bikeways, plazas, sidewalks, lawns, fields, open channels, and stormwater basin floors.

(2)

Whenever design engineers use a curb-opening inlet, the clear space in that curb opening (or each individual clear space, if the curb opening has two or more clear spaces) shall have an area of no more than seven square inches, or be no greater than two inches across the smallest dimension.

(3)

This standard does not apply:

(a)

Where the review agency determines that this standard would cause inadequate hydraulic performance that could not practicably be overcome by using additional or larger storm drain inlets that meet these standards;

(b)

Where flows from the water quality design storm as specified in Article III are conveyed through any device (e.g., end-of-pipe netting facility, manufactured treatment device, or a catch basin hood) that is designed, at a minimum, to prevent delivery of all solid and floatable materials that could not pass through one of the following:

[1]

A rectangular space 4 5/8 inches long 1.5 inches wide (This option does not apply for outfall netting facilities.); or

[2]

A bar screen having a bar spacing of 0.5 inch.

(c)

Where flows are conveyed through a trash rack that has parallel bars with one-inch spacing between the bars, to the elevation of the water quality design storm as specified in Article III of this Part 1; or

(d)

Where the NJDEP determines pursuant to the New Jersey Register of Historic Places Rules at N.J.A.C. 7:4-7.2(c), that action to meet this standard is an undertaking that constitutes an encroachment or will damage or destroy the New Jersey Register listed historic property.

Catch basins. Catch basins are storm drain inlets with or without sumps. Catch basins may provide pretreatment for other stormwater BMPs by capturing large sediments. The sediment and pollutant removal efficiency of catch basins depends on the size of the sump and the performance of routine maintenance to retain the available sediment storage space in the sump. Where catch basins with sumps are proposed, the minimum two-foot separation between the bottom of the sump and seasonally high water table shall be provided.

Open or perforated conveyance piping. Where adequate separation to the seasonal high water table exists, stormwater from the development site may be conveyed to a stormwater basin via a system of perforated pipes. These pipes may be made of PVC or corrugated metal and are available with perforations of varying size and spacing. Perforated pipe specifications shall be certified by a professional engineer. A professional engineer shall certify that perforated conveyance piping will not act to intercept the seasonal high water table and convey groundwater to the stormwater basin. All open or perforated stormwater conveyance systems shall be installed with a minimum separation of two feet from the seasonal high water table.