HomeMy WebLinkAboutCity Council Packet 2025 07-08-25 - pzc#3 additional packet materialAttachment 1, Page 3
Attachment 1, Page 4
Attachment 1, Page 5
Attachment 1, Page 6
Attachment 1, Page 7
Attachment 1, Page 8
Attachment 1, Page 9
Attachment 1, Page 10
Attachment 1, Page 11
Attachment 1, Page 12
Attachment 1, Page 13
Attachment 1, Page 14
Attachment 1, Page 15
Attachment 1, Page 16
Attachment 1, Page 17
Attachment 1, Page 18
Attachment 1, Page 19
Attachment 1, Page 20
Attachment 1, Page 21
Attachment 1, Page 22
Attachment 1, Page 23
Attachment 1, Page 24
Attachment 1, Page 25
Attachment 1, Page 26
Attachment 1, Page 27
Attachment 1, Page 28
Attachment 1, Page 29
Attachment 1, Page 30
Attachment 1, Page 31
Attachment 1, Page 32
Attachment 1, Page 33
Attachment 1, Page 34
Attachment 1, Page 35
Attachment 1, Page 36
Attachment 1, Page 37
Attachment 1, Page 38
Attachment 1, Page 39
Attachment 1, Page 40
Attachment 1, Page 41
Attachment 1, Page 42
Attachment 1, Page 43
Attachment 1, Page 44
Attachment 1, Page 45
Attachment 1, Page 46
Attachment 1, Page 47
Attachment 1, Page 48
Attachment 1, Page 49
Attachment 1, Page 50
Attachment 1, Page 51
Attachment 1, Page 52
Attachment 1, Page 53
Attachment 1, Page 54
Attachment 1, Page 55
Attachment 1, Page 56
Attachment 1, Page 57
Attachment 1, Page 58
Attachment 1, Page 59
Attachment 1, Page 60
Attachment 1, Page 61
Attachment 1, Page 62
Attachment 1, Page 63
Attachment 1, Page 64
Attachment 1, Page 65
Attachment 2, Page 1
Attachment 2, Page 2
Attachment 2, Page 3
Attachment 2, Page 4
Attachment 2, Page 5
Attachment 2, Page 6
Attachment 2, Page 7
Attachment 2, Page 8
Attachment 2, Page 9
Attachment 2, Page 10
Attachment 2, Page 11
Attachment 2, Page 12
Attachment 2, Page 13
Attachment 2, Page 14
Attachment 2, Page 15
Attachment 2, Page 16
Attachment 2, Page 17
Attachment 2, Page 18
Attachment 2, Page 19
Attachment 2, Page 20
Attachment 2, Page 21
Attachment 2, Page 22
Attachment 2, Page 23
Attachment 2, Page 24
Attachment 2, Page 25
Attachment 2, Page 26
Attachment 2, Page 27
Attachment 2, Page 28
Attachment 2, Page 29
Attachment 2, Page 30
Attachment 2, Page 31
Attachment 2, Page 32
Attachment 2, Page 33
Attachment 2, Page 34
Attachment 2, Page 35
Attachment 2, Page 36
Attachment 2, Page 37
Attachment 2, Page 38
Attachment 2, Page 39
Attachment 2, Page 40
Attachment 2, Page 41
Attachment 2, Page 42
Attachment 3, Page 1
Attachment 3, Page 2
Attachment 3, Page 3
Attachment 3, Page 4
Attachment 3, Page 5
Attachment 3, Page 6
Attachment 3, Page 7
Attachment 3, Page 8
Attachment 3, Page 9
Attachment 3, Page 10
Attachment 3, Page 11
Attachment 4, Page 1
Attachment 4, Page 2
Attachment 4, Page 3
Attachment 4, Page 4
Attachment 4, Page 5
Attachment 4, Page 6
Attachment 4, Page 7
Attachment 4, Page 8
Attachment 4, Page 9
Attachment 4, Page 10
Attachment 4, Page 11
Attachment 4, Page 12
Attachment 4, Page 13
Attachment 4, Page 14
Attachment 4, Page 15
Attachment 4, Page 16
Attachment 5, Page 1
Attachment 5, Page 2
Attachment 5, Page 3
Attachment 5, Page 4
Attachment 5, Page 5
Attachment 5, Page 6
Attachment 5, Page 7
Attachment 5, Page 8
Attachment 5, Page 9
Attachment 5, Page 10
Attachment 5, Page 11
Attachment 6, Page 1
Attachment 6, Page 2
Attachment 6, Page 3
Attachment 6, Page 4
Attachment 6, Page 5
Attachment 6, Page 6
Attachment 6, Page 7
Attachment 6, Page 8
Attachment 6, Page 9
Attachment 6, Page 10
Attachment 6, Page 11
Attachment 6, Page 12
Attachment 6, Page 13
Attachment 6, Page 14
Attachment 7
Attachment 8
Attachment 9
Attachment 10, Page 1
Attachment 10, Page 2
Attachment 10, Page 3
Attachment 10, Page 4
Attachment 10, Page 5
Attachment 10, Page 6
Attachment 10, Page 7
Attachment 10, Page 8
Attachment 10, Page 9
Attachment 10, Page 10
Attachment 10, Page 11
Attachment 10, Page 12
Attachment 10, Page 13
Attachment 10, Page 14
Attachment 11, Page 1
Attachment 11, Page 2
NRI 2504 April 2025
PURPOSE AND INTENT
The purpose of this report is to provide officials of the local governing body and other decision-makers
with natural resource information. This information may be useful when undertaking land use decisions
concerning variations, amendments or relief of local zoning ordinances, proposed subdivision of vacant
or agricultural lands and the subsequent development of these lands. This report is a requirement under
Section 22.02a of the Illinois Soil and Water Conservation Districts Act.
The intent of this report is to present the most current natural resource information available in a readily
understandable manner. It contains a description of the present site conditions, the present resources,
and the potential impacts that the proposed change may have on the site and its resources. The natural
resource information was gathered from standardized data, on-site investigations and information
furnished by the petitioner. This report must be read in its entirety so that the relationship between the
natural resource factors and the proposed land use change can be fully understood.
Due to the limitations of scale encountered with the various resource maps, the property boundaries
depicted in the various exhibits in this report provide a generalized representation of the property location
and may not precisely reflect the legal description of the PIQ (Parcel in Question).
This report, when used properly, will provide the basis for proper land use change decisions and
development while protecting the natural resource base of the county. It should not be used in place of
detailed environmental and/or engineering studies that are warranted under most circumstances, but in
conjunction with those studies.
The conclusions of this report in no way indicate that a certain land use is not possible, but it should alert
the reader to possible problems that may occur if the capabilities of the land are ignored. Any questions
on the technical data supplied in this report or if anyone feels that they would like to see more additional
specific information to make the report more effective, please contact:
Kendall County Soil and Water Conservation District
7775A Route 47, Yorkville, IL 60560
Phone: (630) 553-5821 ext. 3
E-mail: Alyse.Olson@il.nacdnet.net
Attachment 11, Page 3
NRI 2504 April 2025
TABLE OF CONTENTS
EXECUTIVE SUMMARY .................................................................................................................................. 1
PARCEL LOCATION ........................................................................................................................................ 8
ARCHAEOLOGIC/CULTURAL RESOURCES INFORMATION ........................................................................... 10
ECOLOGICALLY SENSITIVE AREAS ............................................................................................................... 11
SOILS INFORMATION .................................................................................................................................. 13
SOILS INTERPRETATIONS EXPLANATION..................................................................................................... 15
BUILDING LIMITATIONS .............................................................................................................................. 16
SOIL WATER FEATURES ............................................................................................................................... 22
SOIL EROSION AND SEDIMENT CONTROL ................................................................................................... 24
PRIME FARMLAND SOILS ............................................................................................................................ 25
LAND EVALUATION AND SITE ASSESSMENT (LESA) .................................................................................... 26
LAND USE PLANS ......................................................................................................................................... 28
DRAINAGE, RUNOFF, AND FLOOD INFORMATION ..................................................................................... 28
WATERSHED PLANS .................................................................................................................................... 32
WETLAND INFORMATION ........................................................................................................................... 33
HYDRIC SOILS .............................................................................................................................................. 35
WETLAND AND FLOODPLAIN REGULATIONS .............................................................................................. 37
GLOSSARY.................................................................................................................................................... 38
REFERENCES ................................................................................................................................................ 41
LIST OF FIGURES
FIGURE 1: Soil Map ………………………………..……………………..……………………………………………………..………………… 2
FIGURE 2: Soil Limitations …………..……………………………………………………….…………………………………………………. 4
FIGURE 3: 2021 Plat Map ………………..……………………………………………………….………...………………………………….. 8
FIGURE 4: Aerial Map with NRI Site Boundary ………………………….………….………………………….……………..……... 9
FIGURE 5: Soil Map ………………………………………………………………………………….…………………………………………… 14
FIGURE 6A-6C: Maps of Building Limitations ……………………………………………..……………………………..…….. 19-21
Attachment 11, Page 4
NRI 2504 April 2025
FIGURE 7: Prime Farmland Soils …………………………………….………………………………………..…………………….…….. 25
FIGURE 8: Flood Map ……………………..………………….……………….…………………….………….……………………………… 30
FIGURE 9: Topographic Map ……………………………………………….…………………………..………………….……………….. 31
FIGURE 10: Watershed Map …………………………………………………….……………………………..………………………….… 32
FIGURE 11: Wetland Map ……………………………………………………………………………………………..…….……….………. 34
FIGURE 12: Hydric Soils Map …………………………………………………………………………………….……….…….…………… 36
LIST OF TABLES
TABLE 1: Soils Information ……………………………………………………………….…………………………………………………….. 3
TABLE 2: Soil Limitations ………………………………..………………………………………………….……………………….………….. 4
TABLE 3: Soil Map Unit Descriptions …………………………………………………………….…………………………..………….. 14
TABLE 4: Building Limitations ……………………………………………………………………………………………………………….. 17
TABLE 5: Water Features ………………………………………………………………………………………….……………………..…… 23
TABLE 6: Soil Erosion Potential ……………………………………………………………………………………………….……………. 24
TABLE 7: Prime Farmland Soils …………………………………………………………………………………………………..…………. 25
TABLE 8A: Land Evaluation Computation ………………………………………………………..…………………………..………. 26
TABLE 8B: Site Assessment Computation ………………………………………………………….………………………………….. 27
TABLE 9: LESA Score Summary ……………………………………………………………………………………………………………… 27
TABLE 10: Hydric Soils ………………………..…………………………………………………..…………………………….…..………… 35
Attachment 11, Page 5
Attachment 11, Page 6
NRI 2504 April 2025
2
NATURAL RESOURCE CONSIDERATIONS
SOIL INFORMATION
Based on information from the United States Department of Agriculture-Natural Resources Conservation
Service (USDA-NRCS) 2008 Kendall County Soil Survey, this project area contains the soil types shown in
Figure 1 and Table 1. Please note this does not replace the need for or results of onsite soil testing. If
completed, please refer to onsite soil test results for planning/engineering purposes.
Figure 1: Soil Map
Attachment 11, Page 7
NRI 2504 April 2025
3
Table 1: Soils Information
Soil
Type Soil Name Drainage Class Hydrologic
Group
Hydric
Designation
Farmland
Designation Acres %
Area
152A Drummer silty clay
loam, 0-2% slopes Poorly Drained B/D Hydric Prime Farmland
if Drained 1.9 9.0%
219A Millbrook silt loam,
0-2% slopes
Somewhat
Poorly Drained C/D
Non-Hydric
w/ Hydric
Inclusions
Prime Farmland
if Drained 1.2 5.8%
318C2 Lorenzo loam,
4-6% slopes, eroded Well Drained B Non-Hydric
Farmland of
Statewide
Importance
2.1 10.1%
791A Rush silt loam,
0-2% slopes Well Drained B
Non-Hydric
w/ Hydric
Inclusions
Prime Farmland 7.5 36.1%
791B Rush silt loam,
2-4% slopes Well Drained B
Non-Hydric
w/ Hydric
Inclusions
Prime Farmland 8.1 39.0%
Hydrologic Soil Groups – Soils have been classified into four (A, B, C, D) hydrologic groups based on runoff
characteristics due to rainfall. If a soil is assigned to a dual hydrologic group (A/D, B/D or C/D), the first
letter is for drained areas and the second letter is for undrained areas.
• Hydrologic group A: Soils have 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.
• Hydrologic group B: Soils have a moderate infiltration rate when thoroughly wet, consist chiefly
of moderately deep to deep, moderately well drained to well drained soils that have a moderately
fine to moderately coarse texture. These soils have a moderate rate of water transmission.
• Hydrologic 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.
• Hydrologic 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 high water table, 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.
Hydric Soils – A hydric soil is one that formed under conditions of saturation, flooding, or ponding long
enough during the growing season to develop anaerobic conditions in the upper part of the soil profile
that supports the growth or regeneration of hydrophytic vegetation. Soils with hydric inclusions have map
units dominantly made up of non-hydric soils that may have inclusions of hydric soils in the lower positions
on the landscape. Of the soils found onsite, one is classified as hydric soil (152A Drummer silty clay loam),
one is classified as non-hydric soil (318C2 Lorenzo loam), and three are classified as non-hydric soil with
hydric inclusions likely (219A Millbrook silt loam, 791A Rush silt loam, and 791B Rush silt loam).
Prime Farmland – Prime farmland is land that has the best combination of physical and chemical
characteristics for agricultural production. Prime farmland soils are an important resource to Kendall
County and some of the most productive soils in the United States occur locally. Of the soils found onsite,
two are designated as prime farmland (791A Rush silt loam and 791B Rush silt loam), two are designated
Attachment 11, Page 8
NRI 2504 April 2025
4
as prime farmland if drained (152A Drummer silty clay loam and 219A Millbrook silt loam), and one is
designated as farmland of statewide importance (318C2 Lorenzo loam).
Soil Limitations – The USDA-NRCS Web Soil Survey rates the limitations of soils for dwellings, small
commercial buildings, solar arrays, shallow excavations, lawns/landscaping, local roads and streets, etc.
Soils have different properties which influence the development of building sites. The USDA-NRCS
classifies soils as Not Limited, Somewhat Limited, and Very Limited. Soils that are Not Limited indicates
that the soil has properties that are favorable for the specified use. They will perform well and will have
low maintenance. Soils that are Somewhat Limited are moderately favorable, and their limitations can be
overcome through special planning, design, or installation. Soils that are Very Limited have features that
are unfavorable for the specified use, and their limitations cannot easily be overcome.
Table 2: Soil Limitations
Soil Type Solar Arrays Shallow
Excavations
Lawns/
Landscaping
Local
Roads / Streets
152A Very Limited Very Limited Very Limited Very Limited
219A Very Limited Very Limited Somewhat Limited Very Limited
318C2 Somewhat Limited Somewhat Limited Somewhat Limited Somewhat Limited
791A Very Limited Somewhat Limited Somewhat Limited Very Limited
791B Very Limited Somewhat Limited Somewhat Limited Very Limited
Figure 2: Soil Limitations
KENDALL COUNTY LAND EVALUATION AND SITE ASSESSMENT (LESA)
Decision-makers in Kendall County use the Land Evaluation and Site Assessment (LESA) system to
determine the suitability of a land use change and/or a zoning request as it relates to agricultural land.
The LESA system was developed by the United States Department of Agriculture-Natural Resources
Conservation Service (USDA-NRCS) and takes into consideration local conditions such as physical
characteristics of the land, compatibility of surrounding land-uses, and urban growth factors. The LESA
system is a two-step procedure that includes:
• Land Evaluation (LE): The soils of a given area are rated and placed in groups ranging from the
best to worst suited for a stated agriculture use, cropland, or forestland. The best group is
0
20
40
60
80
100
Solar Arrays Shallow Excavations Lawns/Landscaping Natural Surface Roads
%
OF
SOIL
TYPE OF IMPROVEMENT
SOIL LIMITATIONS
Not Limited
Somewhat Limited
Very Limited
Attachment 11, Page 9
NRI 2504 April 2025
5
assigned a value of 100 and all other groups are assigned lower values. The Land Evaluation is
based on data from the Kendall County Soil Survey. The Kendall County Soil and Water
Conservation District is responsible for this portion of the LESA system.
The Land Evaluation score for this site is 80 out of 100, indicating that the soils are well
suited for agricultural uses.
• Site Assessment (SA): The site is numerically evaluated according to important factors that
contribute to the quality of the site. Each factor selected is assigned values in accordance with the
local needs and objectives. The Site Assessment value is based on a 200-point scale and accounts
for 2/3 of the total score. The Kendall County LESA Committee is responsible for this portion of
the LESA system.
The Site Assessment score for this site is 99 out of 200.
The LESA Score for this site is 179 out of a possible 300, which indicates a low level of protection for the
proposed project site. Selecting the project site with the lowest total points will generally protect the best
farmland located in the most viable areas and maintain and promote the agricultural industry in Kendall
County.
WETLANDS
The U.S. Fish & Wildlife Service’s National Wetlands Inventory map indicates the presence of
wetland(s)/waters on or near the proposed project site. To determine if a wetland is present, a wetland
delineation specialist, who is recognized by the U.S. Army Corps of Engineers, should determine the exact
boundaries and value of the wetlands.
FLOODPLAIN
The Federal Emergency Management Agency’s (FEMA) Flood Insurance Rate Maps (FIRM) for Kendall
County, Community Panel No. 17093C0035H (effective date January 8, 2014) and 17093C0030G (effective
date February 4, 2009) were reviewed to determine the presence of floodplain and floodway areas within
the project site. According to the map, the site does not appear to contain areas of regulated floodplain
or floodway.
SEDIMENT AND EROSION CONTROL
Development on this site should include an erosion and sediment control plan in accordance with local,
state, and federal regulations. Soil erosion on construction sites is a resource concern as suspended
sediment from areas undergoing development is a primary nonpoint source of water pollution. Please
consult the Illinois Urban Manual (https://illinoisurbanmanual.org/) for appropriate best management
practices.
STORMWATER POLLUTION
A National Pollutant Discharge Elimination System (NPDES) permit (Permit No. ILR10) from the Illinois
Environmental Protection Agency (IEPA) is required for stormwater discharges from construction sites
that will disturb 1 or more acres of land. Conditions of the NPDES ILR10 permit require the development
and implementation of a Stormwater Pollution Prevention Plan (SWPPP) to reduce stormwater pollutants
on the construction site before they can cause environmental issues.
Attachment 11, Page 10
NRI 2504 April 2025
6
ECOLOGICAL CONSIDERATIONS
Developers of solar project sites are encouraged to plant native groundcover. Native shrubs, grasses, and
wildflowers offer benefits such as improved erosion control, pesticide avoidance, stormwater infiltration,
wildlife habitat, and reduced overall maintenance. Naturalized areas, once established, are more drought
tolerant, require little to no fertilization, and only need to be mowed once or twice a year. Native fruiting
and flowering plants also provide a food source and habitat for native pollinators which offer the
ecological service of pollinating our agricultural crops.
The district recognizes two potential sources of water pollution from solar farms including cracked panels
and oil leaks or spills from transformers. Cracked panels can leach toxic materials if many broken panels
are exposed to precipitation over a long period of time. To prevent this issue, solar farm operators should
regularly inspect for cracked panels. Cracked or broken panels must be immediately stored under
protective cover and should be periodically transported offsite for recycling or proper offsite storage.
Electrical transformers are used to increase output voltage from solar farms to the electrical grid. These
transformers contain oil, which can leak or spill resulting in environmental damage. To reduce
environmental damage, biodegradable oil can be used in the transformers. Larger transformers typically
use mineral-based oil unless biodegradable oil is specifically requested. Leaks and spills of biodegradable
oil must still be prevented, but the risk for groundwater contamination would be reduced and clean-up
efforts simplified in the event of a release. Secondary containment systems such as trays, membranes, or
vaults can also be used in the event of a leak or spill. Containment systems must be designed to manage
stormwater so adequate containment volume is maintained. This would be the responsibility of the solar
developer.
Attachment 11, Page 11
Attachment 11, Page 12
Attachment 11, Page 13
NRI 2504 April 2025
9
Figure 4: Aerial Map with NRI Project Boundary
Attachment 11, Page 14
NRI 2504 April 2025
10
ARCHAEOLOGIC/CULTURAL RESOURCES
INFORMATION
Simply stated, cultural resources are all the past activities and accomplishments of people. They include
the following: buildings; objects made or used by people; locations; and less tangible resources, such as
stories, dance forms, and holiday traditions.
The Soil and Water Conservation District most often encounters cultural resources as historical properties.
These may be prehistoric or historical sites, buildings, structures, features, or objects. The most common
type of historical property that the Soil and Water Conservation District may encounter is non-structural
archaeological sites. These sites often extend below the soil surface and must be protected against
disruption by development or other earth moving activity if possible. Cultural resources are non-
renewable because there is no way to “grow” a site to replace a disrupted site.
Landowners with historical properties on their land have ownership of that historical property. However,
the State of Illinois owns all the following: human remains, grave markers, burial mounds, and artifacts
associated with graves and human remains.
Non-grave artifacts from archaeological sites and historical buildings are the property of the landowner.
The landowner may choose to disturb a historical property but may not receive federal or state assistance
to do so. If an earth moving activity disturbs human remains, the landowner must contact the county
coroner within 48 hours.
The Illinois State Historic Preservation Office has not been notified of the proposed land use change
by the Kendall County SWCD. There may be historic features in the area. The applicant may need to
contact them according to current Illinois law.
Attachment 11, Page 15
NRI 2504 April 2025
11
ECOLOGICALLY SENSITIVE AREAS
WHAT IS BIOLOGICAL DIVERSITY AND WHY SHOULD IT BE CONSERVED?1
Biological diversity, or biodiversity, is the range of life on our planet. A more thorough definition is
presented by botanist Peter H. Raven: “At the simplest level, biodiversity is the sum total of all the plants,
animals, fungi and microorganisms in the world, or in a particular area; all of their individual variation;
and all of the interactions between them. It is the set of living organisms that make up the fabric of the
planet Earth and allow it to function as it does, by capturing energy from the sun and using it to drive all
of life’s processes; by forming communities of organisms that have, through the several billion years of
life’s history on Earth, altered the nature of the atmosphere, the soil and the water of our Planet; and by
making possible the sustainability of our planet through their life activities now” (Raven 1994).
It is not known how many species occur on our planet. Presently, about 1.4 million species have been
named. It has been estimated that there are perhaps 9 million more that have not been identified. What
is known is that they are vanishing at an unprecedented rate. Reliable estimates show extinction occurring
at a rate several orders of magnitude above “background” in some ecological systems (Wilson 1992,
Hoose 1981).
The reasons for protecting biological diversity are complex, but they fall into four major categories. First,
loss of diversity generally weakens entire natural systems. Healthy ecosystems tend to have many natural
checks and balances. Every species plays a role in maintaining this system. When simplified by the loss of
diversity, the system becomes more susceptible to natural and artificial perturbations. The chances of a
system-wide collapse increase. In parts of the midwestern United States, for example, it was only the
remnant areas of natural prairies that kept soil intact during the dust bowl years of the 1930s (Roush
1982).
Simplified ecosystems are almost always expensive to maintain. For example, when synthetic chemicals
are relied upon to control pests, the target species are not the only ones affected. Their predators are
almost always killed or driven away, exasperating the pest problem. In the meantime, people are
unintentionally breeding pesticide-resistant pests. A process has begun where people become perpetual
guardians of the affected area, which requires the expenditure of financial resources and human ingenuity
to keep the system going.
A second reason for protecting biological diversity is that it represents one of our greatest untapped
resources. Great benefits can be reaped from a single species. About 20 species provide 90% of the world’s
food. Of these 20, just three, wheat, maize, and rice-supply over one half of that food. American wheat
farmers need new varieties every five to 15 years to compete with pests and diseases. Wild strains of
wheat are critical genetic reservoirs for these new varieties.
Further, every species is a potential source of human medicine. In 1980, a published report identified the
market value of prescription drugs from higher plants at over $3 billion. Organic alkaloids, a class of
Attachment 11, Page 16
NRI 2504 April 2025
12
chemical compounds used in medicines, are found in an estimated 20% of plant species. Yet only 2% of
plant species have been screened for these compounds (Hoose 1981).
The third reason for protecting diversity is that humans benefit from natural areas and depend on healthy
ecosystems. The natural world supplies our air, our water, our food and supports human economic
activity. Further, humans are creatures that evolved in a diverse natural environment between forest and
grasslands. People need to be reassured that such places remain. When people speak of “going to the
country,” they generally mean more than getting out of town. For reasons of their own sanity and
wellbeing, they need a holistic, organic experience. Prolonged exposure to urban monotony produces
neuroses, for which cultural and natural diversity cure.
Historically, the lack of attention to biological diversity, and the ecological processes it supports, has
resulted in economic hardships for segments of the basin’s human population.
The final reason for protecting biological diversity is that species and natural systems are intrinsically
valuable. The above reasons have focused on the benefits of the natural world to humans. All things
possess intrinsic value simply because they exist.
BIOLOGICAL RESOURCES CONCERNING THE SUBJECT PARCEL
As part of the Natural Resources Information Report, staff checks office maps to determine if any nature
preserves or ecologically sensitive areas are in the general vicinity of the parcel in question. If there is a
nature preserve in the area, then that resource will be identified as part of the report. The SWCD
recommends that every effort be made to protect that resource. Such efforts should include, but are not
limited to erosion control, sediment control, stormwater management, and groundwater monitoring.
______________________________________________________________________________
1Taken from The Conservation of Biological Diversity in the Great Lakes Ecosystem: Issues and Opportunities, prepared by the
Nature Conservancy Great Lakes Program 79W. Monroe Street, Suite 1309, Chicago, IL 60603, January 1994.
Office maps indicate that there are no nature preserves in the vicinity of the parcel in question (PIQ).
Adjacent to the PIQ is a mapped freshwater emergent wetland to the north and a mapped freshwater
pond to the south. These are ecologically sensitive areas.
Attachment 11, Page 17
NRI 2504 April 2025
13
SOILS INFORMATION
IMPORTANCE OF SOILS INFORMATION
Soils information comes from the Natural Resources Conservation Service Soil Maps and Descriptions for
Kendall County. This information is important to all parties involved in determining the suitability of the
proposed land use change.
Each soil polygon is given a number, which represents its soil type. The letter found after the soil type
number indicates the soils slope class.
Each soil map unit has limitations for a variety of land uses such as septic systems, buildings with
basements, and buildings without basements. It is important to remember that soils do not function
independently of each other. The behavior of a soil depends upon the physical properties of adjacent soil
types, the presence of artificial drainage, soil compaction, and its position in the local landscape.
The limitation categories (not limited, somewhat limited, or very limited) indicate the potential for
difficulty in using that soil unit for the proposed activity and, thus, the degree of need for thorough soil
borings and engineering studies. A limitation does not necessarily mean that the proposed activity cannot
be done on that soil type. It does mean that the reasons for the limitation need to be thoroughly
understood and dealt with to complete the proposed activity successfully. Very limited indicates that the
proposed activity will be more difficult and costly to do on that soil type than on a soil type with a
somewhat limited or not limited rating.
Soil survey interpretations are predictions of soil behavior for specified land uses and specified
management practices. They are based on the soil properties that directly influence the specified use of
the soil. Soil survey interpretations allow users of soil surveys to plan reasonable alternatives for the use
and management of soils.
Soil interpretations do not eliminate the need for on-site study and testing of specific sites for the design
and construction for specific uses. They can be used as a guide for planning more detailed investigations
and for avoiding undesirable sites for an intended use. The scale of the maps and the range of error limit
the use of the soil delineation.
Attachment 11, Page 18
NRI 2504 April 2025
14
Figure 5: Soil Map
Table 3: Soil Map Unit Descriptions
Soil Type Soil Name Acres Percent
152A Drummer silty clay loam, 0-2% slopes 1.9 9.0%
219A Millbrook silt loam, 0-2% slopes 1.2 5.8%
318C2 Lorenzo loam, 4-6% slopes, eroded 2.1 10.1%
791A Rush silt loam, 0-2% slopes 7.5 36.1%
791B Rush silt loam, 2-4% slopes 8.1 39.0%
Source: National Cooperative Soil Survey – USDA-NRCS
Attachment 11, Page 19
NRI 2504 April 2025
15
SOILS INTERPRETATIONS EXPLANATION
GENERAL – NONAGRICULTURAL
These interpretative ratings help engineers, planners, and others to understand how soil properties
influence behavior when used for nonagricultural uses such as building site development or construction
materials. This report gives ratings for proposed uses in terms of limitations and restrictive features. The
tables list only the most restrictive features.
Other features may need treatment to overcome soil limitations for a specific purpose. Ratings come from
the soil's "natural" state, that is, no unusual modification occurs other than that which is considered
normal practice for the rated use. Even though soils may have limitations, an engineer may alter soil
features or adjust building plans for a structure to compensate for most degrees of limitations. Most of
these practices, however, are costly. The final decision in selecting a site for a particular use generally
involves weighing the costs for site preparation and maintenance. Soil properties influence development
of building sites, including the selection of the site, the design of the structure, construction, performance
after construction, and maintenance. Soil limitation ratings of not limited, somewhat limited, and very
limited are given for the types of proposed improvements that are listed or inferred by the petitioner as
entered on the report application and/or zoning petition. The most common types of building limitation
that this report gives limitations ratings for is septic systems. It is understood that engineering practices
can overcome most limitations for buildings with and without basements, and small commercial buildings.
Limitation ratings for these types of buildings are not commonly provided. Organic soils, when present on
the parcel, are referenced in the hydric soils section of the report. This type of soil is considered unsuitable
for all types of construction.
LIMIATIONS RATINGS
• Not Limited: This soil has favorable properties for the use. The degree of limitation is minor. The
people involved can expect good performance and low maintenance.
• Somewhat Limited: This soil has moderately favorable properties for the use. Special planning,
design, or maintenance can overcome this degree of limitation. During some part of the year, the
expected performance is less desirable than for soils rated slight.
• Very Limited: This soil has one or more properties that are unfavorable for the rated use. These
may include the following: steep slopes, bedrock near the surface, flooding, high shrink-swell
potential, a seasonal high water table, or low strength. This degree of limitation generally requires
major soil reclamation, special design, or intensive maintenance, which in most situations is
difficult and costly.
Attachment 11, Page 20
NRI 2504 April 2025
16
BUILDING LIMITATIONS
BUILDING ON POORLY SUITED OR UNSUITABLE SOILS
Building on poorly suited or unsuitable soils can present problems to future property owners such as
cracked foundations, wet basements, lowered structural integrity and high maintenance costs associated
with these problems. The staff of the Kendall County SWCD strongly urges scrutiny by the plat reviewers
when granting parcels with these soils exclusively.
Solar Arrays, Soil-Penetrating Anchor Systems – Ground-based solar arrays are sets of photovoltaic
panels that are not situated on a building or pole. These installations consist of a racking system that holds
the panel in the desired orientation and the foundation structures that hold the racking system to the
ground. Two basic methods are used to hold the systems to the ground, based on site conditions and cost.
One method employs driven piles, screw augers, or concrete piers that penetrate the soil to provide a
stable foundation.
Shallow Excavations – Trenches or holes dug to a maximum depth of 5 or 6 feet for utility lines, open
ditches, or other purposes. Ratings are based on soil properties that influence the ease of digging and the
resistance to sloughing.
Lawns and Landscaping – Require soils on which turf and ornamental trees and shrubs can be established
and maintained (irrigation is not considered in the ratings). The ratings are based on the soil properties
that affect plant growth and trafficability after vegetation is established.
Local Roads and Streets – They 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 soil material
stabilized by lime or cement; and a surface of flexible material (asphalt), rigid material (concrete) or gravel
with a binder. The ratings are based on the soil properties that affect the ease of excavation and grading
and the traffic-supporting capacity.
Attachment 11, Page 21
NRI 2504 April 2025
17
Table 4: Building Limitations
Soil Type Solar Arrays Shallow
Excavations
Lawns &
Landscaping
Local Roads
& Streets Acres %
152A
Very Limited:
Ponding
Depth to saturated zone
Frost action
Low strength
Steel corrosion
Shrink-swell
Very Limited:
Ponding
Depth to saturated zone
Dusty
Unstable excavation walls
Too clayey
Very Limited:
Ponding
Depth to saturated zone
Dusty
Very Limited:
Ponding
Depth to saturated zone
Frost action
Low strength
Shrink-swell
1.9 9.0%
219A
Very Limited:
Frost action
Depth to saturated zone
Steel corrosion
Shrink-swell
Hillslope position
Ponding
Low strength
Very Limited:
Depth to saturated zone
Dusty
Unstable excavation walls
Ponding
Somewhat Limited:
Depth to saturated zone
Dusty
Very Limited:
Frost action
Depth to saturated zone
Shrink-swell
Low strength
Ponding
1.2 5.8%
318C2
Somewhat Limited:
Steel corrosion
Frost action
Hillslope position
Depth to saturated zone
Shrink-swell
Low strength
Somewhat Limited:
Unstable excavation walls
Dusty
Somewhat Limited:
Droughty
Dusty
Depth to saturated zone
Somewhat Limited:
Frost action
Depth to saturated zone
Low strength
Shrink swell
2.1 10.1%
791A
Very Limited:
Frost action
Steel corrosion
Low strength
Shrink-swell
Hillslope position
Ponding
Depth to saturated zone
Somewhat Limited:
Dusty
Unstable excavation walls
Somewhat Limited:
Dusty
Very Limited:
Frost action
Low strength
Shrink-swell
Ponding
Depth to saturated zone
7.5 36.1%
Attachment 11, Page 22
Attachment 11, Page 23
Attachment 11, Page 24
Attachment 11, Page 25
Attachment 11, Page 26
NRI 2504 April 2025
22
SOIL WATER FEATURES
Table 5, below, gives estimates of various soil water features that should be taken into consideration when
reviewing engineering for a land use project.
HYDROLOGIC SOIL GROUPS (HSGs) – The groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the soils are not protected
by vegetation, are thoroughly wet, and receive precipitation from long-duration storms.
• 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 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.
Note: If a soil is assigned to a dual hydrologic group (A/D, B/D or C/D) the first letter is for drained areas
and the second is for undrained areas.
SURFACE RUNOFF – Surface runoff refers to the loss of water from an area by flow over the land surface.
Surface runoff classes are based upon slope, climate and vegetative cover and indicates relative runoff for
very specific conditions (it is assumed that the surface of the soil is bare and that the retention of surface
water resulting from irregularities in the ground surface is minimal). The classes are negligible, very low,
low, medium, high, and very high.
MONTHS – The portion of the year in which a water table, ponding, and/or flooding is most likely to be a
concern.
WATER TABLE – Water table refers to a saturated zone in the soil and the data indicates, by month, depth
to the top (upper limit) and base (lower limit) of the saturated zone in most years. These estimates are
based upon observations of the water table at selected sites and on evidence of a saturated zone (grayish
colors or mottles (redoximorphic features)) in the soil. Note: A saturated zone that lasts for less than a
month is not considered a water table.
PONDING – Ponding refers to standing water in a closed depression, and the data indicates surface water
depth, duration, and frequency of ponding.
Attachment 11, Page 27
NRI 2504 April 2025
23
• Duration: 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.
• Frequency: Expressed as: none meaning ponding is not possible; rare means unlikely but possible
under unusual weather conditions (chance of ponding is 0-5% in any year); occasional means that
it occurs, on the average, once or less in 2 years (chance of ponding is 5 to 50% in any year); and
frequent means that it occurs, on the average, more than once in 2 years (chance of ponding is
more than 50% in any year).
FLOODING – The temporary inundation of an area 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,
and water standing in swamps and marshes is considered ponding rather than flooding.
• Duration: Expressed as: extremely brief if 0.1 hour to 4 hours; very brief if 4 hours to 2 days; brief
if 2 to 7 days; long if 7 to 30 days; and very long if more than 30 days.
• Frequency: Expressed as: none means flooding is not probable; very rare means that it is very
unlikely but possible under extremely unusual weather conditions (chance of flooding is less than
1% in any year); rare means that it is unlikely but possible under unusual weather conditions
(chance of flooding is 1 to 5% in any year); occasional means that it occurs infrequently under
normal weather conditions (chance of flooding is 5 to 50% in any year but is less than 50% in all
months in any year); and very frequent means that it is likely to occur very often under normal
weather conditions (chance of flooding is more than 50% in all months of any year).
Note: The information is based on evidence in the soil profile. In addition, consideration is also given to
local information about the extent and levels of flooding and the relation of each soil on the landscape to
historic floods. 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.
Table 5: Water Features
Soil
Type
Hydrologic
Group
Surface
Runoff Water Table Ponding Flooding
152A B/D Negligible
January – May
Upper Limit: 0.0’-1.0’
Lower Limit: 6.0’
January – May
Surface Water Depth: 0.0’-0.5’
Duration: Brief (2-7 days)
Frequency: Frequent
January – December
Frequency: None
219A C/D Low
January – May
Upper Limit: 0.5’-2.0’
Lower Limit: 6.0’
January – December
Frequency: None
January – December
Frequency: None
318C2 B Medium
January – December
Upper Limit: --
Lower Limit: --
January – December
Frequency: None
January – December
Frequency: None
791A B Low
January – December
Upper Limit: --
Lower Limit: --
January – December
Frequency: None
January – December
Frequency: None
791B B Low
January – December
Upper Limit: --
Lower Limit: --
January – December
Frequency: None
January – December
Frequency: None
Attachment 11, Page 28
NRI 2504 April 2025
24
SOIL EROSION AND SEDIMENT CONTROL
Erosion is the wearing away of the soil by water, wind, and other forces. Soil erosion threatens the Nation's
soil productivity and contributes the most pollutants in our waterways. Water causes about two thirds of
erosion on agricultural land. Four properties, mainly, determine a soil's erodibility: texture, slope,
structure, and organic matter content.
Slope has the most influence on soil erosion potential when the site is under construction. Erosivity and
runoff increase as slope grade increases. The runoff then exerts more force on the particles, breaking their
bonds more readily and carrying them farther before deposition. The longer water flows along a slope
before reaching a major waterway, the greater the potential for erosion.
Soil erosion during and after this proposed construction can be a primary non-point source of water
pollution. Eroded soil during the construction phase can create unsafe conditions on roadways, decrease
the storage capacity of lakes, clog streams and drainage channels, cause deterioration of aquatic habitats,
and increase water treatment costs. Soil erosion also increases the risk of flooding by choking culverts,
ditches, and storm sewers and by reducing the capacity of natural and man-made detention facilities.
The general principles of erosion and sedimentation control measures include:
• Reducing/diverting flow from exposed areas, storing flows, or limiting runoff from exposed areas
• Staging construction to keep disturbed areas to a minimum
• Establishing or maintaining temporary or permanent groundcover
• Retaining sediment on site
• Properly installing, inspecting, and maintaining control measures
Erosion control practices are useful controls only if they are properly located, installed, inspected, and
maintained. Soil erosion and sedimentation control plans, including maintenance responsibilities, should
be clearly communicated to all contractors working on the site.
The SWCD recommends an erosion and sediment control plan for all building sites, especially if there is a
wetland or stream nearby. Additionally, a National Pollutant Discharge Elimination System (NPDES) permit
(Permit No. ILR10) from the Illinois Environmental Protection Agency (IEPA) is required for stormwater
discharges from construction sites that will disturb 1 or more acres of land. Conditions of the NPDES ILR10
permit require the development and implementation of a Stormwater Pollution Prevention Plan (SWPPP)
to reduce stormwater pollutants on the construction site before they can cause environmental issues.
Table 6: Soil Erosion Potential
Soil Type Slope Rating Acreage Percent of Project Area
152A 0-2% Slight 1.9 9.0%
219A 0-2% Slight 1.2 5.8%
318C2 4-6% Moderate 2.1 10.1%
791A 0-2% Slight 7.5 36.1%
791B 2-4% Slight 8.1 39.0%
Attachment 11, Page 29
NRI 2504 April 2025
25
PRIME FARMLAND SOILS
Prime farmland soils are an important resource to Kendall County. Some of the most productive soils in
the United States occur locally. Each soil map unit in the United States is assigned a prime or non-prime
rating. Prime agricultural land does not need to be in the production of food & fiber.
Section 310 of the NRCS general manual states that urban or built-up land on prime farmland soils is not
prime farmland. The percentages of soil map units on the parcel reflect the determination that urban or
built-up land on prime farmland soils is not prime farmland.
Table 7: Prime Farmland Soils
Soil Type Prime Designation Acreage Percent
152A Prime Farmland if Drained 1.9 9.0%
219A Prime Farmland if Drained 1.2 5.8%
318C2 Farmland of Statewide Importance 2.1 10.1%
791A Prime Farmland 7.5 36.1%
791B Prime Farmland 8.1 39.0%
% Prime Farmland 89.9%
Figure 7: Prime Farmland Soils
Attachment 11, Page 30
NRI 2504 April 2025
26
LAND EVALUATION AND SITE ASSESSMENT (LESA)
Decision-makers in Kendall County use the Land Evaluation and Site Assessment (LESA) system to
determine the suitability of a land use change and/or a zoning request as it relates to agricultural land.
The LESA system was developed by the United States Department of Agriculture-Natural Resources
Conservation Service (USDA-NRCS) and takes into consideration local conditions such as physical
characteristics of the land, compatibility of surrounding land-uses, and urban growth factors. The LESA
system is a two-step procedure that includes:
LAND EVALUATION (LE)
The soils of a given area are rated and placed in groups ranging from the best to worst suited for a stated
agriculture use, cropland, or forestland. The best group is assigned a value of 100, and all other groups
are assigned lower values. The Land Evaluation is based on data from the Kendall County Soil Survey. The
LE score is calculated by multiplying the relative value of each soil type by the number of acres of that soil.
The sum of the products is then divided by the total number of acres; the answer is the Land Evaluation
score on this site. The Kendall County Soil and Water Conservation District is responsible for this portion
of the LESA system.
SITE ASSESSMENT (SA)
The site is numerically evaluated according to important factors that contribute to the quality of the site.
Each factor selected is assigned values in accordance with the local needs and objectives. The value group
is a predetermined value based upon prime farmland designation. The Kendall County LESA Committee is
responsible for this portion of the LESA system.
Please Note: A land evaluation (LE) score will be compiled for every project parcel. However, when a
parcel is located within municipal planning boundaries, a site assessment (SA) score is not compiled as the
scoring factors are not applicable. As a result, only the LE score is available, and a full LESA score is
unavailable for the parcel.
Table 8A: Land Evaluation Computation
Soil Type Value Group Relative Value Acres* Product (Relative Value x Acres)
152A 1 100 1.9 190.0
219A 3 87 1.2 104.4
318C2 6 69 2.1 144.9
791A 4 79 7.5 592.5
791B 4 79 8.1 639.9
20.8 1,671.7
LE Calculation (Product of relative value / Total Acres)
1,671.7 / 20.8 = 80.4
LE Score LE = 80
*Acreage listed in this chart provides a generalized representation and may not precisely reflect exact acres of each soil type.
Attachment 11, Page 31
NRI 2504 April 2025
27
The Land Evaluation score for this site is 80, indicating that the soils on this site are designated as land
that is well suited for agricultural uses considering the Land Evaluation score is at or above 80.
Table 8B: Site Assessment Computation
A. Agricultural Land Uses Points
1. Percentage of area in agricultural uses within 1.5 miles of site. (20-10-5-0) 5
2. Current land use adjacent to site. (30-20-15-10-0) 15
3. Percentage of site in agricultural production in any of the last 5 years. (20-15-10-5-0) 20
4. Size of site. (30-15-10-0) 10
B. Compatibility / Impact on Uses
1. Distance from city or village limits. (20-10-0) 0
2. Consistency of proposed use with County Land Resource Management Concept Plan
and/or municipal comprehensive land use plan. (20-10-0)
20
3. Compatibility of agricultural and non-agricultural uses. (15-7-0) 0
C. Existence of Infrastructure
1. Availability of public sewage system. (10-8-6-0) 8
2. Availability of public water system. (10-8-6-0) 8
3. Transportation systems. (15-7-0) 7
4. Distance from fire protection service. (10-8-6-2-0) 6
Site Assessment Score: 99
Land Evaluation Value: 80 + Site Assessment Value: 99 = LESA Score: 179
Table 9: LESA Score Summary
LESA SCORE LEVEL OF PROTECTION
0-200 Low
201-225 Medium
226-250 High
251-300 Very High
The LESA Score for this site is 179 which indicates a low level of protection for the proposed project
site. Selecting the project site with the lowest total points will generally protect the best farmland
located in the most viable areas and maintain and promote the agricultural industry in Kendall County.
Attachment 11, Page 32
NRI 2504 April 2025
28
LAND USE PLANS
Many counties, municipalities, villages, and townships have developed land-use plans. These plans are
intended to reflect the existing and future land-use needs of a given community. Please contact Kendall
County for information regarding their comprehensive land use plan and map.
DRAINAGE, RUNOFF, AND FLOOD INFORMATION
U.S.G.S Topographic maps give information on elevations, which are important mostly to determine
slopes, drainage directions, and watershed information.
Elevations determine the area of impact of floods of record. Slope information determines steepness and
erosion potential. Drainage directions determine where water leaves the PIQ, possibly impacting
surrounding natural resources.
Watershed information is given for changing land use to a subdivision type of development on parcels
greater than 10 acres.
WHAT IS A WATERSHED?
Simply stated, a watershed is the area of land that contributes water to a certain point. The watershed
boundary is important because the area of land in the watershed can now be calculated using an irregular
shape area calculator such as a dot counter or planimeter.
Using regional storm event information, and site-specific soils and land use information, the peak
stormwater flow through the point marked “” for a specified storm event can be calculated. This value
is called a “Q” value (for the given storm event) and is measured in cubic feet per second (CFS).
When construction occurs, the Q value naturally increases because of the increase in impermeable
surfaces. This process decreases the ability of soils to accept and temporarily hold water. Therefore, more
water runs off and increases the Q value.
Theoretically, if each development, no matter how large or small, maintains their preconstruction Q value
after construction by the installation of stormwater management systems, the streams and wetlands and
lakes will not suffer damage from excessive urban stormwater.
For this reason, the Kendall County SWCD recommends that the developer for intense uses, such as a
subdivision, calculate the preconstruction Q value for the exit point(s). A stormwater management system
Attachment 11, Page 33
NRI 2504 April 2025
29
should be designed, installed, and maintained to limit the postconstruction Q value to be at or below the
preconstruction value.
IMPORTANCE OF FLOOD INFORMATION
A floodplain is defined as land adjoining a watercourse (riverine) or an inland depression (non-riverine)
that is subject to periodic inundation by high water. Floodplains are important areas demanding
protection since they have water storage and conveyance functions which affect upstream and
downstream flows, water quality and quantity, and suitability of the land for human activity. Since
floodplains play distinct and vital roles in the hydrologic cycle, development that interferes with their
hydrologic and biologic functions should be carefully considered.
Flooding is both dangerous to people and destructive to their properties. The following maps, when
combined with wetland and topographic information, can help developers and future homeowners to
“sidestep” potential flooding or ponding problems.
Flood Insurance Rate Maps (FIRMs), produced by the Federal Emergency Management Agency (FEMA),
define flood elevation adjacent to tributaries and major bodies of water and superimpose that onto a
simplified USGS topographic map. The scale of the FIRM maps is generally dependent on the size and
density of parcels in that area. This is to correctly determine the parcel location and floodplain location.
The FIRM map has three (3) zones. Zone A includes the 100-year flood (1% annual chance flood), Zone B
or Zone X (shaded) is the 100 to 500-year flood (between limits of the 1% and the 0.2% annual chance
flood), and Zone C or Zone X (unshaded) is outside the floodplain (outside the 0.2% annual chance flood).
The Hydrologic Atlas (H.A.) Series of the Flood of Record Map is also used for the topographic information.
This map is different from the FIRM map mainly because it will show isolated or pocketed flooded areas.
Kendall County uses both these maps in conjunction with each other for flooded area determinations. The
Flood of Record maps show the areas of flood for various years. Both maps stress that the recurrence of
flooding is merely statistical. A 100-year flood may occur twice in one year, or twice in one week, for that
matter.
It should be noted that greater floods than those shown on the two maps are possible. The flood
boundaries indicated provide a historic record only until the map publication date. Additionally, these
flood boundaries are a function of the watershed conditions existing when the maps were produced.
Cumulative changes in runoff characteristics caused by urbanization can result in an increase in flood
height of future flood episodes.
Floodplains play a vital role in reducing the flood damage potential associated with an urbanizing area
and, when left in an undisturbed state, also provide valuable wildlife habitat benefits. If it is the
petitioner's intent to conduct floodplain filling or modification activities, the petitioner, and the Unit of
Government responsible need to consider the potentially adverse effects this type of action could have
on adjacent properties. The change or loss of natural floodplain storage often increases the frequency and
severity of flooding on adjacent property.
Attachment 11, Page 34
NRI 2504 April 2025
30
If the available maps indicate the presence of a floodplain on the PIQ, the petitioner should contact the
IDNR-OWR and FEMA to delineate a floodplain elevation for the parcel. If a portion of the property is
indeed floodplain, applicable state, county, and local regulations will need to be reflected in the site plans.
Another indication of flooding potential can be found in the soils information. Hydric soils indicate the
presence of drainage ways, areas subject to ponding, or a naturally occurring high water table. These need
to be considered along with the floodplain information when developing the site plan and the stormwater
management plan. Development on hydric soils can contribute to the loss of water storage within the soil
and the potential for increased flooding in the area.
Figure 8: Flood Map
Attachment 11, Page 35
NRI 2504 April 2025
31
Figure 9: Topographic Map
This parcel contains slopes of 0% to 6% with an elevation range of approximately 642’-654’ above sea
level. The highest point is in the northwest portion of the site, and the lowest point is along the
northern boundary. According to the FEMA Flood Map (Figure 8), the parcel does not appear to
contain areas of regulated floodplain or floodway. The parcel is mapped as Zone X (unshaded), an
area of minimal flood hazard determined to be outside of the 0.2% annual chance floodplain.
Attachment 11, Page 36
Attachment 11, Page 37
NRI 2504 April 2025
33
WETLAND INFORMATION
IMPORTANCE OF WETLAND INFORMATION
Wetlands function in many ways to provide numerous benefits to society. They control flooding by
offering a slow release of excess water downstream or through the soil. They cleanse water by filtering
out sediment and some pollutants and can function as rechargers of our valuable groundwater. They also
are essential breeding, rearing, and feeding grounds for many species of wildlife.
These benefits are particularly valuable in urbanizing areas as development activity typically adversely
affects water quality, increases the volume of stormwater runoff, and increases the demand for
groundwater. In an area where many individual homes rely on shallow groundwater wells for domestic
water supplies, activities that threaten potential groundwater recharge areas are contrary to the public
good. The conversion of wetlands, with their sediment trapping and nutrient absorbing vegetation, to
biologically barren stormwater detention ponds can cause additional degradation of water quality in
downstream or adjacent areas.
It has been estimated that over 95% of the wetlands that were historically present in Illinois have been
destroyed while only recently has the true environmental significance of wetlands been fully recognized.
America is losing 100,000 acres of wetland a year and has saved 5 million acres total (since 1934). One
acre of wetland can filter 7.3 million gallons of water a year. These are reasons why our wetlands are high
quality and important.
This section contains the National Wetlands Inventory, which is the most comprehensive inventory to
date. The National Wetlands Inventory is reproduced from an aerial photo at a scale of 1” equals 660 feet.
The NRCS developed these maps in cooperation with U.S. EPA (Environmental Protection Agency,) and
the U.S. Fish and Wildlife Service, using the National Food Security Act Manual, 3rd Edition. The main
purpose of these maps is to determine wetland areas on agricultural fields and areas that may be wetlands
but are in a non-agriculture setting.
The National Wetlands Inventory in no way gives an exact delineation of the wetlands, but merely an
outline, or the determination that there is a wetland within the outline. For the final, most accurate
wetland determination of a specific wetland, a wetland delineation must be certified by NRCS staff using
the National Food Security Act Manual (on agricultural land.) On urban land, a certified wetland delineator
must perform the delineation using the ACOE 1987 Manual. See the glossary section for the definitions of
“delineation” and “determination.”
Attachment 11, Page 38
NRI 2504 April 2025
34
Figure 11: Wetland Map
Office maps indicate that mapped wetlands/waters are not present on the parcel in question (PIQ).
To determine the presence of wetlands, a wetland delineation specialist, who is recognized by the
U.S. Army Corps of Engineers, should determine the exact boundaries and value of the wetlands.
Attachment 11, Page 39
NRI 2504 April 2025
35
HYDRIC SOILS
Soils information gives another indication of flooding potential. The soils map on the following page
indicates the soil(s) on the parcel that the Natural Resources Conservation Service indicates as hydric.
Hydric soils, by definition, have seasonal high water at or near the soil surface and/or have potential
flooding or ponding problems. All hydric soils range from poorly suited to unsuitable for building. One
group of the hydric soils are the organic soils, which formed from dead organic material. Organic soils are
unsuitable for building because of not only the high water table but also their subsidence problems.
It is important to add the possibility of hydric inclusions in a soil type. An inclusion is a soil polygon that is
too small to appear on these maps. While relatively insignificant for agricultural use, hydric soil inclusions
become more important to more intense uses such as a residential subdivision.
While considering hydric soils and hydric inclusions, it is noteworthy to mention that subsurface
agriculture drainage tile occurs in almost all poorly drained and somewhat poorly drained soils. Drainage
tile expedites drainage and facilitates farming. It is imperative that these drainage tiles remain
undisturbed. A damaged subsurface drainage tile may return original hydrologic conditions to all the areas
that drained through the tile (ranging from less than one acre to many square miles.)
For an intense land use, the Kendall County SWCD recommends the following: a topographical survey with
1 foot contour intervals to accurately define the flood area on the parcel, an intensive soil survey to define
most accurately the locations of the hydric soils and inclusions, and a drainage tile survey on the area to
locate the tiles that must be preserved to maintain subsurface drainage.
Table 10: Hydric Soils
Soil Types Drainage Class Hydric
Designation
Hydric
Inclusions Likely
Hydric
Rating % Acreage Percent
152A Poorly Drained Hydric N/A 100% 1.9 9.0%
219A Somewhat Poorly Drained Non-Hydric Yes 3% 1.2 5.8%
318C2 Well Drained Non-Hydric No 0% 2.1 10.1%
791A Well Drained Non-Hydric Yes 6% 7.5 36.1%
791B Well Drained Non-Hydric Yes 6% 8.1 39.0%
Attachment 11, Page 40
NRI 2504 April 2025
36
Figure 12: Hydric Soil Map
Attachment 11, Page 41
NRI 2504 April 2025
37
WETLAND AND FLOODPLAIN REGULATIONS
The laws of the United States and the State of Illinois assign certain agencies specific and different
regulatory roles to protect the waters within the State's boundaries. These roles, when considered
together, include protection of navigation channels and harbors, protection against floodway
encroachments, maintenance and enhancement of water quality, protection of fish and wildlife habitat
and recreational resources, and, in general, the protection of total public interest. Unregulated use of the
waters within the State of Illinois could permanently destroy or alter the character of these valuable
resources and adversely impact the public. Therefore, please contact the proper regulatory authorities
when planning any work associated with Illinois waters so that proper consideration and approval can be
obtained.
WHO MUST APPLY?
Anyone proposing to dredge, fill, rip rap, or otherwise alter the banks or beds of, or construct, operate,
or maintain any dock, pier, wharf, sluice, dam, piling, wall, fence, utility, floodplain or floodway subject to
State or Federal regulatory jurisdiction should apply for agency approvals.
REGULATORY AGENCIES
• Wetland or U.S. Waters: U.S. Army Corps of Engineers, Chicago District, 231 South LaSalle Street,
Suite 1500, Chicago, IL 60604. Phone: (312) 846-5530
• Floodplains: Illinois Department of Natural Resources - Office of Water Resources, One Natural
Resources Way, Springfield, IL 62702-1270. Phone: (217) 782-6302
• Water Quality/Erosion Control: Illinois Environmental Protection Agency, 1021 North Grand
Avenue East, P.O. Box 19276, Springfield, IL 62794-9276. Phone: (217) 782-3397
COORDINATION
We recommend early coordination with the regulatory agencies BEFORE finalizing work plans. This allows
the agencies to recommend measures to mitigate or compensate for adverse impacts. Also, the agency
can make possible environmental enhancement provisions early in the project planning stages. This could
reduce time required to process necessary approvals.
PLEASE READ THE FOLLOWING IF YOU ARE PLANNING TO DO ANY WORK NEAR A STREAM (THIS
INCLUDES SMALL UNNAMED STREAMS), LAKE, WETLAND OR FLOODWAY.
CAUTION: Contact with the United States Army Corps of Engineers is strongly advised before
commencement of any work in or near a Waters of the United States. This could save considerable
time and expense. Persons responsible for willful and direct violation of Section 10 of the River and
Harbors Appropriation Act of 1899 or Section 404 of the Clean Water Act are subject to fines ranging
up to $16,000 per day of violation, with a maximum cap of $187,500 in any single enforcement action,
as well as criminal enforcement.
Attachment 11, Page 42
NRI 2504 April 2025
38
GLOSSARY
AGRICULTURAL PROTECTION AREAS (AG AREAS) - Allowed by P.A. 81-1173. An AG AREA consists of a
minimum of 350 acres of farmland, as contiguous and compact as possible. Petitioned by landowners, AG
AREAS protect for a period of ten years initially, then reviewed every eight years thereafter. AG AREA
establishment exempts landowners from local nuisance ordinances directed at farming operations, and
designated land cannot receive special tax assessments on public improvements that do not benefit the
land, e.g. water and sewer lines.
AGRICULTURE - The growing, harvesting and storing of crops including legumes, hay, grain, fruit and truck
or vegetable including dairying, poultry, swine, sheep, beef cattle, pony and horse production, fur farms,
and fish and wildlife farms; farm buildings used for growing, harvesting and preparing crop products for
market, or for use on the farm; roadside stands, farm buildings for storing and protecting farm machinery
and equipment from the elements, for housing livestock or poultry and for preparing livestock or poultry
products for market; farm dwellings occupied by farm owners, operators, tenants or seasonal or year
around hired farm workers.
BEDROCK - Indicates depth at which bedrock occurs. Also lists hardness as rippable or hard.
FLOODING - Indicates frequency, duration, and period during year when floods are likely to occur.
HIGH WATER TABLE - A seasonal high water table is a zone of saturation at the highest average depth
during the wettest part of the year. May be apparent, perched, or artesian kinds of water tables.
• Water table, Apparent: A thick zone of free water in the soil. An apparent water table is indicated
by the level at which water stands in an uncased borehole after adequate time is allowed for
adjustment in the surrounding soil.
• Water table, Artesian: A water table under hydrostatic head, generally beneath an impermeable
layer. When this layer is penetrated, the water level rises in an uncased borehole.
• Water table, Perched: A water table standing above an unsaturated zone. In places an upper, or
perched, water table is separated from a lower one by a dry zone.
DELINEATION - For Wetlands: A series of pink or orange flags placed on the ground by a certified
professional that outlines the wetland boundary on a parcel.
DETERMINATION - A polygon drawn on a map using map information that gives an outline of a wetland.
HYDRIC SOIL - This type of soil is saturated, flooded, or ponded long enough during the growing season
to develop anaerobic conditions in the upper part (USDA Natural Resources Conservation Service 1987).
INTENSIVE SOIL MAPPING - Mapping done on a smaller more intensive scale than a modern soil survey
to determine soil properties of a specific site, e.g. mapping for septic suitability.
Attachment 11, Page 43
NRI 2504 April 2025
39
LAND EVALUATION AND SITE ASSESSMENT (L.E.S.A.) - LESA is a systematic approach for evaluating a
parcel of land and to determine a numerical value for the parcel for farmland preservation purposes.
MODERN SOIL SURVEY - A soil survey is a field investigation of the soils of a specific area, supported by
information from other sources. The kinds of soil in the survey area are identified and their extent shown
on a map, and an accompanying report describes, defines, classifies, and interprets the soils.
Interpretations predict the behavior of the soils under different used and the soils' response to
management. Predictions are made for areas of soil at specific places. Soils information collected in a soil
survey is useful in developing land-use plans and alternatives involving soil management systems and in
evaluating and predicting the effects of land use.
PERMEABILITY - Values listed estimate the range (in rate and time) it takes for downward movement of
water in the major soil layers when saturated but allowed to drain freely. The estimates are based on soil
texture, soil structure, available data on permeability and infiltration tests, and observation of water
movement through soils or other geologic materials.
PIQ - Parcel in question
POTENTIAL FROST ACTION - Damage that may occur to structures and roads due to ice lens formation
causing upward and lateral soil movement. Based primarily on soil texture and wetness.
PRIME FARMLAND - Prime farmland soils are lands that are best suited to food, feed, forage, fiber and
oilseed crops. It may be cropland, pasture, woodland, or other land, but it is not urban and built up land
or water areas. It either is used for food or fiber or is available for those uses. The soil qualities, growing
season, and moisture supply are those needed for a well-managed soil economically to produce a
sustained high yield of crops. Prime farmland produces in highest yields with minimum inputs of energy
and economic resources and farming the land results in the least damage to the environment. Prime
farmland has an adequate and dependable supply of moisture from precipitation or irrigation. The
temperature and growing season are favorable. The level of acidity or alkalinity is acceptable. Prime
farmland has few or no rocks and is permeable to water and air. It is not excessively erodible or saturated
with water for long periods and is not frequently flooded during the growing season. The slope ranges
mainly from 0 to 5 percent (USDA Natural Resources Conservation Service).
SEASONAL - When used in reference to wetlands indicates that the area is flooded only during a portion
of the year.
SHRINK-SWELL POTENTIAL - Indicates volume changes to be expected for the specific soil material with
changes in moisture content.
SOIL MAPPING UNIT - A map unit is a collection of soil areas of miscellaneous areas delineated in mapping.
A map unit is generally an aggregate of the delineations of many different bodies of a kind of soil or
miscellaneous area but may consist of only one delineated body. Taxonomic class names and
accompanying phase terms are used to name soil map units. They are described in terms of ranges of soil
properties within the limits defined for taxa and in terms of ranges of taxadjuncts and inclusions.
Attachment 11, Page 44
NRI 2504 April 2025
40
SOIL SERIES - A group of soils, formed from a particular type of parent material, having horizons that,
except for texture of the A or surface horizon, are similar in all profile characteristics and in arrangement
in the soil profile. Among these characteristics are color, texture, structure, reaction, consistence, and
mineralogical and chemical composition.
SUBSIDENCE - Applies mainly to organic soils after drainage. Soil material subsides due to shrinkage and
oxidation.
TOPSOIL - That portion of the soil profile where higher concentrations of organic material, fertility,
bacterial activity and plant growth take place. Depths of topsoil vary between soil types.
WATERSHED - An area of land that drains to an associated water resource such as a wetland, river or lake.
Depending on the size and topography, watersheds can contain numerous tributaries, such as streams
and ditches, and ponding areas such as detention structures, natural ponds and wetlands.
WETLAND - An area that has a predominance of hydric soils and that is inundated or saturated by surface
or groundwater at a frequency and duration sufficient enough to support, and under normal
circumstances does support, a prevalence of hydrophytic vegetation typically adapted for life in saturated
soil conditions.
Attachment 11, Page 45
NRI 2504 April 2025
41
REFERENCES
Association of Illinois Soil & Water Conservation Districts. 2020. Illinois Urban Manual.
Berg, R. C., and J. P. Kempton. 1984. Potential for contamination of shallow aquifers from land burial of
municipal wastes: Champaign, Illinois, Illinois State Geological Survey map, scale 1:500,000.
Clean Water Act of 1972, Sections 309 and 404.
Federal Emergency Management Agency. National Flood Hazard Layer (NFHL) Viewer.
https://hazards-
fema.maps.arcgis.com/apps/webappviewer/index.html?id=8b0adb51996444d4879338b5529aa
9cd. Accessed February 2025.
Illinois State Geological Survey, Department of Natural Resources. 2021. Geologic Road Map of Illinois.
Kendall County Department of Planning Building and Zoning and Kendall County Soil and Water
Conservation District In cooperation with NRCS, USDA. Land Evaluation and Site Assessment
System.
Kendall County. 2023. Land Resource Management Plan Map.
Natural Resources Conservation Service, United States Department of Agriculture. General Manual, Title
310, Land Use.
Natural Resources Conservation Service, United States Department of Agriculture. 2007. Hydric Soils of
the United States.
Natural Resources Conservation Service, United States Department of Agriculture. Hydrologic Unit
Map for Kendall County.
Natural Resources Conservation Service, United States Department of Agriculture. 1987. Soil Erosion by
Water. Agriculture Information Bulletin 513.
Natural Resources Conservation Service, United States Department of Agriculture. 2008. Soil Survey of
Kendall County.
Natural Resources Conservation Service, United States Department of Agriculture. Web Soil Survey.
http://websoilsurvey.sc.egov.usda.gov/. Accessed February 2025.
Rivers and Harbors Appropriation Act of 1899, Section 10.
Rockford Map Publishers, Inc. 2021. Land Atlas and Plat Book, Kendall County, Illinois, 21st Edition.
United States Fish & Wildlife Service. 2018. National Wetlands Inventory.
https://data.nal.usda.gov/dataset/national-wetlands-inventory. Accessed February 2025.
Nature Conservancy (U.S.) Great Lakes Program. 1994. The Conservation of Biological Diversity in the
Great Lakes Ecosystem: Issues and Opportunities. The Program, 1994.
Attachment 11, Page 46
Noise Impact Considerations
Perivoliotis CSG - Samuel’s Solar 2 LLC
Version 1
February, 2025
Attachment 12, Page 1
2
Table of Contents
Project overview 3
Site location and design 4
Project Design Overview 5
Noise terminology and thresholds 6
Definition
Common Construction Noise
Corona Noise
Vibrations
Federal Noise Regulations
Illinois Noise Regulations
Project Noise Impact 9
Phase I: Construction
Phase II: Operation
Phase III Decommissioning
Conclusion of Noise Impacts 11
Sources 12
Attachment 12, Page 2
3
Project Overview
Zepelak CSG is a community solar garden that will employ a fixed tilt solar array proposed in Kendall
County, IL. The project will be developed on previously cropped and developed farm land. The total area
will encompass approximately 20.1 acres.
The project will consist of three phases which could potentially cause noise pollution: (1) a construction
phase of approximately 6-12 months, (2) a project lifetime of approximately 30-35 years, and (3) a
decommissioning phase of approximately 20-25 weeks.
The following document is a preliminary analysis of potential noise caused by the three phases of this
community solar project. The noise-causing equipment will be highlighted and analyzed for each phase
of the project.
*The following document was prepared by Enterprise Energy LLC, a community solar developer and not
a professional acoustic consultant. Data and information for this analysis was acquired by a 47 page
Noise Impact Analysis performed by AECOM Environmental for a 250MW solar project in a similar
developed farm landscape in Imperial County, California (1).
Attachment 12, Page 3
4
Site Location and Design
Site Address: Zepelak Community Solar Garden,
Samuel’s Solar 2 LLC
9318 Corneils Ave
Yorkville, IL
60560
Site Developer: Enterprise Energy LLC
Developer Contact: Dan Gorman
Tel:
Attachment 12, Page 4
5
Project Design
For standard noise reduction practices, all construction and operating equipment during the project’s
lifetime will be located at least 50’ from the parcel boundary. Decibel thresholds are measured at a
distance of 50’ from the sound source.
All diesel equipment should be operated with appropriate mufflers, and with engine doors closed.
Whenever possible, electrical power should be used in place of generators, to reduce noise.
Construction will occur only between 7:00 AM and 7:00 PM Monday through Friday, 9:00 AM to 5:00 PM
on Saturdays, and no operation of equipment on Sundays
Any inverters located within 100’ of a residence will be shielded with some type of structural barrier to
reduce noise to less than 10dBA continuous noise level.
Facility components include:
1. PV modules and Single Axis Trackers
2. Inverters
3. Transformer
4. Switchgears
Attachment 12, Page 5
6
Noise Terminology and Thresholds
Noise is typically described as unwanted sound. Sound is mechanical energy transmitted as a wave
through a fluid to a hearing organ. Sound is described by frequency and amplitude, that define pitch and
loudness respectively. The audible frequency range for humans is 20Hz-20,000Hz.
Noise effects on humans range from annoyance to hearing impairment, depending on the pitch and
loudness, which is defined in decibels (dB). A-weighted noise levels are decibel measurements, but
weighted similarly to the Richter scale, to reflect how the human ear perceives sound. The human ear
perceives loudness depending on the frequency of the sound, which is different from the purely physical
wave intensity. All noise levels in this report are therefore reported in A-weighted decibels (dBA).
Typical Construction Noise Levels:
Attachment 12, Page 6
7
Corona Noise
Corona noise is emitted when the intensity of an electric field surrounding a conductor exceeds the rating
of its insulator, causing a dissipation of energy that may result in audible noise. Irregularities or water on
the surface of the insulator surface can make audible corona noise more likely. Audible noise from
conductors is more likely during wet weather. See below for a table of noise levels for wet transmission
lines (the “worst-case scenario”).
Vibration and Vibration Noise
Construction can also generate vibrations, defined as waves traveling through mass, such as soil.
Vibrations from construction sources do not typically reach levels that could cause any structural damage
to nearby residences or other structures. Damage could be possible depending on the construction
activity, for structures within 25 feet of activity. Vibrations dissipate greatly due to dispersion and friction
losses the further from the source of vibration, so keeping all residences at least 50 feet away from the
project should eliminate any risk of vibration-borne damage.
Vibrations can, however, cause annoyance to humans. See the table below for effects of vibration on
people and structures
Attachment 12, Page 7
8
In keeping construction activities at least 50’ from occupied residences, no vibrations that exceed
annoyance levels will be experienced at neighboring properties.
Federal Noise Regulations
Federal noise regulations were developed following the recognition of noise impact on humans in the
Noise Control Act of 1972.
The Occupational Safety and Health Administration agency (OSHA) limits noise exposure for workers to
90dB Leq or less for 8 hours and 105 dB Leq for 1 hour. Appropriate noise PPE shall be worn by all
workers.
The EPA recommends that noise levels be limited to 55 dBA average over 24 hours, in order to protect
human welfare. A 70 dBA average should not be exceeded in order to prevent hearing loss (2).
Illinois Pollution Board Regulations
The Illinois Noise Related Statutes and Regulations document (3) classifies our project as Industrial or
Non-building Construction, corresponding to LBCS Function Code 7450. Using this LBCS code classifies
our project as a Class C Land Use according to Illinois Pollution Control Board’s Environmental
Protection Document: Subtitle H: Noise (4).
The Environmental Protection Document: Subtitle H: Noise recommends daytime (6:00AM to 11:00PM)
noise levels be limited to 58 dBA, except explosive noise which cannot exceed 107 dBA, when measured
25’ from neighboring property lines. As construction activities will always be at a minimum 200’ from
neighboring residences, these limits are not likely to be exceeded. However, when construction begins,
sound testing may be done at neighboring parcel lines to confirm levels are in compliance with both the
EPA and the Illinois Noise Regulations.
Attachment 12, Page 8
9
Noise Impact:
Phase I: Construction Activities
Approximately 6-12 months
Initial development would begin with grading and building of the access road, followed by the
establishment of temporary laydown areas, as designated by the final site plan. On this laydown area,
equipment may include, but is not limited to: construction trailer, temporary restroom, parking area,
material receiving and storage, recycling and waste area, construction power sources.
Daily road usage activities include, but are not limited to: delivery of construction equipment, project
materials, and worker trips. Number of vehicles and workers expected could vary throughout the
construction period.
Construction of the array may include, but is not limited to: grading, compacting, excavating. Equipment
used for such activities may include, but is not limited to: backhoes, bulldozers, pile drivers, excavation
equipment, as well as hand tools.
Equipment likely to generate the most noise (as seen in Table 4), are earth moving and pile-driving
equipment, which generate approximately 85 dBA at 50 feet. This maximum noise level would last
between 2-4 minutes at a time. Average noise levels during array construction would be around 75 dBA
at 50 feet.
However, as our project is unlikely to require much, if any grading (other than for the 1250 foot access
road), maximum and average noise levels during construction time would likely be lower than these
“worts-case scenario” levels.
Equipment usage and construction activities will be limited to the hours of 7:00 AM to 7:00 PM Monday
through Friday, 9:00 AM to 5:00 PM on Saturdays, and no operation of equipment on Sundays
Phase II: Operation
Approximately 30-35 years
Operational activities would generate low levels of noise, and be limited to daylight hours (when PV
arrays operate), which is when other ambient noise is generally highest. Daily noise would come from
operation of the inverter when electricity is being produced, the transformer, the small motors for the
trackers, and potentially the corona noise from the feeder lines.
Inverter: The Solectria 250kW inverter is rated at 67 dBA at 10 feet, as per the manufacturer’s data spec
sheet. Using sound attenuation inverse square law, noise levels at 50 feet would therefore be
approximately 53 dBA. This is the maximum noise output of the inverter at 50 feet, so noise levels for
residences more than 100 feet away would be considerably less. Furthermore, the maximum noise levels
would only occur during daylight hours, so the 24-hour average noise level would be much less, and far
below regulatory requirements.
Attachment 12, Page 9
10
Transformer: The exact model of transformer used for this project will be determined by the Utility that is
responsible for our interconnection. However, average decibel levels for medium voltage transformers
between 2001-2500 kVa, appropriate for our project size, are 62 dBA. This level is at 50 feet, and our
transformers will be 100+ feet from any residence.
Single Axis Trackers: These small motors are what use power to slowly rotate the modules throughout
the day to maximize solar input. The trackers rotate from -52° to +52° throughout the day, rotating
roughly 1° every 3.5 minutes. The motors are stored in housing compartments, which greatly reduce the
noise levels such that they should not have any significant effect on the overall project noise impact.
Another possible source of noise would be the friction between the linkages between the tracker rods
and the modules. Again, this noise will be insignificant (5).
Corona Noise: Feeder lines at this site are 12kV which is far below the minimum of 138kV listed in Table
5. As corona noise levels decrease with voltage, the noise emitted from the 12kV feeder line will likely be
negligible.
Phase III: Decommissioning
Approximately 20-25 weeks
Decommissioning will likely consist of activities including but not limited to excavation, ground work,
pile-driving, and most other activities also associated with project construction. Therefore levels of noise
would be similar to those of construction, and will be below regulatory thresholds. Decommissioning
should last only approximately 20-25 weeks.
Attachment 12, Page 10
11
Conclusion:
As no phase of project lifetime (construction, operation, or decommissioning) is likely to exceed federal
or local regulatory thresholds when performed at the setbacks as designed in the site plan, this project
does not plan any further noise mitigation efforts.
Attachment 12, Page 11
12
Sources
1. AECOM. (2014). Noise Impact Analysis: Wistaria Ranch Solar Energy Center Project, Imperial
County, California. Prepared for Wistaria Ranch Solar, LLC. Retrieved from
https://www.icpds.com/assets/planning/final-environmental-impact-reports/wistaria-ranch-solar-en
ergy-center/019appf-noise.pdf.
2. US EPA, OA. “EPA Identifies Noise Levels Affecting Health and Welfare.” Www.epa.gov, 2 Apr. 1974,
www.epa.gov/archive/epa/aboutepa/epa-identifies-noise-levels-affecting-health-and-welfare.html.
3. Illinois Noise Related Statutes and Regulations. (n.d.). Retrieved from
https://noisefree.org/wp-content/uploads/2017/12/illinois.pdf.
4. Illinois Pollution Control Board, Title 35: Environmental Protection, Subtitle H: Noise, Chapter
I: Pollution Control Board, Part 901: Sound Emission Standards and Limitations for
Property Line-Noise-Sources, effective November 1, 2018.
5. Hankard Environmental, Inc. (2019). 1 Noise Measurement and Analysis Results for the Luning Solar
Energy Center. 2 Public Service Commission of Wisconsin. 3 PSC REF#:384115. Retrieved from
[link to document if available].
6. https://www.makeitelectric.org/nema-standards-technologies/nema-standards/
Attachment 12, Page 12
Attachment 13, Page 1
Attachment 13, Page 2
Attachment 13, Page 3
Attachment 13, Page 4
Attachment 13, Page 5
Attachment 13, Page 6
Attachment 13, Page 7
Attachment 13, Page 8
Attachment 13, Page 9
Attachment 13, Page 10