HomeMy WebLinkAboutWPO201900015 Erosion and Sediment Control Narrative 2019-08-09 EROSION AND SEDIMENT CONTROL NARRATIVE
FOR
TIMBERWOOD SQUARE
August 9th, 2019
LOCATION:
Tax Map 46B, Parcels 7, 7A, 7B, and 7C
Rivanna District, Albemarle County, Virginia
EALTy(:,
OWNER / DEVELOPER: o4`; cl
Highlife Townhouse, LLC v DAVID ROBINSON
PO Box 17 Charlottesville, VA 22902 )Lic.No.S
ujo
/60Z
PREPARED BY:
Dominion Engineering and Design, LLC
172 South Pantops Drive
Charlottesville, VA 22903
P: 434.979.8121
F: 434.979.1681
A. MINIMUM STANDARDS (MS):
All applicable Virginia Erosion and Sediment Control Regulations and Minimum Standards
shall be adhered to during all phases of construction. These include, but are not limited to
the following:
1. Permanent or temporary soil stabilization shall be applied to denuded areas within seven
days after final grade is reached on any portion of the site. Temporary soil stabilization shall
be applied within seven days to denuded areas that may not be at final grade but will remain
dormant for longer than 14 days. Permanent stabilization shall be applied to areas that are to
be left dormant for more than one year.
2. During construction of the project, soil stock piles and borrow areas shall be stabilized or
protected with sediment trapping measures. The applicant is responsible for the temporary
protection and permanent stabilization of all soil stockpiles on site as well as borrow areas
and soil intentionally transported from the project site.
3. A permanent vegetative cover shall be established on denuded areas not otherwise
permanently stabilized. Permanent vegetation shall not be considered established until a
ground cover is achieved that is uniform, mature enough to survive and will inhibit erosion.
4. Sediment basins and traps, perimeter dikes, sediment barriers and other measures
intended to trap sediment shall be constructed as a first step in any land-disturbing activity
and shall be made functional before upslope land disturbance takes place.
5. Stabilization measures shall be applied to earthen structures such as dams, dikes and
diversions immediately after installation.
6. Sediment traps and sediment basins shall be designed and constructed based upon the
total drainage area to be served by the trap or basin.
a. The minimum storage capacity of a sediment trap shall be 134 cubic yards per acre of
drainage area and the trap shall only control drainage areas less than three acres.
b. Surface runoff from disturbed areas that is comprised of flow from drainage areas greater
than or equal to three acres shall be controlled by a sediment basin. The minimum storage
capacity of a sediment basin shall be 134 cubic yards per acre of drainage area. The outfall
system shall, at a minimum, maintain the structural integrity of the basin during a 25-year storm
of 24-hour duration. Runoff coefficients used in runoff calculations shall correspond to a bare
earth condition or those conditions expected to exist while the sediment basin is utilized.
7. Cut and fill slopes shall be designed and constructed in a manner that will minimize
erosion. Slopes that are found to be eroding excessively within one year of permanent
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stabilization shall be provided with additional slope stabilizing measures until the problem is
corrected.
8. Concentrated runoff shall not flow down cut or fill slopes unless contained within an
adequate temporary or permanent channel, flume or slope drain structure.
9. Whenever water seeps from a slope face, adequate drainage or other protection shall be
provided.
10. All storm sewer inlets that are made operable during construction shall be protected so
that sediment-laden water cannot enter the conveyance system without first being filtered or
otherwise treated to remove sediment.
11. Before newly constructed stormwater conveyance channels or pipes are made
operational, adequate outlet protection and any required temporary or permanent channel
lining shall be installed in both the conveyance channel and receiving channel.
12. When work in a live watercourse is performed, precautions shall be taken to minimize
encroachment, control sediment transport and stabilize the work area to the greatest extent
possible during construction. Nonerodible material shall be used for the construction of
causeways and cofferdams. Earthen fill may be used for these structures if armored by
nonerodible cover materials.
13. When a live watercourse must be crossed by construction vehicles more than twice in any
six-month period, a temporary vehicular stream crossing constructed of nonerodible material
shall be provided.
14. All applicable federal, state and local requirements pertaining to working in or crossing
live watercourses shall be met.
15. The bed and banks of a watercourse shall be stabilized immediately after work in the
watercourse is completed.
16. Underground utility lines shall be installed in accordance with the following standards in
addition to other applicable criteria:
a. No more than 500 linear feet of trench may be opened at one time.
b. Excavated material shall be placed on the uphill side of trenches.
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c. Effluent from dewatering operations shall be filtered or passed through an approved sediment
trapping device, or both, and discharged in a manner that does not adversely affect flowing
streams or off-site property.
d. Material used for backfilling trenches shall be properly compacted in order to minimize
erosion and promote stabilization.
e. Restabilization shall be accomplished in accordance with this chapter.
f. Applicable safety requirements shall be complied with.
17. Where construction vehicle access routes intersect paved or public roads, provisions shall
be made to minimize the transport of sediment by vehicular tracking onto the paved surface.
Where sediment is transported onto a paved or public road surface, the road surface shall be
cleaned thoroughly at the end of each day. Sediment shall be removed from the roads by
shoveling or sweeping and transported to a sediment control disposal area. Street washing
shall be allowed only after sediment is removed in this manner. This provision shall apply to
individual development lots as well as to larger land-disturbing activities.
18. All temporary erosion and sediment control measures shall be removed within 30 days
after final site stabilization or after the temporary measures are no longer needed, unless
otherwise authorized by the VESCP authority. Trapped sediment and the disturbed soil areas
resulting from the disposition of temporary measures shall be permanently stabilized to
prevent further erosion and sedimentation.
19. Properties and waterways downstream from development sites shall be protected from
sediment deposition, erosion and damage due to increases in volume, velocity and peak flow
rate of stormwater runoff for the stated frequency storm of 24-hour duration in accordance
with the following standards and criteria. Stream restoration and relocation projects that
incorporate natural channel design concepts are not man-made channels and shall be
exempt from any flow rate capacity and velocity requirements for natural or man-made
channels:
a. Concentrated stormwater runoff leaving a development site shall be discharged directly into
an adequate natural or man-made receiving channel, pipe or storm sewer system. For those
sites where runoff is discharged into a pipe or pipe system, downstream stability analyses at the
outfall of the pipe or pipe system shall be performed.
b. Adequacy of all channels and pipes shall be verified in the following manner:
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(1) The applicant shall demonstrate that the total drainage area to the point of analysis within
the channel is 100 times greater than the contributing drainage area of the project in question;
(2) (a) Natural channels shall be analyzed by the use of a two-year storm to verify that
stormwater will not overtop channel banks nor cause erosion of channel bed or banks.
(b) All previously constructed man-made channels shall be analyzed by the use of a 10-year
storm to verify that stormwater will not overtop its banks and by the use of a two-year storm to
demonstrate that stormwater will not cause erosion of channel bed or banks; and
(c) Pipes and storm sewer systems shall be analyzed by the use of a 10-year storm to verify
that stormwater will be contained within the pipe or system.
c. If existing natural receiving channels or previously constructed man-made channels or pipes
are not adequate, the applicant shall:
(1) Improve the channels to a condition where a 10-year storm will not overtop the banks and a
two-year storm will not cause erosion to the channel, the bed, or the banks;
(2) Improve the pipe or pipe system to a condition where the 10-year storm is contained within
the appurtenances;
(3) Develop a site design that will not cause the pre-development peak runoff rate from a two-
year storm to increase when runoff outfalls into a natural channel or will not cause the pre-
development peak runoff rate from a 10-year storm to increase when runoff outfalls into a man-
made channel; or
(4) Provide a combination of channel improvement, stormwater detention or other measures
which is satisfactory to the VESCP authority to prevent downstream erosion.
d. The applicant shall provide evidence of permission to make the improvements.
e. All hydrologic analyses shall be based on the existing watershed characteristics and the
ultimate development condition of the subject project.
f. If the applicant chooses an option that includes stormwater detention, he shall obtain approval
from the VESCP of a plan for maintenance of the detention facilities. The plan shall set forth the
maintenance requirements of the facility and the person responsible for performing the
maintenance.
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g. Outfall from a detention facility shall be discharged to a receiving channel, and energy
dissipators shall be placed at the outfall of all detention facilities as necessary to provide a
stabilized transition from the facility to the receiving channel.
h. All on-site channels must be verified to be adequate.
i. Increased volumes of sheet flows that may cause erosion or sedimentation on adjacent
property shall be diverted to a stable outlet, adequate channel, pipe or pipe system, or to a
detention facility.
j. In applying these stormwater management criteria, individual lots or parcels in a residential,
commercial or industrial development shall not be considered to be separate development
projects. Instead, the development, as a whole, shall be considered to be a single development
project. Hydrologic parameters that reflect the ultimate development condition shall be used in
all engineering calculations.
k. All measures used to protect properties and waterways shall be employed in a manner which
minimizes impacts on the physical, chemical and biological integrity of rivers, streams and other
waters of the state.
I. Any plan approved prior to July 1, 2014, that provides for stormwater management that
addresses any flow rate capacity and velocity requirements for natural or man-made channels
shall satisfy the flow rate capacity and velocity requirements for natural or man-made channels
if the practices are designed to (i) detain the water quality volume and to release it over 48
hours; (ii) detain and release over a 24-hour period the expected rainfall resulting from the one
year, 24-hour storm; and (iii) reduce the allowable peak flow rate resulting from the 1.5, 2, and
10-year, 24-hour storms to a level that is less than or equal to the peak flow rate from the site
assuming it was in a good forested condition, achieved through multiplication of the forested
peak flow rate by a reduction factor that is equal to the runoff volume from the site when it was
in a good forested condition divided by the runoff volume from the site in its proposed condition,
and shall be exempt from any flow rate capacity and velocity requirements for natural or man-
made channels as defined in any regulations promulgated pursuant to § 62.1-44.15:54 or 62.1-
44.15:65 of the Act.
m. For plans approved on and after July 1, 2014, the flow rate capacity and velocity
requirements of§ 62.1-44.15:52 A of the Act and this subsection shall be satisfied by
compliance with water quantity requirements in the Stormwater Management Act (§ 62.1-
44.15:24 et seq. of the Code of Virginia) and attendant regulations, unless such land-disturbing
activities (i) are in accordance with provisions for time limits on applicability of approved design
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criteria in 9VAC25-870-47 or grandfathering in 9VAC25-870-48 of the Virginia Stormwater
Management Program (VSMP) Regulation, in which case the flow rate capacity and velocity
requirements of§ 62.1-44.15:52 A of the Act shall apply, or (ii) are exempt pursuant to § 62.1-
44.15:34 C 7 of the Act.
n. Compliance with the water quantity minimum standards set out in 9VAC25-870-66 of the
Virginia Stormwater Management Program (VSMP) Regulation shall be deemed to satisfy the
requirements of this subdivision 19.
B1. PROJECT DESCRIPTION:
The purpose of this project is to construct 32 townhomes and an office building at the
intersection of Worth Crossing and Timberwood Boulevard. Parking and access will also
be constructed. Also included is the construction of public water, sanitary sewer main &
storm sewer. The total area to be disturbed by this project will be 4.19 acres. In the event
drainage areas change during construction, sediment control structures will be
reconstructed to adequately protect the new or anticipated drainage area per VESCL.
B2. EXISTING SITE CONDITIONS:
There is currently a medical office building and parking /access on parcel 7C, the site is
otherwise vacant.
B3. ADJACENT AREAS:
The site is bounded to the North by Worth Crossing, to the West by Timberwood Blvd., to
the East by a VEPCO Substation, and to the South by clubhouse facilities /open space
for Forest Lakes Community Association and an existing stormwater management facility.
B4. SOIL DESCRIPTIONS:
See Soil Resource Report by the Natural Resources Conservation
Service (NRCS) attached to the Hydraulic/ Hydrologic calculations.
B5. CRITICAL AREAS:
There are limited critical slopes and no streams on this site. Refer to the Erosion and
Sediment Control Plan for more details.
B6. EROSION AND SEDIMENT CONTROL MEASURES:
Unless otherwise indicated, all erosion and sediment control practices will be constructed
and maintained according to the minimum standards and specifications as set forth in the
Virginia Erosion and Sediment Control Handbook, latest edition. The minimum standards
of the Virginia Erosion and Sediment Control Regulations shall be adhered to unless
otherwise waived or approved by variance.
TEMPORARY CONSTRUCTION ENTRANCE (CE) — 3.02
An asphalt pad shall be constructed at the entrance of the project site to provide a means
of removing sediment from the tires of construction vehicles leaving the work site. The
Contractor shall remove any mud from the existing road surface by means of sweeping
and shoveling, in the event the stone pad is not adequate in sediment removal.
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SILT FENCE (SF) — 3.05
Silt fencing will be installed as a first step in construction activities. Location and details
are shown on the plans.
STORM DRAIN INLET PROTECTION (IP) — 3.07
A sediment filter around storm drain inlet to prevent sediment from entering storm
drainage systems. Storm drain inlet protection will be installed according to Virginia
Erosion and Sediment Control regulations. Location and details are shown on the plans.
TEMPORARY DIVERSION DIKE (DD) — 3.09
A temporary diversion dike will be installed before site grading begins, for the purposes of
diverting storm and sediment-laden runoff to the appropriate outlet or trapping facility.
Location and details are shown on the plans.
TEMPORARY SEDIMENT TRAP (ST) — 3.13
A temporary sediment trap will be installed before site grading begins on Phase 3, for the
purpose of detaining sediment-laden runoff from disturbed areas. Location and details of
the sediment traps are shown on the plans.
TEMPORARY SEDIMENT BASINS (SB) — 3.14
A temporary sediment basin will be installed before site grading begins, for the purpose of
detaining sediment-laden runoff from disturbed areas. Location and details of the
sediment basin are shown on the plans.
DUST CONTROL (DC) — 3.39
A variety of methods are available to prevent surface and air movement of dust from
exposed soil surfaces and reduce the presence of airborne substances which may
present health hazards, traffic safety problems or harm animal or plant life.
B7. PERMANENT AND TEMPORARY STABILIZATION:
SURFACE ROUGHENING —3.29
Disturbed areas to be seeded and mulched shall be left in a roughened condition to help
decrease runoff velocities and aid in the establishment of vegetation.
TOPSOILING — 3.30
Topsoil may be stripped from the area to be graded and stockpiles for later use. All
stockpiles which will be left dormant for more than 30 days shall be temporarily seeded. A
topsoil stockpile may be selected onsite by the developer and shall be temporarily
protected with surrounding silt fencing.
TEMPORARY SEEDING — 3.31
Temporary soil stabilization shall be applied within 7 days to denuded areas that may not
be at final grade, but will remain dormant (undisturbed) for longer than 30 days and less
than 1 year. This includes, but is not limited to areas such as soil stockpiles. Seeded
areas shall be limed when necessary at a rate of 2 tons per acre, and fertilized at a rate of
450 lbs. per acre of 10-20-20 (10 lbs. per 1,000 square feet) or equivalent. A Temporary
Seeding Schedule is attached for proper seed selection.
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PERMANENT SEEDING — 3.32
A perennial vegetative covering shall be established on disturbed areas within 7 days of
being brought to final grade on areas not otherwise protected. Selection of the seed
mixture shall depend on the time of year it is to be applied according to the Permanent
Seed Schedule as shown on the drawing. Seeded areas shall be limed when necessary
at a rate of 2 tons per acres, and fertilized at a rate of 1,000 lbs. per acre of 10-20-10 (10
lbs. per 1,000 square feet) or equivalent.
MULCHING — 3.35
All seeded areas shall be mulched with straw immediately following seeding operations.
Straw mulch shall be applied at a rate of two tons per acre.
SOIL STABILIZATION BLANKETS AND MATTING — 3.36
Soil stabilization matting shall be applied in the conveyance areas of the designed
diversions to help reduce velocities and aid in the establishment of vegetation. A detail
showing the proper materials and installation is shown on the plan.
B8. SOIL STOCKPILES AND BORROW AREAS
A designated area for soil stockpiling and staging has been provided.
B9. OFF-SITE AREAS:
There will not be a need for borrow material. Excess material will be stored in a soil stock
pile for future use.
B10. STORM WATER MANAGEMENT:
This project will use grandfathering from the approved plan SDP201100042 dated 11/4/11.
See sheet 8 of the VSMP for details. An existing wet pond facility known as "Arbor Lake"
will provide stormwater quantity while an onsite biofilter will reduce the phosphorous load
and water quantity due to an increase in impervious area from the approved plan.
B11. MAINTENANCE SCHEDULE:
A program of maintenance for the erosion and sediment controls specified in this narrative
and shown on the plans are recommended as follows:
1. The Site Superintendent or his representative shall make a visual inspection of all
erosion and sediment controls on a daily basis until the site is stabilized and especially
after a heavy rainfall to assure that all controls are in place and that none have been
damaged. Any damaged control shall be repaired prior to the end of each workday to
include re-seeding if necessary.
2. All silt trapping devices shall be cleaned out at 50 percent capacity and sediment shall
be disposed of by spreading on site.
3. Gravel outlets shall be checked regularly for sediment buildup that may prevent
drainage. Controls shall be inspected and repaired after each rainfall and cleaned if
sediment has accumulated to half of the device's original height.
4. All earthen structures such as diversion dikes and berms shall be checked daily during
construction for breaching by equipment. Repairs shall be made immediately.
5. Silt fences shall be checked after each rainstorm to assure they have not fallen or
become clogged with silt. All repairs shall be made immediately.
6. All seeded areas shall be inspected regularly to see that good stand is maintained.
Areas will be re-fertilized and re-seeded as necessary.
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7. After construction operations have ended and disturbed areas have been stabilized, all
berms and sediment-trapping devices may be removed, after removal the ground shall
be restored to its natural or proposed condition to include establishment of permanent
vegetation. Removal of any control is contingent upon approval of the County
Inspector.
CONSTRUCTION SEQUENCE
1. CONSTRUCTION ENTRANCE WILL BE CONSTRUCTED AS SHOWN.
2. PROVIDE INLET PROTECTION FOR EX6, EX5A, EX5, EX4A, EX4.
3. INSTALL DOUBLE TURBIDITY CURTAIN.
4. INSTALL SUPER SILT FENCE.
5. INSTALL SEDIMENT BASIN AND DIVERSION WILL BE INSTALLED AS INDICATED
6. INSTALL STORM SEWER PIPE FROM EXISTING DI-2 "EX4" TO PROPOSED
STRUCTURE 1. INLETS TOPS 2 AND 3 SHALL BE BLOCKED UNTIL THE SITE IS
STABILIZED. SPLITTER STRUCTURE 1A TO BIOFILTER SHALL BE PLUGGED UNTIL
SITE IS STABILIZED.
7. EXISTING 54" STORMPIPE INLETS EX2 AND EX7 WILL BE BLOCKED WITH INLET
PROTECTION INITIALLY. THERE WILL BE NO NEED FOR INLET PROTECTION ONCE
NEW TOP ELEVATION. BOTH STRUCTURES WILL HAVE MH-1 TOPS.
8. INSTALL INLET PROTECTION FOR STRUCTURES 5A, 6, 6A, 8, 9, 10, 11, 12, 13, 14, 1.
CULVERT INLET PROTECTION FOR 2A.
9. THE GRADING, ROAD/PARKING. AND UTILITIES WILL BE CONSTRUCTED.
10. DUST CONTROL MEASURES AND PERMANENT SEEDING ALONG THE GRADED
AREAS OF THE SITE SHALL OCCUR WHERE INDICATED.
11. SEDIMENT BASIN 1 WILL BE REMOVED ONCE THE COUNTY INSPECTOR APPROVES
UPLAND STABILIZATION AND THE REMAINING SITE WORK FOR LOTS 25-32 SHALL
TAKE PLACE.
12. INSTALL STORM 1A TO 1 B WITH EW-1. KEEP STRUCTURE 1A PLUGGED UNTIL THE
SITE IS STABILIZED.
13. INSTALL SEDIMENT TRAP AS INDICATED ON SHEET 6.
14. AFTER ALBEMARLE COUNTY E&SC INSPECTOR CONFIRMS SITE STABILIZATION
CONVERT SEDIMENT TRAP TO BIOFILTER AND UNPLUG STRUCTURE 1A TO 1B.
9
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January 17, 2019
Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information
about the properties of the soils in the survey areas. Soil surveys are designed for
many different users, including farmers, ranchers, foresters, agronomists, urban
planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste
disposal, and pollution control can use the surveys to help them understand,
protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil
properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of
soil limitations on various land uses. The landowner or user is responsible for
identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some
cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/
portal/nrcs/main/soils/health/) and certain conservation and engineering
applications. For more detailed information, contact your local USDA Service Center
(https://offices.sc.egov.usda.gov/locator/app?agency=nrcs)or your NRCS State Soil
Scientist (http://www.nres.usda.gov/wps/portal/nres/detail/soils/contactus/?
cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as
septic tank absorption fields. A high water table makes a soil poorly suited to
basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States
Department of Agriculture and other Federal agencies, State agencies including the
Agricultural Experiment Stations, and local agencies. The Natural Resources
Conservation Service (NRCS) has leadership for the Federal part of the National
Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, age, disability,
and where applicable, sex, marital status, familial status, parental status, religion,
sexual orientation, genetic information, political beliefs, reprisal, or because all or a
part of an individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities who require
2
alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write to USDA, Director, Office of
Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or
call (800) 795-3272 (voice)or(202) 720-6382 (TDD). USDA is an equal opportunity
provider and employer.
3
Contents
Preface 2
How Soil Surveys Are Made 5
Soil Map 8
Soil Map 9
Legend 10
Map Unit Legend 11
Map Unit Descriptions 11
Albemarle County, Virginia 13
27B—Elioak loam, 2 to 7 percent slopes 13
28C3—Elioak clay loam, 7 to 15 percent slopes, severely eroded 14
34C—Glenelg loam, 7 to 15 percent slopes 15
34D—Glenelg loam, 15 to 25 percent slopes 16
88—Udorthents, loamy 17
W—Water 17
References 19
4
How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous
areas in a specific area. They include a description of the soils and miscellaneous
areas and their location on the landscape and tables that show soil properties and
limitations affecting various uses. Soil scientists observed the steepness, length,
and shape of the slopes; the general pattern of drainage; the kinds of crops and
native plants; and the kinds of bedrock. They observed and described many soil
profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The
profile extends from the surface down into the unconsolidated material in which the
soil formed or from the surface down to bedrock. The unconsolidated material is
devoid of roots and other living organisms and has not been changed by other
biological activity.
Currently, soils are mapped according to the boundaries of major land resource
areas (MLRAs). MLRAs are geographically associated land resource units that
share common characteristics related to physiography, geology, climate, water
resources, soils, biological resources, and land uses (USDA, 2006). Soil survey
areas typically consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that
is related to the geology, landforms, relief, climate, and natural vegetation of the
area. Each kind of soil and miscellaneous area is associated with a particular kind
of landform or with a segment of the landform. By observing the soils and
miscellaneous areas in the survey area and relating their position to specific
segments of the landform, a soil scientist develops a concept, or model, of how they
were formed. Thus, during mapping, this model enables the soil scientist to predict
with a considerable degree of accuracy the kind of soil or miscellaneous area at a
specific location on the landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented
by an understanding of the soil-vegetation-landscape relationship, are sufficient to
verify predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fragments, distribution of plant roots, reaction, and other features that enable them
to identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character
of soil properties and the arrangement of horizons within the profile. After the soil
5
Custom Soil Resource Report
scientists classified and named the soils in the survey area, they compared the
individual soils with similar soils in the same taxonomic class in other areas so that
they could confirm data and assemble additional data based on experience and
research.
The objective of soil mapping is not to delineate pure map unit components; the
objective is to separate the landscape into landforms or landform segments that
have similar use and management requirements. Each map unit is defined by a
unique combination of soil components and/or miscellaneous areas in predictable
proportions. Some components may be highly contrasting to the other components
of the map unit. The presence of minor components in a map unit in no way
diminishes the usefulness or accuracy of the data. The delineation of such
landforms and landform segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, onsite
investigation is needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of
mapping, intensity of mapping, design of map units, complexity of the landscape,
and experience of the soil scientist. Observations are made to test and refine the
soil-landscape model and predictions and to verify the classification of the soils at
specific locations. Once the soil-landscape model is refined, a significantly smaller
number of measurements of individual soil properties are made and recorded.
These measurements may include field measurements, such as those for color,
depth to bedrock, and texture, and laboratory measurements, such as those for
content of sand, silt, clay, salt, and other components. Properties of each soil
typically vary from one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of
characteristics for the components. The aggregated values are presented. Direct
measurements do not exist for every property presented for every map unit
component. Values for some properties are estimated from combinations of other
properties.
While a soil survey is in progress, samples of some of the soils in the area generally
are collected for laboratory analyses and for engineering tests. Soil scientists
interpret the data from these analyses and tests as well as the field-observed
characteristics and the soil properties to determine the expected behavior of the
soils under different uses. Interpretations for all of the soils are field tested through
observation of the soils in different uses and under different levels of management.
Some interpretations are modified to fit local conditions, and some new
interpretations are developed to meet local needs. Data are assembled from other
sources, such as research information, production records, and field experience of
specialists. For example, data on crop yields under defined levels of management
are assembled from farm records and from field or plot experiments on the same
kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on
such variables as climate and biological activity. Soil conditions are predictable over
long periods of time, but they are not predictable from year to year. For example,
soil scientists can predict with a fairly high degree of accuracy that a given soil will
have a high water table within certain depths in most years, but they cannot predict
that a high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the
survey area, they drew the boundaries of these bodies on aerial photographs and
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Custom Soil Resource Report
identified each as a specific map unit. Aerial photographs show trees, buildings,
fields, roads, and rivers, all of which help in locating boundaries accurately.
7
Soil Map
The soil map section includes the soil map for the defined area of interest, a list of
soil map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
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Custom Soil Resource Report
Soil Map
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3
F. bi
Map Scale:1:2,120 if printed on A landscape(11"x 8.5")sheet
W 120 Meters
N
• --,Feet
0 160 200 400 600
Map projection:Web Mercator Corner coordinates:WGS84 Edge tics:r,1T 1 Zone 17N WGS84
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Custom Soil Resource Report
MAP LEGEND MAP INFORMATION
Area of Interest(AOI) ti4 Spoil Area The soil surveys that comprise your AOI were mapped at
Area of Interest(AOI) 1:15,800.
Stony Spot
Soilsal Very Stony Spot
Soil Map Unit Polygons Warning:Soil Map may not be valid at this scale.
u Wet Spot
.�r Soil Map Unit Lines Enlargement of maps beyond the scale of mapping can cause
Other misunderstandingof the detail of mapping and accuracyof soil
• Soil Map Unit Points pp g
Special Line Features line placement.The maps do not show the small areas of
Special Point Features contrasting soils that could have been shown at a more detailed
V Blowout Water Features scale.
Streams and Canals
Ei Borrow Pit
Transportation Please rely on the bar scale on each map sheet for map
• Clay Spot ++4 Rails measurements.
Closed Depression n/ Interstate Highways
• Gravel Pit Source of Map: Natural Resources Conservation Service
US Routes Web Soil Survey URL:
Gravelly Spot Coordinate System: Web Mercator(EPSG:3857)
Major Roads
at Landfill Local Roads Maps from the Web Soil Survey are based on the Web Mercator
k Lava Flow Background projection,which preserves direction and shape but distorts
distance and area.A projection that preserves area,such as the
ilito Marsh or swamp . Aerial Photography Albers equal-area conic projection,should be used if more
Mine or Quarry accurate calculations of distance or area are required.
• Miscellaneous Water This product is generated from the USDA-NRCS certified data as
0 Perennial Water of the version date(s)listed below.
Rock Outcrop Soil Survey Area: Albemarle County,Virginia
+ Saline Spot Survey Area Data: Version 12,Aug 29,2018
Sandy Spot Soil map units are labeled(as space allows)for map scales
Severely Eroded Spot 1:50,000 or larger.
Sinkhole Date(s)aerial images were photographed: Apr 22,2015—Mar
Slide or Slip 10,2017
oe Sodic Spot The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps.As a result,some minor
shifting of map unit boundaries may be evident.
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Custom Soil Resource Report
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AO1
27B Elioak loam,2 to 7 percent 2.8 14.4%
slopes
28C3 Elioak clay loam,7 to 15 7.7 40.0%
percent slopes,severely
eroded
34C Glenelg loam,7 to 15 percent 1.0 5.2%
slopes
34D Glenelg loam, 15 to 25 percent 0.4 2.0%
slopes
88 f Udorthents,loamy 2.9 14.9%
W Water 4.5 23.6%
Totals for Area of Interest 19.3 100.0%
Map Unit Descriptions
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, along
with the maps, can be used to determine the composition and properties of a unit.
A 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.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
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Custom Soil Resource Report
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
pure taxonomic classes but rather to separate the landscape into landforms or
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, however,
onsite investigation is needed to define and locate the soils and miscellaneous
areas.
An identifying symbol precedes the map unit name in the map unit descriptions.
Each description includes general facts about the unit and gives important soil
properties and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major
horizons that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness,
salinity, degree of erosion, and other characteristics that affect their use. On the
basis of such differences, a soil series is divided into soil phases. Most of the areas
shown on the detailed soil maps are phases of soil series. The name of a soil phase
commonly indicates a feature that affects use or management. For example, Alpha
silt loam, 0 to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps.
The pattern and proportion of the soils or miscellaneous areas are somewhat similar
in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present
or anticipated uses of the map units in the survey area, it was not considered
practical or necessary to map the soils or miscellaneous areas separately. The
pattern and relative proportion of the soils or miscellaneous areas are somewhat
similar. Alpha-Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas
that could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion
of the soils or miscellaneous areas in a mapped area are not uniform. An area can
be made up of only one of the major soils or miscellaneous areas, or it can be made
up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil
material and support little or no vegetation. Rock outcrop is an example.
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Custom Soil Resource Report
Albemarle County, Virginia
27B—Elioak loam, 2 to 7 percent slopes
Map Unit Setting
National map unit symbol: kb8y
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost-free period: 195 to 231 days
Farmland classification: All areas are prime farmland
Map Unit Composition
Elioak and similar soils: 80 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Elioak
Setting
Landform: Hillslopes
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down-slope shape: Convex
Across-slope shape: Convex
Parent material: Residuum weathered from mica schist
Typical profile
H1 - 0 to 8 inches: loam
H2- 8 to 39 inches: silty clay
H3-39 to 79 inches: silt loam
Properties and qualities
Slope: 2 to 7 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water(Ksat): Moderately high to
high (0.20 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Moderate (about 6.6 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: B
Hydric soil rating: No
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Custom Soil Resource Report
28C3—Elioak clay loam, 7 to 15 percent slopes, severely eroded
Map Unit Setting
National map unit symbol: kb91
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost-free period: 195 to 231 days
Farmland classification: Not prime farmland
Map Unit Composition
Elioak and similar soils: 80 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Elioak
Setting
Landform: Hillslopes
Landform position (two-dimensional): Summit
• Landform position (three-dimensional): Interfluve
Down-slope shape: Convex
Across-slope shape: Convex
Parent material: Residuum weathered from mica schist
Typical profile
H1 - 0 to 8 inches: clay loam
H2- 8 to 39 inches: silty clay
H3- 39 to 79 inches: silt loam
Properties and qualities
Slope: 7 to 15 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water(Ksat): Moderately high to
high (0.20 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Low (about 6.0 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: B
Hydric soil rating: No
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Custom Soil Resource Report
34C—Glenelg loam, 7 to 15 percent slopes
Map Unit Setting
National map unit symbol: kb91
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost-free period: 195 to 231 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Glenelg and similar soils: 85 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Glenelg
Setting
Landform: Hillslopes
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down-slope shape: Convex
Across-slope shape: Convex
Parent material: Residuum weathered from mica schist
Typical profile
H1 - 0 to 8 inches: loam
H2-8 to 28 inches: silty clay loam
H3- 28 to 80 inches: loam
Properties and qualities
Slope: 7 to 15 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water(Ksat): Moderately high to
high (0.57 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
• Frequency of ponding: None
Available water storage in profile: High (about 9.7 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: B
Hydric soil rating: No
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Custom Soil Resource Report
34D—Glenelg loam, 15 to 25 percent slopes
Map Unit Setting
National map unit symbol: 2w061
Elevation: 30 to 1,200 feet
Mean annual precipitation: 34 to 46 inches
Mean annual air temperature: 43 to 66 degrees F
Frost-free period: 174 to 211 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Glenelg and similar soils: 90 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Glenelg
Setting
Landform: Hillslopes
Landform position (two-dimensional): Backslope, shoulder
Landform position (three-dimensional): Side slope
Down-slope shape: Convex
Across-slope shape: Convex
Parent material: Residuum weathered from mica schist
Typical profile
Ap-0 to 6 inches: loam
Bt- 6 to 23 inches: loam
C- 23 to 65 inches: loam
Properties and qualities
Slope: 15 to 25 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: High
Capacity of the most limiting layer to transmit water(Ksat): Moderately high to
high (0.57 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Very high (about 13.5 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: B
Hydric soil rating: No
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Custom Soil Resource Report
88—Udorthents, loamy
Map Unit Setting
National map unit symbol: kbfy
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost-free period: 195 to 231 days
Farmland classification: Not prime farmland
Map Unit Composition
Udorthents and similar soils: 85 percent
Minor components: 3 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Udorthents
Setting
Landform: Interfluves
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down-slope shape: Convex
Across-slope shape: Convex
Parent material: Residuum weathered from granite and gneiss
Properties and qualities
Slope: 2 to 25 percent
Depth to restrictive feature: More than 80 inches
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Minor Components
Wehadkee
Percent of map unit: 3 percent
Landform: Flood plains
Down-slope shape: Linear
Across-slope shape: Linear
Hydric soil rating: Yes
W—Water
Map Unit Setting
National map unit symbol: kbgk
Mean annual precipitation: 25 to 65 inches
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Custom Soil Resource Report
Mean annual air temperature: 54 to 59 degrees F
Frost-free period: 195 to 231 days
Farmland classification: Not prime farmland
Map Unit Composition
Water: 100 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
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•
•
References
American Association of State Highway and Transportation Officials (AASHTO).
2004. Standard specifications for transportation materials and methods of sampling
and testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of
soils for engineering purposes. ASTM Standard D2487-00.
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. July 13, 1994. Changes in hydric soils of the United States.
Federal Register. September 18, 2002. 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. http://www.nrcs.usda.gov/wps/portal/
nres/detail/national/soils/?cid=nres142p2_054262
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. http://
www.nres.usda.gov/wps/portal/nres/detail/national/soils/?cid=nres142p2_053577
Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of
Agriculture, Natural Resources Conservation Service. http://
www.nres.usda.gov/wps/portal/nres/detail/national/soils/?cid=nres142p2_053580
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.
United States Department of Agriculture, Natural Resources Conservation Service.
National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/
home/?cid=nres142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.
National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/
detail/national/landuse/rangepasture/?cid=stelprdb1043084
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Custom Soil Resource Report
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/
nres/detail/soils/scientists/?cid=nres142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service.
2006. Land resource regions and major land resource areas of the United States,
the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook
296. http://www.nres.usda.gov/wps/portal/nres/detail/national/soils/?
cid=nres142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land
capability classification. U.S. Department of Agriculture Handbook 210. http://
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf
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