HomeMy WebLinkAboutFinal Capstone Report
The following report is a student effort to evaluate clean water improvements for Lake Cornelia. Development of a more
formal Clean Water Strategy to be led by the City is planned for 2020.
Each semester, the University of Minnesota - College of Science and Engineering requests proposals for senior student
capstone project ideas from local professionals who act as project mentors.
Read the November 2018 Edition: Edina story, “U of M Partners with Edina on Capstone Projects.”
Attachments:
Capstone description of commitments and benefits to mentors
Student final report
CEGE Senior Capstone Design
Mentor Commitments and Potential Benefits
Mentors provide a real world engineering project (current or past). Based on indicated areas of emphasis
and preferences, students are assigned to the projects in teams of 3-5. Ideal projects have a preliminary phase
(analyzing alternatives with a minor cost/benefit component) and some form of design phase. Past projects
have included projects in all areas of civil, environmental, and geo- engineering:
environmental: water treatment, wastewater treatment, site remediation
general civil engineering/municipal engineering: site plans (grading, utility, and hydrologic components)
geo-engineering: landslide stabilization, foundation analyses
structural: building design (overall structural analysis and detailed design of representative portion of
structure), bridge design including structural drawings
transportation: Intersection Control Evaluation (ICE), traffic impact studies, signal optimization, corridor
design
water resources/hydrology: retention ponds, sewer capacity studies, stream restoration, sediment control
Mentors provide a written description of their project, which consists of a one to two paragraph project
description and list of expected tasks. Students review those descriptions to indicate their project preferences.
The instructors assign the projects to the student teams during the first week of class, and the students
immediately contact their mentors to set up an initial meeting to complete a project development work plan. The
work plan further fleshes out the project tasks and expected timeline/deliverables. In addition, the
mentors/teams identify where and when meetings will take place and preferred methods of communication
between mentor/team meetings. Some mentors ask students to prepare detailed agenda and meeting minutes.
Mentors should expect to spend on average about one to two hours per week meeting with the students with
additional email or phone contact over a 13 week period. The students are expected to accommodate your
schedule and your preferred meeting location. Most often students meet their mentors at the mentors’ offices (it
is helpful for students to see and work in a professional office). Each student on the team is expected to work an
average of eight (8) hours per week on their selected project in addition to the time they spend in class each
week. The design project culminates in a final oral presentation and project report. The reports are 15 pages plus
appendices, which can be quite extensive (e.g., contain structural drawings and sample calculations). Students
submit three drafts of the reports (1st draft, midterm, and final) during the semester.
Commitments:
Mentors provide project description including list of tasks.
Mentors provide background information and technical assistance on the project for the students.
Mentors provide guidance to the students, but let the team make important decisions.
Mentors are encouraged to provide feedback on second (near final) draft of written reports.
Mentors are encouraged to attend final oral presentations in the Civil Engineering Building
Potential Benefits to Mentors:
Mentors receive continuing education credit towards their required PDHs.
Mentors help strengthen our profession by providing a vital education component.
Mentors work with students that your firm may want to hire in the future.
Mentors receive reimbursement for parking expenses when on campus.
Mentors are invited to attend a reception and receive a plaque or small gift honoring their service.
Mentors may obtain real help on a current project from the students in exploring various design options for
which the mentors themselves may not be able to dedicate sufficient time or budget to accomplish.
Group 11 Engineering Company
University of Minnesota
Department of Civil, Environmental, and Geo-Engineering
500 Pillsbury Drive SE
Minneapolis, MN 55455
May 3rd, 2018
Ross Bintner, PE
City of Edina
7450 Metro Boulevard
Edina, MN 55439
RE: Lake Cornelia Clean Water Strategies
Dear Mr.Bintner,
This letter is in response to your request of a feasibility analysis to determine the best
strategies to meet clean-water standards for Lake Cornelia. Attached is the full report. Four Best
Management Practices (BMPs) were chosen to target phosphorus in its various forms
throughout the watershed. These options are: carp management, an alum treatment plant,
street sweeping, and infiltration basins.
For carp removal, the cost per pound of phosphorus prevented from resuspension is
approximately $23.17. An alum treatment plant was the most expensive option at $1461 per
pound of phosphors removed. In-lake alum dosing would cost $207 per pound of phosphorus
removed. The infiltration basins cost approximately $790 per pound of phosphorus removed.
Additional street sweeping would cost $198 per pound of phosphorus removed from the
watershed.
Our final recommendation is to include all of these BMPs except the alum treatment
plant in order to reduce phosphorus concentrations within Lake Cornelia. These BMPs have the
potential to remove 122 pounds of phosphorus, or approximately 31% of the total phosphorus
loading into Lake Cornelia. Carp Management also has the potential to prevent the
resuspension of 370 pounds of in-lake phosphorus. This recommendation is extensive but
addresses the many forms of phosphorus loads into Lake Cornelia.
Thank you for the support from the City of Edina and Barr Engineering on this project.
Please do not hesitate to contact us if you require any further information.
Sincerely,
Emily Castanias, Hayley Anderson, Aaron Kilpo, Katarzyna Oszajec
Prepared by: Emily Castanias, Hayley Anderson, Aaron Kilpo, and Katarzyna Oszajec
Prepared for: The City of Edina, Minnesota
Team Mentors: Ross Bintner, and Jessica Wilson; City of Edina
Sarah Stratton, and Janna Kieffer; Barr Engineering
Submitted May 3rd 2018
Lake Cornelia
Clean Water Strategies
Lake Cornelia Clean Water Strategies | i
Certification Page
By signing below, the team members submit that this report was prepared by them and is their
original work to the best of their abilities.
Hayley Anderson
Emily Castanias
Aaron Kilpo
Katarzyna Oszajec
Lake Cornelia Clean Water Strategies | ii
Executive Summary
The City of Edina has requested a feasibility study to determine the best strategies to
meet clean-water standards for Lake Cornelia. Lake Cornelia’s northern and southern basins
have both entered the Minnesota Pollution Control Agency (MPCA) list of impaired waters for
2018. Lake health indicators for Lake Cornelia, including phosphorus concentration, secchi-
depth, and chlorophyll-a concentration, do not meet MPCA shallow-lake standards.
The goal of this study was to determine the best management practices (BMPs) in order
to reduce the phosphorus concentration within Lake Cornelia. Four BMPs were chosen to target
phosphorus loads throughout the watershed. These options are:
1. Carp Management: Preventing in-lake phosphorus loadings.
2. Alum Treatment Plant: Removing In-lake or watershed phosphorus loadings
3. In-Lake Alum Dosing: Removing In-lake phosphorus from Lake Cornelia
4. Street Sweeping: Targeting phosphorus loads prior to entering the storm sewer
5. Infiltration Basins: Intercepting storm sewer phosphorus before entering Lake Cornelia
Carp management is a viable strategy involving data collection, carp removal and barrier
installation. For carp removal, the cost per pound of phosphorus prevented from entering the
water column is approximately $23.17. An alum treatment plant can effectively remove
dissolved phosphorus with a treatment system. However, an alum treatment plant was the most
expensive option at approximately $1461 per pound of phosphors removed. A less expensive
option to remove dissolved phosphorus from the lake is in-lake alum dosing. In-lake alum
dosing would cost $207 per pound of phosphorus removed. Phosphorus loadings from the
watershed were also targeted with infiltration basins in the clover loops of the Highway 100 and
Highway 62 interchange. The infiltration basins cost approximately $790 per pound of
phosphorus removed. Increasing the current rate of street sweeping would also reduce
phosphorus loads into the lake while improving the quality of the roads around Lake Cornelia.
Additional street sweeping would cost $198 per pound of phosphorus removed from the
watershed.
Our final recommendation is to include all of these BMPs except the alum treatment
plant in order to reduce phosphorus concentrations within Lake Cornelia. These BMPs have the
potential to remove 122 pounds of phosphorus from the watershed and Lake Cornelia, which
accounts for approximately 31% of the total phosphorus loading into Lake Cornelia. Carp
Management also has the potential to prevent the resuspension of 370 pounds of in-lake
phosphorus. This recommendation is extensive but addresses the many forms of phosphorus
loads into Lake Cornelia.
Lake Cornelia Clean Water Strategies | iii
Table of Contents
1.0 Introduction……………………………………………………………..………..…………... 1
2.0 Background……………………………………………………………………….……….… 2
3.0 Treatment Design Options and Methodology……….………..…………………….…. 4
3.1 In-Lake BMPs……………………………..……………….……………………………. 4
3.1.1 Carp Management……………………………………………………………… 4
3.1.2 Alum Treatment Plant……………………………………………………......... 7
3.1.3 In-Lake Alum Dosing………………………………………………………….…11
3.2 Out-of-Lake BMPs…………………………………….…………………………………. 13
3.2.1 Infiltration Basin.……..………...………....…………………………………….. 13
3.2.2 Street Sweeping....………………..………………...…………………………...15
4.0 Sustainability Considerations…………….…................................................................17
5.0 Recommendations and Conclusion…………..………………………………………...... 18
5.1 Phosphorus Removal…………………………………………………………………….. 18
5.2 Impact on Lake Health……………………………………………………………………. 19
5.3 Final BMP Costs…………………………………………………………………………... 20
5.4 Layering and Sequencing……………………………………………………………….. 20
6.0 References…………………………………………......…………………………………….. 22
Appendices...……………………………………………….………….……………………….... 24
Appendix A : Lake Cornelia Maps……..……….………………………………………..... 25
Appendix B: Cost Analysis Calculations………………………………………………….. 32
Appendix C: Engineering Costs……………………………………………………………. 43
Appendix D: Section Authors………………………………………………………………. 44
Lake Cornelia Clean Water Strategies | iv
Table of Tables
Table 1.1 Current Trophic State Index values vs MPCE Standards………………………...... 1
Table 3.1.1 DNR Fisheries Report Carp Sampling Data……………………………………….. 4
Table 5.1.1 Phosphorus Removal for Each BMP per year……………………………………... 18
Table 5.3.1 Final BMP Cost Estimates………………………………………………………….... 20
Table B.1 Phosphorus Removal Calculations………………………………………………….... 32
Table B.2 Cost Estimate for Carp Removal Over 10-Year Lifespan………………………….. 33
Table B.3 Interpolation of Alum Treatment Plant Cost………………………………………….. 34
Table B.4 Phosphorus Removed by Alum Treatment Plant………………………………….... 34
Table B.5 Alum Treatment Annual Plant Operation and Maintenance Costs…………………35
Table B.6 Annual Cost For In-Lake Alum Treatment…………………………………………….36
Table B.7 Northeast Infiltration Basin Phosphorus Removal Calculations…………..……….. 37
Table B.8 Northeast Infiltration Basin Construction Costs ………………..……..…………….. 38
Table B.9 Southwest Infiltration Basin Construction Costs…………………………………….. 39
Table B.10 Infiltration Basin Annual Operation and Maintenance Costs…………………..…. 40
Table B.11 Infiltration Basin Cost-Benefit Analysis…………………………………………..…. 40
Table B.12 Street Sweeping Phosphorus Removal Calculations…………………….……….. 42
Table B.13 Street Sweeping Cost Estimate Calculations over 25-Year lifespan……………. 42
Table C.1 Engineering Budget for completion of Feasibility Analysis …………………………43
Table D.1 Section Authors………………………………………………………………………….44
Table of Figures
Figure 2.1 Lake Cornelia and Surrounding Area………………………………………………... 2
Figure 3.2 Two Potential sites for Alum Treatment Plant…………………………………….… 8
Figure 5.1 Estimated Phosphorus Removal Following BMP Implementation…………….….. 19
Figure A.1 North and South Lake Cornelia Sub-Watershed Map……………………………... 26
Figure A.3 North And South Lake Cornelia Sub-Watershed Phosphorus Loadings……….... 27
Figure A.3 Map of Proposed NC_62 Subwatersheds…………………………………………... 28
Figure A.4 Map of Proposed Storm sewer to NC_62b Subwatershed………………………... 28
Figure A.5 North Lake Cornelia Street Sweeping Zone……………………………………….... 30
Figure A.6 South Lake Cornelia Street Sweeping Zone……………………………………...... 31
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1.0 Introduction
Lake Cornelia is a shallow 58-acre lake located in Edina near Highway 62 and France
Avenue. In recent years Lake Cornelia has struggled with toxic algal blooms and high pollutant
levels stemming from excess phosphorus concentrations. The 2018 Minnesota Pollution Control
Agency (MPCA) impaired waters list includes Lake Cornelia’s northern and southern basins.
Lake health indicators are above recommended levels set by the State of Minnesota. According
to the 2010 Lake Cornelia Use Attainability Analysis (UAA), the current Trophic State Index
(TSISD) values are beyond recommended ranges (Barr Engineering, 2010). Current TSISD
values are listed in Table 1.1.
Table 1.1: Current Trophic State Index values vs MPCE Standards
Current Index Level MPCA Shallow Lake Standards
TSISD 73 60-70
Chlorophyll-a 51.0 [µg/L] <20 [µg/L]
Secchi-Depth 0.4 [m] >1.0 [m]
Phosphorus Concentration 153 [µg/L] <60 [µg/L]
The goal of this project is to identify possible best management practices (BMPs) to
improve the water quality of Lake Cornelia. Best management practices are structural or
nonstructural systems that help target and remove nonpoint pollutants in the environment.
Some possible BMP’s identified were carp management, an alum treatment plant, in-lake alum
dosing, an infiltration basin, and street sweeping. The recommended BMPs target the various
pathways in which phosphorus enters Lake Cornelia.
This document outlines each of the five chosen BMPs and recommends which BMPs to
used based on their ability to sustainably and cost-effectively reduce the phosphorus levels
within Lake Cornelia. Then, the potential impact the recommended BMPs would have on Lake
Cornelia is analyzed. Finally, an implementation strategy for the recommended BMPs is
outlined.
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2.0 Background
Before the 975 acre Lake Cornelia watershed was developed, it comprised mostly
basswood, sugar maple, and oak forests. The general topography of the watershed varies from
flat to rolling. The area that is now Lake Cornelia was traditionally a wetland, which explains why
it is so shallow. Currently, the entire watershed is fully developed. It comprises 44% low density
residential, 22% commercial, 10% highway, 9% open water, 7% high density residential, 4%
developed park, 2% high impervious institutional, 1% wetland , and <1% industrial/office (Barr
Engineering, 2010). Future land use is not expected to change, so the quality and quantity of
stormwater runoff should remain constant. A satellite map of Lake Cornelia and the surrounding
watershed is shown below in figure 2.1
Figure 2.1: Lake Cornelia and Surrounding Area
Several models have been used to estimate the total phosphorus loading that the lake
would experience with no development. The MnLEAP model was used to estimate a baseline
total phosphorus concentration in Lake Cornelia of 55-97 µg/L. A previous study estimated a
baseline total concentration of 27-66 µg/L (Vighi, Chiaudani, 1985). In 2008 Lake Cornelia had a
summer average of 153 µg/L total phosphorus concentration (Barr Engineering, 2010). The
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Lake Cornelia Clean Water Strategies | 3
models of natural phosphorus concentration indicate that achieving the Nine Mile Creek
Watershed District (NMCWD) Level III classification goal should be attainable.
The watershed currently accounts for 71-82% of annual phosphorus loading in North
Cornelia, and 87-93% in South Cornelia, which includes the loading from North Cornelia. This
includes stormwater runoff and discharge from the Southdale Mall cooling system. Sources of
phosphorus in urban runoff include organic material, pet waste, road salt, and fertilizer. These
materials drain into the storm sewer network and flow into Lake Cornelia. Approximately 88% of
water loading and 82% of phosphorus loading into South Cornelia come from North Cornelia.
The remaining phosphorus loading comes from internal sources (Barr Engineering, 2010). An
invasion of curly-leaf pondweed releases large amounts of phosphorus each summer upon
death. Common carp, which are historically abundant in Lake Cornelia, also release settled
phosphorus back into the water column. Based on P8 phosphorus loading modeling, it was
determined that the subwatersheds NC_62 and NC_ 4 have the highest phosphorus
contribution to Lake Cornelia. This high phosphorus load comes from the large amount of
impervious area in NC_4 and the lake of existing pre-treatment in NC_62. The loads from the
modeling are shown in Figure A.2 in Appendix A.
The current trophic level of Lake Cornelia exceeds hypereutrophic levels and NMCWD
classifies the lake as a Level IV lake. Level IV lakes are categorized as primarily for runoff
management and serve little to no recreational purpose. Furthermore, the lake more than
doubles the MPCA Shallow Lake Water Quality standards for total phosphorus (TP), which call
for a TP concentration of less than 60 µg/L (Barr Engineering, 2010).
The water clarity of the lake limits vegetation to a depth of three feet underwater. The
dominant vegetation of the lake is cattails, but the invasive curly leaf pondweed are also
pervasive. Green algae is the dominant form of phytoplankton in the lake, and both basins
experience blue-green algal blooms in mid to late summer. The blue-green algae in the lakes
are known to produce hepatotoxin, a toxin that damages the liver (Barr Engineering, 2010). The
lake is stocked annually with bluegill for fishing, but a 2010 Minnesota Department of Natural
Resources (MNDNR) survey found black bullhead, black crappie, common carp, goldfish, green
sunfish, pumpkinseed sunfish, and yellow perch. Based on the dissolved oxygen content of the
lake, winter fish kills are highly probable, which makes estimating fish populations difficult
(MNDNR, 2015).
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Lake Cornelia Clean Water Strategies | 4
3.0 Treatment Design Options and Methodology
3.1 In-Lake BMP Strategy
The two main internal sources of phosphorus are curly-leaf pondweed die-off, and the
mixing of phosphorus in the sediment due to weather, climate, and benthivorous fish. Water
quality simulations from the Lake Cornelia show that in-lake release of phosphorus accounts for
10 to 19 percent of existing phosphorus loading to North Cornelia and roughly 5 to 11 percent of
phosphorus loading to South Cornelia. Curly-leaf pondweed has become increasingly abundant
since 2008, and carp populations have also fluctuated, leading to uncertainty on their total
impact on the lake (Barr Engineering, 2010). Managing these problems will reduce phosphorus
levels in Lake Cornelia. However, curly-leaf pondweed management will not be addressed in
this report as the City of Edina is working separately with the Lake Association to address this
issue.
3.1.1 Carp Management
Based on DNR fisheries reports from 2005 and 2010, carp are a prevalent benthivorous
fish within Lake Cornelia. Table 3.1 indicates the amount of carp caught in the 2005 and 2010
Minnesota Department of Natural Resources (MNDNR) fisheries Lake Surveys and their normal
ranges. Also, due to the ability of carp to rapidly populate or enter the lake from outside sources,
the population could have significantly changed since the 2010 estimate. However, dissolved
oxygen readings from 2010 indicate a likelihood of winterkills in cold winters (MNDNR, 2015).
Table 3.1.1: DNR Fisheries Report Carp Sampling Data
Year Trapping Gear Catch Per Unit Effort Normal Range
2005 Standard Gill Nets 33.00 1.5-11.6
2005 Standard Trap Nets 26.83 0.4-2.9
2010 Standard Gill Nets 17.00 1.5-11.6
2010 Standard Trap Nets 2.33 0.4-2.9
(source: DNR Fisheries Lake Surveys, 2010)
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Lake Cornelia Clean Water Strategies | 5
Residents indicated they could once see abundant carp in the lake, and populations
have decreased in recent years. The same resident noted the occurrence of recent winterkills in
Lake Cornelia. This report is supported by the MNDNR who have also reported winter-kills in
2010 and 2014. Dissolved oxygen readings in the summer also indicated a likelihood for
winterkills most winters. Therefore carp are likely migrating into the lake annually and do not
survive the winter. (MNDNR, 2015)
Numerous studies have shown that common carp have a significant detrimental impact
on lake quality. Carp can survive in a wide range of conditions including shallow eutrophic
systems such as Lake Cornelia. Total phosphorus and total suspended solids levels are
correlated with carp density (Bajer, Sorenson, 2009). Common carp will increase nutrient levels
in lakes because they vigorously disturb lake sediment in their foraging and spawning
behaviors. This releases nutrients trapped in sediment back into the water column. Additionally,
carp’s behavior releases loosely clumped sediment which is more prone to re-suspension by
wind action. In a shallow lake like Lake Cornelia, this effect is expounded by the fact that wind
can hold sediment in suspension (Beaver Dam CMP, 2015).
University of Minnesota research indicates that when carp biomass exceeds 89 pounds
per acre, severe negative impacts occur to the lake ecosystem. The University of Minnesota
report also indicated that a density of 26 lbs/ acre had no discernible effects on lake health
(Bajer, Sorenson 2009). One study estimated that 1 pound of carp produced 0.11 pounds of
phosphorus per year (LaMarra 1975) These estimates have both been widely accepted and
used in Total Maximum Daily Load (TMDL) reports and Management Plans throughout the
Midwest. These reports include but are not limited to: Cedar Lake and McMahon (Carl’s) Lake
(2010), Lotus Lake Management Plan (2018), Beaver Dam Lake Comprehensive Management
Plan (2015), and the Lake Cornelia User Attainability Analysis (2010). These reports have been
used to determine whether a Lake is a good candidate for carp management, and how much
phosphorus re-suspension is prevented through carp management.
Carp management involves multiple tasks to ensure the process is viable and
sustainable. First, an accurate estimate of carp populations must be obtained. This can be
employed with two different methodologies; a mark-recapture population estimate and a catch
per unit effort electrofishing model. The mark-recapture estimate involves capturing a large
number of carp, marking them with a fin clip, releasing them, and then recapturing a portion of
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them at a later date after they mix with the general population. From the number of marked
carp recaptured, and the total captured, the number of individuals can be estimated. Average
weights are used to calculate the total biomass. The second method would be to electrofish a
portion of the shoreline and track the number of carp captured during a specific unit of time. A
model is then used to determine the number of carp per acre.
If the carp density is found to exceed the accepted 89 pounds per acre, then removal
and prevention are the next steps. To find out where the carp are, high frequency transmitters
are deployed by surgically implanting them in 8-10 carp. This is called the judas technique
since the implanted carp mix within carp aggregations and show the possible locations of
connected nursery sites outside the lake (Havranek, 2018).
Once more information is obtained, strategies for carp removal, predator stocking,
barriers, etc. can be considered. Removal involves either contracted seining (dragnet fishing),
electrofishing or boxnetting. Then, to prevent carp from re-entering the lake preventative
measures should be taken. Because winterkills are prevalent within Lake Cornelia, preventative
barriers can be highly effective after a large winter kill to keep carp from re-entering into the
lake. There are no natural streams or creeks flowing into Lake Cornelia, so grated barriers
which can be fit into pipe-inlets would be the most effective preventative barrier for Lake
Cornelia. Grated barriers can be retrofit on to existing pipes or culverts, and would need
occasional cleanouts to prevent clogging by debris.
A basic cost estimate for collecting the right amount of data, including the population
estimates and tracking, is a one time cost of approximately $15,000-$30,000. If removal is then
deemed necessary, hiring a contracted fisherman would cost an additional $10,000-$20,000
based on the size of the population (Havranek, 2018). Physical barriers are estimated to cost
$4,000 per barrier and could be installed at any point during the process. These barriers would
also incur maintenance costs, as estimated in Appendix B. After approximately five years, the
size of the population should be reassessed with electrofishing, and this population estimate will
cost approximately $5,500 at the time of the estimation. If deemed necessary, the second
removal effort would cost an additional $10,000-$20,000 dollars at the time of removal. These
are typically multi-year projects that require an adaptive approach based on the data that is
collected and how complex and interconnected the system is.
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Carp populations will be assumed to be at 89 lbs/acre. This assumption indicates that
carp population are dense enough to impact lake health, but are not in extreme abundance. A
reduction goal of 26 lbs/acre will be used because no negative lake health impacts were
indicated at that level. (Bajer, Sorenson 2009). By assuming a total reduction of 59 lbs/ acre,
and using a total acreage of 58 acres, carp management has the potential to prevent the
resuspension of 370 pounds of phosphorus each year. Based on a total cost estimate of
$52,000 - $87,000 dollars, carp management would cost approximately $13.88 to $23.17 per
pound of phosphorus each year. A level of uncertainty exists for these numbers as the final
phosphorus removal is highly dependent upon the existing density of carp within the lake, which
is currently unmeasured. The final costs of the removal process depends upon the initial
measured density of carp, whether the density of carp warrants carp removal, and the
effectiveness of carp removal if it is implemented. See Appendix B for detailed cost estimate
information.
3.1.2 Alum Treatment Plant
The UAA for Lake Cornelia water quality indicates that 47% of the phosphorus found in
Lake Cornelia is dissolved phosphorus (Barr Engineering, 2010). Unlike particulate
phosphorus, dissolved phosphorus is fed on by algae. Since algae is the main problem of Lake
Cornelia it is important to target the removal of dissolved phosphorus. Dissolved phosphorus is
the most decomposed form of phosphorus, meaning that the dissolved phosphorus particles are
micro-sized. This means that these particles are too small to settle out on their own. Since these
particles are micro-sized, the only way to treat it is to have the dissolved phosphorus bind to
another particle to change the state that the phosphorus is in. Once the phosphorus state is
changed it is not available for the algae as a food source.
One way to treat this type of phosphorus is to allow it to bind to another particle to create
a larger compound that can then settle out. Therefore, one way to remove the dissolved
phosphorus is to use alum treatment. Alum treatment works by introducing a nontoxic and
soluble material, known as alum or aluminum sulfate, into the water. Upon contact with the
water it becomes a floc or aluminum hydroxide; this floc dissolves into aluminum ions. The
aluminum ions bind to the dissolved phosphorus to create aluminum phosphate. This compound
is insoluble in water and therefore settle to the bottom of the lake. This compound cannot be
broken by an physical activity, so once the phosphorus is in the aluminum phosphate state it will
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stay that way. Aluminum phosphate is a nontoxic compound and non-hazardous compound to
living organisms, therefore if left in the water it will not harm the lake. As the compound settles
out it also can entrap other suspended solids and force those particles to settle out. (Wisconsin
Department of Natural Resources)
One type of alum treatment is to create a alum treatment plant either upstream from one
of the inlets to the lake or near the lake so the water can be pumped out of the lake into the
alum treatment plant. The option that would make the most sense for Lake Cornelia would be to
place an alum treatment plant on the east side of the lake and to pump water actively into the
treatment plant. This is because the area upstream from Lake Cornelia is a fully developed
residential area with little room to build a treatment plant. Two potential sites for the alum
treatment plant can be seen below in Figure 3.2. By placing the treatment plant on the east side
of the lake, the plant will be primarily treating the water coming from the commercial area of
Edina, which as seen in Figure A.2 is a watershed that has a bigger loading of phosphorus than
some of the other watersheds surrounding Lake Cornelia. The treatment plant consists of a
monitoring station, the dosing point, and the settlement basin.
Figure 3.2: Two Potential sites for Alum Treatment Plant
The alum treatment plant requires a station that monitors the conditions of the water
being pumped into the plant, including the amount of dissolved phosphorus found in the water,
pH, and temperature. Based on the conditions of the water the optimal amount of alum to dose
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the water with will be determined. This will make sure not too much alum is being put into the
water, and the system is being as cost efficient as possible. The water will be first pumped out
of the lake and put through the monitoring station to make sure the most up to date information
is being used. The water is then passed through the alum treatment plant where the water is
dosed with the correct amount of alum. The water then flows a short distance to the
sedimentation basin where the aluminum phosphate can settle out. The sedimentation basin
can be considered a detention pond as it just holds the water for a short contact period. The
clean is then pumped back into the lake. (WSB & Associates) The settlement basin has to be
designed in the most cost-efficient manner, due to the fact that particles have a settling velocity
that follows Stokes Law. This law states that particles that are denser and larger will settle out
faster. Therefore, the basin could be made very long so that almost everything settles out or
made not as long and risk some aluminum phosphate travelling downstream. The area of the
basin will depend on the flow going through that basin, the average particle size, the density of
the particle and the percentage of aluminum phosphate that is being allowed to make it through
the basin. Since the water is being pumped through the system at a steady rate this gives an
important constant in determining how big the basin should be. The percentage of aluminum
phosphate allowed to pass through the basin is also a fixed constant so the only variable is the
average particle size of aluminum phosphate. This can be tested directly with the lake water to
be the most accurate. Once all these factors are accounted the settlement basin can be sized
appropriately.
There are a few concerns when dealing with an alum treatment plant. An important
concern is taking care of the deposited aluminum phosphate in the settlement basin. This is a
by-product that needs to be disposed of to make sure that the basin is working under the design
conditions. The sludge can be given to a facility for aluminum recovery to try to get some money
to make the project as expensive, or it can be deposited in a landfill. Another concern is making
sure the plant does not get overwhelmed with too much water flowing into the system.
Therefore, the pump system has to be working properly making sure that the plant is not being
overwhelmed even when the lake is experiencing high in-flows. A final concern is making sure
all the equipment is working properly. Regular maintenance will have to be done to make sure
everything is working properly and there will have to be professionals hired in order to make
sure that the plant is working properly and efficiently.
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Since there are all these concerns, the money needed to install and run this plant is
significant. The initial capital cost of this plant was determined to be around $935,000. This
includes setting up the monitoring station, the building of the alum treatment plant, the building
of the settlement basin, and clearing the appropriate amount of land to make this treatment
plant possible. This cost was interpolated based on similar alum treatment plants found in the
state of Minnesota. Table B.3 in the appendix shows the data that was used from other lakes in
this interpolation. The lakes that were used in this interpolation were: Fish Lake in Eagan,
Tanners Lake in Oakdale, and Crystal Lake in Robbinsdale. The two lakes that were given more
weight when doing the interpolation were Fish Lake, and Crystal Lake. Fish Lake was given
more weight because it is the closest lake in size, and Crystal Lake because it uses a treatment
facility similar one to the proposed one for Lake Cornelia. The other lakes use a treatment
facility upstream of the lake and therefore do not have to pump the water making the cost of the
plant lower.
On average it was found that the annual maintenance costs of such a plant were
$30,000-$40,000 from data of the same lakes that were used for the interpolation of the capital
cost which can be seen in Table B.3. This covers the maintenance and upkeep of all the
equipment, making sure that the monitoring station is working properly, and the removal of the
settled aluminum phosphate from the bottom of the sedimentation basin. Overall, this would be
a 1.6-million-dollar project. Since this number was interpolated and the facility was not designed
the uncertainty is about 25%.
To determine how much phosphorus this plant could remove annually data from the
Crystal Lake treatment facility was used. This is because this facility is very similar to the one
being proposed for lake Cornelia. It was estimated that the treatment plant for Lake Cornelia
could remove approximately 50 pounds of phosphorus. This calculation was done by taking the
pounds of phosphorus removed by the Crystal Lake facility and multiplying it by a factor of 0.57.
This factor accounts for the phosphorus loading of Lake Cornelia (247 lbs.) (Barr
Engineering,2010) compared to the phosphorus loading of Crystal Lake (430 lbs.),(Wenck
Associates, 2016) as seen in Table B.4. As can be seen this is on the lower end of how much
phosphorus can be removed, to give the highest possible price. Also since these numbers are
based off of number from Crystal Lake the uncertainty for this calculation is about 30%. In order
to compare the cost of all BMPs a denominator of dollar per pound of phosphorus removed per
year was used, and the breakdown of this can be seen in Table B.5. Therefore, after making a
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lifetime cost analysis, it was determined that it would be about $1461/lb of P/yr. This makes it
the most expensive strategy but it is also the only strategy that would remove the dissolved
phosphorus that is found in the lake.
Designing an alum treatment plant takes a lot of in field research to determine the
current conditions of the water, what happens to the water conditions when a storm passes
through the area or more water flow is going through the watershed, and how the conditions
change based on the seasons. Therefore, all these things should be looked at before designing
and installing the alum treatment plant in order to ensure that plant is built to be as cost effective
as possible.
3.1.3 In-Lake Alum Dosing
Another treatment option for alum treatment is in-lake alum dosing. In-lake dosing
requires the alum to be released directly into the lake, this is done by using a boat to
methodically spread the alum throughout the lake and make sure that all part of the lake is
dosed with the alum. Due to this lake being a shallow lake the movement of the boat through
the lake is enough to ensure that the alum is mixed consistently through the lake, and can
therefore bind to the most phosphorus. The chemical reaction can take place and the aluminum
phosphate is allowed to settle out at the bottom of the lake. This is a onetime treatment method
for the dissolved phosphorus found in the lake. It will take care of the dissolved phosphorus
found currently in the lake but it will not remove any future phosphorus that comes into the lake.
The aluminum phosphate at the bottom of the lake creates a phosphorus layer which acts as a
protective barrier that prevents the resuspension of the phosphorus found in the sediment of the
lake back into the water column. The resuspension of phosphorus from the sediment is a source
of internal loading for the lake, so this protective layer will reduce the annual internal
phosphorus load. The City of Edina did some studies for in-lake alum dosing for Lake Cornelia
in 2011 and found that this protective layer would be effective for anywhere from 7 to 10 years
as long as there is no physical disturbance of the layer. The disturbance of the layer will not
cause the phosphorus to change back into dissolved phosphorus, but it will allow for the
resuspension of the phosphorus, therefore adding to the dissolved phosphorus already found in
the lake. A secondary benefit to the lake is short term lake clarity. This is due to the fact that as
the aluminum phosphate settles to the bottom of the lake other suspended particles are also
captured and therefore forced to settle to the bottom as well. This will only improve the clarity of
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the lake as the aluminum phosphate is settling out as soon as it is done there is nothing left to
force the suspended particles to settle out and the clarity of the lake will return to what it was
previously. (Barr Engineering,2010)
There are a few concerns when applying in-lake alum dosing as a treatment to natural
lakes. One concern is keeping the lake at a pH for the alum to be used in an effective way.
When aluminum is added to water it decreases the pH of the water, as the pH decreases
aluminum favors the formation of an insoluble aluminum hydroxide versus the soluble one
needed for the phosphorus to be removed. In order to counteract is naturally occurring decrease
in pH a buffer needs to be added in order to ensure that the lake stays at a favorable pH of 6 to
8, where alum dosing is most effective. Another concern is what to do with the aluminum
phosphate layer at the bottom of the lake. (Kennedy, 1982) Aluminum phosphate itself is not
harmful to aquatic life or humans so it can be left at the bottom of the lake. Yet, if another dose
of alum is to be administered that layer should be removed so that the new layer can effective
prevent that resuspension. Therefore, at one point the aluminum phosphate will have to be
removed, and this would involve the dredging of the lake. Dredging will also get rid of any other
clay, silts and overall improve the quality of the lake. Based on what type of sediment is found at
the bottom of the lake dredging can be relatively cost effective or not.
In 2011, Barr Engineering calculated how much phosphorus would be removed through
in-lake alum dosing and how much this would cost the city of Edina. According to the UAA in-
lake alum treatment the annual internal load of phosphorus would be reduced by 40 to 53 lbs.
The uncertainty of this removal is 5%, due to the fact that most calculations for this were already
done but there may be a slight change based on the change of internal phosphorus loading over
the past years. The cost of in-lake alum treatment calculated by Barr in 2011 was $90,000. This
includes the alum treatment and the buffer solution needed to make sure that the treatment is
effective. It does not include dredging as that is option, and varies based on the conditions of
the lake. (Barr Engineering,2010) This number was adjusted to include inflation; the cost of this
project today would be $104,000. The uncertainty of this number is 2% because all calculations
for the treatment were already done and just had to be fixed for inflation These numbers were
then converted to dollar per pound of phosphorus removed per year; this calculation was done
over the lifetime of the BMP. The result was that alum treatment would cost $207 per pound of
phosphorus removed. The uncertainty for this final number is around 4%, because all the
numbers used in this calculation had a low uncertainty. A detailed calculation for the cost per
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pound phosphorus removed per year can be found in Table B.6. This is a very affordable option
for the City of Edina, and is one way to reduce the dissolved phosphorus in the lake.
In-lake alum treatment targets the phosphorus that come from internal sources of the
lake, mainly the sediment. According to the UAA about 14% of the total phosphorus comes from
internal loading. In-lake alum treatment is treating that 14% in the long term, in the first one or
two years it will also target the phosphorus coming from external sources, making in-lake alum
treatment more effective if the phosphorus load coming into the lake is not high. These external
sources make up a larger percentage of the total phosphorus coming into the lake. According to
the UAA the external loading of Lake Cornelia is 85%. The alum treatment facility would target
the external phosphorus loading. If the city of Edina does want Lake Cornelia to reach MPCA
standards in-lake alum treatment is a good place to start but the external phosphorus loading is
the real problem, and should be targeted. (Barr Engineering,2010)
3.2 Out-of-Lake BMPs
Most of the phosphorus that is found in Lake Cornelia comes from out of the lake.
According to the UAA, about 85% of the phosphorus found in lake Cornelia comes from the
surrounding watershed (Barr Engineering, 2010). Phosphorus rich stormwater drains from the
residential and commercial areas around the lake into Lake Cornelia. The following out of lake
BMPs would be implemented throughout the watershed. The point of these out of lake
strategies is to remove phosphorus from the stormwater before it enters the lake. Therefore, the
placement of these BMPs need to be strategic and cost effective.
3.2.1 Infiltration Basin
Infiltration basins are landscaped depressions or shallow basins that are used to treat
stormwater runoff. Stormwater is directed into the basin and infiltrates through the soil where it
undergoes physical and chemical remediation. An infiltration basin can effectively remove
particulate phosphorus via filtration, as well as dissolved phosphorus via sorption. The portion of
the water that infiltrates into the deep groundwater undergoes 100% removal of total
phosphorus. During big storm events, the excess flow is drained into an outlet structure which
directs the water into the storm drain.
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An infiltration basin is typically composed of seven elements: 1) a grass buffer strip, 2)
vegetation, 3) a shallow ponding area, 4) mulch, 5) engineered soils, 6) a sand bed, and 7) an
underdrain system. The grass buffer strip decreases the velocity of the water and begins to filter
out suspended solids. The vegetation helps to remove excess nutrients through nutrient cycling.
The shallow ponding area allows for storage of excess runoff, and promotes the settling of
particulate matter. A mulch layer is placed in the basin, which encourages biological
degradation of pollutants, and reduces soil erosion. Engineered soils should be used, as they
increase the removal rate of phosphorus and other nutrients and pollutants. A sand bed at the
bottom allows for drainage into the underdrain system that would direct the water into Lake
Cornelia, or the storm drain system if utilized off-site.
Most of the surrounding sub-watersheds drain into ponds before the water enters Lake
Cornelia. This provides some treatment because the ponds act as settling basins for particulate
phosphorus. However, the largest subwatershed, NC-62, enters the lake untreated. For this
reason, the NC-62 watershed was made a priority for an out-of-lake treatment option. The area
within the loops of the cloverleaf interchange on Highways 100 and 62, located northwest of
Lake Cornelia, was determined to be the most feasible locations for an infiltration basin. This
site was chosen because it is one of the few locations in the watershed that has available land,
and because a storm drain passes directly underneath. Two basins were designed, with one
going in the northeast loop and one going in the southwest loop of the cloverleaf interchange.
The watersheds draining into the basins were delineated to determine the respective
contributing drainage areas. The northeast basin was determined to have a drainage area of 41
acres, while the southwest basin was found to have a drainage area of 37.74 acres. Using
design criteria from the Minnesota Stormwater Manual, the basins were designed according to
their drainage area (Minnesota Stormwater Manual, 2018). The basins were designed to be
circular, with a depth of four feet. The first ten feet of radius are to have a slope of 10:1 (H:V)
and the next nine feet are to have a slope of 3:1 (H:V). The remaining radius making up the floor
of the basin is to be flat. Using cost estimates from the Minnesota Stormwater Manual, the
construction cost would be about $259,228 for the northeast basin and $287,568 for the
southwest basin (Minnesota Stormwater Manual, 2015). Annual operation and maintenance
costs were calculated to be about $5250 for each basin, for a total of $10,500. Cost estimate
calculations are provided in Appendix B. It should be noted that these are preliminary estimates,
and that a more comprehensive cost analysis should be prepared prior to construction.
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In order to estimate the amount of phosphorus removed each year we used the P8
model provided by Barr engineering. We calculated that the NC-62 subwatershed contributes
0.55 lb P/acre/year. Assuming that the basin captures and treats 90% percent of the annual
flow, the basins would prevent a total of 39.4 lbs of TP from entering Lake Cornelia each year. A
cost analysis provided in Appendix B shows that over a 25 year lifespan, the cost of removal
would be about $790/lb P.
3.2.2 Street Sweeping
Street sweeping is a strategy that reduces potential sources of phosphorus and
sediments/solids from entering storm sewers or water bodies. Sweeping commonly happens
during the spring after the snow melts and in the fall when the leaves have fallen. Mechanical
broom or vacuum sweepers collect leaves and debris on roads. There are three strategies that
can be used for sweeping; baseline, which occurs once every fall and spring, monthly, and bi-
weekly. Currently, Edina uses the baseline effort and only sweeps twice a year. All strategies
only sweep during snow-free seasons (April through October). The city also upgraded from
mechanical sweepers to regenerative air sweepers in 2014, which decreased total solids (TS)
and total phosphorus (TP) loading from the watershed to the lake. With this current strategy,
the estimated TS and TP watershed load recovery is 29,008 lbs and 23.2 lbs.These phosphorus
load estimations were provided by the City of Edina Street Sweeping Manual (CESSMP, 2018).
The phosphorus budget for North Cornelia from external sources for an average climate
is 334 lbs. The North Cornelia street sweeping zone comprises 43.5 curb miles and is
considered to have residential land use type and a high service level according to the Cornelia
Water Resources Management Plan (Barr Engineering, 2017). The street sweeping zones for
both North and South Cornelia are highlighted in dark grey in Figures A.5 and A.6, located in
Appendix A. Load reductions (TS and TP) for priority waters were found using pollutant removal
efficiencies estimations through P8 modeling in 2015 (Edina Street Sweeping Management
Plan, 2015). According to the analysis in the CESSMP, monthly sweeping estimates yield a total
watershed load recovery (TP) of 51 lbs annually. This is about 225% TP reduction to the
waterbody, compared to baseline effort the city is using now. An even better strategy is bi-
weekly sweeping. CESSMP estimates yield a total watershed load recovery (TP) of 74.9 lbs.
This is about 323% TP reduction to the waterbody, compared to baseline effort the city is using
now.
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Lake Cornelia Clean Water Strategies | 16
Cost estimates for each sweeping strategy were provided in the CESSMP for North
Cornelia. Upgrading to the monthly strategy would cost an additional $198 per pound recovered.
From this analysis, the monthly strategy would be the most cost-efficient strategy, The curb mile
cost would decrease from $66/curb mile to $37/curb mile, and total cost would change to
$11,234 per sweep season.
The South Cornelia sweeping area only contains 3.7 curb miles and is also of high
service level according to the Edina CWRMP. If the same strategy for North Cornelia were
implemented on South Cornelia, an additional 2.5 pounds of phosphorus would be recovered
annually (during sweep season) from the lake, also calculated by the CESSMP. The upgrade
from baseline to monthly would cost an additional $5,975 annually (during sweep season).
From the load reduction and cost estimates, a few recommendations can be made. If the
city of Edina increases the number of sweepings to monthly (during the snow free season), the
phosphorus recovery will increase by a maximum of 225%. The cost to upgrade to this strategy,
given the city’s present implemented strategy for North Cornelia would be $5506, and an
additional 27.8 pounds of phosphorus would be recovered per year. It is not recommended that
street sweeping be carried out in the South Cornelia sweeping zone. The south sweep zone has
limited curb miles, and sweeping here would cost about the same as the north, but with little
phosphorus removal.
According to the city, Edina currently only has one street sweeper. Regenerative air
sweepers are not required to implement a monthly sweeping strategy, but will increase the
phosphorus recovery to the lake. The sweepers use compressed natural gas and sweep up
more debris without releasing harmful emissions. If the city chose to upgrade additional fleet, it
would be $23,700 for each vehicle with an additional annual maintenance cost of $4,800 (Edina
Street Seeping Manual, 2018).
There is an added benefit to the public if the city were to upgrade to a monthly strategy.
The Lake Cornelia Residents Association claims that bikers have complained of gravel and
debris on the curbs, so upgrading the effort would solve an additional public concern.
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Lake Cornelia Clean Water Strategies | 17
4.0 Sustainability Considerations
The goal driving our team to find solutions that reduce phosphorus loading to the lake
comes from a need for public access to safe resources and to limit exposure to health hazards.
Reducing the phosphorus load to Lake Cornelia will result in a decrease of algae, which could
potentially make the lake safe for limited recreational use. Since our design’s motivation is to
benefit the public’s safety while minimizing environmental impact, our project is inherently
sustainable.
Within the BMPs we chose, there is room to recommend sustainable features. Within
carp management, sustainability is addressed by recommending the use of preventative
barriers. By preventing the migration of carp into the lake, less money and resources will need
to be spent on future carp removal efforts. When considering street sweeping, adding more curb
cuts would allow runoff to be directed to a more pervious area to collect in storm sewers to be
treated. This would also make the sidewalks more accessible to bikers and pedestrians.
While all of our recommendations establish a more sustainable environment for the lake,
there are a still a couple concerns about sustainability to consider. First, most street sweepers
run on diesel fuel, and are a generator of carbon dioxide. Second, continually running an alum
treatment plant requires a considerable amount of energy. When Edina decides how to address
algae problem in Lake Cornelia, they may want to consider how their choices fit into the city’s
clean energy goals.
It is important these solutions recommended not only benefit the environment, but
benefit the city of Edina’s social and economic health. The four BMPs will reduce the amount of
phosphorus in the lake, which will in-turn reduce the amount of algae in the lake, making it safe
for recreational use. Cleaning this lake will give the city of Edina another community gathering
spot and recreational attraction to the city, which will boost social and economic growth.
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Lake Cornelia Clean Water Strategies | 18
5.0 Recommendations and Conclusions
Based on the costs and phosphorus removals above, a final set of recommendations is
outlined below. Total phosphorus removal from the recommended BMPs, the potential impact
the BMPs may have on lake health, the total costs of the recommended BMPs, and a suggested
implementation plan are outlined in parts 5.1 to 5.4,
5.1 Phosphorus Removal
In order to reduce the phosphorus levels in Lake Cornelia, the BMPs that were chosen
collectively to pertain to different parts of the watershed in order to provide a full scope of
options. Carp management provides targeting the prevention of in-lake dissolved phosphorus
loadings. The second proposed BMP, street sweeping, is an out-of-lake strategy that targets the
prevention of particulate phosphorus before entering storm sewer. Infiltration basins and the
alum treatment plant are both out-of-lake structural methods that target dissolved phosphorus.
Table 5.1.1. shows the total phosphorus removed from each BMP.
Another part necessary to develop and implement our solutions was to interpret the
phosphorus loading throughout the watershed that goes into North Lake Cornelia. Based on
phosphorus loading maps, it was determined that the sub watersheds NC_62 and NC_ 4 have
the highest phosphorus contribution to Lake Cornelia. This high phosphorus load comes from
the large amount of impervious area in NC_4 and the lake of existing pre-treatment in NC_62.
Table 5.1.1. Phosphorus Removal for Each BMP per year.
Best Management Practice Phosphorus Removal
Street Sweeping 28 [lbs/yr]
Infiltration Basin 39 [lbs/yr]
In-Lake Alum Dosing 50 [lbs/yr]
Alum Treatment Plant 50 [lbs/yr]
Carp Management 370 [lbs/yr]
TOTAL 537 [lbs/yr]
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Lake Cornelia Clean Water Strategies | 19
5.2 Impact on Lake Health
The goal for identifying the proper BMP’s for the lake was to bring the lake to a
hypereutrophic state. According to modeling performed by Barr Engineering, 48% of the
watershed’s (out-of-lake) phosphorus load and 78% of the in-lake phosphorus load must be
removed *Barr Engineering, 2018). Our team calculated that the two out-of-lake treatments,
street sweeping and the infiltration basin, would remove only 20% of the watershed phosphorus
load. The two in-lake treatments, carp management and in-lake alum dosing, are estimated to
remove 91% of the in-lake loading. Additionally, the phosphorus contribution from carp is not
included in the original phosphorus loading models, so the additional benefit of carp
management is not reflected in these numbers.
Figure 5.2.1 below illustrates the total phosphorus removed with each BMP and the total
phosphorus removal required to meet MPCA standards. We can see that our BMP’s remove a
lot of phosphorus, but still collectively fall short of the MPCA standards. If Edina were to add an
alum treatment plant in the future, it would help the lake get closer to the desired MPCA
standards, but the collective scenarios fall short even with this addition. Combined, these BMP’s
may not remove enough phosphorus to meet MPCA standards based on the models from Barr
Engineering, but they will be a good starting point for further investigation by the City of Edina.
Figure 5.1: Estimated Phosphorus Removal Following BMP Implementation
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Lake Cornelia Clean Water Strategies | 20
5.3 Final BMP Costs
Capital and annual operations and maintenance costs were calculated and analyzed for
each BMP that our team chose. The alum treatment plant was estimated to be the most
expensive option, and would cost twice as much as our second most expensive BMP, the
infiltration basin. Although the alum treatment plant removes a comparable amount phosphorus
compared to most of the BMP’s identified, it’s high cost makes it an unfavorable option. For this
reason, we do not recommend that the City of Edina to install an alum treatment plant. Total
cost estimates for all BMPs are shown in Table 5.3.1.
Table 5.3.1: Final BMP Cost Estimates
Street
Sweeping
In-lake Alum
Dosing
Infiltration
Basin
Carp
Removal
Total Costs
Capital Costs N/A $104,000 $594,000 $45,500 $743,500
Annual O&M
Costs
$5,506 N/A $10,500 $2,425 $18,431
Cost per
pound of
Phosphorus*
$198 $207 $790 $23 $304
(Average)
*Over BMP lifespan
5.4 Layering and Sequencing
The recommended BMPs target phosphorus found in different stages throughout the
watershed. Street sweeping is a preventative strategy that prevents the phosphorus from ever
entering the watershed. The infiltration basin is a flow interception strategy that the targets the
removal of phosphorus throughout the watershed. In-lake alum dosing is an internal strategy
that targets the removal of phosphorus already found in the lake. Finally, carp removal is an in-
lake preventative strategy that prevents phosphorus from resuspending in the water column.
Due to these strategies targeting different parts of the phosphorus cycle they have a synergistic
effect on each other. Meaning that one strategy will influence the efficiency of the other.
There are two examples of this found throughout the treatment process. One example of
these effects can be seen between street sweeping and the infiltration basin. If street sweeping
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Lake Cornelia Clean Water Strategies | 21
is used more often it will prevent some phosphorus from entering the watershed. This means
that not as much phosphorus will be in the water that is flowing through the infiltration basin.
Thus, the infiltration basin can be sized smaller to compensate for the reduced phosphorus
load. Carp removal and in-lake alum dosing also have a synergistic relationship. If carp removal
is effective and removes all of the carp in the lake, there will be less aquatic life found in the lake
to disrupt the protective layer that is formed through in-lake dosing. Since this protective barrier
is not being disrupted it is more efficient at reducing the internal phosphorus loading.
Due to these effects that the BMPs have on each other, a proper implementation
sequence for the BMPs is important to ensure the BMPs are cost effective and sized
appropriately. First, The City of Edina should implement carp removal and increased street
sweeping. This will prevent phosphorus from entering the watershed, and make sure that
sediment found at the bottom of Lake Cornelia is undisturbed. Once these two BMPs are in
place, and the effects of each strategy has been quantified, the city should install the infiltration
basins. The basin should then be sized appropriately to account for phosphorus removed with
street sweeping. Finally, The City of Edina should implement in-lake alum treatment. The
decrease in external load from previous BMPs will help reduce dissolved phosphorus levels in
the lake after the initial dose of alum.
After implementing the recommended BMPs the city should reassess the quality of Lake
Cornelia. If MPCA standards are not met, additional BMPs should be considered. Alternative
BMPs the city could investigate are: iron filter media, installing underground removal basins,
installing a pond in the north-west corner of the wetlands of Lake Cornelia, using alum dosing
on swimming pool pond of NC_4, bio haven floating islands, and additional community
engagement.
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6.0 References
Anderson, K., Williamson, J. (2018) Lotus Lake Management Plan. (Polk County Land and
Water Resource Department). Balsam Lake, Wisconsin.
Bajer, P. G., & Sorensen, P. W. (2014). Effects of common carp on phosphorus concentrations,
water clarity, and vegetation density: A whole system experiment in a thermally stratified
lake. Hydrobiologia, 746(1), 303-311. doi:10.1007/s10750-014-1937-y
Bajer, P. G., Sullivan, G., & Sorensen, P. W. (2009). Effects of a rapidly increasing population of
common carp on vegetative cover and waterfowl in a recently restored Midwestern
shallow lake. Hydrobiologia, 632(1), 235-245. doi:10.1007/s10750-009-9844-3
Barr Engineering. (2010, January) Lake Cornelia Use Attainability Analysis. (Nine Mile Creek
Watershed District). Edina, Minnesota.
Barr Engineering. (2011, June) Cedar Lake and McMahon (Carl’s) Lake Total Maximum Daily
Load Report Draft. (Scott Watershed Management Organization). Scott County,
Minnesota.
Barr Engineering. (2017, November). Comprehensive Water Resource Management Plan Draft.
(The City of Edina). Edina, Minnesota.
Barr Engineering. (2018) Lower Minnesota River WRAPS. (Minnesota Pollution Control
Agency). Minnesota
Butterfield, B., Hoyman, T., Cibulka, D., & Heath, E. (2015, July). Beaver Dam Lake
Comprehensive Management Plan (Wisconsin Department of Natural Resources).
Dodge Couny, Wisconsin.
Carp Management Questions [E-mail to T. Havranek]. (2018, February 10).
City of Eagan. (210). Fish Lake Nutrient TMDL implementation Plan(Tech.). doi:wq-iw7-27c
Edina Street Sweeping Management Plan. (2015).
Retrieved from https://edinamn.gov/DocumentCenter/View/3887
Emmons and Olivier Resources, Inc. (2017, January 16). Upper Prior Lake In-Lake Phosphorus
Management Plan. Prior Lake, Minnesota.
Emmons and Olivier Resources, Inc. (2010, May). Silver Lake TMDL. (Rice Creek Watershed
District). Columbia Heights, Minnesota.
Kennedy, R. H., & Cook, G. D. (1982). Control Of Lake Phosphorus With Aluminum Sulfate:
Dose Determination And Application Techniques. Journal of the American Water
Resources Association,18(3), 389-395. doi:10.1111/j.1752-1688.1982.tb00005.x
Lake-Link Inc. (n.d.). Tanners. Retrieved February/March, 2018, from http://www.lake-
link.com/minnesota-lakes/washington-county/tanners-lake/9729/
Lamarra, V. A. (1975). Digestive activities of carp as a major contributor to the nutrient loading
of lakes. SIL Proceedings, 1922-2010,19(3), 2461-2468.
doi:10.1080/03680770.1974.11896330
Minnesota Department of Natural Resources. (n.d.). Fish Lake | Minnesota Department of
Natural Resources. Retrieved February/March, 2018, from
https://www.dnr.state.mn.us/fishing/fin/kidsponds/fish.html
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Lake Cornelia Clean Water Strategies | 23
Minnesota Department of Natural Resources. (2018). Cornelia Lake | Minnesota Department of
Natural Resources. Retrieved February/March, 2018, from
https://www.dnr.state.mn.us/fishing/fin/kidsponds/cornelia.html
Minnesota Department of Natural Resources. (2010). Fisheries Lake Survey. Retrieved
February 20, 2018, from
http://www.dnr.state.mn.us/lakefind/showreport.html?downum=27002800
Minnesota Department of Natural Resources. (2015). Local Winterkills & Other Fish Die-Offs.
Retrieved February 20, 2018, from
https://www.dnr.state.mn.us/areas/fisheries/westmetro/fishkills.html
Minnesota Pollution Control Agency. (2018). Guidance Manual for Assessing the Quality of
Minnesota Surface Waters for Determination of Impairment.
Retrieved March 10, 2018, from
https://www.pca.state.mn.us/sites/default/files/wq-iw1-04j.pdf
Minnesota Pollution Control Agency. (2013, March 20). Tanners Lake - alum injection for
phosphorus removal. Retrieved February/March, 2018, from
https://stormwater.pca.state.mn.us/index.php?title=Tanners_Lake_-
_alum_injection_for_phosphorus_removal
Minnesota Stormwater Manual. (2015). Bioretention Device Cost Estimate Worksheet.
Retrieved from
https://stormwater.pca.state.mn.us/index.php/Bioretention_device_cost_estimate_works
heet
Minnesota Stormwater Manual. (2018, February 14). Design Criteria for Infiltration. Retrieved
from https://stormwater.pca.state.mn.us/index.php?title=Design_criteria_for_infiltration
Street Sweeping. (2018). Retrieved March, 2018, from
https://www.edinamn.gov/348/Street-Sweeping
Street Sweeping for Trees. (2013). Retrieved March, 2018, from
https://stormwater.pca.state.mn.us/index.php?title=Street_sweeping_for_trees
Vighi, M., & Chiaudani, G. (1985). A simple method to estimate lake phosphorus concentrations
resulting from natural, background, loadings. Water Research, 19(8), 987-991.
doi:10.1016/0043-1354(85)90367-7.
Wenck Associates, Inc. (2016, June). Crystal Lake Nutrient TMDL Five Year Review(Tech. No.
B1240-0151). Doi:wq-iw8-07n
Wisconsin Department of Natural Resources. (2013, March). Alum Treatments to Control
Phosphorus in Lakes[PDF].
WSB & Associates Inc. (2017, May 4) Integrated Pest Management Plan for Carp. (Prior
Lake-Spring Lake Watershed District). Scott County, Minnesota.
WSB & Associates. (n.d.). Crystal Lake Flocculation Treatment System | Robbinsdale, MN.
Retrieved February/March, 2018, from https://www.wsbeng.com/projects/prj134
WSB & Associates. (2017, November 8). Achieving Lake TMDLs with Innovative Urban
BMPs[PPT]. WSB.
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Lake Cornelia Clean Water Strategies | 24
Appendices
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Appendix A: Lake Cornelia Maps
Figures A.5 through A.5 were used to analyze the existing and proposed characteristics
of Lake Cornelia and its surrounding watersheds. All figures were made in ArcMap with the use
of GIS data provided by Barr Engineering. These maps are used to illustrate sub-watershed
locations, phosphorus loads entering Lake Cornelia, proposed infiltration basin layouts, and
street-sweeping locations.
Existing and proposed subwatershed are outlined in figure A.1. Existing phosphorus
loads into Lake Cornelia were modeled in ArcMap with data from P8 modeling outputs.
Modeling data was provided by Barr Engineering. The following loads, shown in Figure A.2
depict the existing phosphorus loads from each watershed on a per acre basis, after passing
through existing stormwater ponds. The loadings reflect the cumulative removal from existing
ponds.
Two infiltration basins were designed to intercept flow from NC_62 and are shown in
Figure A.3. The drainage areas for these infiltration basis were determined with the use of
existing contour data and storm sewer data provided by Barr Engineering. The infiltration basin
in the southwest clover loop of the MN-100 and MN-62 interchange was not connected to
existing storm-sewer. Figure A.4 shows the proposed storm-sewer needed to connect NC_62b
to existing gravity-main lines.
Streets cleaned with street sweeping in the North Cornelia watershed are outlined in
Figure A.5 and A.6.
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Figure A.1 North And South Lake Cornelia Sub-Watershed Map
(Barr Engineering P8 Modeling, 2018)
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Figure A.2 North And South Lake Cornelia Subwatershed Phosphorus Loadings
(Barr Engineering P8 Modeling, 2018)
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Figure A.3 Map of Proposed NC_62 Subwatersheds
(Barr Engineering P8 Modeling, 2018)
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Figure A.4 Map of Proposed Storm sewer to NC_62b Subwatershed
(Barr Engineering P8 Modeling, 2018)
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Figure A.5 North Lake Cornelia Street Sweeping Zone
(Edina Street Sweeping Management Plan,2015)
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Figure A.6 South Lake Cornelia Street Sweeping Zone
(Edina Street Sweeping Management Plan,2015)
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Appendix B: Cost Analysis Calculations
Tables B.1 to B.13 were all used to show the cost efficiency estimates for each BMP.
The tables show how much phosphorus is removed by each BMP, the cost estimates for each
specific BMP, or the dollar per pound of phosphorus removed per year. The sources for the raw
data in the tables is cited below each table. Each BMP has its own cost and phosphorus
removal estimate.
Carp Management
Total amount of phosphorus removed with the use of carp management was based on
assumed carp populations found in Lake Cornelia. Table B.1 highlights the assumed current
carp densities and the goal densities after removal. Total estimates for the cost of carp removal
were calculated over ten years. The costs shown in Table B.2. These costs are dependent upon
estimated carp densities prior to and after initial carp removal.
Table B.1: Phosphorus Removal Calculations
Lake Size 58 [acres]
Assumed Carp Population 89 [lb carp /acre]
Target Carp Population 30 [lb carp/acre]
Assumed Carp Removal 59 [lb carp/acre]
Carp Phosphorus Impact 0.11 [lb P/lb carp/year]
Total P Removal 376.42 [lbP/year]
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Table B.2: Cost Estimate for Carp Removal Over 10-Year Lifespan
Low Estimate High Estimate Units
Data Collection 15,000 30,000 [$]
Carp Removal 10,000 20,000 [$]
Barrier Installation 8,000 8,000 [$]
Second Population Estimation
(Using Electrofishing/ CPUE)
5,500 5,500 [$]
Second Removal Effort 10,000 20,000 [$]
Barrier Clean-Out* 3750 3750 [$]
TOTALS 52,250 87,250 [$]
Cost/ lb Phosphorus/year $13.88 $23.18 [$/lbP/year]
Contingent upon data collection
Contingent upon data collection and second population estimation
*Calculated over 10 years, assuming $25/hour, once a month May-Aug
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Alum Treatment Plant
Table B.3 shows other lakes that use an out-lake alum treatment. It compares the size of
the lake, the capital cost for building each facility and the annual maintenance cost. Using the
size of the lake and the capital cost as data, an interpolation was done to determine the capital
cost for the treatment plant near Lake Cornelia. Table B.4 shows the calculated amount of
phosphorus removed by the treatment plant in Lake Cornelia based off the amount of
phosphorus removed by the treatment plant in Crystal Lake. The correction factor used to
equate the two is based on how the levels of phosphorus found in the each lake.
Table B.3: Interpolation of Alum Treatment Plant Cost
Lake Size (acre) Year
Implemented
Capital Cost ($) Annual Cost ($)
Fish 30 2011 510,400 30,000
Cornelia 58
Tanners 74 1998 663,000 30,000
Crystal 89 2012 1,400,000 40,000
Source: City of Eagan, Lake-Link Inc.,Minnesota Department of Natural Resources-Fish Lake,
Minnesota Department of Natural Resources-Lake Cornelia, Minnesota Pollution Control
Agency(2013), WSB & Associates(2017)
Table B.4 Phosphorus Removed by Alum Treatment Plant
Phosphorus Removed in
Crystal Lake (lbs.)
Phosphorus correction
factor
Phosphorus Removed in
Lake Cornelia (lbs.)
80 0.57 45.6
90 0.57 51.3
100 0.57 57.0
110 0.57 62.7
120 0.57 68.4
130 0.57 74.1
Source: WSB & Associates(2017)
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In-Lake Alum Treatment
Table B.5: Alum Treatment Annual Plant Operation and Maintenance Costs
Year Amount of P
Removed (lb)
Annual Cost ($) Sum of Cost ($) $/lb of P/yr
0 50 935,000 935,000 18,700
1 100 30,000 965,000 9,650
2 150 30,000 995,000 6,633.33
3 200 30,000 1,025,000 5,125
4 250 30,000 1,055,000 4,220.00
5 300 30,000 1,085,000 3,616.66
6 350 30,000 1,115,000 3,185.71
7 400 30,000 1,145,000 2,862.50
8 450 30,000 1,175,000 2,611.11
9 500 30,000 1,205,000 2,410.00
10 550 30,000 1,235,000 2,245.45
11 600 30,000 1,265,000 2,108.33
12 650 30,000 1,295,000 1,992.31
13 700 30,000 1,325,000 1,892.86
14 750 30,000 1,355,000 1,806.66
15 800 30,000 1,385,000 1,731.25
16 850 30,000 1,415,000 1,664.71
17 900 30,000 1,445,000 1,605.55
18 950 30,000 1,475,000 1,552.63
19 1,000 30,000 1,505,000 1,505.00
20 1,050 30,000 1,535,000 1,461.90
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Table B.6: Annual Cost for In-Lake Alum Treatment
Year Phosphorus
Removed (lbs.)
Sum of Cost ($) $/lb of P
removed/yr.
1 50 104,000 2,080
2 100 104,000 1,040
3 150 104,000 693.3
4 200 104,000 520.0
5 250 104,000 416.0
6 300 104,000 346.7
7 350 104,000 297.1
8 400 104,000 260.0
9 450 104,000 231.1
10 500 104,000 208.0
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Lake Cornelia Clean Water Strategies | 37
Infiltration Basin
Table B.7: Northeast Infiltration Basin Phosphorus Removal Calculations
Basin Diameter 77.33 [yards]
Basin Area 5110 [square yards]
Grading Area 1478.32 [square yards]
Excavation Area 3631.68 [square yards]
Drainage Area 41 [acres]
Phosphorus Concentration 0.55 [lb/acre]
Phosphorus Removed 20.7 [lb/year]
Table B.8: Southwest Infiltration Basin Phosphorus Removal Calculations
Basin Diameter 74.67 [yards]
Basin Area 4778.33 [square yards]
Grading Area 1425.90 [square yards]
Excavation Area 3352.43 [square yards]
Drainage Area 37.74 [acres]
Phosphorus Concentration 0.55 [lb/acre]
Phosphorus Removed 18.7 [lb/year]
Estimated Construction Cost for the Northeast infiltration basin found in watershed NC_62. Unit
cost based on average costs for such an expense.
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Lake Cornelia Clean Water Strategies | 38
Table B.8: Northeast Infiltration Basin Construction Costs
Expense Units Quantity Unit Cost Cost
Site Formation
Excavation square yard 3631.68 $ 10.00 $ 36,316.81
Grading square yard 1478.32 $ 1.50 $ 2,217.48
Hauling off-site square yard 5110.00 $ 5.50 $ 28,105.00
Structural Components
Underdrain linear foot 300 $ 30.00 $ 9,000.00
Inlet structure each 1 $ 1,500.00 $ 1,500.00
Outlet Structure each 1 $ 2,500.00 $ 2,500.00
Site Restoration
Filter strip square yard 5110.00 $ - $ -
Soil preparation square yard 5110.00 $ 30.00 $ 153,300.00
Seeding square yard 1478.32 $ 0.50 $ 739.16
Mulch square yard 5110.00 $ 5.00 $ 25,550.00
TOTAL CONSTRUCTION
COST
$ 259,228.45
(source: Minnesota Stormwater Manual)
Estimated Construction Cost for the southwest infiltration basin found in watershed NC_62. Unit
cost based on average costs for such an expense.
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Lake Cornelia Clean Water Strategies | 39
Table B.9 Southwest Infiltration Basin Construction Costs
Expense Units Quantity Unit Cost Cost
Site Formation
Excavation square yard 3352.428427 $ 10.00 $ 33,524.28
Grading square yard 1425.901573 $ 1.50 $ 2,138.85
Hauling off-site square yard 4778.33 $ 5.50 $ 26,280.82
Structural Components
Underdrain linear foot 1589 $ 30.00 $ 47,670.00
Inlet structure each 5 $ 1,500.00 $ 7,500.00
Outlet Structure each 1 $ 2,500.00 $ 2,500.00
Site Restoration
Filter strip square yard 4778.33 $
-
$ -
Soil preparation square yard 4778.33 $ 30.00 $ 143,349.90
Seeding square yard 1425.901573 $ 0.50 $ 712.95
Mulch square yard 4778.33 $ 5.00 $ 23,891.65
TOTAL CONSTRUCTION
COST
$ 287,568.45
(source: Minnesota Stormwater Manual)
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Lake Cornelia Clean Water Strategies | 40
Table B.10: Infiltration Basin Annual Operation and Maintenance Costs
Expense Units Quantity Unit Cost Cost
Debris Removal per visit 2 $ 50.00 $ 100.00
Weed control per visit 5 $ 50.00 $ 250.00
Sediment removal per year 0.2 $ 500.00 $ 100.00
Mow filter strips per visit 6 $ 50.00 $ 300.00
Erosion repair square yard 50 $ 75.00 $ 3,750.00
Inspection per visit 6 $ 125.00 $ 750.00
Total Annual Cost $ 5,250.00
(source: Minnesota Stormwater Manual)
Table B.11: Infiltration Basin Cost-Benefit Analysis
Combined Cost Benefit Analysis
Year Cost Cost Sum Lbs
Phosphorus
Total P
Removed
Cost/lb P
0 $ 546,796.90 $ 546,796.90 39.4 39.4 $ 13,878.09
1 $ 10,500.00 $ 557,296.90 39.4 78.8 $ 7,072.30
2 $ 10,500.00 $ 567,796.90 39.4 118.2 $ 4,803.70
3 $ 10,500.00 $ 578,296.90 39.4 157.6 $ 3,669.40
4 $ 10,500.00 $ 588,796.90 39.4 197 $ 2,988.82
5 $ 10,500.00 $ 599,296.90 39.4 236.4 $ 2,535.10
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6 $ 10,500.00 $ 609,796.90 39.4 275.8 $ 2,211.01
7 $ 10,500.00 $ 620,296.90 39.4 315.2 $ 1,967.95
8 $ 10,500.00 $ 630,796.90 39.4 354.6 $ 1,778.90
9 $ 10,500.00 $ 641,296.90 39.4 394 $ 1,627.66
10 $ 10,500.00 $ 651,796.90 39.4 433.4 $ 1,503.92
11 $ 10,500.00 $ 662,296.90 39.4 472.8 $ 1,400.80
12 $ 10,500.00 $ 672,796.90 39.4 512.2 $ 1,313.54
13 $ 10,500.00 $ 683,296.90 39.4 551.6 $ 1,238.75
14 $ 10,500.00 $ 693,796.90 39.4 591 $ 1,173.94
15 $ 10,500.00 $ 704,296.90 39.4 630.4 $ 1,117.22
16 $ 10,500.00 $ 714,796.90 39.4 669.8 $ 1,067.18
17 $ 10,500.00 $ 725,296.90 39.4 709.2 $ 1,022.70
18 $ 10,500.00 $ 735,796.90 39.4 748.6 $ 982.90
19 $ 10,500.00 $ 746,296.90 39.4 788 $ 947.08
20 $ 10,500.00 $ 756,796.90 39.4 827.4 $ 914.67
21 $ 10,500.00 $ 767,296.90 39.4 866.8 $ 885.21
22 $ 10,500.00 $ 777,796.90 39.4 906.2 $ 858.31
23 $ 10,500.00 $ 788,296.90 39.4 945.6 $ 833.65
24 $ 10,500.00 $ 798,796.90 39.4 985 $ 810.96
25 $ 10,500.00 $ 809,296.90 39.4 1024.4 $ 790.02
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Lake Cornelia Clean Water Strategies | 42
Street Sweeping
The following phosphorus recoveries and cost estimations are taken from the Edina
Street Sweeping Management Plan (2015).
Table B.12: Street Sweeping Phosphorus Removal Calculations
Sweeping Strategy Phosphorus Recovered [lbs/year]
Baseline
(Edina’s Current Strategy)
23.2
Monthly
(Proposed Strategy)
51
Final Proposed* 27.8
(Source: Edina Street Sweeping Management Plan)
*This strategy represents the difference between the current and proposed practice. The final
estimated cost is only the additional amount Edina will need to pay for the upgrade. This
represents the final cost estimation for this BMP.
Table B.13: Street Sweeping Cost Estimate Calculations over 25-Year lifespan
Sweeping Strategy Cost for Removal
[$/lb P/year]
Annual Cost
[$/year]
Total Lifespan Cost
[$]
Baseline
(Edina’s Current
Strategy)
247 5,278 131,950
Monthly
(Proposed Strategy)
198 11,234 280,850
Final Proposed* -27 5,956 148,900
(Source: Edina Street Sweeping Management Plan)
If the city chooses to move forward with the monthly upgrade, additional regenerative air
sweepers may be needed.
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Lake Cornelia Clean Water Strategies | 43
Appendix C: Budget for Completion of Feasibility Analysis
A comparison of the estimated total number of hours required to complete the project
and the actual total number of hours spent completing the project.
Table C.1: Budget for completion of Feasibility Analysis for clean water strategies for Lake
Cornelia
Project Task Projected
Time
Expenditure
Projected
Cost
Responsible
Team
Member1
Actual Time
Expenditure
Actual
Cost
Project Plan 10 800 Hayley 10 800
Meet with Mentors 70 5600 Emily 48.5 3880
Biweekly Project
Reports
20 1600 Aaron
20.3 1624
Report Writing, Drafts
and Final
92 7360 Kasia
87.25 6980
Presentations (Midterm
and Final)
45 3600 Hayley
30.5 2440
Class Time 240 19200 Emily 232 18560
Background research 20 1600 Aaron 11.5 920
Researching Possible
BMPs and compiling a
list
15 1200 Kasia
20.25 1620
Determine Main loading
and best BMP locations
10 800 Hayley
13.75 1100
Meeting with Lake
Cornelia Association
16 1280 Emily
16 1280
Determine feasible
BMPs
20 1600 Aaron
6 480
Determine Cost of
feasible BMPs
30 2400 Kasia
28 2240
TOTALS 588 47040 524.05 41924
1. Cost has been estimated using an hourly billing rate of $80 for each team member.
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Appendix D: Section Authors
The main authors and co-authors of each report section are outlined below in Table D.1.
The lead authors are listed first, and the co-authors are listed second and third.
Table D.1: Section Authors
Section Title Lead Author, Co-Author(s)
-- Cover Letter Katarzyna Oszajec, Emily Castanias
-- Executive Summary Emily Castanias
1.0 Introduction Emily Castanias
2.0 Background Aaron Kilpo, Emily Castanias
3.1.1 Carp Management Emily Castanias
3.1.2 Alum Treatment Katarzyna Oszajec
3.2.1 Infiltration Basin Aaron Kilpo
3.2.2 Street Sweeping Hayley Anderson
4.0 Sustainability Considerations Hayley Anderson, Aaron Kilpo
5.0 Recommendations and
Considerations
Hayley Anderson, Katarzyna Oszajec, Emily
Castanias
6.0 References Full Team Collaboration
Appendix A Lake Cornelia Maps Full Team Collaboration
Appendix B Cost Analysis Calculations Full Team Collaboration
Appendix C Engineering Costs Full Team Collaboration