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U.S. DEPARTMENT OF AGRICULTURE PAGE 1 OF 1
NATURAL RESOURCES CONSERVATION SERVICE 03/29/99
PRIME FARMLAND
William Ward
Map Soil name
symbol
21fDacono clay loam, 0 to 1 percent slopes (where irrigated)
39 '` ;Nunn loam, 0 to 1 percent slopes (where irrigated)
2002-1448
(The information in this report indicates the dominant soil condition but does not eliminate the need for onsite
investigation)
r0
M symbol Shallow Dwellings Dwellings
Oil name excavations without Small Local roads Lawns and
with commercial and streets landscaping
basements ' basements buildings
21:
Dacono---------- Severe: Slight
cutbanks cave g Slight Slight Slight Slight
39: xla►4
Nunn (Slight Ig
U.S. DEPARTMENT OF AGRICULTU E "'`"C�' 7,Stot �C�t61 Slight
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NATURAL RESOURCES CONSERVATION SERVICE ICY PAGE 2 OF 2
03/29/99
BUILDING SITE DEVELOPMENT
Endnote -- BUILDING SITE DEVELOPMENT
This report shows the degree and kind of soil limitations that affect shallow excavations, dwellings with and without
basements, small commercial buildings, local roads and streets, and lawns and landscaping. The limitations are
"Slight", "Moderate", or "Severe". The limitations are considered "Slight" if soil properties and site features are
generally favorable for the indicated use and limitaions are minor and easily overcome; "Moderate" if soil properties
or site features are not favorable for the indicated use and special planning, design, or maintenance is needed to
over(7)or minimize the limitations; and "Severe" if soil properties or site features are so unfavorable or so
diffit to overcome that special design, significant increases in construction costs, and possibly increased
maintenance are required. Special feasibility studies may be required where the soil limitations are severe.
SHALLOW EXCAVATIONS are trenches or holes dug to a maximum depth of 5 or 6 feet for basements, graves, utility lines,
open ditches, and other purposes. The ratings are based on soil properties, site features, and observed performance of
the soils. The ease of digging, filling, and compacting is affected by the depth to bedrock, a cemented pan, or a very
firm dense layer; stone content; soil texture; and slope. The time of the year that excavations can be made is
affected by the depth to a seasonal high water table and the susceptibility of the soil to flooding. The resistance of
the excavation walls or bands to sloughing or caving is affected by soil texture and the depth to the water table.
DWELLINGS AND SMALL COMMERCIAL BUILDINGS are structures built on shallow foundations on undisturbed soil. The load
limit is the same as that for single-family dwellings no higher than three stories. Ratings are made for small
commercial buildings without basements, for dwellings with basements, and for dwellings without basements. The ratings
are based on soil properties, site features, and observed performance of the soils. A high water table, depth to bedrock
or to a cemented pan, large stones, slope, and flooding affect the ease of excavation and construction. Landscaping
and grading that require cuts and fills of more than 5 or 6 feet are not considered.
LOCAL ROADS AND STREETS have an all-weather surface and carry automobile and light truck traffic all year. They
have a subgrade of cut or fill soil material, a base of gravel, crushed rock, or stabilized soil material, and a
flexible or rigid surface. Cuts and fills are generally properties, site features, and observed performance of the
soils. Depth to bedrock or to a cemented pan, a high water table, flooding, large stones, and slope affect the ease of
excavating and grading. Soil strength (as inferred from the engineering classification of the soil), shrink-swell
potential, frost action potential, and depth to a high water table affect the traffic-supporting capacity.
LAW OD LANDSCAPING require soils on which turf and ornamental trees and shrubs can be established and
maintained. The ratings are based on soil properties, site features, and observed performance of the soils. Soil
reaction, a high water table, depth to bedrock or to a cemented pan, the available water capacity in the upper 40
inches, and the content of salts, sodium, and sulfidic materials affect plant growth. Flooding, wetness, slope,
stoniness, and the amount of sand, clay, or organic matter in the surface layer affect trafficability after vegetation
is established.
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I , . NONTECHNICAL SOILS DESCRIPTIOP0RT Q
N. • William Ward
N ; Soil name and description
Sy
21 Dacono clay loam, 0 to 1 percent slopes
The Dacono soil is a deep, well drained soil. It is
formed on terraces from mixed alluvial material. The
surface is a clay loam, as is the subsoil. The
underlying material is a very gravelly sand. The soils
have moderately slow permeability. Their available
water holding capacity is moderate. Roots penetrate to
20 to 40 inches. Runoff is slow and the erosion hazard
is moderate.
39 Nunn loam, 0 to 1 percent slopes
The Nunn soil is a deep, well drained soil. It is
formed on terraces from eolian material. The surface
is a loam. The subsoil is clay loam. The underlying
material is clay loam and sandy loam. The soils have
moderately slow permeability. Their available water
holding capacity is high. Roots penetrate to 60 inches
or more. Runoff is slow and the erosion hazard due to
wind is moderate.
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U.S. DEPARTMENT OF AGRICULTURE PAGE 1 OF 2Q
NATURALRESOURCES CONSERVATION SERVICE 03/29/99
O CHEMICAL PROPERTIES OF THE SOILS
William Ward
---------------------- ------------
I I I I
1 I i
Map symbol ; Depth ; Clay Cation- Soil ; Calcium Gypsum Salinity; Sodium
and soil name exchange reaction ;carbonate adsorption
capacity ratio
In Pct meq/1008 pH Pct Pct mmhos/cm
21:
Dacono 0-12 27-40 25.0-45.0 6.6-7.8 --- --- --- ---
12-21 35-60 60.0-70.0 7.4-8.4 0-5 --- --- ---
21-27 15-35 20.0-40.0 7.4-8.4 0-10 --- 0-2 ---
27-60 0-5 2.0-10.0 7.4-8.4 5-15 --- 0-2 ---
39: I
Nunn ; 0-9 20-27:15.0-30.0 6.1-7.8 --- --- --- ; ---
9-29 35-50:15.0-30.0 6.1-8.4 0-15 --- 0-2 ; ---
29-60 15-25: 5.0-15.0 7.4-8.4 4-15 --- 0-2 ; ---
I I I
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U.S, DEPARTMENT OF AGRICULTURE PAGE 2 OF 2 Q
NATURAL RESOURCES CONSERVATION SERVICE 03/29/99
CHEMICAL PROPERTIES OF THE SOILS
Endnote -- CHEMICAL PROPERTIES OF THE SOILS
This report shows estimates of some characteristics and features that affect soil behavior.
These estimates are given for the major layers of each soil in the survey area. The estimates
are based on field observations and on test data for these and similar soils.
CLAY as a soil separate consists of mineral soil particles that are less than 0.002
millimeter in diameter. In this report, the estimated clay content of each major soil layer
is given as a percentage, by weight, of the soil material that is less than 2 millimeters in
diameter. The amount and kind of clay greatly affect the fertility and physical condition of
the soil. They determine the ability of the soil to adsorb cations and to retain moisture.
They influence shrink-swell potential, permeability, and plasticity, the ease of soil
dispersion, and other soil properties. The amount and kind of clay in a soil also affect
tillage and earthmoving operations.
CATION EXCHANGE CAPACITY (CEC) is the total amount of cations held in a soil in such
a way that they can be removed only by exchanging with another cation in the natural soil
solution. CEC is a measure of the ability of a soil to retain cations, some of which are
plant nutrients. Soils with low CEC hold few cations and may require more frequent
applications of fertilizers than soils with high CEC. Soils with high CEC have the potential
to retain cations, thus reducing the possibility of pollution of ground water.
SOACTION is a measure of acidity or alkalinity and is expressed as a range in pH
yak, The range in pH of each major horizon is based on many field tests. For many soils,
values have been verified by laboratory analyses. Soil reaction is important in selecting
crops and other plants, in evaluating soil amendments for fertility and stabilization, and
in determining the risk of corrosion.
CALCIUM CARBONATE is the percentage by weight of calcium carbonate in the fine-earth
material, less than 2 millimeters in size.
GYPSUM is the percentage by weight of hydrated calcium sulfates 20 millimeters or
smaller in size, in the soil.
SALINITY is a measure of soluble salts in the soil at saturation. It is expressed
as the electrical conductivity of the saturation extract, in millimhos per centimeter
at 25 degrees C. Estimates are based on field and laboratory measurements at representative
sites of nonirrigated soils.
The salinity of irrigated soils is affected by the quality of the irrigation water
and by the frequency of water application. Hence, the salinity of soils in individual fields
can differ greatly from the value given in the report. Salinity affects the suitability of
a soil for crop production, the stability of soil if used as construction material, and
the potential of the soil to corrode metal and concrete.
SODIUM ADSORPTION RATIO (SAR) expresses the relative activity of sodium ions in
exchange reactions in the soil. SAR is a measure of the amount of sodium relative to
i calcium and magnesium in the water extract from saturated soil paste.
U.S. DEPARTMENT OF AGRICULTURE PAGE 1 OF 4
NATURAL RESOURCES CONSERVATION SERVICE 03/29/99
PHYSICAL PROPERTIES OF SOILS
William Ward
(Entries under "Erosion factors--T" apply to the entire profile. Entries under "Wind erodibility group" and
"Wind erodability index" apply only to the surface layer)
;Erosion factors;Wind Wind
Map symbol Depth ' Clay ; Moist Permea- Available: Shrink- ;Organic;_________ ___;erodi- erodi-
and soil name bulk bility water swell ' matter; ;bility bility
density capacity potential K ; Kf T ;group index
In Pct g/cc In/hr In/in Pct
21:
Dacono 0-12 27-40 1.20-1.30 0.20-0.60 0.19-0.21 Moderate 2.0-4.0 0.17 0.17 3 4 86
12-21 35-60 1.25-1.35 0.20-0.60 0.15-0.21 High 1.0-2.0 0.24 0.43
21-27 15-35 1.25-1.35 0.60-2.00 0.13-0.18 Moderate 1.0-2.0 0.28 0.28
27-60 0-5 1.50-1.60 >20.00 0.03-0.05 Low 0.5-1.0 0.10 0.64
39: ,
Nunn 0-9 20-27;1.25-1.40 0.60-2.00 0.14-0.17 Low 2.0-4.0 0.24 0.24 5 6 48
9-29 35-50;1.35-1.40 0.06-0.20 0.15-0.18 High 0.5-2.0 0.28 0.32
- - -29 60 , 15-25:1.35-1.45 2.00-6.00 0.11 0.14:Low 0.0-0.5 0.20 0.24
1
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U.S. DEPARTMENT OF AGRICULTURE OPAGE 2 OF 4
FATURAL RESOURCES CONSERVATION SERVICE `-� 03/29/99
OPHYSICAL PROPERTIES OF SOILS
Endnote -- PHYSICAL PROPERTIES OF SOILS
This report shows estimates of some characteristics and features that affect soil behavior. These estimates
are given for the major layers of each soil in the survey area. The estimates are based on field observations
and on test data for these and similar soils.
CLAY as a soil separate consists of mineral soil particles that are less than 0.002 millimeter in diameter.
In this report, the estimated clay content of each major soil layer is given as a percentage, by weight, of the
soil material that is less than 2 millimeters in diameter. The amount and kind of clay greatly affect the
fertility and physical condition of the soil. They determine the ability of the soil to adsorb cations and
to retain moisture. They influence shrink-swell potential, permeability, plasticity, the ease of soil
dispersion, and other soil properties, The amount and kind of clay in a soil also affect tillage and
earthmoving operations.
MOIST BULK DENSITY is the weight of soil (ovendry) per unit volume. Volume is measured when the soil is
at field moisture capacity, the moisture content at 1/3 bar moisture tension. Weight is determined after
drying the soil at 105 degrees C. In this report, the estimated moist bulk density of each major soil
horizon is expressed in grams per cubic centimeter of soil material that is less than 2 millimeters in
diameter. Bulk density data are used to compute shrink-swell potential, available water capacity, total
pore space, and other soil properties. The moist bulk density of a soil indicates the pore space available for
water and roots. A bulk density of more than 1.6 can restrict water storage and root penetration. Moist
bulk density is influenced by texture, kind of clay, content of organic matter, and soil structure.
PEILITY refers to the ability of a soil to transmit water or air. The estimates indicate the
rate of downward movement of water when the soil is saturated. They are based on soil characteristics
observed in the field, particularly structure, porosity, and texture. Permeability is considered in
the design of soil drainage systems, septic tank absorption fields, and construction where the rate of
water movement under saturated conditions affects behavior.
AVAILABLE WATER CAPACITY refers to the quantity of water that the soil is capable of storing for use by
plants. The capacity for water storage is given in inches of water per inch of soil for each major soil layer.
The capacity varies, depending on soil properties that affect the retention of water and the depth of the root
zone. The most important properties are the content of organic matter, soil texture, bulk density, and soil
structure. Available water capacity is an important factor in the choice of plants or crops to be grown and in
the design and management of irrigation systems. Available water capacity is not an estimate of the quantity of
water actually available to plants at any given time.
SHRINK-SWELL POTENTIAL is the potential for volume change in a soil with a loss or gain of moisture. Volume
change occurs mainly because of the interaction of clay minerals with water and varies with the amount and type
of clay minerals in the soil. The size of the load on the soil and the magnitude of the change in soil moisture
content influence the amount of swelling of soils in place. Laboratory measurements of swelling of undisturbed
clods were made for many soils. For others, swelling was estimated on the basis of the kind and amount of
clay minerals in the sail and on measurements of similar soils. If the shrink-swell potential is rated moderate
to very high, shrinking and swelling can cause damage to buildings, roads, and other structures. Special design
is often needed. Shrink-swell potential classes are based on the change in length of an unconfined clod as
moisture content is increased from air-dry to field capacity. The change is based on the soil fraction less
than 2 millimeters in diameter. The classes are "Low," a change of less than 3 percent; "Moderate," 3 to 6
percent; and "High," more than 6 percent. "Very high," greater than 9 percent, is sometimes used.
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U.S. DEPARTMENT OF AGRICULTURE '. ;1 °AGE 3 OF 4
NATURAL RESOURCES CONSERVATION SERVICE 03/29/99
PHYSICAL PROPERTIES OF SOILS
Endnote -- PHYSICAL PROPERTIES OF SOILS--Continued
ORGANIC MATTER is the plant and animal residue in the soil at various stages of decomposition. In report J,
the estimated content of organic matter is expressed as a percentage, by weight, of the soil material that is
less than 2 millimeters in diameter. The content of organic matter in a soil can be maintained or increased by
returning crop residue to the soil. Organic matter affects the available water capacity, infiltration rate, and
tilth. It is a source of nitrogen and other nutrients for crops.
EROSION FACTOR K indicates the susceptibility of the whole soil (including rocks and rock fragments) to
sheet and rill erosion by water. Factor K is one of six factors used in the Universal Soil Loss Equation (USLE)
to predict the average annual rate of soil loss by sheet and rill erosion in tons per acre per year. The
estimates are based primarily on percentage of silt, sand, and organic matter (up to 4 percent) and on soil
structure and permeability. Values of K range from 0.05 to 0.69. The higher the value, the more susceptible
the soil is to sheet and rill erosion by water.
EROSION FACTOR Kf is like EROSION FACTOR K but it is for the fine-earth fraction of the soil. Rocks and
rock fragments are not considered.
EROSION FACTOR T is an estimate of the maximum average annual rate of soil erosion by wind or water that can
occur without affecting crop productivity over a sustained period. The rate is in tons per acre per year.
WIND ERODIBILITY GROUPS are made up of soils that have similar properties affecting their resistance to wind
eriiiqo in cultivated areas. The groups indicate the susceptibility of soil to wind erosion. Soils are grouped
ac ng to the following distinctions:
1. Coarse sands, sands, fine sands, and very fine sands.
These soils are generally not suitable for crops. They are
extremely erodible, and vegetation is difficult to
establish.
2. Loamy coarse sands, loamy sands, loamy fine sands, loamy
very fine sands, and sapric soil material. These soils are
very highly erodible. Crops can be grown if intensive
measures to control wind erosion are used.
3. Coarse sandy loams, sandy loams, fine sandy loams, and
very fine sandy loans. These soils are highly erodible.
Crops can be grown if intensive measures to control wind
erosion are used.
4L, Calcareous loans, silt loans, clay loans, and silty clay
loans. These soils are erodible. Crops can be grown if
intensive measures to control wind erosion are used.
4. Clays, silty clays, noncalcareous clay loans, and silty
clay loans that are more than 35 percent clay. These soils
are moderately erodible. Crops can be grown if measures to
control wind erosion are used.
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U.S. DEPARTMENT OF AGRICULTURE OPAGE 4 OF 4
.NATURAL RESOURCES CONSERVATION SERVICE 03/29/99
OPHYSICAL PROPERTIES OF SOILS
Endnote -- PHYSICAL PROPERTIES OF SOILS--Continued
5. Noncalcareous loams and silt loams that are less than 20
percent clay and sandy clay loans, sandy clays, and heroic
soil material. These soils are slightly erodible. Crops
can be grown if measures to control wind erosion are used.
6. Noncalcareous loams and silt loans that are more than 20
percent clay and noncalcareous clay loans that are less than
35 percent clay. These soils are very slightly erodible.
Crops can be grown if ordinary measures to control wind
erosion are used.
7. Silts, noncalcareous silty clay loans that are less than
35 percent clay, and fibric soil material. These soils are
very slightly erodible. Crops can be grown if ordinary
measures to control wind erosion are used.
S. Soils that are not subject to wind erosion because of
coarse fragments an the surface or because of surface
wetness.
TtopiSiD ERODIBILITY INDEX is used in the wind erosion equation (WED). The index number indicates the
a of soil lost in tans per acre per year. The range of wind erodibility index numbers is 0 to 300.
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U.S. DEPARTMENT OF AGRICULTURE 1 OF 3
NATURAL RESOURCES CONSERVATION SERVICE 03/29/99
•
WATER FEATURES
William Ward
Flooding High water table and ponding
------------------------ ---
Map symbol Hydro- Water ; ; Maximum
and soil name logic Frequency Duration Months table ; Kind of ; Months Ponding ponding
group depth ;water table; duration depth
Ft ; Ft
21:
Dacono 8 None --- --- >6.0 --- --- --- ---
39:
Nunn C None --- --- )6.0 --- --- --- ---
C)
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U.S. DEPARTMENT OF AGRICULTURE E 2 OF 3
f1ATURAL RESOURCES CONSERVATION SERVICE 03/29/99
WATER FEATURES
Endnote -- WATER FEATURES
This report gives estimates of various soil water features. The estimates are used in land use planning that involves
engineering considerations.
Hydrologic soil groups are used to estimate runoff from precipitation. Soils not protected by vegetation are
assigned to one of four groups. They are grouped according to the infiltration of water when the soils are thoroughly
wet and receive precipitation from long-duration storms. The four hydrologic soil groups are:
Group " A". Soils having a high infiltration rate (low
runoff potential) when thoroughly wet. These consist mainly
of deep, well drained to excessively drained sands or
gravelly sands. These soils have a high rate of water
transmission.
Group "B". Soils having a moderate infiltration rate when
thoroughly wet, These consist chiefly of moderately deep or
deep, moderately well drained or well drained soils that
have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group "C". Soils having a slow infiltration rate when
thoroughly wet. These consist chiefly of soils having a
layer that impedes the downward movement of water or soils
of moderately fine texture or fine texture. These soils
have a slow rate of water transmission.
Group "D". Soils having a very slow infiltration rate (high
runoff potential) when thoroughly wet. These consist
chiefly of clays that have a high shrink-swell potential,
soils that have a permanent high water table, soils that
have a claypan or clay layer at or near the surface, and
soils that are shallow over nearly impervious material.
These soils have a very slow rate of water transmission.
If a soil is assigned to two hydrologic groups in this report, the first letter is for drained areas and the second
is for undrained areas. Flooding, the temporary inundation of an area, is caused by overflowing streams, by runoff from
adjacent slopes, or by tides. Water standing for short periods after rainfall or snowmelt is not considered
flooding, nor is water in swamps and marshes. This report gives the frequency and duration of flooding and
the time of year when flooding is most likely. Frequency, duration, and probable dates of occurrence are estimated.
Frequency is expressed as "None", "Rare", "Occasional", and "Frequent". "None" means that flooding is not probable;
"Rare" that it is unlikely but possible under unusual weather conditions; "Occasional" that it occurs, on the
average, once or less in 2 years; and "Frequent" that it occurs, on the average, more than once in 2 years.
Duration is expressed as "Very brief" if less than 2 days, "Brief" if 2 to 7 days, "Long" if 7 to 30 days, and "Very
long" if more than 30 days. The information is based on evidence in the soil profile, namely thin strata of gravel,
sand, silt, or clay deposited by floodwater; irregular decrease in organic matter content with increasing depth;
arence of distinctive horizons that form in soils that are not subject to flooding. Also considered are local
in .. .ration about the extent and levels of flooding and the relation of each soil on the landscape to historic floods.
U.S. DEPARTMENT OF AGRICULTURE OE 3 OF 3
NATURAL RESOURCES CONSERVATION SERVICE 03/29/99
OWATER FEATURES
Endnote -- WATER FEATURES--Continued
Information on the extent of flooding based on soil data is less specific than that provided by detailed engineering
surveys that delineate flood-prone areas at specific flood frequency levels.
High water table (seasonal) is the highest level of a saturated zone in the soil in most years. The depth to a
seasonal high water table applies to undrained soils. The estimates are based mainly on the evidence of a saturated
zone, namely grayish colors or mottles in the soil. Indicated in this report are the depth to the seasonal high
water table; the kind of water table, that is, "Apparent", "Artesian", or "Perched"; and the months of the year that
the water table commonly is high. A water table that is seasonally high for less than 1 month is not indicated in
this report.
An "Apparent" water table is a thick zone of free water in the soil. It is indicated by the level at which water
stands in an uncased borehole after adequate time is allowed for adjustment in the surrounding soil.
An "Artesian" water table exists under a hydrostatic beneath an impermeable layer. When the impermeable layer has been
penetrated by a cased borehole, the water rises. The final level of the water in the cased borehole is characterized as
an artesian water table.
A "Perched" water table is water standing above an unsaturated zone. In places an upper, or "Perched", water
table is separated from a lower one by a dry zone. Only saturated zones within a depth of about 6 feet are
indicated.
Pon is standing water in a closed depression. The water is removed only by deep percolation, transpiration,
evaporation, or a combination of these processes.
This report gives the depth and duration of ponding and the time of year when ponding is most likely. Depth, duration,
and probable dates of occurrence are estimated.
Depth is expressed as the depth of ponded water in feet above the soil surface. Duration is expressed as "Very
brief" if less than 2 days, "Brief" if 2 to 7 days, "Long" if 7 to 30 days, and "Very long" if more than 30 days. The
information is based on the relation of each soil on the landscape to historic ponding and on local information about
the extent and levels of ponding.
U.S. DEPARTMENT OF AGRICULTURE PO 1 OF 2
NATURAL RESgURCES CONSERVATION SERVICE 03/29/99
SOIL FEATURES
William Ward
Bedrock ; Cemented pan Subsidence Risk of corrosion
Potential
Map symbol ; frost action Uncoated
and soil name Depth Hardness Depth ; Kind Initial Total steel ; Concrete
In In ; In In
21:
Dacono >60 --- --- ; --- --- --- ;Low High Low
39:
Nunn >60 --- --- --- --- Moderate High Low
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U.S. •
DEPARTMENT OF AGRICULTURE PAO 2 OF 2
)ATUkAL RESOURCES CONSERVATION SERVICE 03/29/99
SOIL FEATURES
Endnote -- SOIL FEATURES
This report gives estimates of various soil features. The estimates are used in land use planning that involves
engineering considerations.
Depth to bedrock is given if bedrock is within a depth of 5 feet. The depth is based on many soil borings and on
observations during soil mapping. The rock is either "Soft" or "Hard". If the rock is "Soft" or fractured, excavations
can be made with trenching machines, backhoes, or small rippers. If the rock is "Hard" or massive, blasting or
special equipment generally is needed for excavation.
Cemented pans are cemented or indurated subsurface layers within a depth of 5 feet. Such pans cause difficulty in
excavation. Pans are classified as "Thin" or "Thick". A "Thin" pan is less than 3 inches thick if continuously
indurated or less than 18 inches thick if discontinuous or fractured. Excavations can be made by trenching machines,
backhoes, or small rippers. A "Thick" pan is more than 3 inches thick if continuously indurated or more than 18
inches thick if discontinuous or fractured. Such a pan is so thick or massive that blasting or special equipment is
needed in excavation.
Subsidence is the settlement of organic soils or of saturated mineral soils of very low density. Subsidence
results from either desiccation and shrinkage or oxidation of organic material, or both, following drainage.
Subsidence takes place gradually, usually over a period of several years. This report shows the expected initial
subsidence, which usually is a result of drainage, and total subsidence, which usually is a result of oxidation. Not
shown in the report is subsidence caused by an imposed surface load or by the withdrawal of ground water throughout
aylensive area as a result of lowering the water table.
Potential frost action is the likelihood of upward or lateral expansion of the soil caused by the formation of
segregated ice lenses (frost heave) and the subsequent collapse of the soil and loss of strength on thawing. Frost
action occurs when moisture moves into the freezing zone of the soil. Temperature, texture, density, permeability,
content of organic matter, and depth to the water table are the most important factors considered in evaluating the
potential for frost action. It is assumed that the soil is not insulated by vegetation or snow and is not artificially
drained. Silty and highly structured clayey soils that have a high water table in winter are the most susceptible to
frost action. Nell drained, very gravelly, or very sandy soils are the least susceptible. Frost heave and low soil
strength during thawing cause damage mainly to pavements and other rigid structures.
Risk of corrosion pertains to potential soil-induced electrochemical or chemical action that dissolves or weakens
uncoated steel or concrete. The rate of corrosion of uncoated steel is related to such factors as soil moisture,
particle-size distribution, acidity, and electrical conductivity of the soil. The rate of corrosion of concrete
is based mainly on the sulfate and sodium content, texture, moisture content, and acidity of the soil. Special
site examination and design may be needed if the combination of factors creates a severe corrosion environment. The steel
installations that intersect soil boundaries or soil layers is more susceptible to corrosion than steel in
installations that are entirely within one kind of soil or within one soil layer. For uncoated steel, the risk of
corrosion, expressed as "Low", "Moderate", or "High", is based on soil drainage class, total acidity, electrical
resistivity near field capacity, and electrical conductivity of the saturation extract.
For concrete, the risk of corrosion is also expressed as "Low", "Moderate", or "High". It is based on soil texture,
acidity, and amount of sulfates in the saturation extract.
C)
U.S. DEPARTMENT OF AGRICULTURE ()PAGE
PAGE 1 OF 3
NATURAL RESOURCES CONSERVATION SERVICE 03/29/99
SANITARY FACILITIES
William Ward
(The information in this report indicates the dominant soil condition but does not eliminate the need for onsite
investigation)
I I I
I 1 1
Map symbol Septic tank ; Sewage lagoon Trench Area ; Daily cover
and soil name absorption ; areas sanitary sanitary for landfill
fields landfill landfill
1 I
21:
Dacono Severe: Severe: Severe: Slight ;Poor:
poor filter seepage too sandy ; seepage,
too sandy,
small stones
39:
Nunn Severe: :Severe: :Slight Slight ;Fair:
percs slowly seepage ; small stones
I I 1 I
U.S. DEPARTMENT OF AGRICULTURE OAGE 2 OF 3
NATURAL RESOURCES CONSERVATION SERVICE 03/29/99
SANITARY FACILITIES
Endnote -- SANITARY FACILITIES
This report shows the degree and kind of soil limitations that affect septic tank absorption fields, sewage lagoons,
and sanitary landfills. The limitations are considered "Slight" if soil properties and site features generally are
favorable for the indicated use and limitations are minor and easily overcome; "Moderate" if soil properties or site
features are not favorable for the indicated use and special planning, design, or maintenance is needed to overcome or
minimize the limitations; and "Severe" if soil properties or site features are so unfavorable or so difficult to overcome
that special design, significant increases in construction costs, and possibly increased maintenance are required.
This report also shows the suitability of the soils for use as daily cover for landfills. A rating of "Good" indicates
that soil properties and site features are favorable for the use and good performance and low maintenance can be
expected; "Fair" indicates that soil properties and site features are moderately favorable for the use and one or
more soil properties or site features make the soil less desirable than the soils rated "Good"; and "Poor" indicates
that one or more soil properties or site features are unfavorable for the use and overcoming the unfavorable
properties requires special design, extra maintenance, or costly alteration.
SEPTIC TANK ABSORPTION FIELDS are areas in which effluent from a septic tank is distributed into the soil through
subsurface tiles or perforated pipe. Only that part of the soil between depths of 24 to 72 inches is evaluated. The
ratings are base on soil properties, site features, and observed performance of the soils. Permeability, a high
water table, depth to bedrock or to a cemented pan, and flooding affect absorption of the effluent. Large stones
and bedrock or a cemented pan interfere with installation. Unsatisfactory performance of septic tank absorption fields,
including excessively slow absorption of effluent, surfacing of effluent, and hillside seepage, can affect public health.
Groundwater can be polluted if highly permeable sand and gravel or fractured bedrock is less than 4 feet below the
bajamq the absorption field, if slope is excessive, or if the water table is near the surface. There must be
urn fated soil material beneath the absorption field to filter the effluent effectively. Many local ordinances
require that this material be of a certain thickness.
SEWAGE LAGOONS are shallow ponds constructed to hold sewage while aerobic bacteria decompose the solid and liquid
wastes. Lagoons should have a nearly level floor surrounded by cut slopes or embankments of compacted soil. Lagoons
generally are designed to hold the sewage within a depth of 2 to 5 feet. Nearly impervious soil material for the lagoon
floor and sides is required to minimize seepage and contamination of ground water. This report gives ratings for
the natural soil that makes up the lagoon floor. The surface layer and, generally, 1 or 2 feet of soil material
below the surface layer are excavated to provide material for the embankments. The ratings are based on soil
properties, site features, and observed performance of the soils. Considered in the ratings are slope, permeability, a
high water table, depth to bedrock or to a cemented pan, flooding, large stones, and content of organic matter.
Excessive seepage due to rapid permeability of the soil or a water table that is high enough to raise the level of sewage
in the lagoon causes a lagoon to function unsatisfactorily. Pollution results if seepage is excessive or if floodwater
overtops the lagoon. A high content of organic matter is detrimental to proper functioning of the lagoon because it
inhibits aerobic activity. Slope, bedrock, and cemented pans can cause construction problems, and large stones can
hinder compaction of the lagoon floor,
SANITARY LANDFILLS are areas where solid waste is disposed of by burying it in soil. There are two types of landfill,
trench and area. In a trench landfill, the waste is placed in a trench. It is spread, compacted, and covered daily
with a thin layer of soil excavated at the site. In an area landfill, the waste is placed in successive layers on the
surface of the soil. The waste is spread, compacted, and covered daily with a thin layer of soil form a source away
from the site. Both types of landfill must be able to bear heavy vehicular traffic. Both types involve a risk of
groundwater pollution. Ease of excavation and revegetation need to be considered. The ratings in this report are based
O
U.S. DEPARTMENT OF AGRICULTURE PAGE 3 OF 3
NATURAL RESOURCES CONSERVATION SERVICE 03/29/99
' O•
SANITARY FACILITIES
End,�te -- SANITARY FACILITIES--Continued
on so l properties, site features, and observed performance of the soils. Permeability, depth to bedrock or to a
cemented pan, a high water table, slope, and flooding affect both types of landfill. Texture, stones and boulders,
highly organic layers, soil reaction, and content of salts and sodium affect trench type landfills. Unless otherwise
stated, the ratings apply only to that part of the soil within a depth of about 6 feet. For deeper trenches, a
limitation rate "Slight" or "Moderate" may not be valid. Onsite investigation is needed.
DAILY COVER FOR LANDFILL is the soil material that is used to cover compacted solid waste in an area type sanitary
landfill. The soil material is obtained offsite, transported to the landfill, and spread over the waste.
Soil texture, wetness, coarse fragments, and slope affect the ease of removing and spreading the material during wet
and dry periods. Loamy or silty soils that are free of large stones or excess gravel are the best cover for a
landfill. Clayey soils may be sticky or cloddy and are difficult to spread; sandy soils are subject to soil
blowing. After soil material has been removed, the soil material remaining in the borrow area must be thick enough
over bedrock, a cemented pan, or the water table to permit revegetation. The soil material used as final cover for a
landfill should be suitable for plants. The surface layer generally has the best workability, more organic matter than
the rest of the profile, and the best potential for plants. Material from the surface layer should be stockpiled for use
as the final cover.
IrElfieWEgFebRit§VAMA SERVICE PAGE 63Qf9/9R
BUILDING SITE DEVELOPMENT
William Ward
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