HomeMy WebLinkAboutNC0043532_Environmental Assessment_19941011NPDES DOCUHENT SCANNING COVER SHEET
NPDES Permit:
NC0043532
West Stanly / Oakboro WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
1
Document Date:
October 11, 1994
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AN ENVIRONMENTAL ASSESSMENT
Title of Activity
Town of Oakboro
Water and Waste Water Service to Annexed Areas
Responsible Agency,
Department of Environment, Health and Natural Resources
Division of Environmental Management
Name, Address and Telephone Number of State Agency Contact Person
Ms. Monica Swihart
Water Quality Planning
Division of Environmental Management
P.O. Box 29535
Raleigh, North Carolina 27626-0535
Telephone: (919) 733-5083
Garner, N.C. Boone, N.C.
October 11,1994
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Page 1
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TABLE OF CONTENTS
SECTION PAGE
1.) EXISTING ENVIRONMENT 2
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2.) PROJECT SUMMARY 2
1.4 3.) NEED FOR Tfil PROPOSED PROJECT 4
1.1 4.) ALTERNATIVE ANALYSIS 5
5.) ENVIRONMENTAL CONSEQUENCES 10
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6.) MITIGATIVE MEASURES 16
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7.) SUMMARY 16
APPENDIX 1- ANNEXATION STUDY
m, APPENDIX 2- DEHNR LETTER DETAILING SPECULATIVE LIMITS
FIGURE 1- ROAD MAP
FIGURE 2 - ANNEXATION AREA 1
FIGURE 3 - ANNEXATION AREA 2
FIGURE 4 - ANNEXATION AREA 3
FIGURE 5 - ANNEXATION AREA 4
'.' FIGURE 6 - PREVIOUS CORPORATE LIlVIITS
FIGURE 7 - SOIL SURVEY MAP
r., FIGURE 8 - US GEOLOGICAL SURVEY MAP
FIGURE 9 - TYPICAL SOILS PROFILE
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TABLE 11 - SANITARY FACILITY EVALUATION FROM SOIL SURVEY
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1.) EXISTING ENVIRONMENT
Topography
Oakboro lies in the southwestern portion of central North Carolina in the Rocky River
basin. A road map of Oakboro is shown in Figure 1. The topography in this region varies
from nearly level to gently sloping. Elevations in the Oakboro planning area range from
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500 to 550 feet above mean sea level. Drainage characteristics in and around the
Oakboro planning area vary from somewhat poorly drained to well drained due to soil
types, gradual slopes and low-lying areas. Drainage from the Oakboro area flows south
into the Rocky River which continues east until it joins with the Pee Dee River. The Pee
Dee River flows southeast and eventually enters the Atlantic Ocean.
Land Use
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Land use within the Planning Area is controlled by the Town of Oakboro. The Town's
jurisdiction is limited to the area within its Town Limits and extraterritorial sections. The
Oakboro Town Council adopted the current zoning ordinance to regulate residential and
commercial development and use of all public and private land within the Town's
for' jurisdiction. The Planning Board reviews plans for development and makes
recommendations regarding growth in Oakboro. In addition, the Planning Board advises
the Town Council on each rezoning request.
The majority of land in the Oakboro planning area is used for single family residences and
some small farms. However, there are some industrial and commercial enterprises within
the Oakboro Town Limits.
2.) PROJECT SUMMARY
An Annexation Study for this annexation project is attached to this document as
Appendix 1. This study details the annexation areas and the improvements proposed
within each area. There are four annexation areas to be added as part of this project, and
the basic purpose of each annexation project is to serve all annexed properties with public
water and sewer connections. Most of the lines added will be new sewer lines, although
there will be some water line work directed toward the upgrade of existing lines which
are undersized or antiquated.
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In addition to the line work, an expansion to the existing waste water treatment plant is
proposed to increase their capacity from 0.5 MGD to 0.9 MGD. The expansion may
include a new grit chamber, bar screening equipment, pumps and controls, aeration basin,
aeration equipment, and secondary clarifier. There will also be provisions for sludge
management to satisfy EPA guidelines, and improvements or additions to the chlorination
and dechlorination capabilities. It is estimated that this annexation project could generate
as much as 25,000 gallons per day of additional waste water flow. In addition to the
annexation increases, at least two schools within Stanly County would like to be able to
connect onto the Oakboro waste water treatment plant.
The performance of the waste water treatment plant will be targeted toward the
speculative limits provided by the DEHNR in their letter of July 28, 1994. The limits
expressed are as follows:
Long Creek
Rocky River
Parameter
Summer
Winter
Summer
Winter
Waste flow
(MGD)
0.9
0.9
0.9
0.9
BOD5
(mg/1)
9
18
9
18
NH3-N
(mg/1)
3
6
3
6
DO
(mg/1)
5
5
5
5
TSS
(mg/0
30
30
30
30
Fecal Coliform
(#/100m1)
200
200
200
200
pH
(SU)
6-9
6-9
6-9
6-9
Chlorine
(µ)
28
28
28
28
The water supply for the Town of Oakboro is obtained from a 12" water main that is
connected to the Stanly County system and one well which is located at the corner of
Misty Lane and Ashley Drive. The water supply available to Oakboro through these two
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sources is sufficient to supply all of their current water needs plus the needs of the
annexed areas. Oakboro also has a 100,000 gallon elevated storage tank to provide for
water storage and to increase pressure in their water distribution lines. The main water
meter for the 12" water line is located at the intersection of North Haywood Street and
1.1
East Eighth Street. It is proposed as part of this annexation project to move the main
water meter to the new corporate limits to prevent duplicate distribution lines within the
corporate limits. Since the Town cannot place taps on the water main in advance of the
main meter, any connections desired behind the meter would have to be served with
distribution lines that run parallel to and probably adjacent to the water main. Moving the
water meter to the edge of the corporate limits would preclude that possibility until
additional areas are annexed.
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Financing for this project will be provided through FmHA and/or through the issuance of
revenue bonds from a local bank. Construction should begin on this project within
eighteen months of the completion of the review of the environmental assessment.
3.) NEED FOR THE PROPOSED PROJECT
The Town of Oakboro is projected to expand from a 1992 population of 1206 to a
population of 1488 by the year 2000, and a population of 1558 by the year 2010. The
annexed areas represent recent housing increases, and the general growth trend in Stanly
County approximates the same growth rate in Oakboro. The population is expected to
grow from 6000 in 1992 to 7590 in the year 2000, and to 11238 in the year 2010. Towns
are legally required to provide certain services to annexed areas, and water and sewer
services are included in these services. Since these areas have already been annexed, the
Town will be required to provide service to these areas. Portions of these areas are
�► served by existing lines, some of which will not be adequate to serve as part of the
distribution and collection system for the overall utility plan for newly annexed areas.
Plan sheets showing the annexed areas and the proposed water and sewer distribution
systems are attached as Figures 2-5.
The waste water treatment plant will need to be expanded to meet the increased flow that
will result from the expanded collection system that will serve the annexed areas. In
addition to the annexed areas, two schools within reach of the Oakboro waste water
collection system are considering connecting onto public sewer due to the failure of their
onsite septic systems. Consolidating the collection system such that the schools and the
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new industry can be connected onto a single collection line and piped to a site where the
sewage can be treated in a well designed and monitored treatment system will help to
reduce costs of treatment within Stanly County and will also allow for the removal of
septic systems which are failing and could create groundwater contamination problems.
4.) ALTERNATIVE ANALYSIS
In many cases, there are viable alternatives to the expansion of mechanical waste water
treatment plants that discharge to surface waters. Spray irrigation systems, constructed
wetlands, routing increased or surplus flows to existing plants that are underutilized, and
the requirement that additional industries, commercial developments, or residential
developments construct their own waste water treatment systems are all options to
increasing the capacity of an existing plant. Allowing the existing plant to remain in place
and preventing flow expansion through flow moratoriums or removal of excessive
infiltration and inflow are also possibilities. All of these alternatives will be discussed in
detail for Oakboro, with the advantages and disadvantages of each described. It is
important to note that as with any alternative analysis, virtually any option can be made
to work if it is assumed that neither time or money is a constraint. Since time and money
are usually the major constraints on the design and selection process, the alternative
selected is usually chosen because it is the most efficient and practical solution in terms of
time and money for the foreseeable future. With these criteria in mind, the discussion of
the alternative analysis is as follows:
SPRAY IRRIGATION SYSTEMS
Spray irrigation systems can be an excellent means of waste water disposal. Influent can
be pretreated in ponds or lagoons to remove the majority of the BOD and suspended
solids, and the effluent from the pre treatment is then land applied over a relatively large
area of land with a suitable cover crop. The land application of waste water can create
some cash return if the cover crop selected has economic value, and so the cover crop is
often selected on that basis. Cover crops selected may be rotated on a seasonal or annual
basis, or a combination of both. Depending on the exact nature of the waste water,
application of water on the crops may provide both a consistent source of water and
essential plant nutrients, and the result may be luxurious plant growth. Since the waste
water is applied on land, it is relatively easy to inspect the application area for problems
of puddling, soil poisoning, erosion, or uneven application.
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Spray irrigation also has some limitations. The land application area will be relatively
large, with an equal area set aside as a reserve area. All soil intended for land application
must be compatible with that type of treatment, and be able to drain reasonably well as
well as provide adequate treatment of the waste water in the soil. Also, it is essential that
a suitable cover crop can be maintained year round to provide a sink for the plant
nutrients contained in the waste water, to help prevent erosion, to provide a sink for any
heavy metals in the waste water, and to allow for a greater evaporation rate from the
ground through the increased surface area provided by lush plant growth. Soil types or
climates which are unsuitable for year round crops or with poorly drained or very coarse
soils will not be economically adaptable to spray irrigation systems. Also, large land areas
that can be used for this type of treatment must be available at a reasonable cost. Spray
irrigation systems also require constant maintenance and observation to keep them
running at peak efficiency.
In the case of Oakboro, some of the criteria for a spray irrigation system appear to be
met. The soil map made by the Soil Conservation Service indicates that the majority of
the soils around the Oakboro area are moderately well drained. The predominant soils in
the Oakboro area are the Misenheimer-Kirksey-Badin series, and these soils are
characterized by a loamy surface layer, and a loamy to clayey subsoil. These soils occur
primarily on nearly level to gentle slopes, and in depressions or along the flats of
intermittent drainage ways. A soils map from the Soil Survey of Stanly County published
by the Soil Conservation Service is included as Figure 7. The climate in the area is also
favorable for crop growth, with a long growing season and adequate rainfall.
Closer examination of the soil profiles reveals some serious limitations of the soils for use
in septic or spray application systems. The relatively shallow surface and subsurface soils
are underlain by argillite, or slate, which creates an effectively impermeable layer to
drainage. The typical soil profile shown in Figure 9 for the area shows a shallow and
substantial slate layer which inhibits soil drainage and treatment. Table 11 from the Soil
Survey indicates that the Badin, Kirksey, and Misenheimer soil types all have severe
limitations for use as sanitary facilities due to the shallow depth to rock and to excessive
clay.
The soil properties are also poorly suited to crop production. The Soil Survey states that
"None of the soils in Stanly County have enough natural fertility to produce economic
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returns on crops." Corn and soybeans are the primary crops in Stanly County, and the
Badin soils are suitable for some production of these crops provided that lime is added to
the soil regularly to control the soil pH. The naturally occurring soil tends to be acidic
enough that the availability of nutrients in the soil is reduced, and high acidity can also
increase the amount of exchangeable aluminum in the soil to the point where it becomes
toxic to the plants. Continuous monitoring and proper management can control the soil
acidity and fertility, but the requirements of such strict soil management when coupled
with the monitoring and management requirements of the applied waste water make the
operation of a spray irrigation system that much more difficult.
Because of the typical profile and crop production characteristics of the soil are generally
unfavorable for spray irrigation in the Oakboro area, the likelihood that a suitable site for
a spray application site will be found is poor. If the search area for an application area is
expanded to the northeast where the existing waste water treatment plant is located, the
same basic problems will occur even though the soil types are slightly different. Slightly
better soils are located to the northwest, but even if a usable application area could be
found there, the sewage collection system for Oakboro would have to .be rerouted to
accommodate the change in location for waste treatment. Even so, the soils there would
only be marginally usable for this type of treatment. Given the practical obstacles to the
alternative to spray application, this alternative does not appear to be economically
viable.
CONSTRUCTED WETLANDS
Constructed wetlands are an environmentally sound way of providing waste water
treatment for small communities. Constructed wetlands provide a manmade setting that
resembles a natural wetland to filter waste water. A typical constructed wetland consists
of a primary treatment lagoon, followed by one or several cells of secondary treatment in
a constructed wetland channel. The channel is constructed of a layer of gravel, soil, and
mulch resting on a liner. Wetland species plants are rooted into the soil base within the
channel. Primary treatment removes the bulk of the biological oxygen demand and
settleable solids. The constructed wetlands function to purify the waste water by
removing plant nutrients such as nitrogen and by trapping solid particles within the root
mass. Trace metals are also absorbed by the plant roots and by other organisms in the
wetland. The root mass helps to inhibit erosion of the soil base, and the solid particles
that collect over time help to restore any soil losses. Tertiary treatment can be provided in
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additional cells similar to the secondary cells, but the liner may be deleted to allow water
to infiltrate into the soil.
Constructed wetlands have several advantages over mechanical treatment systems. They
are aesthetically pleasing, they can be designed to use very little energy, and they can
provide habitat for some wetland species. Constructed wetlands also have some
disadvantages to mechanical treatment systems. Their treatment efficiency is subject to
temperature and sunlight, there is little or no opportunity to fine tune the treatment
process by mechanical control, the plants and organisms in the cells can be very sensitive
to toxins in the waste water, and replacement or maintenance is difficult and time
consuming. Constructed wetlands normally also require a larger land area than
mechanical treatment systems.
It is important to note that both mechanical treatment systems and constructed wetlands
both use similar biological processes to treat and purify water. Since constructed
wetlands do not have mechanical aeration, the water tends to have a lower oxygen
content, and the bacteria that digest the waste water are largely facultative or anaerobes.
Bacteria that digest the carbon in the more oxygen rich environments of mechanical
treatment plants tend be obligate aerobes, as well as facultative bacteria. In either type of
plant, it is likely that all types of bacteria will exist, and in either case, the processes by
which the bacteria take up the carbon to incorporate into their cell structure is similar.
In this case, constructed wetlands would likely be a poor choice for waste water
treatment. The growing population in Oakboro and Stanly County coupled with the
industrial input to the waste water treatment stream makes the use of constructed
wetlands less viable. Industrial contributions to waste water often create uneven flow
conditions, and the wetlands environment can be damaged by waste water components
from industries. Also, wetlands systems work best when a stable flow is maintained since
there is no way to mechanically alter the rate of flow through the plant. An area with a
growing population will have a difficult time in maintaining quality effluent flow with the
wetlands system. If the plant is designed for a larger flow initially, waste water may
remain in the system too long and an algal build up will result, creating problems with
suspended solids and biological oxygen demand. If the plant is designed for the initial
capacity, increased flow over time may result in retention times too short to obtain
adequate digestion of the waste water. Cells can be added over time to compensate for
increased flow, but such large scale additions are an imprecise way to control effluent
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Page 9
quality. Given these problems, constructed wetlands will not be the best choice for
Oakboro's needs.
ROUTING FLOW TO UNDERUTILIZED TREATMENT PLANTS
In some instances, a municipality will have more than one waste water treatment plant,
and flow is often routed to the plants in a disproportionate way. In the case of Oakboro,
there are no other underutilized plants in the area, so this option does not exist for the
Town of Oakboro.
REQUIRING PRIVATE TREATMENT SYSTEMS
Many private homes and some industries have their own waste water treatment plants or
septic systems. The reliability of these systems is always in question, since many of these
systems are not well monitored or maintained. Often problems will not be found until
long after the groundwater has been contaminated. These systems can be made to work
satisfactorily, given good soils, adequate design and construction review for the waste
water treatment systems, proper monitoring, and proper maintenance. For Oakboro,
where the typical soils have severe limitations for septic systems, requiring private
systems for all new residents will serve only to inhibit development. Requiring new
industries to provide their own waste water treatment plants would also serve to inhibit
development. Because the community is trying to expand its population and employment
base, requiring private septic and treatment systems is not an economically viable option.
CONTINUATION OF THE EXISTING CONDITIONS
The overall population growth rate in Stanly County is expected to be 3-5% annually,
depending on economic factors. The potential for the siting of new industry within the
county seems very favorable, and could dramatically change the rate at which Stanly
County will grow. At the same time, two large schools near Oakboro have septic systems
that are failing, and need alternate means of waste water treatment. The annexation of the
four areas outlined in the Annexation Study will require that Oakboro provide an
expanded waste water collection system. The possibility of beginning a comprehensive
program to remove infiltration and inflow from the waste water collection system may
provide some additional capacity, but such a program will not be able to create sufficient
capacity to make up for the increased demand. Given that the capacity of the existing
\ W es -a
Page 10
plant is needed for existing flows, and given that the expanding population coupled with
the failure of local septic systems will require some additional waste water treatment
capacity, allowing the existing conditions to continue indefinitely is not a viable option.
1.4 Since none of the other alternatives discussed are economically or physically practical,
the only viable alternative appears to be to expand the waste water collection system, the
water distribution system, and to expand the waste water treatment plant as proposed.
5.) ENVIRONMENTAL CONSEQUENCES
In general, the expansion of water and sewer systems into developed areas is not an
environmentally damaging process. Water and sewer lines are normally placed along
existing streets, and the expansion of waste water or water treatment plants normally
0.1 occurs at the site of the existing plants. Expanding public water and sewer systems allows
private systems to be removed or at least abandoned, and reduces the risk of ground
water or surface water contamination. Public systems monitor waste and water flows,
and have some means .of controlling the rate of flow through usage rates and the quality
of flow by monitoring influent at one or more points across their system. In most cases,
even where utility piping extends through wetlands or other environmentally sensitive
areas, these areas are only disturbed during construction, and then restored to their
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original condition after construction. Environmental damage is minimal, and significant
improvements to ground water and surface water quality are often realized.
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Environmental impacts will be discussed for a range of categories. Also discussed will be
mitigative measures for categories where environmental impacts are significant.
9.1 CHANGES IN LAND USE
Installation of water and sewer lines through annexed areas should not affect any existing
land uses. These utility lines will be located in the right-of-way of existing streets or in
narrow easements across existing lots. New pump station sites will be located on very
small lots located by the Town of Oakboro, and these lots will have either dedicated
easements or will be bought by the Town. The waste water treatment facility
improvements will be constructed on the same site as the existing waste water treatment
plant, so no change in land use will occur.
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WETLANDS
The Soil Survey for the Oakboro area shows no indication of distinct areas of extended
wetlands. The Kirksey soil series (indicated as K1cB on the soils map) is located along
natural drainage ways, and the typical soil profile for this soil type begins to show gray
mottles at a depth of 8-18 inches, making the location of wetlands on this soil type
possible but not probable. The Oakboro series (indicated as Oa on the soils map) is
located in flood plain areas, which also occurs along natural drainage ways in the
Oakboro area. This soil type is frequently flooded, although it may not be saturated to
any depth for most of the year. Isolated or narrow sections of wetlands may be located
along the edges of the drainage ways, and some gravity sewer lines may be located along
the fringes of these areas since the drainage ways are natural low points along the
contours. Since all of the outfall lines in these areas will be located along relatively
narrow drainage ways in previously developed areas, it is very unlikely that any
undisturbed wetland areas of any significant size exist. Any disturbance to these areas will
be minimal, and all areas will be restored to their original condition after construction. All
construction work in these areas will be limited to narrow construction corridors, and will
have native topsoil replaced in the backfilled trenches. Where applicable, Nationwide
permit #12 will be obtained from the U.S. Army Corps of Engineers to cover work that
may occur in jurisdictional wetlands.
Areas of potential wetland impacts exist primarily in Annexation Area 1 and Annexation
Area 2 where outfall lines follow natural drainage ways. The length of the lines running
through these drainage ways is approximately 5000 linear feet. All of these areas lie
within developed areas, so any areas of previously undisturbed wetlands that exist will be
small and isolated pockets. While such pockets may retain their ability to help absorb
storm water runoff peaks and provide some filtration of storm water, it is unlikely that
they would harbor any significant wildlife habitat due to their small and fragmented
nature. If these isolated wetlands exist, they will be able to continue to function after they
have been restored from construction as well as they have been before.
Page 12
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PRIME OR UNIQUE AGRICULTURAL LANDS
There are no areas of special concern related to agricultural lands. Most of the soil types
in the Oakboro area are suitable for agriculture only with the use of soil amendments. The
most common soil amendments required will be lime to control soil pH and nitrogen to
improve soil fertility. The acid nature of the predominant soil types can create problems
with aluminum toxicity in the soil, can kill or inhibit the growth of beneficial bacteria, and
can make essential plants nutrients less available to plants.
The soil types most common to the Oakboro area are the Badin series, the Kirksey series,
and the 1Vflsenheimer series. The Kirksey series have moderate limitations to agricultural
use, with the primary limitation being that the soils are prone to erosion. The Badin and
Nfisenheimer soil have severe limitations to cultivation, with the Badin soils being limited
by their erosive properties and the Misenheimer soils limited by frequent wetness.
Soybeans, corn, and wheat crops will have fair to poor results.
Installation of water and sewer piping has little or no affect on agricultural lands even if
they exist, and since there are no areas of special concern in the project area, no impacts
on agricultural lands will be realized as a result of this project.
PUBLIC LANDS
There are no public lands or parks affected by this project.
SCENIC AND RECREATIONAL AREAS
There are no scenic or recreational areas affected by this project.
1.4
AREAS OF ARCHAEOLOGICAL OR HISTORICAL VALUE
Annexation plans were reviewed by the North Carolina State Historic Preservation Office
to determine whether or not the proposed utility lines and pump stations conflicted with
pin known historic or archaeological sites. It was determined that none of the proposed work
will affect known historic or archaeological sites. There were some historic structures
Page 13
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located in the Oakboro area, but these structures were well removed from any planned
construction work.
AIR QUALITY
Air quality will not be adversely affected by this project. The improvements at the waste
water treatment facility may serve to reduce ammonia emissions from the treatment
systems, and in doing so may improve the air quality in the treatment plant area. Other
areas where water or sewer utilities lines are installed should not be impacted significantly
by this project.
GROUNDWATER QUALITY
Groundwater quality will not be adversely affected by this project. Groundwater quality
may be improved significantly in areas where existing septic systems will be removed or
abandoned in favor of the public collection system for waste water. Groundwater quality
downstream of the outfall for the waste water treatment plant may also be improved as a
result of the improved effluent quality from the waste water treatment plant.
NOISE LEVELS
Noise levels should not be adversely affected by this project in any significant way. There
may be a slight increase in noise levels in areas immediately adjacent to pumping stations
or to the waste water treatment plant. These increases should not be significant enough to
be noticeable by any residents, nor will they be significant enough to have any impact on
wildlife.
WATER SUPPLIES
This project will draw water from a single well which is located at the corner of Misty
Lane and Ashley Drive and from a 12" water main supplied by Stanly County. Stanley
County buys their water from the City of Albemarle, which uses Tuckertown Reservoir
as their water source. The City of Albemarle has estimated that the Tuckertown
Reservoir, which is fed by the Yadkin River, has sufficient capacity to serve the needs of
Stanly County for at least the next hundred years. Stanly County currently has a pumping
capacity of 3.0 MGD, which can be upgraded in the future if the need arises. There is
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Page 14
ample supply of water within Stanly County to serve all of the residents for the
foreseeable future.
FISH AND THEIR HABITATS
Fish habitats should not be adversely affected by this project. Water quality of the effluent
from the expanded and improved waste water treatment plant will be better than the
existing effluent. The plant is currently permitted to discharge into two streams, Long
Creek and Rocky River. The instream waste concentration (IWC) at the Long Creek
location will be 30% at the proposed plant capacity of 0.9 MGD. The IWC at the Rocky
River discharge point will be 5%. Chronic toxicity monitoring on a quarterly basis will
remain a condition of the permit at both locations. Both chlorination and dechlorination
are proposed for the proposed plant expansion, and the residual chlorine limit set by the
permit will be 28 14/1. Depending on the condition of the existing chlorination facilities,
an alternative method of disinfection may be used instead of chlorine injection. If chlorine
is used, a dechlorination process will be designed to comply with the chlorine residual
limit as a minimum.
The plant expansion will have the greatest effect on the stream at the Long Creek
location, where the IWC will be highest. Changing the quantity of flow in a stream can
have a significant effect on the ecology of the stream, since the flow rate affects both
water velocity and the depth of the water. A significant increase in velocity can also
create problems with erosion. Some effect might be realized at Long Creek, if the town
were to ever use that discharge point at full capacity exclusively and continuously after
the plant has been expanded. Since the town will be using two discharge points for a
period of time after the plant has expanded, after which the Rocky River discharge point
will be used exclusively, it is unlikely that the 30% IWC at Long Creek will ever be
reached. More probable values of the IWC should vary from 5-10% as a maximum. Once
the town begins to use the Rocky River discharge point exclusively where the full
capacity IWC is 5%, the risk of affecting stream ecology by flow increase should be
negligible. Flow increases in streams that represent no more than a 5-10% increase in
normal stream flow are unlikely to create any significant impacts.
Page 15
WILDLIFE AND THEIR. HABITATS
A review of the maps at the Natural Heritage division of the North Carolina Parks and
Recreation Department was made to determine whether or not there were any rare or
endangered species of plants or animals in the Oakboro area. The maps did not indicate
any rare or endangered species within the annexation area proposed. Since the areas
being annexed are already largely developed and fragmented by the existing street
network, it is unlikely that they harbor any significant wildlife habitat for any animals
other than urban species such as squirrels and other rodents.
INTRODUCTION OF TOXIC SUBSTANCES
No toxic substances should be introduced as a result of this project. If toxic substances
exist in the waste water stream, there is a possibility that they may be passed forward
either in the effluent discharged into Rocky River or Long Creek or in the sludge that will
be the byproduct of the waste water treatment process. In either case, toxic substances
will not be a product of the treatment process. Little control can be exerted over
businesses and residents who choose to waste toxic substances by putting them into the
waste water collection system. Standard treatment processes are designed for domestic
waste, with some provisions made for known pollutants or contaminants that may occur
as part of an industrial process that contributes to the waste water stream. If unexpected
toxic substances enter the treatment system, they may or may not respond to the
treatment system. If they do pass through the treatment plant, there is at least the
opportunity that their presence will be detected, and that may allow the opportunity to
trace the source of the substance and prevent further problems. This situation is an
improvement over allowing these substances to pass unnoticed into the groundwater
through private septic or waste treatment systems.
EUTROPHICATION OF EXISTING WATERS
The risk of eutrophication of existing waters should be reduced as a result of this
expansion project since the improvements to the waste water treatment system will
substantially reduce the nutrient loading in the waste water, and so will reduce the
nutrient loading in Rocky River and Long Creek at the discharge points. No other
existing waters should be affected by this project.
Page 16
6.) MITIGATIVE MEASURES
No mitigative measures should be required for this project, since no significant
environmental impacts will be realized as a result of the construction of the waste water
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treatment plant improvements or utility lines. During construction, any work which takes
place in environmentally sensitive areas will be restricted to narrow corridors, and care
will be taken to replace native topsoil in the top of backfilled trenches to their original
contours. No stream crossings are anticipated as part of this project, but if such crossings
�► should be required, they will be made by crossings perpendicular to the stream at narrow
stream sections. Backfill of trenches along all easements and roadways will be reseeded
with grasses compatible with local soils and climate. Specific locations of individual lines
will be set to minimize impacts on neighborhoods.
7.) SUMMARY
This project will have a minimal impact on the local environment. The greatest
disturbance to the local community and to the environment will be during construction,
�► and efforts will be made to minimize impacts on local residents and to restore natural
areas to their original condition. The net effect of the constructed system on the
,_, environment will likely improve the quality of the surface waters and ground waters in the
area, and will not damage any sensitive environmental areas.
APPENDIX 1
ANNEXATION STUDY
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EXECUTIVE SUMMARY:
The Town of Oakboro has annexed property along its existing corporate limits. The
existing water and sewer facilities in the annexed areas are limited and unable to provide
the service needed. Adequate water and sanitary sewer service must be provided to these
areas of annexation by the Town of Oakboro. In order to provide these services the
existing infrastructure must be improved and additional utilities constructed.
1.0 Introduction
Oakboro has annexed areas along all four sides of town, expanding the corporate limits to
include these areas. It is necessary for the Town of Oakboro to supply all areas within
corporate limits with adequate water and wastewater services. Throughout this report,
the property annexed by the Town of Oakboro will be divided into four (4) separate areas
and references will be made to each specific area.
The first area of annexation (Area I) is located along the northwest side of Oakboro, north
of S.R. 1112. Area I is approximately 230 acres of mostly residential and commercial
properties with proposed land use being primarily residential in nature.
The second area of annexation (Area II) is located along the northeast side of Oakboro,
east of Eighth Street and north of NC 138. Area II is approximately 50 acres of
public/utility and residential properties with proposed land use being primarily residential
in nature.
The third area of annexation (Area III) is located along the southeast side of Oakboro, on
the south side of the Norfolk Southern Railway and east of S.R. 1103. Area III is
approximately 65 acres of industrial and residential properties with proposed land use
being primarily industrial in nature.
The fourth area of annexation (Area IV) is located along the southwest side of Oakboro,
south of S.R. 1112 and west of S.R. 1103. Area IV is approximately 65 acres of
residential and industrial properties with proposed land use remaining residential and
industrial in nature.
The purpose of this report is to inform the Town of Oakboro the extent of the utility
improvements required to adequately serve each of these areas of annexation. All sections
of Oakboro, including, the annexed areas will have access to water and sanitary sewer
services. The possibility of future increases in water and wastewater demands has been
incorporated into these proposed plans. . For this report, Municipal Engineering prepared
complete overall maps of the existing and proposed water and wastewater systems of the
Town of Oakboro.
3
2.0 Annexation Area I
2.1 Land Use
The majority of the land in Area I is currently being used for residential purposes with
some areas being used for public/utility, commercial, and industrial purposes. The
majority of the non -developed land in this area has been zoned for residential use ( lot
sizes are a minimum of 10,000 square feet).
2.2 Existing Utilities
2.2.1 Water System
Currently, there are several water lines located in Annexation Area I. These existing water
lines are 3/4", 1 1/2", 2", and 4" pipes. There is also a 12" county water main in Area I
which is located along the north margin of NC 205. There are customers in Area I who
are currently being served by these lines. However, it is necessary for service to be
increased in order to reach the entire area of annexation.
2.2.2 Sanitary Sewer System
Currently, in Annexation Area I, there is an 8 inch gravity sewer line that discharges into a
pump station (existing pump station # 1) which feeds a 2 inch sewer force main. This
system eventually discharges into the main pumping station which feeds the wastewater
treatment plant. It is assumed that sewer service to this area will have to be increased in
order to adequately serve all of Area I.
2.3 Proposed Utilities
2.3.1 Water System
It is recommended that upgrades and additions be made to the existing water distribution
infrastructure in Annexation Area I. These improvements are needed to service the
properties which currently do not have adequate water connections and to provide fire
protection. These changes include the following:
a.) Move the county meter vault from E. Eighth Street to N. Main Street (NC 205) near
the new corporate limits. The existing 12" water main will enter and exit the meter vault
at this new location.
b.) A new 4" water line will be placed along Rainbow Drive and connected to an existing
4" line along Pecan Drive. This new line will be approximately 600 linear feet and will add
service to 3 additional, residential parcels of land.
4
c.) Two new 6" water lines will be placed along roads which extend from N. Main Street
(NC 205) southwest for approximately 800 linear feet each . These new lines will add
service to undeveloped residential areas on the west side of Annexation Area I.
►► d.) A new 6" water line will be connected at the corner of N. Main Street and W. Eleventh
Street (S.R. 1113) and will extend along W. Eleventh Street to Hurley Road. This new
line will be approximately 1600 linear feet and will provide service to 13 additional,
4.1 residential lots.
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e.) A new 6" water main will be extended along E. Tenth Street from the 12" line at the
corner of N. Main Street and E. Tenth Street to connect with an existing 2" water line
near Allison Street. This line will be approximately 2900 linear feet and will also connect
with 300 linear feet of new 6" water line on Cross Creek Drive. These lines will serve
more than 30 residential parcels in the eastern portion of Annexation Area I.
f.) All new water lines which are 6 inches in diameter or larger will have fire hydrants
placed at a maximum interval of 850 feet apart to provide adequate fire protection.
2.3.2 Sanitary Sewer System
It is recommended that additions to the existing sanitary sewer system be made in order to
provide adequate service to all properties in Annexation Area I. These additions include
the following:
a.) An 8" gravity sewer main will be extended along N. Main Street (NC 205) and will
collect near the intersection of N. Main Street and Allison Branch. This main line will be
approximately 2400 linear feet and will serve as a collector line for the southwestern side
of Annexation Area I.
b.) An 8" gravity sewer line will be extended along W. Eleventh Street and connect with
the main line on NC 205. This line will be approximately 1600 linear feet and will serve
25 additional residential parcels of land.
c.) An 8" gravity sewer line will be extended along W. Tenth Street and will connect to
the new 8" gravity sewer main on N. Main Street. This line will be approximately 1300
linear feet and will serve residential parcels within Annexation Area I and the existing
corporate limits as well.
d.) The northeast section of Annexation Area I will be serviced by a series of 8" gravity
sewer lines. These lines will be extended_ along Pecan Drive, Cross Creek Drive, Rainbow
Drive, Elizabeth Lane, Ashley Drive, Allison Street, and East Tenth Street. This will be
approximately 8000 linear feet of new 8" gravity sewer line which will collect at a new
pump station # 1.
5
e.) The southwest section of Annexation Area I will be serviced by two 8" gravity sewer
lines. These lines will be approximately 800 linear feet each and will service a residential
area.
f.) A new 10" gravity sewer main will be extended from a main collection point on N.
Main Street and follow a low-lying area for approximately 3000 linear feet. This new line
will feed the new pump station # 1.
g.) Existing pump station #1 will be taken off line and the inflow will be redirected to the
new 10" sewer main. The pumps from old pump station no. 1 will be moved to old pump
station no. 4 and become new pump station no. 2.
h.) A new 8" gravity sewer line will be extended from the southwestern section of
Annexation Area I through a low-lying area for approximately 1100 linear feet. This new .
line will connect with the main collection area on N. Main Street.
i.) A new 8" gravity sewer line will extend from existing pump station no. 6 to existing
pump station no. 7 (existing pump stations nos. 6 and 7 will be removed). This new
gravity sewer line will then extend to the collection point on Cross Creek Drive. This new
line will be approximately 2400 linear feet.
j.) New pump station # 1 will receive the wastewater collection from Annexation Area I as
well as the northwestern section of the existing corporate limits. This new pump station
will use approximately 1000 linear feet of 6" force main to carry the wastewater to a
higher elevation near Misty Lane. A new 10" gravity sewer main will then carry the
wastewater to E. Eighth Street then to E. Fifth Street and finally to an existing 15" sewer
line which leads to the main pump station. This new line will be approximately 3000 linear
feet.
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3.0 Annexation Area II
3.1 Land Use
The majority of the land in Area II is currently being used for residential purposes.
However, there is some public/utility property as well. The majority of the non -developed
land in Area II has been zoned for residential use.
3.2 Existing Utilities
3.2.1 Water System
Currently, there are several water lines located in Annexation Area II. These existing
water lines are 3/4", 2" and 8" pipes which are currently serving customers. It is assumed
that more lines will be needed in order to adequately serve this entire area. New water
lines will probably have to be larger than the existing lines as well.
3.2.2 Sanitary Sewer System
Currently, in Annexation Area II, there are 8" and 10" gravity sewer lines that eventually
discharge to the main pumping station which feeds the wastewater treatment plant. It is
assumed that sewer service to this area will have to be increased in order to adequately
serve all of Area II.
3.3 Proposed Utilities
3.3.1 Water System
It is recommended that additions be made to the existing water distribution system in
Annexation Area II in order to extend service to the new corporate limits. These
additions are to include the following:
a.) A new 6" line will be extended along E. Seventh Street from N. Long Street into
Annexation Area II. This new line will be approximately 400 linear feet and will serve 3
(three) additional, public/utility and residential parcels.
b.) A new 6" line will be extended along E. Third Street from the previous corporate limits
into Annexation Area II. This new line will be approximately 300 linear feet and will serve
3 (three) additional, residential parcels.
c.) A new 6" water main will be extended along First Street from Main Street to the new
corporate limits. This new line will be approximately 1900 linear feet and will improve
existing service to the area along First Street as well as serving 7 (seven) additional parcels
in. Annexation Area II.
7
d.) A new 6" water main will be extended along Alonzo Road (S.R. 1974) from Aquadale
Road to the new corporate limits. This new line will be approximately 1400 linear feet
and will improve service to commercial and residential areas within the old corporate
limits. Service will be provided to 4 (four) additional, residential parcels.
e.) All new water lines which are 6 inches in diameter or larger will have fire hydrants
placed at a maximum interval of 850 feet apart to provide adequate fire protection.
3.3.2 Sanitary Sewer System
It is recommended that additions be made to the existing sanitary sewer system in
Annexation Area II in order to extend service to properties which are currently not being
served. These additions include the following:
a.) A new 8" gravity sewer line will be extended along E. Seventh Street from Annexation
Area II to an existing 8" main in the intersection of E. Seventh Street and N. Long Street.
This line will be approximately 400 linear feet and will provide service to two additional
parcels of land.
b.) A new 8" gravity sewer line will be extended along E. Fifth Street into Annexation
Area II, turn and extend along a road easement to an existing 10" sewer main . This line
will be approximately 800 linear feet and will provide service to nine additional residential
parcels of land.
c.) A new 8" gravity sewer line will be extended along First Street and through an
easement to connect with an existing 8" sewer main. This new line will be approximately
900 linear feet and will provide service to six additional parcels of land.
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4.0 Annexation Area III
4.1 Land Use
The majority of the land in Area III is currently being used for industrial purposes.
However, there is some residential property as well. The majority of the non -developed
land in Area III has been zoned for industrial use.
4.2 Existing Utilities
4.2.1 Water System
Currently, there are several water lines located in Annexation Area M. These existing
water lines are 6" pipes and are currently serving customers. It is assumed that the Town
of Oakboro will have to install more water lines in order to provide adequate service to
this entire area.
4.2.2 Sanitary Sewer System
Currently, in Annexation Area III, there is an 8" gravity sewer line which discharges into
existing pump station no. 2 which feeds an 8" sewer force main. This line eventually
discharges into the main pumping station which feeds the wastewater treatment plant. It is
assumed that sanitary sewer service to this area will have to be increased in order to
adequately serve all of Area III.
4.3 Proposed Utilities
4.3.1 Water System
It is recommended that improvements and additions be made to the existing water
distribution system in Annexation Area III. Low water pressures have been reported in
this area due to the extensive water demands placed on the system by the Stanley Mills
plant. Therefore the followingchanges are
required: g
F=,, a.) A new 10" water main will be connected to the 12" main at the corner of N. Main
Street and W. Eighth Street. This new line will extend approximately 3000 linear feet
along an alley 1/2 block south of Main Street to a proposed bore under the Norfolk
1.R Southern Railway. This 10" main will supply the additional water pressure needed in
Annexation Area III.
b.) A new 6" water line will be added to connect existing lines on Rocky River Road and
James Street. This new line will be approximately 700 linear feet and will complete a loop
from the bore under the Norfolk Southern Railway, south along Rocky River Road to
"'" James Street and then northwest along NC 742 back to the Rocky River Road.
9
c.) All new water lines which are 6 inches in diameter or larger will have fire hydrants
placed at a maximum interval of 850 feet apart to provide adequate fire protection.
4.3.2 Sanitary Sewer System
Adequate sewer service needs to be provided to all properties in Annexation Area III. It
is recommended that the following addition be made to the existing sanitary sewer system
in Annexation Area III.
a.) A new 8" gravity sewer line will be extended along Rocky River Road and James
Street. This new sewer main will be approximately 4300 linear feet and will connect to
existing pump station no. 2 (new pump station no. 3) on James Street. This new line will
provide service to 34 additional parcels of land.
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5.0 Annexation Area IV
5.1 Land Use
The majority of the land in Area IV is currently being used for industrial and residential
purposes. Also, Area IV has been zoned to continue with industrial and residential uses in
the future.
5.2 Existing Utilities
5.2.1 Water System
Currently, there are several water lines and an industrial storage tank in Annexation Area
0.1
IV. The water lines are 3/4", 2", and 6" pipes which are presently serving customers. The
Town of Oakboro will probably have to install more water lines in order to provide service
fan to this entire area.
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5.2.2 Sanitary Sewer System
Currently, in Annexation Area IV, there are several 6" and 8" gravity sewer lines which
discharge into existing pump station no. 3 (new pump station no. 4) which feeds a 4"
sewer force main. Eventually this system discharges into the main pumping station which
feeds the wastewater treatment plant. It is assumed that sewer service to this area will
have to be increased in order to adequately serve all of Area IV.
5.3 Proposed Utilities
5.3.1 Water System
Pia It is recommended that additions be made to the existing water distribution system in
Annexation Area IV in order to provide adequate service to all properties. These
additions are to include the following:
a.) A new 6" water line will be placed along a portion of Rock Church Road and Hill Road
to connect existing 6" lines on W. Second Street and Rock Church Road. This new line
will be approximately 350 linear feet and will provide service to 5 additional residential
parcels of land.
b.) A new 6" water main will be connected to another new 6" water main at the
intersection of W. Eleventh Street and Hurley Road. This new line will be extended along
Hurley Road to connect with a water line on W. Eighth Street and then along W. Eighth
Street to the Norfolk Southern Railway. The entire line will be approximately 1700 linear
feet and will provide service to residential and industrial users in Annexation Area IV.
11
c.) A new 8" water main will be connected to the new 10" water main placed underneath
the Norfolk Southern Railway and will extend to the existing 6" water main on W. Second
Street. This new line will be approximately 1200 linear feet and will improve service to
Annexation Area IV.
d.) A new 6" water main will be extended from the existing 6" line on Hamilton Road west
and north to Silver Road. This new line will connect to existing lines on Silver Road in
order to adequately supply the area southwest of the new corporate limits. This new line
will be approximately 2700 linear feet and will service both industrial and residential areas.
e.) All new water lines which are 6 inches in diameter or larger will have fire hydrants
placed at a maximum interval of 850 feet apart to provide adequate fire protection.
5.3.2 Sanitary Sewer System
It is recommended that additions be made to the existing sanitary sewer system in
Annexation Area IV in order to extend service to the new corporate limits. These
additions include the following:
a.) A new 8" gravity sewer main will be extended along W. Second Street from.the new
corporate limits to existing pump station no. 3 (new pump station no. 4) near Hamilton
Road. This new line will be approximately 1100 linear feet and will serve ten additional
parcels of land.
b.) A new 8" gravity sewer main will be extended along W. Seventh Street from
Annexation Area IV to an existing sewer line on Pine Street. This new line will extend
approximately 400 linear feet and will provide service to 6 additional parcels of land.
c.) A new 8" gravity sewer main will be placed on Hurley Road and will connect to
another new sewer line on W. Eleventh Street. This line will be approximately 200 linear
feet and will provide service to an additional industrial portion of Annexation Area IV.
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6.0 Existing Corporate Limits
6.1 Proposed Utilities
6.1.1 Water System
It is recommended that additions and improvements be made to the existing water
distribution system inside of the existing corporate limits. These improvements include the
addition of a 10" water main in an alley 1/2 block south of Main Street, an 8" water main
between Main Street and West Second Street, a 6" water main on First Street, and a 6"
water main on Alonzo Street which have been previously described.
6.1.2 Sanitary Sewer System
It is recommended that additions and improvements be made to the existing sanitary sewer
system inside of the existing corporate limits. These improvements include the addition of
a new 8" gravity sewer main from existing pump station no. 6 to existing pump station no.
7, a new 8" gravity sewer main from existing pump station no. 7 to Cross Creek Drive, a
new 8" gravity sewer main on Rocky River Road, and an 8" gravity sewer main on West
Tenth Street which have been previously described. Existing pump station nos.. 4, 5, 6,
and 7 will be removed. Pump station no. 4 will become new pump station no. 2 as the
pumps from old pump station no. 1 are relocated here.
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7.1 Water Supply
The Town of Oakboro is provided with water from the county water system through a 12"
water main. This main enters Oakboro along NC 205 and connects to a county meter
vault near the intersection of North Haywood Street and East Eighth Street. This
connection provides some pressure for Oakboro's existing water supply system. It is
recommended that this meter vault be moved to a point along N. Main Street where the
12" county water main enters the new corporate limits. Oakboro also acquires water from
a well located at the corner of Misty Lane and Ashley Drive. This well is capable of
supplying 135 gpm.
7.2 Water Storage
The Division of Health Services of the North Carolina Department of Environment, Health
and Natural Resources requires a minimum storage capacity of one (1) day's supply for
water storage. This can be a combination of elevated tanks and ground storage tanks with
booster pumps. Oakboro currently has one 100,000 gallon elevated storage tank located
along North Haywood Street. The water stored in this elevated tank provides most of the
pressure for Oakboro's existing water supply system. It is assumed that Oakboro can
depend upon Stanley County for their water storage. Since Stanley County supplies
Oakboro with water the county should also have sufficient storage capacity.
7.3 Wastewater Pumping Stations
7.3.1 Existing Pump Stations
As previously mentioned, there is one pumping station in each of Annexation Areas I, III
and IV and four pump stations within the existing corporate limits. These pumps feed
sewer force mains which are connected to a network of other sewer lines and pumping
stations throughout Oakboro. This network is connected to the main 15" gravity sewer
line which runs north from Oakboro to the main pumping station. This pump feeds a 10"
sewer force main which discharges to the wastewater treatment plant. Currently there are
no pumping stations in Annexation Area II.
7.3.2 Proposed Pump Stations
It is recommended that existing pump stations numbers 1, 4, 5, 6, and 7 be removed from
service. The inflows to these stations will be rerouted as previously described. Pump
stations numbers 2 and 3 will remain in service with no changes being necessary. The
pumps from old station no. 1 will replace the pumps at old station no. 4 which will
become new pump station no. 2. This upgrade is needed due to the extra inflow at pump
station #5. A new pumping station (pump station # 1) will be constructed in Annexation
Area I and will provide service as previously described.
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7.4 Wastewater Treatment Plant
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Improvements must be made to the existing wastewater treatment plant in order to
handle the increased inflow produced by the annexed areas. The annexed areas could
increase the wastewater treatment plant's inflow by as much as 300,000 gallons per day. It
is recommended that the wastewater treatment plant be expanded from a capacity of 0.5
MGD to 0.9 MGD. This expansion should include a new grit chamber, bar screening
equipment, pumps and controls, aeration basin, aeration equipment and secondary
clarifier. There should also be return sludge pumping station modifications, chlorination
basin enlargement, de -chlorination additions, an increased sludge digestion volume, new
digestion basin equipment and electrical improvements.
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8.0 Probable Costs
8.1 Wastewater Treatment Expansion (0.5 MGD to 0.9 MGD)
I. Preliminary Treatment
A.) New Grit Chamber and Bar Screening Equipment $60,000
II. Influent Pumping Station
A.) New Pumps and Controls $95,000
III. Aeration Basins
A.) New Aeration Basin $160,000-
B.) New Aeration Equipment $75,000
IV. Clarification
A.) New Secondary Clarifier $135,000
B.) Return Sludge Pumping Station Modifications $65,000
C.) Miscellaneous Structures and Piping $40,000
V. Disinfection
A.) Chlorination Basin Enlargement $40,000
B.) De -chlorination Addition $25,000
VI. Sludge Digestion
A.) Addition Sludge Digestion Volume $75,000
B.) New Digestion Basin Equipment $15,000
VII. Electrical Improvements •$95.000
Subtotal $880,000
30 % Contingency, Design and Observation $264,000
GRAND TOTAL $1,144,000
• 16
8.2 Annexation Water Improvements
I. Area I
A. Rainbow Drive $3,000
B. Cross Creek Drive $900
C. Southwestern Section $8,000
D. West Eleventh Street $14,400
E. Tenth Street $26,100
F. Miscellaneous
1.) Purchase 3800' of County 12" Waterline $30,400
2.) Relocate County Water Meter Vault $6,000
Subtotal $88,800
II. Area II
A. East Seventh Street $2,000
B. East Third Street $900
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C. First Street $17,100
D. Alonzo Road $12,600
Subtotal $32,600
III. Area III
A. Rocky River Road $6,300
B. Main Street $63,000
Subtotal $69,300
IV. Area IV
A. Rock Church Road and Hill Road $1,050
B. West Eighth Street and Hurley Street $15,300
C. Miscellaneous
1.) S. Main Street to W. Second Street $18,000
2.) Hamilton Road to Silver Road $24,300
3.) Bore Under Norfolk Southern R/R $17,000
Subtotal $75,650
Water Improvements Subtotal $266,350
30% Contingency, Design and Observation $79,900
GRAND TOTAL $346,250
17
8.3 Annexation Sewer Improvements
I. Area I
A. Pecan Drive $55,000
B. North Main Street $60,000
C. Rainbow Drive $12,500
D. Cross Creek Drive $45,000
E. Elizabeth Lane, Misty Lane,
Ashley Drive & Allison Street $70,000
F. Southwestern Section $40,000
G. West Eleventh Street $45,000
H. Tenth Street $50,000
I. Miscellaneous
1.) Gravity Sewer - Southwestern Section to N. Main $27,500
2.) Gravity Sewer - North Main to New Pump Station No. 1 $81,000
3.) Force Main - New Pump Sta. No. 1 to 15" Gravity Main $90,000
4.) Gravity Sewer - Old Pump Sta. No. 6 to Cross Creek Dr. $60,000
5.) Remove Old Pump Station No. 1 $4,000
6.) Construct New Pump Sta. No. 1 $60,000
Subtotal $700,000
II. Area II
A. East Seventh Street $10,000
B. East Fifth Street $20,000
C. First Street $22,500
Subtotal $52,500
III. Area III
A. Rocky River Road $67,500
B. James Street $40.000
Subtotal $107,500
IV. Area IV
A. West Eighth Street and Hurley Street $5,000
B. West Second Street $27,500
C. West Seventh Street $10,000
D. Miscellaneous
1.) Remove old Pump Sta. No. 4 and Relocate
Old Pump Sta. No. 1 to New Pump Sta. No. 2 $10.000
Subtotal $52,500
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V. Miscellaneous
A. Remove Old Pump Sta. Nos. 5, 6, & 7 $14,500
B. Asphalt Replacement $93,000
C. Rock Excavation $450,000
Subtotal $557,500
Sewer Improvements Subtotal
30% Contingency, Design and Observation
$1,470,000
$441,000
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GRAND TOTAL $1,911,000
The above estimates reflect current construction costs. Actual costs will vary depending
on the scope of work included and current market rates for various elements. Final cost
estimates are made as part of engineering services and will be available prior to bidding
any project.
9.0 Conclusion
The cost of providing adequate water and wastewater services to Oakboro's existing
corporate limits and annexation areas as they now exist is estimated to be $3,401,250.
APPENDIX 2
DEHNR LETTER DETAILING SPECULATIVE
.' LIMITS
State of North Carolina
Department of Environment,
Health and Natural Resources
Division of Environmental Management
James B. Hunt, Jr., Governor
Jonathan B. Howes, Secretary
A. Preston Howard, Jr., P.E., Director
July 28, 1994
The Honorable Fetzer E. Hartsell, Mayor
Town of Oakboro
Post Office Box 610
Oakboro, North Carolina 28129
DEEHNF
AEG 4 c94
5,
SUBJECT: Speculative Limits for Town of Oakboro Wastewater Treatment Plant
NPDES Permit No. NC0043532
Stanly County
IONA
Dear Mayor Hartsell:
— A speculative analysis for the proposed expansion of the Oakboro Wastewater
Treatment Plant to 0.9 MGD at the existing location on Long Creek and the proposed
relocation of the discharge to the Rocky River has been completed by the Technical Support
— Branch. In order to receive final permit limits, a formal application will have to be
submitted to the Division's Permits and Engineering Unit.
In 1993 the Division of Environmental Management (DEM) conducted a study
—
(excerpts attached) on the Rocky River Watershed to determine the level of treatment which
will protect the dissolved oxygen standard as well as prevent any one discharge from using
up 100 percent of the available assimilative capacity of the river. Results from this study
indicate that any new or expanding discharge in the lower watersheds of the Rocky River
should receive a total Biochemical Oxygen Demand ultimate (BODu = CBOD + NBOD) of
32 mg/1 or less.
Based on available information the tentative limits for conventional constituents are:
Long Creek Rocky River
Summer Winter Summer Winter
Wasteflow (MGD) 0.9 0.9 0.9 0.9
— BOD5 (mg/1)* 9 18 9 18
N113-N (mg/1)* 3 6 3 6
DO (mg/1) 5 5 5 5
TSS (mg/1) 30 30 30 30
Fecal Coliform (#/100m1) 200 200 200 200
pH (SU) 6-9 6-9 6-9 6-9
Chlorine (4/1) 28 28 28 28
* See attached graph for potential effluent limit combinations.
POEM
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone 919-733-5083 FAX 919-733-9919
An Equal Opportunity Affirmative Action Employer 50% recycled/ 1 O% post -consumer paper
-Page 2-
Letter to Mayor Hartsell
It should be noted that the tentative NH3N limits were evaluated and are based on
the protection of Long Creek against instream ammonia toxicity. North Carolina is
currently evaluating all NPDES dischargers for ammonia toxicity and following EPA
guidance to protect the waters for an instream criteria of 1 mg/l in the summer and 1.8 mg/1
in the winter, under 7Q10 flow conditions. The tentative NH3N and BOD5 limits for the
Rocky River discharge location are based on a BODu of 32 mg/1 or less. To convert
NH3N to NBOD a multiplier of 4.5 is used. Current Division procedure and the
percentage of industrial waste in the effluent yield a CBOD/BODS ratio of 2:1. See
attached graph for possible alternative NH3N and BOD5 limits for the Rocky River
discharge location. The Rocky River discharge summer limits for NH3N and BOD5 can
range from NH3N maximum of 4 with a corresponding BOD5 limit of 7 mg/1 to an NH3N
minimum limit of 2 mg/1 with a corresponding BOD5 maximum of 11 mg/l.
In addition, under current DEM procedure, dechlorination and chlorine limits are
now recommended for all new or expanding dischargers proposing the use of chlorine for
disinfection. An acceptable level of chlorine in your effluent is 28 }ig/1 to ensure protection
against acute toxicity. The process of chlorination/de-chlorination or an alternate form of
disinfection, such as ultraviolet radiation, should allow the facility to comply with the total
residual chlorine limit.
The instream waste concentration (IWC) at the Long Creek location is 30% at 0.90
MGD; the IWC at the Rocky River location is 5% at 0.90 MGD. A chronic toxicity testing
requirement with quarterly monitoring will remain a condition of the NPDES permit for
both discharge locations. The effluent concentration at which there may be no observable
inhibition of reproduction or significant mortality will be based on the IWC at both
discharge locations. A complete evaluation of limits and monitoring requirements for
metals and other toxicants will have to be addressed at the time of formal NPDES
application. Due to the IWC, the effluent limits for the parameters of concern will most
likely be less stringent at the proposed relocation site on the Rocky River then at the
existing location on Long Creek. Information concerning these constituents is not readily
available but the Town can assume that effluent limits and/or monitoring for chromium,
nickel, lead, cyanide, mercury, copper, zinc, fluoride, sulfide, aluminum, arsenic, iron,
manganese, selenium, tin, oil and grease, MBAS, and silver should be included.
DEM has implemented a statewide basin water quality management initiative. Our
schedule for implementation in the Yadkin Kiver Basin is set for i 8. The plan will
attempt to address all sources of point and nonpoint pollutants where deemed necessary to
protect or restore water quality standards. In addressing interaction of sources, wasteload
allocations may be affected. Those facilities that already have committed to high levels of
treatment technology are least likely to be affected
Fag
-Page 3-
Letter to Mayor Hartsell
This information should provide some assistance in your planning endeavors. As
previously mentioned, final NPDES effluent limitations will be determined after a formal
permit application has been submitted to the Division. If there are any additional questions
concerning this matter, please feel free to contact Ruth Swanek or Michelle Wilson of my
staff at (919) 733-5083.
DLS/MMW
cc: Municipal Engineering Services Co.,
Mooresville Regional Office
Permits and Engineering Unit
Central Files
nald L. S t,
Assistant Chief for Tex upport
Water Quality Section
P.A.; David Dickenson, P.E.
A QUAL2E-TJNCAS APPLICATION TO THE
ROCKY RIVER AND MALLARD CREEK.
• CABARRUS, IREDELL, AND MECKLENBURG COUNTIES
NORTH CAROLINA.
NORTH CAROLINA DEPARTMENT OF ENVIRONMENT, HEALTH
AND NATURAL RESOURCES
This report has been approved for relea
Steve W. Tedder, Chief
Water Quality Section
N.C. Division of Environmental Management
Date
•
'�rd3(f6�
r
i
{
EXECUTIVE SUMMARY
Water quality models for three sections of the Rocky River and its tributaries were
joined to produce one calibrated model for 47.6 stream miles in the Yadkin River basin.
This model was used to predict dissolved oxygen and biochemical oxygen demand
concentrations at,low flow conditions for both permitted and summer average discharge
conditions.
The general objective of this project was to provide a tool to assist with
management of wastewater discharge issues in the upper watershed of the Rocky River.
A more specific objective of the project was to provide a model that could be used to
determine the appropriate waste load allocation for the Charlotte -Mecklenburg Utility
Department (CMUD) Mallard Creek WWTP. CMUD has applied for an expansion of the
Mallard Creek WWTP from 3 to 6 MGD.
ResuIts from this model indicate that water quality in the upper watershed of the
Rocky River is not adequately protected by the current NPDES permit effluent limits.
Under current operating conditions, that are well below permitted loads, the DO standard
`' is not predicted to be violated in the Rocky River study area. However, three DO sags are
predicted to drop to or near the stream standard, indicating that little assimilative capacity
remains for oxygen consuming wastes. It is recommended that no new or expanded
PPR
discharges be permitted in the study area unless an evaluation of engineering alternatives
shows that it is the most environmentally sound alternative. If new or expanding
discharges are permitted, they should receive best available technology limits in the
watersheds above the confluence of Mallard Creek and the Rocky River, due to severely
limited assimilative capacity. Any new or expanding discharge in the lower watersheds of
the Rocky River should receive a total BODu limit of 32 mg/I or less, equivalent to 10
mg/l BOD5 and 4 mg/I NH3 for typical domestic discharges. This level of treatment will
protect the DO standard as well as preventing any one discharge from using up 100
'a' percent of the available assimilative capacity of the river.
In addition, it is recommended that Mooresville WWTP, Mallard Creek WWTP,
and Concord WWTP be encouraged to continue to meet advanced treatment levels. Upon
1.9
expansion or modification, Mooresville WWTP and Concord WWTP should receive more
advanced treatment requirements that will protect water quality in the Rocky River. This
will mean advanced tertiary treatment at the Mooresville WWTP and limits at least as
stringent as 10 mg/1 BOD5 (5.7 mg/1 CBODS) and 4 mg/1 NH3 at the Concord WWTP.
ii
2
Oakboro Wastewater Treatment Plant
Expansion to 0.90 MGD
Possible Limits for BODu = 32 mg/1
LONG CREEK LOCATION
NH3-N (mg/1)
Potential effluent limit combinations:
BODS NH3-N
11 2
• 9 3
r
8
7
Oakboro Wastewater Treatment Plant
Expansion and Relocation 0.90 MGD
Possible Limits for BODu = 32mg/l
ROCKY RIVER LOCATION
2.00 3.00 4.00
NH3-N (mg/I)
Potential effluent limit combinations:
BOD5 NH3-N
11 2
9 3
7 4
1000
0
1000
3000
FIGURE 1
ROAD MAP
MUNICIPAL ENGINEERING SERVICES CO., P.A.
CONSULTING ENGINEERS
BOONE, N.C. GARNER, N.C.
LEGEND
L
PROPOSED SEWER MAIN
PROPOSED WATER MAIN
ANNEXATION BOUNDARY
EXISTING CORPORATE BOUNDARY
ANNEXATION AREA # 1
FIGURE 2
ANNEXATION AREA #1
GOO 0 SOO
MUNICIPAL ENGINEERING SERVICES CO., P.A.
CONSULTING ENGINEERS
BOONE, N.C. GARNER, N.C.
LEGEND
PROPOSED SEWER MAIN
PROPOSED WATER MAIN
ANNEXATION BOUNDARY
EXISTING CORPORATE BOUNDARY
FIGURE 3
ANNEXATION AREA #2
MUNICIPAL ENGINEERING SERVICES CO., P.A.
CONSULTING ENGINEERS
BOONE, N.C. GARNER, N.C.
Yi%041
, 41h7 i A&S
%Iii. Adto "NW
AnNiri,hat.,,, aiiiiim,....___
IWEITI
MeV
1. jerigr
14 4.\.... to, IL
New Pa 14
IP 1.......11 \ 116 41c Tito,
-4,Adal 0
' 441.0.-
Er
NW
2
wir
1006
LEGEND
ANNEXATION AREA # 3
PROPOSED SEWER MAIN
PROPOSED WATER MAIN
ANNEXATION BOUNDARY
EXISTING CORPORATE BOUNDARY
504.11},0,4
N
N
FIGURE 4
ANNEXATION AREA #3
500 ❑ 600
MUNICIPAL ENGINEERING SERVICES CO., P.A.
CONSULTING ENGINEERS
BOONE, N.C. GARNER, N.C.
ANNEXATION AREA 1 4
v \ ANNEXATION AREA 1 1
LEGEND
PROPOSED SEWER MAIN
PROPOSED WATER MAIN
ANNEXATION BOUNDARY
EXISTING CORPORATE BOUNDARY
N
N
ANNEXATION AREA r 3
N
FIGURE 6
PREVIOUS CORPORATE LIMITS
MUNICIPAL ENGINEERING SERVICES CO., P.A.
CONSULTING ENGINEERS
BOONE, N.C. GARNER, N.C.
FIGURE 7
SOIL SURVEY MAP
MUNICIPAL ENGINEERING SERVICES CO., P.A.
CONSULTING ENGINEERS
800NE . N.C.
GARNER, N.C.
• . 'b _
- • .../43 •
0587 • ' - ••
4 • -------- _
nbr
•
• 1570
."..527
•
0
5,)0
I 7
495 •.•
0
0
/,-
(.--
.)
/
.„--
. i103
• • 4' •
• .,,,tr=
,•••
0
FIGURE 8
U.S.G.S. MAP
MUNICIPAL ENGINEERING SERVICES CO., P.A.
CONSULTING ENGINEERS
BOONE, N. C. • GARNER, N. C.
Misenheimer
I y:::.'
i
ti • ' Misenheimer
•
Badin
•
Kirksey‘ •�
-=-2••••"'• Misenheimer
Figure .—Relationship of the soils in the Misenheimer-Kirksey-Badin general soil map unit.
FIGURE 9
TYPICAL SOILS PROFILE
MUNICIPAL ENGINEERING SERVICES CO., P.A.
CONSULTING ENGINEERS
BOONE, N.C. GARNER, N.C.
Stanly County, North Carolina
PR
TABLE 11.--SANITARY FACILITIES
[Some terms that describe restrictive soil features are defined in the Glossary. See text for definitions of
PR "slight," "good," and other terms. Absence of an entry indicates that the soil was not rated. The
information in this table indicates the dominant soil condition; it does not eliminate the need for
onsite investigation]
Map symbol and
soil name
Septic tank
absorption
fields
Sewage lagoon
areas
Trench
sanitary
landfill
Area
sanitary
landfill
Daily cover
for landfill
BaB
Badin
BaD
Badin
BaF
mr Badin
PRI
BbB:
Badin
Urban land.
BbD:
Badin
mm Urban land.
PRI
Ch, Ck
Severe:
depth to rock.
Chewacla
Co
Severe:
depth to rock.
Congaree
EcB
Enon
EcD, EnC
Enon
fI EnE
fRol
Severe:
depth to rock,
slope.
Severe:
depth to rock.
Enon
GeB, GfB2
Georgeville
Severe:
depth to rock,
slope.
Severe:
flooding,
wetness.
Severe:
flooding,
wetness.
Severe:
percs slowly.
Severe:
percs slowly.
Severe:
percs slowly,
slope.
Moderate:
percs slowly.
Severe:
depth to rock.
Severe:
depth to rock,
slope.
Severe:
depth' -to rock,
slope.
Severe:
depth to rock.
Severe:
depth to rock,
slope.
Severe:
flooding,
wetness.
Severe:
flooding,
wetness.
Moderate:
slope.
Severe:
slope.
Severe:
slope.
Moderate:
seepage,
slope.
Severe:
depth to rock,
too clayey.
Severe:
depth to rock,
too clayey.
Severe:
depth to rock,
slope,
too clayey.
Severe:
depth to rock,
too clayey.
Severe:
depth to rock,
slope,
too clayey.
Severe:
flooding,
wetness.
Severe:
flooding,
wetness.
Severe:
too clayey.
Severe:
too clayey.
Severe:
slope,
too clayey.
Moderate:
too clayey.
Severe:
depth to rock.
Severe:
depth to rock.
Severe:
depth to rock,
slope.
Severe:
depth to rock.
Severe:
depth to rock,
slope.
Severe:
flooding,
wetness.
Severe:
flooding,
wetness.
Slight
Poor:
area reclaim,
too clayey,
hard to pack.
Poor:
area reclaim,
too clayey,
hard to pack.
Moderate:
slope.
Severe:
slope.
Slight
Poor:
area reclaim,
too clayey,
hard to pack.
Poor:
area reclaim,
too clayey,
hard to pack.
Poor:
area reclaim,
too clayey,
hard to pack.
Poor:
hard to pack,
wetness.
Fair:
wetness.
Poor:
too clayey,
hard to pack.
Poor:
too clayey,
hard to pack.
Poor:
too clayey,
hard to pack,
slope.
Fair:
too clayey,
hard to pack.
Soil Survey
TABLE 11. - -SANITARY FACILITIES --Continued
r
Map symbol and
soil name
Septic tank
absorption
fields
Sewage lagoon
areas
Trench
sanitary
landfill
Area
sanitary
landfill
Daily cover
for landfill
GoC
Goldston
GoF
Goldston
HeB
Hiwassee
HeD
Hiwassee
KkB
Kirksey
MhB
Misenheimer
Oa
Oakboro
Qu.
Quarries
TaF
Tatum
TbB
Tatum
TbD
Tatum
TcB2
Tatum
TcD2
Tatum
Severe:
depth to rock.
Severe:
depth to rock,
slope.
Moderate:
percs slowly.
Moderate:
percs slowly,
slope.
Severe:
wetness,
percs slowly.
Severe:
depth to rock,
wetness.
Severe:
flooding,
wetness.
Severe:
slope.
Moderate:
depth to rock,
percs slowly.
Moderate:
depth to rock,
percs slowly,
slope.
Moderate:
depth to rock,
percs slowly.
Moderate:
depth to rock,
percs slowly,
slope.
Severe:
seepage,
depth to rock,
slope.
Severe:
seepage,
depth to rock,
slope.
Moderate:
seepage,
slope.
Severe:
slope.
Severe:
wetness.
Severe:
seepage,
depth to rock,
wetness.
Severe:
flooding,
wetness.
Severe:
slope.
Moderate:
seepage,
depth to
slope.
Severe:
slope.
rock,
Moderate:
seepage,
depth to rock,
slope..
Severe:
slope.
Severe:
depth to rock,
seepage.
Severe:
depth to rock,
seepage,
slope.
Moderate:
too clayey.
Moderate:
slope,
too clayey.
Severe:
depth to rock,
wetness. •
Severe:
depth to rock,
seepage,
wetness.
Severe:
flooding,
depth to rock,
wetness.
Severer:,
slope,
too clayey,
depth to rock.
Severe:
too clayey,
depth to rock.
Severe:
too clayey,
depth to rock.
Severe:
too clayey,
depth to rock.
Severe:
too clayey,
depth to rock.
Severe:
depth to rock,
seepage.
Severe:
depth to rock,
seepage,
slope.
Slight
Moderate:
slope.
Moderate:
depth to rock,
wetness.
Severe:
seepage,
depth to rock,
wetness.
Severe:
flooding,
wetness.
Severe:
slope.
Moderate:
depth to rock.
Moderate:
slope,
depth to rock.
Moderate:
depth to rock.
Moderate:
slope,
depth to rock.
Poor:
area reclaim,
small stones.
Poor:
area reclaim,
small stones,
slope.
Fair:
too clayey,
hard to pack.
Fair:
too clayey,
hard to pack,
slope.
Fair:
area reclaim,
too clayey.
Poor:
thin layer,
wetness,
depth to rock.
Fair:
area reclaim,
wetness,
thin layer.
Poor:
too clayey,
hard to pack,
small stones.
Poor:
too clayey,
hard to pack,
small stones.
Poor:
too clayey,
hard to pack,
small stones.
Poor:
too clayey,
hard to pack,
small stones.
Poor:
too clayey,
hard to pack,
small stones.
r
Stanly County, North Carolina
TABLE 11. - -SANITARY FACILITIES --Continued
Map symbol and
soil name
Septic tank
absorption
fields
Sewage lagoon
areas
Trench
sanitary
landfill
Area
sanitary
landfill
Daily cover
for landfill
ma TdB:
Tatum
Urban land.
Ud.
Udorthents
Ur.
Urban land
UwC
Uwharrie
UwF
Uwharrie
Moderate:
depth to rock,
percs slowly.
Moderate:
percs slowly,
slope,
large stones.
Severe:
slope.
Moderate:
seepage,
depth to rock,
slope.
Severe:
large stones,
slope.
Severe:
large stones,
slope.
Severe:
too clayey,
depth to rock.
Severe:
too clayey.
Severe:
too clayey,
slope.
Moderate:
depth to rock..
Moderate:
slope.
Severe:
slope.
Poor:
too clayey,
hard to pack,
small stones.
Poor:
too clayey.
Poor:
too clayey,
slope.
r;t