The document summarizes a proposal by Stromboli Environmental to remediate contaminated soil at a former industrial site in Euclid, Ohio. The soil contains elevated levels of tetrachloroethane and dichloroethane that are contaminating local groundwater. The proposal involves using a six-stage countercurrent extraction system over two years to reduce contaminant concentrations to acceptable levels. An analysis determined this design would achieve remediation goals at the lowest cost of $724,720.47. The summary addresses concerns of local stakeholders and argues Stromboli Environmental is well-qualified to complete the soil remediation project on schedule and budget.

1. Soil Extraction Project
A Project Report for CHE 2014
Submitted to the Faculty of the
Department of Chemical Engineering
Worcester Polytechnic Institute
Worcester, MA 01609
May 2, 2016
Coal Rocks!
“What’s that rock? It’s coal!”
Benjamin Drury
Weiran Gao
Natalie Thompson
Elizabeth Towle

2. To​: A. Peterson, Executive Vice President and D. DiBiasio, Vice President, Environmental
Consulting Division
From​: Ben Drury, Weiran Gao, Natalie Thompson, and Elizabeth Towle on behalf of Stromboli
Environmental Design Teams
Subject​: Hazardous Waste Site Remediation Proposal
Date​: April 30, 2016
Position Summaries
As this is a large project, there are many stakeholders involved. One of the groups who have
perhaps the most eligible concerns is the mall store owners of the nearby shopping mall. If this
soil is polluted and causing drinking water contamination then there is a serious health risk. No
one will want to come to the mall and thus their specific stores if by drinking from a water
fountain you could get sick. From a purely economic standpoint, the mall store owners support
this decontamination project. Nonetheless, they still want to know more about the project before
they get fully behind it. Information such as, the timeline of the project and the possible
implications on their customers will be crucial to the mall.
Another group that supports this project is the residents of the surrounding area. If it has been
proven that there is drinking water contamination at their local mall, what is to say that their own
homes are not polluted? The residents are also concerned about how this project will affect them
in different ways, whether it be noise during inconvenient hours or simply an eyesore for the
neighborhood.
Meanwhile, the condominium company wants to build as soon as possible so that they can start
renting out the condominiums and making money as soon as possible. Therefore, the
condominium company opposes any delays to their construction, which includes our two year
project to purify the soil. Thusly, they want to know the timeline of the project, if it can be
shortened in any way, and if it would be possible to start building while we are purifying the soil.

3. The local environmental activists on the other hand, support our project because we are purifying
the soil and making the environment safer and better. They want to know any possible side
effects of our project and where we will put the contaminated water.
The Conservative Commission will be pushing for a company to clean the contaminated area so
that an indirect release into Lake Erie doesn’t occur. We would inform the Conservative
Commission that our new method is the most efficient and will take the least amount of time.
The goals of the EPA encompass those of the Conservative Commission and also include the
safety of the surrounding population and other areas. Informing the EPA of our technology and
the beneficial impact our work will have on the community would convince them of our
potential. The soil will only contain 8 ppm of TCE and 4 ppm of DCE, the water will be sent
offsite for treatment.
The goals of the City Officials and the Mayor are to increase the economic development of the
city and will likely be antagonistic towards our plans if the decontamination process takes too
long, therefore it might be wise to go to them for money to increase either the amount of stages
in the countercurrent device, or the amount of countercurrent systems we use. Discussing the
increase in public approval due to the local government protecting its citizens will assist in
acquiring the bid from them.

4. Introduction
The old Chase Brass and Copper facility in Euclid, Ohio has contaminated soil that is harming
the surrounding area’s water supply. As a part of the Stromboli Environmental consulting
company, our team performed a technical and economical analysis to determine the mechanisms
of this hazardous waste site remediation proposal, and considered if it is feasible and cost
effective. Our goal was to identify the best design for our extraction unit. Although there are
several groups who are hesitant about our proposed process, we are confident in our
recommendations and our abilities to appease these concerns at the public hearing. The soil
needs to be treated for the safety of the surrounding residents, the local malls, and any future
people who live on this property. Our proposed process, described herein, is the best and
cheapest way to accomplish this goal.
Methodology
This process will be viewed as immiscible, as no soil will be permitted to leave with the water.
Some water may leave with the soil, as this is unavoidable, but should not affect our calculations.
As the water evaporated from the soil, it will lower the concentrations beneath our calculated
values. We will use a countercurrent extraction process, as this will allow us to achieve purity
levels in the soil with less solvent overall and stages than crossflow.
Figure 1: Countercurrent immiscible extraction example

5. This process was designed to achieve purity specifications of 8 ppm for TCE and 4 ppm for
DCE. This will be an acceptable level for the environment given, where ground water and rain
will dilute these levels further. Further, this extraction is designed to fit within a two year time
frame, including two weeks of setup time and two weeks of take down at the periphery of our
stay in Ohio. We accounted for a 56 hour work week, as we do not want to become a nuisance to
nearby residents by operating at night, leaving us with 8 hours 7 days per week. The variable we
adjusted to suit these needs was the amount of solvent used for the given amount of diluent. This
would in turn affect the number of stages required, and the level of solute in the solvent after it
was used.
Our process optimized these variables to produce the lowest cost possible. Our costs included a
fixed overhead cost of $100,000 to cover permits and other administrative costs. The cost of
leaching itself would include $6,000 per stage, and $1.10 per solvent flow in lb/hr. The solvent
will be sent to an external site afterwards to be treated, and this site will pay $250 per ppm of the
solute in this solvent, which allowed us to subtract that from the leaching cost. Labor costs will
be triple those of leaching costs, and site maintenance will cost an additional 2.5 those of
leaching costs. With this in mind, the cost optimization was a balance between increasing the
cost discreetly as the amount of solvent per diluent decreases and causes the number of stages to
increase, and the continuous decrease of cost as the amount of solvent per diluent decreases and
causes the solvent/hour cost to decrease. Therefore, at any given number of stages, the optimum
amount of solvent per diluent would be the least that could be used and maintain that number of
stages. From there, these optimum values were compared and the design was created to minimize
these costs.

6. Results and Discussion
Using the equilibrium data provided and the technical data supplied by the field, we were able to
form an X-Y diagram of the soil composition. From there we were able to step off stages and
test out different costs. The equilibrium data and the final stages stepped can be found in
Appendix 4. Based on the following data we have chosen a countercurrent extraction process
with six stages. As can be seen in Table 1, a design with six stages can allow for the lowest
overall cost, $724,720.47. A process with 3, 4, 5, or 7 stages would cost more. A full cost
analysis can be seen in Table 3 later on.
Table 1: Overall cost analysis comparison for 3 through 7 stages
Stages Solute in Solvent (ppm) Optimum Slope Overall Cost
3 25 0.5 $ 905,527.75
4 31.5 0.63 $783,505.16
5 36.5 0.73 $735,107.19
6 40 0.8 $724,720.47
7 42.5 0.85 $732,850.88
Figure 4: Countercurrent extraction process diagram
Above is a general image of our design, containing six countercurrent extraction stages.

7. Table 2: Leaching calculations for 6 stages
Quantity Unit cost Total
Stages 6 $6,000.00 $36,000.00
Flow (lb/hr) 6.37 x 10​4
$1.10 $70,110.84
Solute Level (ppm) 40 $250.00 -$10,000.00
Total Leaching $96,110.84
As can be seen above, this design has a flow of 6.37*10​4​
lbs/hr with an output composition of 40
ppm. The details of these calculations can be located in Appendix 3.
Table 3: Full cost calculations for 6 stages
Item Total
Overhead Cost $100,000.00
Leaching $96,110.84
Labor $288,332.52
Preparation and Maintenance $240,277.10
Total Cost $724,720.47
This design will allow us to successfully decrease the concentration of TCE and DCE in the 2.85
x 10​8​
lbs of soil to 8 ppm and 4 ppm respectively within two years.

8. Conclusion
Though a multitude of interested parties exist in this particular issue, and with different groups
comes different interest, goals, and ideals, our design will be able to address these concerns
while improving the environment of Euclid, Ohio. Groups such as residents, mall store owners
and the Conservative Commission are mostly concerned with soil purification so that the
contamination will not lead to serious consequences and health risks. For groups like the
condominium company and city officials, time is the main concern, as the extraction process will
impede their progress in making profits. By allying ourselves with those who wish to clean the
area and assuring our opposition that it is within their best interests, we are hopeful that
acquiring the bid is both feasible and an eventuality.
Our design addresses these concerns and achieves our goals to assure safety for all involved.
After analyzing the cost of each component during the extraction process, a six stage
countercurrent extraction system was designed to achieve the optimal balance between cost and
efficiency. As the system will run 8 hours per day and 7 days per week, we will be able to
complete the extraction process within two years. The total cost of the system is estimated to be
$724,720.47, and the concentrations of TCE and DCE in the 2.85 x 10​8​
lbs of soil are expected to
be reduced below 8 ppm and 4 ppm respectively. Using our design, Euclid, Ohio will soon be a
safe location once again.

9. Appendices
Appendix 1: Finding the mass of the soil
Specific gravity of soil = 1.4
Density of water = 62.428
15 ft deep
5 acres of soil = 217800 ft​2
Volume of soil = (217800 ft​2​
)x(15 ft) = 3267000 ft​3
Mass of soil = (3267000 ft​3​
)*(1.4)*(62.428 lb/ft​3​
) = 285,533,190 lbs
2.85 x 10​8​
lbs / 5600 hrs / 2000 lb/ton ⁡≅ 25 tons/hour (as specified)
Appendix 2: Finding the total mass of the water
Mass of soil = 285,533,190 lbs
Slope = 0.8 = Diluent/Solvent
Solvent = Diluent/0.8 = 285,533,190 lbs/0.8 = 356927917.5 lbs water
Appendix 3: Cost Calculations
Finding the leaching cost:
Leaching cost = (number of stages)F​1​ + (solvent flow, lb/h)F​2​ – (solute level in exiting solvent,
ppm)F​3
Where:
F​1​ = $6,000 per stage
F​2​ = $1.10 per solvent flow in lb/h
F​3​ = $250 per ppm
6 Stages
356927917.5 lbs water/5600 hours = 6.37*10​4 ​
lb/he
33.6 ppm TCE + 6.4 ppm DCE = 40 ppm
Leaching cost = (6)($6,000) + (6.37*10​4​
)($1.10) + (40)($250)
Leaching cost = $96,110.84

10. Finding labor cost:
Labor cost = 3*Leaching cost
Labor cost = $288,332.50
Finding cost of site preparation and maintenance:
Cost of site preparation and maintenance = 2.5*Leaching cost
Cost of site preparation and maintenance = $240,277.10
Finding total cost:
Total cost = Overhead cost + Leaching cost + Labor cost + Preparation and maintenance cost
Total cost = $724.720.47
Appendix 4: Equilibrium Data and Stages
Figure 2: Stage stepping for TCE

11. Figure 3: Stage stepping for DCE

12. Transcript of our presentation:
Hello! We are here to present to you today about the hazardous waste site remediation project
proposed by Stromboli Environmental.
Slide 2
Our goal is to purify the soil at the old Chase Brass and Copper facility here in Euclid, Ohio
through countercurrent extraction. This soil has been contaminated with tetrachloroethane (on
average 50 parts per million) and dichloroethane (on average 12 parts per million) and needs to
be treated for the safety of the surrounding residents, the local malls, and any future people who
live on this property. These chemicals may go from the soil to the drinking water, threatening the
health of those nearby, therefore we seek to act quickly to remedy this situation.
Slide 3
We decided to use an Immiscible Counter Current extraction, as not enough soil will be leaving
with the water to make the system miscible. This design will allow us to remove the toxins in the
most cost effective way possible.
Slide 4
Our goal for this two year project is to reduce the amount of TCE to 8 parts per million and
DCE to 4 parts per million. This will be an acceptable level for the environment given, where
ground water and rain will dilute these levels further.
Slide 5
Here we used the following equations for cost optimization. Other than the fixed $100,000 of
overhead and administration cost, the additional costs are all related to the leaching cost. This
tells us that designing a system that balances stage quantity, solvent flow rate, and solute level in
the exiting solvent to achieve optimal leaching cost is important.
Slide 6
This table shows the total cost with various stages. At any given amount of stages, the following
represents the cheapest possible option, with the least solvent required. We calculated the total
cost of extraction system with 3 through 7 stages, and determined 6 stage extraction process is
the most cost effective. In other words, we are making sure that you get the most bang for your
buck.

13. Slide 7
Using the equilibrium data provided we were able to determine how many stages were
necessary. As you can see, DCE requires fewer stages than TCE. Due to the fact that we will be
removing both of these chemicals at the same time, we will need to use however many stages
TCE requires.
Slide 8
Our design will consist of a countercurrent system with 6 stages, as shown below. A steady
stream of soil will enter from the left with water entering from the right. This design will allow
us to successfully decrease the concentration of TCE and DCE in the 2.85 x 10​8​
lbs of soil to 8
ppm and 4 ppm respectively within two years.
Slide 9
We have broken up the overall cost here to show where the money will be going. The optimal
leaching cost using this 6 stages design is ​$96,110.84, which gives an​ estimated overall cost of
about 7 hundred thousand dollars.
Slide 10
We are the most qualified company to complete this task. As you have seen, we understand the
cost and how the money needs to be distributed. We have an excellent design that will purify the
soil well. As for the timeline, we understand that 2 years sounds like a long time, but we assure
you that this time will be a necessary investment in your town’s future safety.
Slide 11
Thank you for considering Stromboli Environmental, we won’t let you down! Any Questions?