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Map Unit Description (Brief, Generated)
Weld County,Colorado,Northern Part
[Minor map unit components are excluded from this report]
Map unit: 31 -Kim-Mitchell complex,0 to 6 percent slopes
Component: Kim(45%)
The Kim component makes up 45 percent of the map unit. Slopes are 0 to 6 percent. This component is on plains,alluvial fans. The
parent material consists of calcareous loamy alluvium.Depth to a root restrictive layer is greater than 60 inches. The natural drainage
class is well drained. Water movement in the most restrictive layer is moderately high. Available water to a depth of 60 inches is high.
Shrink-swell potential is low. This soil is not flooded.It is not ponded. There is no zone of water saturation within a depth of 72 inches.
Organic matter content in the surface horizon is about 1 percent This component is in the R067BY002CO Loamy(formerly Loamy
Plains)ecological site.Nonirrigated land capability classification is 4e.Irrigated land capability classification is 4e. This soil does not
meet hydric criteria. The calcium carbonate equivalent within 40 inches, typically,does not exceed 10 percent
Component: Mitchell(40%)
The Mitchell component makes up 40 percent of the map unit.Slopes are 0 to 6 percent This component is on plains,alluvial fans. The
parent material consists of calcareous loamy alluvium.Depth to a root restrictive layer is greater than 60 inches. The natural drainage
class is well drained. Water movement in the most restrictive layer is moderately high. Available water to a depth of 60 inches is high.
Shrink-swell potential is low. This soil is not flooded.It is not ponded. There is no zone of water saturation within a depth of 72 inches.
Organic matter content in the surface horizon is about 1 percent This component is in the R067BY009CO Siltstone Plains ecological
site.Nonirrigated land capability classification is 4e. Irrigated land capability classification is 4e. This soil does not meet hydric criteria.
The calcium carbonate equivalent within 40 inches, typically,does not exceed 13 percent
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EXHIBIT
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USDA Natural Resources
Tabular Data Version:6
aConservation Service Tabular Data Version Date:02/11/2008 2009-2546
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Map Unit Description (Brief, Generated)
The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area.The map unit
descriptions in this report,along with the maps,can be used to determine the composition and properties of a unit.
map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas.A map unit is identified
and named according to the taxonomic classification of the dominant soils.Within a taxonomic class there are precisely defined limits for the properties
of the soils.On the landscape,however,the soils are natural phenomena,and they have the characteristic variability of all natural phenomena.Thus,
the range of some observed properties may extend beyond the limits defined for a taxonomic class.Areas of soils of a single taxonomic class rarely,if
ever,can be mapped without including areas of other taxonomic classes.Consequently,every map unit is made up of the soils or miscellaneous areas
for which it is named and some minor components that belong to taxonomic classes other than those of the major soils.
The Map Unit Description(Brief,Generated)report displays a generated description of the major soils that occur in a map unit. Descriptions of non-soil
(miscellaneous areas)and minor map unit components are not included. This description is generated from the underlying soil attribute data.
Additional information about the map units described in this report is available in other Soil Data Mart reports,which give properties of the soils and the
limitations,capabilities,and potentials for many uses. Also,the narratives that accompany the Soil Data Mart reports define some of the properties
included in the map unit descriptions.
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Tabular Data Version:6
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Hydric Soils
Weld County,Colorado,Northern Part
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Percent
Map symbol and Hydric Hydric
map unit name Component of map Landform rating criteria
unit
31:
Kim-Mitchell complex,0 to 6 percent Aquic Haplustolls 1 Swales Yes 3
slopes
Explanation of hydric criteria codes:
1. All Histels except for Folistels,and Histosols except for Folists.
2. Soils in Aquic suborders,great groups,or subgroups,Albolls suborder,Historthels great group,
Histoturbels great group,Pachic subgroups,or Cumulic subgroups that:
A.are somewhat poorly drained and have a water table at the surface(0.0 feet)
during the growing season,or
B.are poorly drained or very poorly drained and have either:
1.)a water table at the surface(0.0 feet)during the growing season if textures are
coarse sand,sand,or fine sand in all layers within a depth of 20 inches,or
2.)a water table at a depth of 0.5 foot or less during the growing season if permeability
is equal to or greater than 6.0 in/hr in all layers within a depth of 20 inches,or
3.)a water table at a depth of 1.0 foot or less during the growing season if permeability
is less than 6.0 in/hr in any layer within a depth of 20 inches.
3. Soils that are frequently ponded for long or very long duration during the growing season.
4. Soils that are frequently flooded for long or very long duration during the growing season.
iiiThis table lists the map unit components that are rated as hydric soils in the survey area.This list can help in planning land uses;however,onsite
kvestigation is recommended to determine the hydric soils on a specific site(National Research Council,1995;Hurt and Vasilas,2006).
The three essential characteristics of wetlands are hydrophytic vegetation,hydric soils,and wetland hydrology(Cowardin and others, 1979;U.S.
Army Corps of Engineers, 1987;National Research Council,1995;Tiner,1985).Criteria for all of the characteristics must be met for areas to be
identified as wetlands.Undrained hydric soils that have natural vegetation should support a dominant population of ecological wetland plant species.
Hydric soils that have been converted to other uses should be capable of being restored to wetlands.
Hydric soils are defined by the National Technical Committee for Hydric Soils(NTCHS)as soils that formed under conditions of saturation,flooding,
or ponding long enough during the growing season to develop anaerobic conditions in the upper part(Federal Register,1994).These soils,under
natural conditions,are either saturated or inundated long enough during the growing season to support the growth and reproduction of hydrophytic
vegetation.
The NTCHS definition identifies general soil properties that are associated with wetness.In order to determine whether a specific soil is a hydric soil
or nonhydric soil,however,more specific information,such as information about the depth and duration of the water table,is needed.Thus,criteria that
identify those estimated soil properties unique to hydric soils have been established(Federal Register,2002).These criteria are used to identify map
unit components that normally are associated with wetlands.The criteria used are selected estimated soil properties that are described in"Soil
Taxonomy"(Soil Survey Staff, 1999)and"Keys to Soil Taxonomy"(Soil Survey Staff,2006)and in the"Soil Survey Manual"(Soil Survey Division Staff,
1993).
If soils are wet enough for a long enough period of time to be considered hydric,they should exhibit certain properties that can be easily observed in
the field.These visible properties are indicators of hydric soils.The indicators used to make onsite determinations of hydric soils are specified in"Field
Indicators of Hydric Soils in the United States"(Hurt and Vasilas,2006).
Hydric soils are identified by examining and describing the soil to a depth of about 20 inches.This depth may be greater if determination of an
appropriate indicator so requires. It is always recommended that soils be excavated and described to the depth necessary for an understanding of the
redoximorphic processes.Then,using the completed soil descriptions,soil scientists can compare the soil features required by each indicator and
specify which indicators have been matched with the conditions observed in the soil.The soil can be identified as a hydric soil if at least one of the
approved indicators is present.
Map units that are dominantly made up of hydric soils may have small areas,or inclusions,of nonhydric soils in the higher positions on the landform,
and map units dominantly made up of nonhydric soils may have inclusions of hydric soils in the lower positions on the landform.
The criteria for hydric soils are represented by codes in the table(for example,2B3).Definitions for the codes are as follows:
USA Natural Resources
Tabular Data Version:6
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Hydric Soils
1.All Histels except for Folistels,and Histosols except for Folists.
2.Soils in Aquic suborders,great groups,or subgroups,Albolls suborder,Historthels great group,Histoturbels great group,Pachic subgroups,or
ocumulic subgroups that:
A.are somewhat poorly drained and have a water table at the
surface(0.0 feet)during the growing season,or
B.are poorly drained or very poorly drained and have either:
1)a water table at the surface(0.0 feet)during the growing season
if textures are coarse sand,sand,or fine sand in all layers within a depth
of 20 inches,or
2)a water table at a depth of 0.5 foot or less during the growing season
if saturated hydraulic conductivity(Ksat)is equal to or greater than 6.0 in/hr
in all layers within a depth of 20 inches,or
3)a water table at a depth of 1.0 foot or less during the growing season if
saturated hydraulic conductivity(Ksat)is less than 6.0 in/hr in any layer
within a depth of 20 inches.
3.Soils that are frequently ponded for long or very long duration during the growing season.
4.Soils that are frequently flooded for long or very long duration during the growing season.
References:
Cowardin,L.M.,V.Carter,F.C.Golet,and E.T.LaRoe. 1979.Classification of wetlands and deep-water habitats of the United States.U.S.Fish and
Wildlife Service FWS/OBS-79/31.
Federal Register.September 18,2002.Hydric soils of the United States.
Federal Register.July 13,1994.Changes in hydric soils of the United States.
Hurt,G.W.,and L.M.Vasilas,editors.Version 6.0,2006.Field indicators of hydric soils in the United States.
National Research Council.1995.Wetlands:Characteristics and boundaries.
Soil Survey Division Staff. 1993.Soil survey manual.Soil Conservation Service.U.S.Department of Agriculture Handbook 18.
Soil Survey Staff.2006.Keys to soil taxonomy.10th edition.U.S.Department of Agriculture,Natural Resources Conservation Service.
Soil Survey Staff.1999.Soil taxonomy:A basic system of soil classification for making and interpreting soil surveys.2nd edition.Natural Resources
Conservation Service.U.S.Department of Agriculture Handbook 436.
Tiner,R'.W.,Jr. 1985.Wetlands of Delaware.U.S.Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental.
•Control,Wetlands Section.
United States Army Corps of Engineers,Environmental Laboratory.1987.Corps of Engineers wetlands delineation manual.Waterways Experiment
Station Technical Report Y-87-1.
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Chemical Soil Properties
Weld County,Colorado,Northern Part
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Cation- Effective Calcium Sodium
Map symbol cation-
Depth exchange Soil reaction carbon- Gypsum Salinity adsorption
and soil name exchange
capacity ate ratio
capacity
In meq/100 g meq/100 g pH Pct Pct mmhos/cm
31:
Kim 0-3 5.0-20 — 7.4-8.4 5-15 0 0.0 0
3-7 10-20 -- 7.4-8.4 5-15 0 0.0 0
7-60 5.0-15 — 7.4-8.4 5-15 0 0.0-4.0 0
Mitchell 0-7 5.0-15 --- 7.4-8.4 5-10 0 0.0 0
7-60 4.0-10 -- 7.4-8.4 10-15 0 0.0 0
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USDANatural Resources This report shows only the major soils in each map unit Others may exist.
Tabular Data Version:6
WConservation Service Tabular Data Version Date:02/11/2008 Page 1 of 2
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Chemical Soil Properties
This table shows estimates of some chemical characteristics and features that affect soil behavior.These estimates are given for the layers of each
soil in the survey area.The estimates are based on field observations and on test data for these and similar soils.
• "Depth"to the upper and lower boundaries of each layer is indicated.
"Cation-exchange capacity"is the total amount of extractable cations that can be held by the soil,expressed in terms of milliequivalents per 100
grams of soil at neutrality(pH 7.0)or at some other stated pH value.Soils having a low cation-exchange capacity hold fewer cations and may require
more frequent applications of fertilizer than soils having a high cation-exchange capacity.The ability to retain cations reduces the hazard of
ground-water pollution.
"Effective cafionexchange capacity"refers to the sum of extractable cations plus aluminum expressed in terms of milliequivalents per 100 grams of
soil.It is determined for soils that have pH of less than 5.5.
"Soil reaction"is a measure of acidity or alkalinity. It 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"equivalent is the percent of carbonates,by weight,in the fraction of the soil less than 2 millimeters in size.The availability of
plant nutrients is influenced by the amount of carbonates in the soil.
"Gypsum"is expressed as a percent,by weight,of hydrated calcium sulfates in the fraction of the soil less than 20 millimeters in size.Gypsum is
partially soluble in water.Soils that have a high content of gypsum may collapse if the gypsum is removed by percolating water.
"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 table.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)is a measure of the amount of sodium(Na)relative to calcium(Ca)and magnesium(Mg)in the water extract from
saturated soil paste.It is the ratio of the Na concentration divided by the square root of one-half of the Ca+Mg concentration.Soils that have SAR
values of 13 or more may be characterized by an increased dispersion of organic matter and clay particles,reduced saturated hydraulic conductivity
and aeration,and a general degradation of soil structure.
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USDANatural Resources This report shows only the major soils in each map unit Others may exist
Tabular Data Version:6
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Physical Soil Properties .
Weld County,Colorado,Northern Part
Erosion factors Wnd Wind
Saturated Available Linear
Map symbol Moist bulk Organic erodi- erodi-
and soil name Depth Sand Silt Clay density hydraulic water exlensi- matter bility bility
conductivity capacity bility Kw Kf T group index
In Pct Pct Pet g/cc micro m/sec In/In Pct Pct
31: •Kim 0-3 - - 15-27 1.25-1.40 4.00-42.00 0.14-0.18 0.0-2.9 0.5-1.0 .37 .37 5 4L 86
3-7 - - 20-35 1.25-1.40 1.41-4.23 0.16-0.20 0.0-2.9 0.5-1.0 .24 .24
7-60 - - 15-27 1.25-1.40 4.00-42.00 0.14-0.18 0.0-2.9 0.0-0.5 .43 .43
Mitchell 0-7 -- - 12-20 1.15-1.30 4.00-42.00 0.15-0.20 0.0-2.9 0.5-1.0 .43 .43 5 4L 86
7-60 - -- 10-18 1.15-1.30 14.11-42.33 0.15-0.20 0.0-2.9 0.5-1.0 .43 .43
USDANatural Resources This report shows only the major soils in each map unit Others may exist.
Tabular Data Version:6
Conservation Service Tabular Data Version Date:02/11/2008 Page 1 of 3
Physical Soil Properties
This table shows estimates of some physical characteristics and features that affect soil behavior.These estimates are given for the layers of each soil in the survey area.The estimates are based
on field observations and on test data for these and similar soils.
"Depth"to the upper and lower boundaries of each layer is indicated.
Particle size is the effective diameter of a soil particle as measured by sedimentation,sieving,or micrometric methods.Particle sizes are expressed as lasses with specific effective diameter class
limits.The broad classes are sand,silt,and day,ranging from the larger to the smaller.
"Sand"as a soil separate consists of mineral soil particles that are 0.05 millimeter to 2 millimeters in diameter.In this table,the estimated sand content of each soil layer is given as a percentage,
by weight,of the soil material that is less than 2 millimeters in diameter.
"Silt"as a soil separate consists of mineral soil particles that are 0.002 to 0.05 millimeter in diameter.In this table,the estimated silt content of each soil layer is given as a percentage,by weight,of
the soil material that is less than 2 millimeters in diameter.
"Clay"as a soil separate consists of mineral soil particles that are less than 0.002 millimeter in diameter.In this table,the estimated clay content of each soil layer is given as a percentage,by •
weight,of the soil material that is less than 2 millimeters in diameter.
The content of sand,silt,and clay affects the physical behavior of a soil.Particle size is important for engineering and agronomic interpretations,for determination of soil hydrologic qualities,and
for soil classification.
The amount and kind of clay affect the fertility and physical condition of the soil and the ability of the soil to adsorb cations and to retain moisture.They influence shrink-swell potential,saturated
hydraulic conductivity(Ksat),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,that is,the moisture content at 1/3-or 1/10-bar(33kPa or 1 okPa)
moisture tension.Weight is determined after the soil is dried at 105 degrees C.In the table,the estimated moist bulk density of each 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 linear extensibility,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.Depending on soil texture,a bulk density of more than 1.4 can restrict water storage and root penetration.Moist
bulk density is influenced by texture,kind of clay,content of organic matter,and soil structure.
"Saturated hydraulic conductivity(Ksat)"refers to the ease with which pores in a saturated soil transmit water.The estimates in the table are expressed in terms of micrometers per second.They
are based on soil characteristics observed in the field,particularly structure,porosity,and texture.Saturated hydraulic conductivity(Ksat)is considered in the design of soil drainage systems and
septic tank absorption fields.
"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 soil
layer.The capacity varies,depending on soil properties that affect retention of water.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. •
"Linear extensibility"refers to the change in length of an unconfined clod as moisture content is decreased from a moist to a dry state.It is an expression of the volume change between the water
content of the God at 1/3-or 1/10-bar tension(33kPa or 10kPa tension)and oven dryness.The volume change is reported in the table as percent change for the whole soil.The amount and type of
clay minerals in the soil influence volume change.
Linear extensibility is used to determine the shrink-swell potential of soils.The shrink-swell potential is low if the soil has a linear extensibility of less than 3 percent;moderate if 3 to 6 percent;high
if 6 to 9 percent;and very high if more than 9 percent.If the linear extensibility is more than 3,shrinking and swelling can cause damage to buildings,roads,and other structures and to plant roots.
Special design commonly is needed.
"Organic matter"is the plant and animal residue in the soil at various stages of decomposition.In this table,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 by returning crop residue to the soil.Organic matter has a positive effect on available water capacity,water infiltration,soil organism
activity,and filth.It is a source of nitrogen and other nutrients for crops and soil organisms.
USDANatural Resources This report shows only the major soils in each map unit.Others may exist.
Tabular Data Version:6
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Physical Soil Properties
"Erosion factors"are shown in the table as the K factor(Kw and Kt)and the T factor.Erosion factor K indicates the susceptibility of a soil to sheet and rill erosion by water.Factor K is one of six
factors used in the Universal Soil Loss Equation(USLE)and the Revised Universal Soil Loss Equation(RUSLE)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 and on soil structure and Ksat.Values of K range from 0.02 to 0.69.Other factors being equal,the higher
the value,the more susceptible the soil is to sheet and rill erosion by water.
"Erosion factor Kw"indicates the erodibility of the whole soil.The estimates are modified by the presence of rock fragments.
"Erosion factor Kf"indicates the erodibility of the fine-earth fraction,or the material less than 2 millimeters in size.
"Erosion factor T"is an estimate of the maximum average annual rate of soil erosion by wind and/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 susceptibility to wind erosion in cultivated areas.The soils assigned to group 1 are the most susceptible to
wind erosion,and those assigned to group 8 are the least susceptible.The groups are described in the"National Soil Survey Handbook." •
"Wind erodibility index"is a numerical value indicating the susceptibility of soil to wind erosion,or the tons per acre per year that can be expected to be lost to wind erosion.There is a close
correlation between wind erosion and the texture of the surface layer,the size and durability of surface Gods,rock fragments,organic matter,and a calcareous reaction.Soil moisture and frozen soil
layers also influence wind erosion.
Reference:
United States Department of Agriculture,Natural Resources Conservation Service.National soil survey handbook,title 430-VI.(http://www.soils.usda.gov)
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USDANatural Resources This report shows only the major soils in each map unit Others may east.
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Soil Features •
Weld County,Colorado, Northern Part
Restrictive layer Subsidence Potential Risk of corrosion
Map symbol for frost
and soil name Kind Depth to Thickness Hardness Initial Total action Uncoated Concrete
top steel
In In In In
31:
Kim — — — — 0 — Low High Low
Mitchell — — — — 0 — Low Moderate Low •
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USDANatural Resources This report shows only the major soils in each map unit Others may exist.
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Soil Features
This table gives estimates of various soil features.The estimates are used in land use planning that involves engineering considerations.
A"restrictive layer"is a nearly continuous layer that has one or more physical,chemical,or thermal properties that significantly impede the movement of water and air through the soil or that restrict
roots or otherwise provide an unfavorable root environment.Examples are bedrock,cemented layers,dense layers,and frozen layers.The table indicates the hardness and thickness of the restrictive
layer,both of which significantly affect the ease of excavation."Depth to top"is the vertical distance from the soil surface to the upper boundary of the restrictive layer.
"Subsidence"is the settlement of organic soils or of saturated mineral soils of very low density.Subsidence generally 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.The table shows the expected initial subsidence,which usually is a result of drainage,and total
subsidence,which results from a combination of factors.
"Potential for 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,saturated hydraulic conductivity(Ksat),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.Well drained,very gravelly,or very sandy soils are the least susceptible.
Frost heave and low soil strength during thawing cause damage to pavements and other rigid structures. •
"Risk of corrosion"pertains to potential soil-induced electrochemical or chemical action that corrodes 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 results in a severe hazard of corrosion.The steel or concrete in installations that
intersect soil boundaries or soil layers is more susceptible to corrosion than the steel or concrete 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 also is expressed as"low,"""moderate,"or"high."It is based on soil texture,acidity,and amount of sulfates in the saturation extract.
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USDANatural Resources This report shows only the major soils in each map unit Others may exist.
Tabular Data Version:6
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