Abstract: The objective of this project is to design the infrastructure for an information collection system that will make it possible to evaluate and compare the performance, environmental impacts, and costs of two alternative deicers. In order to construct the comparative study, research on deicers was conducted from books and periodical articles obtained from the M.S.O.E library, Milwaukee Public Library, and the World Wide Web. Interviews with companies and environmental agencies were also conducted to obtain current technological and regulatory information that pertain to the field of deicing. Sodium chloride, or common road salt, is by far the most popular chemical deicer in the United States (10 million tons were applied nationwide in 1999), because it is reliable, inexpensive (approximately $30 per ton), and easy to handle and apply.
However salt is known to have damaging effects, such as increasing the rate of corrosion of vehicles and constructions metals, it has also been linked to the increase in chloride concentrations in both surface and groundwater, and its adverse effects on roadside soil and vegetation. Recognizing these drawbacks and knowing that deicing is essential to maintain safe winter driving conditions (application of roadsalt reduces road injury accidents by 88%), calcium magnesium acetate (CMA, $400 per ton), has been proposed as an alternative to roadsalt. Some governmental units (e.g. Wisconsin Department of Transportation) have been using CMA for deicing purposes, however, only small-scale projects were found in the state of Wisconsin. Therefore, a controlled comparative study is proposed to address these issues and quantify and compare the direct and indirect costs of both CMA and salt deicers. The proposed information collection system will include but not be limited to cost data on highway construction, equipment, labor, maintenance, highway resurfacing and deicing material costs. The study will also include environmental monitoring data on chloride and BOD concentration levels. Performance, measured as accident rates as a direct consequence of deicer applications, will also be monitored. The collected data will ultimately give three parameters - performance, cost and environmental impacts - to use in weighing alternative deicers.
Abstract: Source-separated urine presents an opportunity to reuse valuable nutrients -- nitrogen, phosphorus and potassium -- found in urine. The purpose of this report is to analyze the urine source-separation system and evaluate the possibility for implementation in the United States. The process has been researched and tested in various other countries, but has not been installed in the United States.
Research was first conducted on case studies of source-separated urine, to analyze how other countries were implementing the system. Additionally, the characteristics of urine and needs of crops, specifically corn, were looked at and discussed. Finally, a theoretical case in the United States was evaluated and a life-cycle cost was found. Pollution prevention was also addressed.
This report found that urine source-separation has been successfully conducted in other countries and could also be installed in the United States with a few technical adjustments. There is a 20-year payback period over the entire source-separation system, but with advances in toilet technology and increased costs of nutrient treatment, the payback could reduce dramatically. The technology and engineering behind the system are not likely to be problematic. Human acceptance and economic drivers of the urine source-separation system will likely be the larger problem.
Abstract: Companies developing new pharmaceuticals are under increasing pressure to get new drugs to market quickly. One approach to making drug molecules is the use of bioreactor processes. To produce the desired expression, the rate and environment in which the organism grows is critical. Researchers optimize these conditions based on data determined from samples taken from bioreactors. Currently, many facilities manually take these samples. On-line monitoring offers the advantages of more frequent time points and minimized labor requirements. This results in quicker process optimization decisions. Two main limitations exist for on-line monitoring: sample volume requirements and transport time.
The system described in this thesis allows samples to be injected into a carrier stream of water minimizing the volume of sample required and decoupling the transport flow rate from the flow rate of the in-situ filter. Depending on the fluidic parameters of sample volume, flow rate, tubing inner diameter, and tubing length, air slugs may need to be injected to prevent or reduce sample dispersion. A model was developed to predict the conditions under which air slug injection would be required. Model predictions are preferred over experimental determinations because they eliminate additional set up testing, and sample and reagents consumption. In this work, the axial dispersed plug flow model (ADPFM) as solved by Kolev for the condition where the sample injection is approximated by a rectangular function was modeled using MATLAB software. A mixed tank model was appended in series to the ADPFM to provide better agreement with experimental results. Modeled and experimental data showed quantitative correlation for sample loop and flow rate variations while only qualitative trends for reactor length and tubing inner diameter.
Abstract: Wisconsin Engraving, Inc., engraves metal molds for the plastics industry. Within the last decade, they have been faced with many challenges while trying to manage problems with the wastewater that discharges into the sanitary sewer system. Some of their problems include: having sample reports being submitted incorrectly, their waste water containing high metal concentrations and having a low pH.
This project was undertaken in order to determine the best way to handle Wisconsin Engraving’s wastewater and included: an inventory of all manufacturing processes that generate wastewater with the intent to minimize or eliminate these discharges a review of technical options for minimizing or eliminating the discharges in the sanitary sewer, and an economic analysis of the various technical options.
Many different avenues have been used to conduct my research for this investigation. The main ideas stemmed from interviews with the owner of Wisconsin Engraving, and from the review of ten year’s worth of data from the Milwaukee Metropolitan Sewerage District. The best solution to this problem began to emerge as I performed the economic analyses, which are summarized in tables in section D. I had four real choices to choose from, and deciding which one to use depended on the economic analyses. As an immediate action, I feel Wisconsin Engraving should choose to ship all of their processed wastewater off site; this is a good choice both economically and environmentally. As a long-term solution, the mechanical etching (laser engraving machine) should be considered because of the minimal amount of waste generated. An auxiliary conclusion from this project is the fact that even though a company may try being “environmentally friendly”, financial restrictions may get in the way of pursuing that dream. Sometimes, a company might need to take a “middle road”, choosing an alternative that, while in compliance with environmental regulations, might not be the most environmentally advantageous, and yet is economically viable.
Abstract: The emerging legislative action to prohibit the use of ion exchange water softeners presents a unique opportunity for new technologies that may help improve water quality throughout the United States. Forward osmosis offers a viable alternative to those systems with advantages in reduced energy consumption and high rejection of a wide range of contaminants. This process requires the use of a second step for creating potable water. The purpose of this report is to analyze the technical and economical feasibility of using forward osmosis as an alternative to conventional ion exchange water softening.
Bench-scale testing was conducted to evaluate the effectiveness of using forward osmosis to remove hardness from water. Four different influent hardness concentrations were evaluated for their percent hardness rejected and the flux across the membrane: 0 mg/l as CaCO3, 10 mg/l as CaCO3, 100 mg/l as CaCO3, and 500 mg/l as CaCO3. The results of these tests were used as input to a mass balance model to estimate the overall hardness removal of the forward osmosis process in conjunction with a second processing step using reverse osmosis.
This report found that forward osmosis is able to remove 70% of the hardness ions from a water stream. Using the results from the laboratory data, the performance of the forward osmosis system was compared against a conventional softener. This report found that while the forward osmosis system has a fairly competitive hardness rejection rate, it adds more than 75 times the amount of salt as ion exchange into the environment every year. Acquisition and maintenance costs are double those of a self-regenerating system while operation costs are fifty times higher. There are many areas within forward osmosis for further research, such as creating draw solution recycling, generating new draw solutions, membrane commercialization, and exploring other second step options that will allow forward osmosis to become a more viable water treatment option in the future.
Abstract: This project develops a baseline characterization of input flows of construction materials, fuels and water; materials remaining on site as stock; and outputs to the environment as waste and emissions for Construction Specification Institute (CSI) division 31 (site work) and 3 (concrete construction) for construction of the Milwaukee School of Engineering Kern Center.
Division 31 site activities included removal of sidewalks and asphalt pavement, excavation of soil, and installation of the soil retention system. Division 31 inputs included concrete, steel, wood, diesel fuel, gasoline, and electricity. Concrete, steel, and wood accounted for 86%, 8%, and 7% respectively of the input construction materials characterized and quantified. Diesel fuel accounted for nearly 99% of the energy inputs. Gasoline and electricity accounted for the remainder. Ninety eight percent of concrete, 100% of steel, and 100% of wood inputs were estimated to remain onsite. Sixty one percent of outputs were estimated to be air emissions. Thirty four percent of the air emissions occurred onsite from consumption of energy inputs. Embodied air emissions accounted for 27% of the emissions resulting from manufacturing input materials. Thirty seven percent of the outputs were solid waste; 33% generated onsite (landfilled contaminated soil and washout from concrete trucks) and 4% off site or embodied solid wastes.
CSI division 3 included installation of the building foundation and cast-in-place and pre-cast concrete activities. Division 3 inputs included concrete, steel, wood, concrete sealant, diesel fuel, gasoline, and electricity. Concrete, steel, wood, and concrete sealant accounted for nearly 97% and 3%, respectively of input construction materials. Diesel fuel, gasoline, and electricity accounted for 64%, 36%, and less than 1% respectively of energy inputs. The percentages of input concrete and steel remaining on site during division 3 site activities were the same as division 31. However, only 60% of wood and 25% of concrete sealant inputs was estimated to remain onsite. Seventy-eight percent of the outputs were air emissions. Embodied air emissions accounted for 66% of the total emissions whereas 12% of the air emissions were generated onsite. Solid wastes accounted for 15% of division 3 outputs. Ten percent of the solid wastes were generated onsite as washout from concrete trucks. Embodied solid wastes accounted for 5% of the outputs. Seven percent of outputs were waterborne wastes with over 99% generated onsite from washout of concrete trucks and domestic wastewater.
Overall, 61% of the total outputs from CSI division 31 and 3 are estimated to have occurred prior to on site construction activities. This is due to the large fraction of building materials containing embodied wastes and energy introduced during CSI division 3. Summarizing the total environmental impacts of both divisions, 73% of the total outputs were estimated to be air emissions. Diesel fuel accounted for over 77% of the emissions released on site during construction activities. Solid waste outputs accounted for 21% of the total outputs. Currently, construction data is not collected, organized, and evaluated. Completing a project on time, under budget, and complying with environmental laws and regulations are their goals. Reducing emissions from construction vehicles, facilitating carpooling of construction workers, reducing soil tracked off site and reducing washout wastes from concrete trucks were a few activities identified by this project as ways for the construction industry to reduce environmental burdens on site.
Abstract: Redevelopment of the Menomonee Valley has long been viewed by developers as an uneconomical prospect. Extensive physical and environmental issues in the soils within the Menomonee Valley have forced many developers to the urban fringe to construct facilities on virgin land known as Greenfield sites. Recent legislation has been enacted to assist parties in redeveloping potentially impacted sites known as Brownfield sites.
A study of two distinct developments in the Menomonee Valley indicates that the development of large industrial facilities within the Menomonee Valley would not be economically feasible due to the high costs of addressing the physical and environmental issues. However, the study does indicate that smaller, multi-story mixed-use developments can be completed in the Menomonee Valley. Future development in the Menomonee Valley should focus on smaller, lighter-weight buildings which support lighter live loads than conventional industrial structures.
Abstract: Air quality regulations have been a focus of attention by many in light of the growing concern over climate change and the possibility of its being caused by anthropogenic means. The recent U.S. Supreme Court case, Massachusetts v. Environmental Protection Agency, declared Carbon Dioxide (CO2) to be an air pollutant. Under the Clean Air Act (CAA), the Environmental Protection Agency (EPA) must regulate all air pollutants. It has been established that CO2 is a Greenhouse Gas (GHG), which is thought to cause a blanketing effect in the lower atmosphere, trapping solar radiation and gradually increasing the temperature of the earth. By virtue of the decision reached in Massachusetts v. Environmental Protection Agency, the EPA must now regulate CO2.
Coal-fired power plants are the largest stationary source of CO2, making them the most likely candidate for regulation. Coal-fired power plants currently produce most of the electricity that is consumed in the United States. A March 2012 new regulation proposal by the EPA sets an air emission limit on CO2 for all new electric utility generating units, regardless of fuel source, at 1000 lbs./mega-watt hour (MWH). This level is currently lower than the achievable limit for coal-fired power plants without some type of carbon capture technology. Carbon capture technology has not been proven for large scale use and is likely to take years to perfect. New natural gas-fired power plants are able to produce the same amount of energy as coal-fired power plants, and still be under the 1000 lbs./MWH limit of the March 2012 proposal. The goal of this thesis is to answer the question: Is the EPA's decision -- to limit CO2 emissions at 1000 lbs./MWH for all new electric generating units -- an environmentally and economically feasible solution? To evaluate this regulation, a normative dimensional analysis and an empirical proposal with respect to its effects on human health, the environment, and the coal industry. The result of the analysis is a number of important findings. It is found that the EPA's March 2012 proposal should have a beneficial effect on human health and on the environment. The effect of the proposal on the coal industry is likely to be largely in agreement with the EPA's own assessment; the direct effect on the coal industry is projected to be little or negligible. Other regulations, i.e., mercury control, will have a greater impact than the CO2 proposed regulation.1
1This report was finalized before the September 20th standards were published.
Abstract: In recent history, the social and environmental effects that dairy producers have on their surrounding community have come under review, revealing the need for a manure management system that not only stores waste, but reduces odors and greenhouse gas emissions. One such manure management system that meets these needs, as well as produces a source of renewable energy, is an anaerobic digestion system.
Anaerobic digestion systems are generally utilized on dairy farms with herds of 500 head or more. It was the objective of this paper to determine the feasibility of installing a system on a farm with a herd size of 100-500 head. As a case study, Knigge Farms of Omro, Wisconsin, having a herd of 205 head, was chosen.
An anaerobic digestion system degrades volatile solids within the dairy cattle waste stream, producing biogas and a stabilized effluent. The biogas is then captured and can be used to generate thermal and/or electrical energy for use on the farm, or sold to the utility for profit.
The system in this project was designed to be reliable, therefore only equipment that has had a long service history in treating agricultural wastes was considered, making the system more predictable and robust. Based on the total waste stream produced at Knigge Farms, the system designed utilized a plug flow digester, screw press, and a microturbine. The plug flow digester was designed for a hydraulic retention time of 22 days at 1000F, producing a stabilized effluent and approximately 14,000 cubic feet of biogas per day. The screw press was sized to separate only enough solids to meet the bedding requirements of the farm. With biogas as the fuel, the microturbine was expected to produce approximately 19.9 kW of electrical power, and enough thermal energy to heat the influent waste, and maintain the operating temperature within the plug flow digester.
With these specifications, the system reduced total greenhouse gas emissions by 276 tons of carbon dioxide equivalents per year, and had a net present value of approximately $83,900 over 20 years. However, this design was not economically feasible for Knigge Farms. This system, with a capital investment of approximately $213,000 and a simple payback period of approximately 20 years, does not provide a favorable return on investment considering the volatility of the dairy market.
Although the particular design proposed was not economically feasible, other designs of an anaerobic digestion system for small dairies may yield more favorable results. As an example, approximately 48% of the capital cost of the entire system was associated with the gas handling equipment. If a water heater was used instead of a microturbine, and a market for excess separated solids could be identified, an anaerobic digestion system may become more economically feasible. Additionally, new advancements in anaerobic digestion technology could have the potential to reduce capitol and/or operation and maintenance costs.
Abstract: The area along the south shore of Okauchee Lake known as Ice House Bay has experienced storm water management problems, including localized street flooding, damage to private property due to flooding, and contributions of sediment and associated pollutants deposited on the bed of Ice House Bay. At the request of the Okauchee Lake Management District (OLMD), a study has been performed to analyze the problems and a series of alternative measures to remedy the situation.
Three alternatives were analyzed: a sedimentation basin, a mechanical system, and a filtration enhancement in open channels. These options are for the reduction of non-point source pollution that Okauchee Lake Management District can implement locally with the help of the Towns of Summit and Oconomowoc. Each option seeks to remove or reduce the pounds of total suspended solids that are carried by stormwater discharging to Ice House Bay. A wet extended detention pond, bio-retention swale, a Downstream Defender, and no action were analyzed for their cost and effectiveness at removing total suspended solids from the stormwater runoff.
Each stormwater management option was designed and analyzed for their ability to reduce the pounds of total suspended solids being discharged into Ice House Bay and the cost of the option. The cost of each design was determined using RS Means. The reduction of total suspended solids was determined using the Source Loading And Management Model (SLAMM). The bio-retention swale removed the most amount of TSS from the stormwater runoff (8,200 lbs); while the Downstream Defender removed the least (5,550 lbs). The no action alternative was the least expensive of the alternatives with a total cost of $49,000. The wet extended detention pond was the most expensive with a total cost of $160,000. TheWet extended detention pond costs $1.37 per pound of solids removed, the Downstream Defender costs $1.04 per pound of solids removed, the bio-retention swale costs $0.76 per pound of solids removed, while no action costs $0.07 per pound of solids removed.
Based on the data presented, the alternative recommended to the Okauchee Lake Management District is to not install one of the stormwater management devices analyzed. The stormwater management devices do not justify their prices based on their removal abilities. At this time, MSOE recommends further analysis of the drainage area and analyzing the freeway runoff separate from the residential runoff. However, that analysis was not completed within this report.
Abstract: The city of Milwaukee, Wisconsin has experienced an increase in the number of foreclosures since the economic recession that began in December 2008. The availability of small, vacant residential lots prompted Milwaukee officials to promote the use of these properties for urban gardens, providing a benefit to neighborhoods rather than a blighting influence. The local food movement has created an interest in urban gardening, but has also revealed concerns on the safety of urban soil. This concern has impelled gardeners to sample soil in an effort to cut down the cost of bringing clean soil, while ensuring gardeners are not exposed to harmful impacts. Wisconsin's low regulatory thresholds for polycyclic aromatic hydrocarbons (PAHs) can result in regulatory action for sites with no known source release, causing property owners to be wary of sampling in fear of a costly cleanup action.
To illustrate how conservative soil cleanup standards for polycyclic aromatic hydrocarbons in the state of Wisconsin are, seven vacant residential properties in the city of Milwaukee were sampled. Analytical data for PAHs in the near surface soil, or direct contact zone, were compared to standards in Ohio and Illinois. Analytical results showed regulatory action would be taken on seven of seven sites based on Wisconsin standards, while Ohio and Illinois standards would result in regulatory action on only four of seven sites. Based on the individual sample results on each site, remedial costs for these sites if they were located in Ohio or Illinois would be 40% less than the cost of remediation in Wisconsin. These results present an opportunity for Wisconsin regulatory authorities to review justifications for increasing low thresholds for PAH concentrations in near surface soil.
Abstract: The Riveredge Nature Center in Newburg, WI, utilizes a subsurface flow constructed wetland to treat wastewater. The wetland was over-designed, and to date, has performed to design capacity in removing biochemical oxygen demand (BOD) and nitrogen (N). The purpose of this project was to increase the organic and nitrogen load to the wetland, to determine the systems capacity, and to compare the results with current engineering models to determine if they would accurately predict the wetland’s performance.
To increase the organic and nitrogen load to the wetland, synthetic wastewater was added to the system’s septic tanks. To determine the effects of increased loading into the wetlands samples were analyzed for Chemical Oxygen Demand (COD), ammonia, and nitrates.
Mass loading of organics was increased to almost ten times the normal level. Sample analysis for COD with an EPA approved block digester and colorimeter gave imprecise results. COD removal ranged from 50-100%. The mass loading capacity of the wetland appears to range from 3 to 5 lbs./day BOD based on COD effluent concentrations during the experiment. Nitrogen loading to the system was not increased dramatically. Ammonia concentrations up to approximately 63 mg/L (highest concentration) were added to the system. Ammonia removal ranged from 50-90%. Nitrates were not present at any point within the system. Increased nitrogen loading had no significant effects on effluent quality. First-order plug-flow and complete-mix equations used to predict COD concentrations in effluent, had an average difference throughout the wetland of 33 mg/L and 34 mg/L, respectively, when compared to experimental values. These effluent predictions were closer to experimental values from the midpoint of the system.
Longer-term study and more precision sampling techniques would be beneficial for determining the wetland’s capacity. The system may have equilibrated to the highest BOD influent concentrations given more time.
Abstract: The Milwaukee Metropolitan Sewerage District (MMSD) produces Milorganite from biosolids. Milorganite is a dry granulated lawn fertilizer. As more and more municipalities produce marketable fertilizer from wastewater treatment byproducts, the market for Milorganite and other biosolids is becoming more competitive Developing alternative markets for wastewater treatment byproducts is both environmentally and economically attractive.
A treatability study was conducted to establish the efficacy of Milorganite as a nutrient source in the remediation of soil contaminated with diesel fuel. The study was done by comparing the performance of Milorganite to that of another granulated lawn fertilizer. Test chambers were constructed and the experiment designed following the guidelines established for the soil remediation technology of Biopiles. An additional goal of the study was to define a method that could be repeated with other contaminants using Milorganite as the nutrient source.
The study results indicate that Milorganite may indeed prove useful for this purpose. A 95-96% reduction in Diesel Range Organics (DRO) was achieved over the 12 weeks of study. The results also indicate that when Milorganite is used, there is a synergistic effect between degradation of the contaminant and metabolism of the nutrient source. When degradation rates were computed from respiration test data based on the equation derived for metabolism of the contaminant, DRO results derived from respiration testing were found to agree well with those obtained from analytical testing.
Abstract: Uncertainty and variability in parameters such as hydraulic conductivity, biodegradation rate constant and spatial distribution of the source of contaminants influence the plume size and clean up time. While no one technology can adequately address the complexity and dynamism of contaminant migration in soil and groundwater, engineering technologies are typically evaluated on their reliability, simplicity and stability. This thesis examines the feasibility of enhancing the remediation of a local petroleum hydrocarbon polluted site using bioelectrokinetics. Bioelectrokinetics utilized direct current to facilitate contaminant interaction and mobilization. As a technology that has shown promise both as a cost-effective and rapid remediation option, bioelectrokinetics has successfully been deployed on polychlorinated biphenyls, chlorinated hydrocarbons and heavy metals. This thesis evaluates the feasibility of espousing these successes to petroleum hydrocarbon pollutants. In the evaluation and selection of a remedial system for contaminated sites, it is a common practice amongst practitioners to collate the best benefits of various technologies that ensure better returns on efficiency and optimum cleanup. This is especially most appropriate for multi-phased contaminants (a combination of cationic and anionic metals and organic contaminants) where consolidated technologies such as electrokinetic-chemical oxidation/reduction, electrochemical geooxidation, bioelectrokinetic remediation, electrokinetic-phytoremediation, electrokinetic-thermal desorption, electrokinetic-permeable reactive barriers, electrokinetic-stabilization, electrokinetic-barriers, electrochemical ion exchange amongst other innovative approaches have been demonstrated to attain excellent results.
Whether integrated or deployed alone, remediation technologies must be structured to address the requirements of mass removal, receptor protection, and an appropriate cleanup time with deference to human health and the environment. Despite the popularity of intrinsic remediation, its deployment is short of satisfying these requirements especially in the light of changing regulatory policy on soil and groundwater cleanup standards. Bench test results and performance data from peer reviewed journals, along with site specific information obtained from public files, form the basis of calculations to estimate the sustainability of the bioelectrokinetic approach. Furthermore, this project also outlines certain opportunities and difficulties in initiating and implementing bioelectrokinetic remediation. The potential to address vapor intrusion risk assessment and post-closure plume migration contingencies are addressed in this capstone design project report. Overall, the evaluations of this thesis do not conclusively demonstrate the efficacy of the conceptual system as a cost-effective remedial option for the chosen site. It, nevertheless, puts forward a strong argument for its use with petroleum hydrocarbon waste given the depth of the data presented. This thesis therefore holds that bioelectrokinetics provides a greater value over traditional methods where time is of paramount importance.
Abstract: Environmental management systems, such as that specified by ISO 14001, are recent developments in the commercial world. Rockwell Automation is currently implementing Environmental Management Systems in all of its facilities and is obtaining third-party certification to ISO 14001. The Milwaukee campus is the largest and most diverse facility within the company. The purpose of this project is to develop a systematic approach to conducting an efficient and effective assessment of the activities occurring at that campus and how they interact with the environment.
A literature search was conducted for information regarding ISO 14001 assessments, pollution prevention opportunity assessments and general decision-making methodologies. Background information was collected on ISO 14001 and its public policy implications. A screening-level assessment method was proposed, fine-tuned and tested utilizing a sub-set of five manufacturing departments within the Rockwell Automation Milwaukee Campus.
Several standard tools were developed as a part of the assessment method: an activity information collection form, a worksheet for aspects, an impact rating system, and a summary format. The project illustrated that a systematic approach can yield valid and consistent results without consuming and inordinate amount of time and resources. This documented method allows future assessments to be compared to the current baseline. It eliminates questions concerning variability due to the method itself.
Abstract: From the early 19th century to the mid 20th century, manufactured gas plants (MPGs) generated coal tar as a by-product of manufactured gas. Often, when these sites were abandoned, coal tar remained in the structures, including the tar separator, tar wells, and gas holders. Such areas are often targeted for source removal actions, because over the decades during operation and since decommissioning, the coal tar has in many cases migrated from its original locations to deeper and more widespread areas of contamination, while maintaining its properties as a dense non-aqueous phase liquid. Remedial actions at MGP sites typically focus on ex situ remediation of coal tar residues in soil and groundwater.
Unconventional in situ treatment is also coming into use, because of the long time frame required for conventional pump-and-treat or open-ended containment options for groundwater currently in use. In one documented study, a vapor extraction system is uses as an intermediate treatment step to reduce the fraction of benzene in the coal tar contained within a gas holder to reduce ignitability. In situ flushing of coal tar residuals has also been demonstrated as a viable approach to in situ remediation of coal tars in soil and groundwater. Finally, although not currently applied at coal tar sites, in situ steam injection, a more aggressive variation of air sparging has been successfully used at other types of contamination sites, such as petroleum contamination at underground storage tank sites. The following design project summarizes the design of a steam-enhanced extraction system for removal of coal tar and dissolved contaminant residuals at a notional MGP site in order to reduce contaminant mass and mobility.
Abstract: The primary purpose of this study is to evaluate the Municipal Solid Waste (MSW) stream as a source of renewable energy by comparing energy recovery from the baseline situation-landfilling to that of the alternative-waste-to-energy (WTE). The City of Milwaukee which is located in Southeast Wisconsin is used as a case study. The State of Wisconsin has a Renewable Portfolio Standard (RPS) and is moving towards renewable energy goals. Legislation enacted in March 2006 increased renewable-energy requirements and established an overall statewide renewable-energy goal of 10% by December 31, 2015. We Energies in their Power the Future program has targeted 5% of their retail electricity sales to be generated from renewable (winds, solar, and biomass) energy sources by 2011.
To maximize the resource value in MSW it is important to address each component of the MSW separately as the individual components of MSW vary considerably in energy content. Plastics have high energy content at around 14000 Btu/lb. MSW with food waste (70% water) and recyclables (glass, metals) removed is a potential fuel for WTE systems, which recover energy resources in residual MSW, particularly waste paper and plastics. Food degrades rapidly before landfill liners go on the the lignin in wood doesn’t degrade anaerobically in a landfull. Hence, the energy in biodegradable components of MSW, such as food, wood, is largely lost when MSW is landfilled.
Based on many assumptions and calculations, it is estimated that City of Milwaukee’s MSW contains total energy of 3.02E+12 Btu/year and around 5230 Btu/lb which can be recovered when MSW is mass burned in a WTE facility. Switching to WTE can generate a net of 17 MW of energy. Excluding the amount of energy obtained from plastics, a fossil fuel derived material approximately, 16 MW can contribute towards Wisconsin’s Renewable Portfolio Standard thus meeting the goal of obtaining energy from renewable resource.
Implementing WTE for the City of Milwaukee would reduce the release of 12,477 metric tons of carbon dioxide equivalent GHG emission into the atmosphere each year when compared to landfilling. Also, energy analysis shows that WTE can reduce the energy usage by 726,936 million Btu each year which is equivalent of eliminating 10,645 passenger cars, 125,334 barrels of oil and 5,812,170 gallons of gasoline.
WTE has a potential to recover energy resources in residual MSW. Therefore a WTE plant for the City of Milwaukee can supply power 365-days-a-year; 24-hours a day hence promoting energy diversity, while helping the city meet the challenge of trash disposal. The tipping fee for the City of Milwaukee of $30/ton is cheap when compared to WTE at $56/ton. However, it is important to compare waste management to current mining operations; particularly for metals, the energy savings from using recycled metals is so high. WTE can be centrally located for the City of Milwaukee which will lower the dollars spent on transportation. By defining WTE power as a renewable fuel, Wisconsin can promote both conservation of non-renewable fossil fuels and environmental quality of air and water resources. WTE facility can be a steady, viable, and environmentally sound method to dispose of trash.
Abstract: In order to achieve improved pretreatment of the wastewater effluent for Steeltech Manufacturing, this study of pretreatment chemicals was initiated. The purpose was to determine the most efficient chemicals for removing zinc and nickel from Steeltech's wastewater for an E-Coat systems's nine stage pretreatment (wash and phosphating system), especially, the wastewaters produced by Stages One and Two. In conjunction with determining effective chemicals, the cost of treating with those chemicals should reduce the cost per gallon of treating Steeltech's wastewaters. The final choice of chemicals should produce an effluent containing zinc and nickel concentrations below Steeltech's permit limits at a decreased cost compared to past treatment costs.
First, the determination of the appropriate chemicals and their effectiveness in the treatment process was made through jar (bench) testing. The testing methodology included the adjustment of pH, the use of inorganic metal salts such as ferric chloride and various aluminum based salts, and organic polymers used as coagulants and flocculants. The pH adjustments and chemicals were tested in multiple combinations to ascertain the most effective treatment during bench testing on Stage One wastewater. The results from these tests were used to determine the chemical combinations and dosage plus the pH adjustments required for the pilot tests for Stage One. Then the chemicals that treated effectively in the pilot tests from Stage One were used in the treatment of other stages in subsequent jar and pilot testing.
By February 1998, Stages One and Two were successfully treated. At an initial pH of two, the chemicals calcium chloride, ferric chloride, MaFloc 2012, and Booth Control 8009 were used in the treatment of the wastewater. In the neutralizing tank, the formation of a pink floc occurred as the pH was raised to ten. The addition of MaFloc 951 created fast settling flock and clear, yellow tinted effluent. The nickel and zinc concentration in the effluent were less than Steeltech's discharge permit limits of 2.38mg/l and 1.48 mg/l (monthly averages), respectively.
During March 1998, Stages Three, Four, Five, and Eight were successfully treated using only ferric chloride and calcium chloride, and then, flocculation with MaFloc 951. Again, Steeltech's effluent was below its permit limits for zinc and nickel. Also, Stage Seven's pretreatment required ferric chloride, calcium chloride, and MaFloc2012 to treat the wastewater to meet the permit limits.
Before this study, Steeltech hauled Stages One and Two off-site and was inconsistent in the treatment of its wastewater. As a result of the project, Steeltech treats all of its wastewater streams to the requirements of its discharge permit.. An estimated savings of $450,000.00 per year in avoided chemical costs, hauling fees, and permit violation penalties was obtained as a result of this project.
Abstract: The southeastern region for the State of Wisconsin contains high levels of Radium-226 and Radium-228 in drinking water supplies. The concentrations exceed the USEPA MCL of 5 pCi/L for combined radium-226 and radium-228.
The focus of this project was to evaluate various treatment technologies for known data from a municipality located in Southeastern Wisconsin. An alternatives analysis was conducted for various technologies to determine the best treatment technology for the alternatives analysis, conceptual design and cost analysis associated with the treatment prevention system. The alternatives analysis was conducted by using technical papers that performed bench, pilot, or full-scale studies on each alternative. A screening criteria was applied to determine the best treatment technology for the system. The well pumps at a maximum flowrate of 3.6 MGD with a hardness of 250 ppm and a combined radium concentration of 10 pCi/L. After careful consideration of all alternatives, a cation exchange unit was selected for the proposed treatment technology. Assuming a 95% radium removal efficiency, the concentration of radium in the treated water can then be used for blending of the other City wells to bring the levels of radium below the NIPDWR limit. No bench-scale studies were performed to optimize the system.
The system will consist of 5 columns treating 3.6 MGD of radium-contaminated water. Secondary wastes produced include wastewater containing a radium concentration level of 638 pCi/L and the resin media itself containing 1,159 pCi/g after five years. The total cost of this system over a 25 year equipment life and a 7% interest rate is $93 million. To break down the $93 million between total capital and O&M costs is $22 million and $71 million, respectively.
Abstract: Groundwater extracted from wells to supply the city of Torreon in Mexico contains high levels of arsenic. In some wells, the concentration exceeds the Mexican concentration limit of 25 ppb.
The objective of this capstone project was to evaluate the technical and economic feasibility of using chemical coprecipitation with ferric chloride to remove arsenic from groundwater. A series of laboratory bench-scale treatability studies were conducted to evaluate the effectiveness of the coprecipitation process, and a system was designed to treat the municipality’s average flow rate of 27 liters per second while complying with the current World Health Organization standard of 10 ppb. Additionally, an evaluation of the life cycle costs and pollution prevention benefits for such a system in Torreon was assessed.
In the current study, chemical coprecipitation proved to be a technology suitable for treating arsenic in groundwater because of its low costs of implementation, operation, and maintenance.
Abstract: Publicly Owned Treatment Works (POTWs) are being subjected to increasing regulatory, political, and social pressures to produce a “safe” biosolids product. Biosolids are a significant source of needed nutrients for plant and crop growth. The Brookfield Fox River Water Pollution Control Center (FRWPCC) currently produces a Class B biosolids product, which contains a significant density of pathogenic organisms. The objective of this project is to utilize temperature phased anaerobic digestion (TPAD) treatment to meet Class A biosolids requirements. Currently, the high pathogen concentration in the FRWPCC biosolids is the only condition prohibiting Class A status.
The experimental process was conducted in three sequential phases. The intent in Phase I was to environmentally adapt four laboratory-scale primary anaerobic digesters, with two operated as mesophilic temperature reactors (35 C) and two as thermophilic temperature reactors (55C). Phase I was concluded when monitoring suggested that microcosm stabilization had been achieved. Phase II instituted phasing of the process in both modes (i.e. mesophilic-thermophilic and thermophilic-mesophilic). This phase achieved Class A pathogen reduction success and demonstrated that the thermophilic-mesophilic mode was operationally preferred based on increased volatile solids reduction and organic loading capacity. These findings translate into reduced biosolids generation volume, increased treatment capacity, and higher methane gas production, which is available as an alternate fuel source. The intent of Phase III was to fine-tune the operational boundaries in regard to temperature and loading of organic matter. This phase concluded that TPAD offers the ability to stabilize organic matter with greatly reduced solids retention times than traditional mesophilic anaerobic digestion while still producing a socially acceptable resource.
Abstract: This Capstone Design involves an economic analysis of ultraviolet (UV) versus chlorine disinfection at the Brookfield Fox River Water Pollution Control Center (FRWPCC). The purpose of this project was to determine if it is economically feasible for the plant to modify their existing chlorine disinfection system to UV disinfection.
In order to determine the feasibility of switching disinfection technologies, an extensive literature review was conducted to make sure that the UV disinfection includes the characteristics of an appropriate disinfecting agent. After the literature review, ultraviolet transmittance (UVT) testing was conducted over a one-week time period so two manufacturers, Trojan Technologies, Inc. and Wedeco UV Technologies, could recommend an UV disinfection system. Next, multiple wastewater treatment plants (WWTPs) in the state of Wisconsin were contacted to determine the initial capital and annual operation and maintenance (O&M) costs associated with their systems. These costs were then put into cost curves according to the average plant flow rate to estimate similar costs for the FRWPCC.
Upon estimating the costs from the cost curves, they were compared to the system selections by the two manufacturers and to the current chlorine disinfection costs experienced by the FRWPCC. Through UVT testing it was determined that the wastewater to the disinfection process at the FRWPCC had a minimum of 70% UVT. With the UVT and permit requirements of the plant, Trojan Technologies, Inc recommended the Trojan UV4000 Plus, which is a medium-pressure, non-contact type reactor with lamps parallel to flow.
The system as a total of 108 lamps and costs $616,200. Wedeco UV Technologies recommended the Wedeco TAK 55, which is a low-pressure, high-intensity, non-contact type reactor with lamps parallel to flow. This system operated with 432 lamps and costs $820,500. From the cost curves it was estimated that for the FRWPCC it would cost $714,000 in initial equipment with O&M costs of $6,750; $10,700; and $5,700 for energy/electrical requirements; lamp replacements; and chemicals, maintenance, and lamp cleaning, respectively.
The costs estimated from the cost curves were close to the costs estimated by the two manufacturers, suggesting that the cost curves were an accurate representation of the actual costs. In comparing the net present value (NPV) of the baseline chlorine disinfection to UV disinfection, it was found that the existing system was $236,481, while modifying the system to UV disinfection was $1,849,664.
Looking the payback period, it was determined that the costs per year exceeded the savings per year for UV, yielding no payback period. Finally, from a pollution prevention aspect, UV disinfection eliminated chloroform as a hazardous waste, but introduced a minimal amount of mercury hazardous waste. At the same time, UV disinfection requires more electricity than chlorine disinfection requiring the consumption of more coal at the local power plant and the associated air emissions.
In this analysis, it was determined that UV disinfection is not economically viable at this time due to the existing costs for chlorine disinfection and the estimated costs for UV disinfection but should be considered from a safety aspect for the community and plant operators.
Abstract: Water is an abused resource, and in many places it is lacking in quality and quantity. As more areas around the world are running out of water, including areas in the United States, it is important water is used as efficiently as possible. Currently, Milwaukee, Wisconsin has a large clean water source, Lake Michigan, whose water supply is protected by the Great Lakes Compact. However, this compact has already been compromised, and water from Lake Michigan is being pumped to areas where the flow does not travel back into the body of water. The future may include lower water quality and quantities leading to a decrease in water availability as well as an increase in the price for water.
This thesis includes a comparative study between two low cost systems used in small scale wastewater treatment applications, the membrane bioreactor and the constructed wetland. The study was completed for the Northwestern Mutual Life North Office Building, located in downtown Milwaukee, Wisconsin, for the waste that is generated at that site. A literature review was completed for wastewater treatment of the two processes, including case studies from international, national, and regional applications. Both the membrane bioreactor and constructed wetland systems were applied to the Northwestern Mutual Life North Office Building generation, and a cost analysis was performed between the two systems, including the payback periods. The results of this study indicate that the on-site treatment of wastewater does not provide an adequate payback period for Northwestern Mutual Life to re-use the treated wastewater their building generates throughout the year.
Abstract: As the world's population continues to grow, the use of water resources generates larger amounts of wastewater that are collected and treated to protect public health and the environment. The municipal wastewater treatment process stabilizes collected solids, most commonly done through the process of anaerobic digestion. Anaerobic digestion is the anaerobic biological decomposition of organic solid material that concomitantly destroys harmful pathogens, thus reduces the risk of disease transmission to the public.
The objective of this research is to evaluate the impact of replacing the existing anaerobic digesters with Egg-Shaped Digesters at the Waukesha WWTP. The evaluation of ESD life-cycle performance, including capital operating and maintenance costs, is reviewed versus continued operation of a conventional anaerobic digester. Life cycle costs are defined as the overall cost of an alternative to the WWTP operation over a twenty year planning period. Capital costs include necessary structures and equipment to install ESDs at the WWTP.
This study involved analysis of data collected daily over a three-year period at an operational wastewater facility in the United States. To review the feasibility of the ESDs, a large amount of data needed to be sorted and analyzed to evaluate efficiency and effectiveness of the existing anaerobic digestion system.
Egg-Shaped Digesters are efficient in passing through sand and grit, while producing volatile solids reductions that exceed conventional digester performance. There is less need for removal of ESDs from service to be cleaned or repaired as the shape and mixing systems keep a minimal amount of build-up from occurring at the bottom of the tank and scum build-up at the surface. Data from operating ESD systems can provide guidance on which designs are the most cost effective in future use. With a draft tube assembly used to induce flow throughout the digester, and heat exchangers to assist boilers in heating the contents, a wastewater utility can reduce capital costs and construction expenses.
For Waukesha's plant, the researcher recommends not adding the Egg-Shaped Digesters at this time. Their existing conventional digesters are operating at the high end of the typical volatile solids reduction with annual maintenance and upkeep of one digester out of service each year. They have adequate storage of the final cake product and sufficient fields to apply it during the spring and fall months. The only use of their existing biogas is for the two hot water boilers that serve the digester building. Figuring that electrical and heating consumption is the same when comparing the conventional pancake digester and the ESD, it is possible to determine that the plant would not experience a payback at this time. The initial construction costs are also significantly higher for an ESD than refurbishment of the existing conventional digesters.
In order to make the addition worthwhile, and feasible, the plant would also need to add projects that would utilize the biogas, such as fuel cells, additional heating equipment for other buildings, and generators or turbines to create electricity for the plant to use. These are all upgrades that should be further analyzed along with the payback periods that they would experience.
Abstract: This report provides an analysis and recommendations related to the recent establishment of a Lab Management Plan (LMP) at the Milwaukee School of Engineering (MSOE). It includes a history of the Resource Conservation and Recovery Act and the recently promulgated Subpart K regulations. This background defines the governmental authority driving the process, as well as the issues with compliance by academic institutions, which led to alternative standards designated as Subpart K.The report includes a discussion of MSOE’s recent efforts to correct environmental violations, as well as an exploration of the associated cost of compliance. Additionally, a cost analysis of the defunct Safety Officer position allows a financial comparison to estimated penalty amounts.
MSOE selected Subpart K as the hazardous waste standard applicable to laboratories containing hazardous materials. Implementation included the retention of an independent environmental consultant to develop an LMP. Surveys of laboratory technicians provide feedback on issues related to the changes within the laboratories as a result of the LMP, and identify areas for further development.
Conclusions are defined and supported and recommendations are outlined, including revising the LMP to include procedures for reporting non-compliances, hiring a full-time environmental professional at MSOE, developing an environmental policy, and expanding the LMP to include specific elements found in environmental management systems.
These actions will complete development of a coherent informal Environmental Management System at MSOE. This will provide a solid foundation for compliance, communication, and future growth of the environmental program.
Abstract: The purpose of this paper is to point out the challenges in treating trace contaminants with an aerated submerged fixed film biological reactor system when low contaminant specific discharge limitations are established as treatment objective. This analysis focuses on one particular pilot treatment system that was constructed to treat groundwater contaminated with acetone at concentrations between 2 and 6.6 mg/L; methyl ethyl ketone (MEK) between 4.4 and 16 mg/L; tetahydrofuran (THF) between 7.8 and 21 mg/L; and toluene between .08 mg/L and 2.2 mg/L. The contaminated groundwater plume originated from a closed landfill that is listed on the United States Environmental Protection Agency's (USEPA) National Priorities List (NPL).
Three groundwater extraction wells were installed down gradient of the groundwater contaminant plume for extraction of the contaminated groundwater. This water was pumped from all three wells to an influent equalization tank for mixing and flow equalization. The water was then pumped into an aerated submerged fixed film bioreactor (SFFB) for biological degradation of the contaminants. The SFFB utilized a fixed in place corrugated PVC cross-flow media. The contaminated groundwater was deficient in nitrogen and phosphorous so urea and ortho-phosphate were fed to the system to meet the biological demand. The SFFB was followed by a down stream inclined plate clarifier and solids storage tank. The USEPA set contaminant specific discharge limits for acetone of 50 mcg/L, MEK of 50 mcg/L, THF of 100 mcg/L, and toluene of 25 mcg/L.
Sixteen months of operating data from the SFFB was used in this study. The study demonstrated that the SFFB is very successful at removing greater than 99% of the target contaminants with low influent contaminant concentrations and very low effluent contaminant objectives. The average mass loading of acetone, MEK, THF, and toluene during operation of the pilot scale system were 0.14 lbs/day, 0.39 lbs/day, 0.56 lbs/day, and 0.04 lbs/day respectively. The pilot system performance was analyzed to determine the required minimum surface area required to treat the groundwater to a level below the contaminant specific discharge limits for each contaminant. THF was determined to require the greatest surface area to treat below the contaminant specific discharge limit, and had a maximum loading rate of 0.015 lbs of THF per 1,000 square feet of media surface area per day.
This study reinforces the importance of bench scale testing of pilot scale testing of SFFB's prior to the final design of a full scale treatment system in order to determine the removal rate of each contaminant, particularly when the system is designed to treat trace contaminants or there are contaminant specific discharge limitations placed on the treatment systems effluent.
Abstract: A Milwaukee investment casting facility generates hazardous waste sludge through operation of their Kolene™ investment casting cleaning system. The hazardous sludge generated consists of silicates, caustic soda and heavy metals including hexavalent chromium leached from the stainless steel parts by molten caustic soda during the cleaning process.
The production, handling the disposal of the hazardous waste presents health and safety issues and economic risks to the facility. In an effort to reduce the risks associated with the current casting cleaning process (i.e. the generation of hazardous waste), a feasibility study has been completed to identify an alternative hazardous sludge treatment processes that have potential for pollution prevention and risk reduction. The alternatives considered are: 1) Water jet casting cleaning technology, 2) Traditional metal precipitation wastewater pre-treatment of the hazardous sludge; and 3) A proprietary sludge treatment process.
The evaluation of the applicability and performance of these three selected alternatives was based on the production and performance of the current cleaning process. Specifically, each of these alternatives was evaluated and compared based on performance related to: technical feasibility, product quality, changes in regulatory status or facility processes, changes in employee health and safety, economic viability, changes in company operations and the potential for pollution prevention, waste minimization and / or energy reduction.
A relatively detailed evaluation of the proprietary sludge treatment process indicates that this alternative can effectively eliminate the generation of hazardous waste and the associated regulatory requirements, while not affecting product quality, or facility operations. The economic evaluation indicates that through completion fo recommended supplemental pilot and bench scale testing of the process this alternative may prove to be competitive with the existing waste disposal system. However, this alternative may not improve employee health or safety.
Abstract: The City of Milwaukee can look to Chicago for ways to improve its municipal solid waste (MSW) and recycling management. Chicago’s “Blue Bag” recycling program provides a good model of Milwaukee to use in analyzing alternatives to their own MSW and recyclables collection. This report analyzes the impact of Milwaukee implementing a co-collection – a single, source-separated collection of MSW and recyclables. Factors considered include composition of materials, fuel usage, collection and sorting costs, market value of recyclables, materials in the collection and quantity of recyclables that become landfilled as residuals. This report compares and analyzes the MSW and recycling management costs of Chicago and Milwaukee. Impacts of a single, source-separated collection are applied to Milwaukee.
The recommendation is for Milwaukee to implement a single-source-separated collection for MSW and recyclables. The materials would be placed in four separate bags: MSW, paper, glass, and other containers. Residents of Milwaukee would be required to purchase their own bags and the City would supply stickers to differentiate recyclables from MSW. Sorting of the MSW from the recyclables would occur at the transfer stations, minimizing the capital costs of a sorting facility. The MSW would be transported to the landfill and the recyclables would be transferred to the mixed refuse facility (MRF). Milwaukee would be able to use its existing MSW collection vehicles. Fuel use would be reduced with a co-collection. A reduction in fuel use results in a significant cost savings and a decrease in emissions. An annual cost savings for the City of Milwaukee would amount to approximately $3,670,000. Ten-year savings at a three percent interest rate compounded annually are estimated to be $42,070,000.
Abstract: The traditional method for removing hexavalent chromium contaminants from a wastewater is facilitated by the addition of numerous chemicals (e.g. Sulfuric Acid, Sodium Metabisulfite, and Lime). These chemicals and their byproducts post significant safety and operational concerns for the operators of the wastewater process. In addition, these concerns are overshadowed by the fact that the end product of the chemical treatment is Chromium Hydroxide, a material which is considered a hazardous waste.
An alternative approach to chemical treatment is Electrocoagulation, an in situ method of generating ions through the process of electrolysis. This approach eliminates the need for hazardous feedstock chemicals and ultimately reduces the chromium contaminants to insoluble chromic oxide. This reduces overall environmental liabilities while reducing potential harm to workers operating the process. Results obtained through this experiment indicate that out of three factors, treatment time, applied voltage, and applied current, applied voltage has little or no impact on the rate of the reduction reaction. Conversely, treatment time and applied current are both significant contributors to the reaction rate and are also additive in their combined effects. Further analysis also indicates the reaction is governed by first-order kinetics with a rate constant of 0.16 min−1.
Abstract:There are many methods available to treat wastewater. Each of the different methods has advantages and disadvantages depending on the characteristics of the wastewater to be treated. Some of these methods are well suited for a variable waste stream while others cannot effectively handle fluctuations in wastewater characteristics. The goal of this project was to develop the preliminary design criteria and order-of-magnitude costing estimate for new facilities to treat the highly variable wastewater from Aldrich Chemical Company.
An alternatives analysis of granular activated carbon, biological treatment, UV/Oxidation, and air stripping was performed. Each of the treatment technologies were evaluated based upon the following five criteria: commercially proven technique, effective to meet discharge limits, capital and operating and maintenance costs, secondary wastes generated, and specific advantages and disadvantages. Upon performing the alternatives analysis, granular activated carbon with flow equalization was selected as the treatment technology for preliminary design.
It is worth noting that UV/Oxidation, in particular UV-hydrogen peroxide, technologies are very desirable for their ability of eliminating contaminants. This ability allows for pollution prevention and in the end less cost because there are few to no secondary wastes to dispose. However, the UV technologies have their limitations. Highly variable, high strength wastewater with large background UV absorbance does not lend itself well to treatment with UV technology. This is the type of wastewater that is present at Aldrich, and therefore UV technology will not be very effective in meeting discharge limitations.
A granular activated carbon system was designed to achieve the discharge limits. The system consists of a flow equalization tank, pH adjustment unit, big filter unit, and carbon unit. The system was designed to minimize carbon usage. A wastewater sampling program was recommended to identify possible sources of contamination that could be reduced to help minimize carbon usage. An Order-of-Magnitude cost analysis was performed. The estimated total capital cost of the system components is $369,000. Operating and maintenance costs are estimated at $701,000 per year. The cost of carbon to treat 5,200,000 gallons a year would be $0.075 per gallon. The net present value of the system for an interest rate of 7% and an equipment lifespan of 20 years is estimated to be $7,626,000.
Abstract: Foundry production workers have historically had a high degree of risk for occupational exposure to silica dust, which can result in the lung disease, silicosis. A mathematical model was developed to assess indoor air quality and to evaluate potential control options for reducing the concentration of respirable particulate and its silica content, thereby minimizing such worker exposure. The model was developed to provide management, engineers, and industrial hygienists with a quantitative means to evaluate the technological feasibility of various control techniques prior to committing capital and resources towards implementing such controls. Based on the conservative assumption that respirable particulate behaves as a gas with respect to dispersion, a correlation was drawn between background respirable particulate concentrations and tracer gas dispersion data. In turn, this correlation was used to predict the impacts of potential control options that could be employed to reduce respirable particulate and silica dust concentrations. Such control options included both source reduction and dispersion controls.
Baseline facility operating conditions (e.g., physical layout, ventilation system, emission sources, air flow patterns) were first analyzed to accurately characterize the area under investigation. The indoor air quality was then assessed by using conventional respirable particulate and area filter sampling techniques. Concurrent with such sampling, tracer gas dispersion sampling was performed to assess the dispersion of respirable particulate emissions from specific emission sources. A direct correlation between background respirable particulate concentrations and compiled tracer gas dispersion data was then calculated and optimized to allow for such a correlation to be used to predict the impacts of potential control options. Using a desktop computer equipped with three-dimensional contouring software, concentration profiles were generated to compare both the individual and combined impacts of source reduction and dispersion control techniques.
As a result of this mathematical modeling approach, it was concluded that a combination of two control options would be most effective at reducing respirable particulate concentrations and its silica content. Specifically, the source control that was recommended was to remove sand, the primary source of silica dust, from foundry returns through the use of an effective cleaning method, such as shot-blasting or a rotary media drum. In addition, zone-balancing of the supply and exhaust ventilation systems was recommended to control the dispersion of respirable particulates, thereby effectively leveling background respirable particulate concentrations by breaking-up the prevailing air flow patterns that had resulted in cross contamination.
Abstract: This project encompasses a conceptual engineering design and associated costs for equipment installation for the physical decomposition of brewer’s wet grain prior to anaerobic digestion. A particle size reduction method, using a double-disk attrition mill was chosen, as the core focus of the design. In addition, two wastewater streams that are currently discharging to the municipality, were identified as a potential source for diluting the brewer’s wet grain to meet the total solids concentration necessary for anaerobic digestion. Elements of the proposed design include the following, 1) diverter valves on the grain load-out lines, 2) a de-watering press prior to the mills, 3) two double-disk attrition mills for mechanical decomposition, 4) a sump pump and tank to divert the identified wastewater stream, 5) a mixing tank and agitator to mix the miller brewer’s wet grain and the diverted wastewater stream and, 6) all associated piping and conveyance systems.
Capital costs and Operation and Maintenance costs were determined for each of the design elements listed above. “Order of Magnitude” costs for both capital and operation and maintenance were calculated. These costs were then combined with costs previously determined for an anaerobic digestor including costs for sludge disposal. A Net Present Value for the project was then calculated and found to be negative. This indicates that the project would not be worth pursuing from a risk-adjusted standpoint. However, if a couple of cost factors, such as the declining price of grain sold as cattle feed and increasing energy prices continue their present trends, it may make the Net Present Value more attractive in a 3-4 year time frame.
Abstract: The purpose of this analysis was to compare the actual performance of a wastewater treatment plant with the predicted operation of a wastewater treatment plant. The goal was to find out which operation process in the secondary system was limiting the treatment capacity of the plant and to eliminate that problem with some suggested upgrades and then to cost these upgrades.
For this analysis, the Oconomowoc Wastewater Treatment Plant was chosen for study based on the fact that they have steadily operated under the same processes for the past several years and had reliable data readily available. The operating envelope methodology was selected for the analysis. This methodology takes into account aeration volume, clarifier capacity and oxygen transfer, developing an envelope of operation within which a plant can run within and not have operational problems. Under average flow and loading conditions, the plant was found to be operating outside of the envelope of operation due to a lack of aeration volume.
A proposed upgrade is to add two additional aeration tanks to give the required volume to treat the waste. However, this proposed upgrade will create a need for additional oxygen since aeration volume is related to the necessary oxygen to treat the waste. In order to supply additional oxygen, an existing 75 horsepower blower must be replaced with a 100 horsepower blower. With these two upgrades, the plant should be able to operate effectively.
The sludge pumps for the return and wasted sludge were checked and found to be within operating limits based upon the simulated maximum loadings. However, it would be recommended that a further study be done on the sludge thickeners as well as the solids holding facility to ensure they still have sufficient capacity to handle the increased solids loadings used for this analysis.
Abstract: Redacted Company and subsidiary companies manufacture plumbing faucets, plumbing fixtures, fine furniture, cabinetry, tile and stone, engines, and generators. These operations generate wood waste from either manufacturing or shipping. The annual disposal of Kohler wood waste accounts for redacted tons of pallets, redacted tons of scrap wood, and redacted tons of sawdust. The majority of this waste material is currently landfilled at an annual cost of $ redacted at an average of redacted per ton. [7]
The objectives of this project were to reduce wood waste disposal costs, reduce the volume of landfilled wood waste through recycling, develop a wood waste recycling analysis tool for decision makers, and use the analysis tool to determine the best disposal option at three Kohler facilities with wood wastes of scrap wood, sawdust, and pallets. Kohler Main Campus (Kohler, Wisconsin) was analyzed for scrap wood disposal, Baker Furniture- Mocksville (Mocksville, North Carolina) was analyzed for sawdust disposal, and Spartanburg (Spartanburg, South Carolina) was analyzed for pallet disposal. Each disposal alternative was compared to the current option of landfilling the material. The best alternatives for managing wood waste at Kohler were selected using a matrix that was developed based on particle size, risks (including treated wood or contamination), costs and marketability. The alternatives chosen for Spartanburg pallets was to repair and return pallets, for Kohler Main Campus scrap wood was to produce landscape mulch, and for Baker-Mocksville sawdust was to use it as boiler fuel.
Abstract: Lead is the most widely used of the non-ferrous metals due to its physical, chemical, and electrical properties. The use of this material does not come without its challenges. These challenges result from the significant liability associated with the adverse environmental, health, and safety effects. The first part of this study includes a discussion of the toxicology and the regulation of lead to demonstrate this liability. A lead-based manufacturing process at a radiator manufacturing facility was then targeted to investigate potential abatement alternatives to minimize or eliminate the impacts of lead from the facility.
A USEPA recommended control technology review and selection process, known as a Best Available Control Technology (BACT) analysis, was used to evaluate potential abatement alternatives. These alternatives included material substitution, product substitution, and add-on control devices. The BACT analysis determined that material and product substitution may be viable long-term solutions, however, were not technologically feasible at this time. Therefore, four general categories of add-on control devices, including mechanical collectors, fabric filters, wet collectors, and electrostatic precipitators, were evaluated based on the BACT screening criteria. This evaluation identified a cartridge filter system as the most stringent and economic technology available. After identifying a cartridge filter system as the most appropriate control device, a complete design was developed to fit the specific application. The design includes system specifications and financial information needed to complete the installation.
Abstract: This paper presents a summary of a study conducted to: 1) estimate the number of obsolete computers ready for recycling or disposal in Wisconsin, 2) assess Wisconsin’s private and public infrastructure for recycling computers, 3) identify gaps in service and barriers to recycling, and 4) determine program costs and potential funding for state or county computer collection programs. The study gathered data to estimate the number of existing computers in Wisconsin and to project the number of computers to be sold in Wisconsin over the next three years. This data was then used to develop a model that estimated the number of computers that were and will be recycled and disposed of from 1989 to 2005 in Wisconsin. A number of computer recycling forms were contacted to determine the number of computers that were recycled in 2002, recycling costs, and the services that they provide. The number of computers that were estimated to be recycled in 2002, 490,000, compares favorable to the number reported by the computer recycling forms, 436,000.
Computer collection pilot programs from other states were reviewed to estimate collection program costs in Wisconsin. In 2002, an estimated 194,000 computers were disposed of in Wisconsin. At an average collection program cost of $0.23 per pound of used computer equipment collected, implementing collection programs in Wisconsin to collect and recycle the 194,000 would cost approximately $2.2 million. The current public and private recycling industry has sufficient capacity over the next three years to recycle computers at the estimated rate. However, if collection programs are implemented to capture the computers that are currently being disposed of in Wisconsin, existing recycling forms will need to increase capacity or excess computers will need to be sent out-of-state for recycling.
Abstract: A railroad company is currently implementing a three year program to evaluate the use of vegetation (phytoremediation) as a technically and economically feasible alternative to off-site remediation and disposal of petroleum impacted soils. Valuable data will be generated to demonstrate the effectiveness of the innovative technology, to further define suitable plant species and applications in Wisconsin, and to gain acceptance from the WDNR and the public. The MSOE capstone design project will complement the study by performing a small-scale treatability study to assess the phyto-toxicity of various contaminant concentrations in the soil.
Phytoremediation is the use of plants to remediate contaminated soil, taking advantage of the plant's natural abilities to take up, accumulate, and/or degrade contaminants. This technology has shown promise in the laboratory and field tests on soils containing petroleum hydrocarbons and may be feasible at transportation facilities which often have sufficient area for phytoremediation/landspreading treatment plots.
Abstract: Over the course of twenty years, the Presidio Square Apartments has been struggling with the presence of high concentrations of chlorinated hydrocarbons in soil and groundwater samples. Contamination at the residential complex is being attributed to previous waste dumping activities that occurred during the 1960’s, and prior to the construction of the buildings. The primary contaminants encountered at the site have included tetrachloroethene (PCE), trichloroethene (TCE), 1,2-dichloroethylene (DCE) and vinyl chloride (VC), among others. These compounds are listed as substances of public health concern and are strictly regulated under the Wisconsin Administrative Code. Extensive remediation efforts have been performed at the site, including a sub-slab-depressurization system, enhanced anaerobic reductive dechlorination, soil removal, and chemical oxidation. After the in-situ treatment, most of the contamination was removed. Parent compounds like PCE and TCE have decreased by several orders of magnitude, and in some points, they no longer exist. In contrast, the concentration of daughter compounds such as 1,2-Dichloroethylene and vinyl chloride are present in high concentrations in soil and groundwater samples. Moreover, they are expected to increase since most of the parent compounds have been degraded. Compared with the initial concentration, there is a significant improvement in clean up, but persistent pollutants remain in the area and continuous actions are required by the Wisconsin Department of Natural Resources before closure status may be granted. On the other hand, the degradation products are more unstable and toxic than their predecessors.
The United States Environmental Protection Agency (EPA) has classified vinyl chloride as a human carcinogen. Chronic exposure through inhalation and oral ingestion are related to liver damage and other harmful effects. Vinyl chloride is also one of the 188 hazardous air pollutants listed under the Clean Air Act Amendments. The administrative code has established limits of 0.2 micrograms/liter in groundwater, and in almost all the monitoring wells at the site, the enforcement is being exceeded. Therefore, the assessment of an effective technology is crucial to mitigate any human risk associated with pollutants exposure.
This capstone project has investigated the feasibility of emulsified zero valent iron (EZVI) as an alternative technology to reduce chlorinated solvents at the site. The use of EZVI has received increased attention, since it has shown tremendous promise in the environmental sector for soil and groundwater remediation. EZVI has a number of features that make it ideally suitable for remediation, such as biotic and abiotic degradation, and ability to sequester chlorinated hydrocarbons. The primary application of the EZVI technology is treatment of DNAPL source zones, but it is also capable of treating dissolved-phase chemicals. This study reviews the current knowledge of emulsified zero valent iron and its performance in degrading chlorinated hydrocarbons. The aim is to provide a comprehensive review of documents published by the United States Protection Agency, the National Aeronautics and Space Administration, research papers, conference proceedings, journal articles, patents, and a variety of peer reviewed documents and books focused in soil and groundwater remediation. This analysis of relevant literature was leveraged to present the feasibility analysis of EZVI as an alternative remediation technology at the Presidio Square Apartments Complex.
Abstract: Increased environmental restrictions and rising energy costs have reinforced the need to develop technology that can produce electricity from digester gas at a wastewater treatment facility and reduce air emissions of methane (CH4) and carbon dioxide (CO2). Fuel cells provide the potential for clean and efficient distributed power by combining hydrogen with oxygen in an electrochemical process to produce electricity, heat and water. They have the ability to exhibit an electrical efficiency in excess of 60 percent and overall energy efficiency of 85 percent when waste heat is recovered in a cogeneration, or combined heat and power, configuration. There are currently six main types of fuel cells; however, molten carbonate fuel cells (MCFCs) are practical for wastewater treatment facilities. They can achieve high electrical outputs and don’t require significant derating of power output due to the dilute methane content of the digester gas. In addition, the CO2 component in digester gas is beneficial for the cathode reaction in the MCFC.
The City of Waukesha’s Wastewater Treatment Facility (WWTF) uses anaerobic digestion to reduce volatile solids (VS) and stabilize the biosolids produced. The average bio-gas production at the Waukesha WWTF during 2005 was 110,200 cubic feet per day, which results in 2,662,700 Btu/hr of renewable bio-gas energy. Currently, some of the digester gas is used to fire boilers to produce steam for heating, while the rest of the gas is flared to avoid odors. However, at the current rate, Waukesha could install a 250 kW fuel cell to harvest the digester gas produced at the facility.
FuelCell Energy, Inc. is a corporation that manufactures MCFCs which can operate on digester gas. They currently have a direct fuel cell (DFC® 300MA) that can produce 250 kW of electrical energy and recover 300,000 Btu/hr of thermal energy while operating on natural gas or digester gas. If the DFC® 300MA fuel cell were implemented into the Waukesha WWTF, there is the potential to produce approximately 1,809,978 kWh/year and 23,717 therms/year of thermal energy for digester heating. In addition, by using the fuel cell as an alternative source of energy, there would be a combined reduction of approximately 5,820,900 lbs. of air and greenhouse gas emissions from WE Energies, the local electrical provider, and the WWTF, in which 5,790,000 lbs. would be CO2.
At the current time, installing the DFC® 300MA fuel cell at the Waukesha WWTF is not feasible. The estimated cost of installing fuel cell power plant is $1,260,000, with operating and maintenance (O&M) costs of approximately $25,000 per year ($0.014/kWh). Along with the annual O&M costs, the fuel cell stack module has to be replaced five times during its 30-year life to ensure maximum performance, and this is estimated to cost $300,000 each replacement. In addition, by incorporating the fuel cell into the facility, some of the digester gas previously used as fuel for building and digester heating will be consumed by the fuel cell. As a result, an additional 30,000 therms of natural gas will have to be purchased from WE Energies each year, which will cost an estimated $28,370 per year. Therefore, the net present value (NPV) of installing of the DFC® 300MA fuel cell power plant would be -$1,370,000, assuming an interest rate of 6 percent. The negative NPV suggests that this project is not feasible at the present time, mainly due to the high capital cost of the fuel cell power plant and fuel cell stack module, and the number of times the stack has to be replaced over the life of the fuel cell.
Abstract: As personal and industrial demands for energy grow, so do the demands for new and readily available forms of energy and technology. Through the use of what are called “renewable” energy sources, industries have found both environmental and financial benefits. One specific benefactor of renewable energy sources are Publicly Owned Treatment Works (POTW). One such POTW, the Fox River Water Pollution Control Center (FRWPCC) located in Brookfield, Wisconsin, has shown renewable energy potential from the bio-gas produced in the anaerobic digestion complex. However, currently only half of this renewable resource is being utilized using gas boilers, while the unused bio-gas is waste flared.
This study focuses on the utilization of the bio-gas produced at the FRWPCC using Stirling external combustion engines. This technology offers two main forms of energy to the plant. These two forms are electrical power and heat, which can be used for both the plant mechanical processes and building heat. The specific Stirling model studied is the STM Power Model 260, 55 kilowatt-hour PowerUnit. The main focus of this study is to see if implementing the Stirling units will provide enough savings to the FRWPCC to cover the initial capital costs of construction. The conclusion of this study finds that there is definitely enough evidence to show that the implementation of the Stirling external enging technology would be feasible in both bio-gas utilization and financial savings to the plant.
Abstract: Spent brewers grain is sold to local farmers as a feed product, and most of the breweries’ spent grains are taken off-site as a wet slurry. That slurry is 15% TS, and of the 15% TS, 95% are VS. Breweries have a high degree of focus on sustaining spent grain revenue, and any changes to the net worth of the spent grain are noticed immediately. Currently spent grain revenue is trending downward at most breweries. The net worth of the spent grain is decreasing due to the introduction of corn gluten, a byproduct produced from ethanol facilities, and the reduction in the number of large cattle herds across the United States. These current trends will cause the spent grain net worth to decrease further in the future. In light of these trends, a major brewing company in the Midwest launched an investigation into ways they can sustain or increase their spent grain revenue.
In association with the Milwaukee School of Engineering, the brewing company launched an investigation into the applicability of anaerobically digesting spent grain to produce biogas as an alternative fuel source. The Biochemical Methane Potential Test was done to determine the amount of methane that can be produced per gram of spent grain VS. Bench-scale test results showed that 0.430 ± 0.027 liters of methane was produced pergram of spent grain VS. There was also a 41% reduction of TS and a 59% reduction of VS observed during the test. An estimated 2.4 million therms can be generated per year from spent grain anaerobic digestion at each brewery. Hydraulic retention times were as follows for spent grain VS added: 2 g VS/L ≅ 14 days; 5 g VS/l ≅ 25 days; 7 g VS/l ≅ 27 days.
Based on the promising bench-scale test results, a present-worth cost analysis was performed to evaluate the economic feasibility of implementing full-scale anaerobic treatment of spent grains at all of the brewing companies’ breweries located across the United States. Some breweries consume coal as their main fuel source, and as a result of the low cost of coal the applicability of increasing spent grain revenue at these breweries by anaerobically digesting spent grains to produce biogas was not economically attractive. The other breweries consume natural gas as their primary fuel source. Anaerobically digesting spent grains at these breweries to produce biogas could significantly increase the net worth of the spent grains. The natural gas consuming breweries where this process would be most applicable would be the Brewery #1 and Brewery #2. The Brewery #1 had an ROI of 13.16% and an NPV of $1,116,267 (with an interest rate of 5%), and the Brewery #2 had an ROI of 10.90% and an NPV of $598,184 (with an interest rate of 5%). The NPV and ROI figures are expected to increase in the future as a result of the expected net revenue decrease of the spent grains and the expected increase of natural gas prices.
Abstract: Frost Farms is an 800-cow dairy farm located in Waterford, Wisconsin. Currently, animal waste at the farm is collected below the housing and milking parlors and stored until it is landspread. Due to strict regulations, landspreading can only be done twice a year.
There are many possibilities for treating the animal waste at Frost Farms to produce more usable byproducts. One process is that of thermophilic anaerobic digestion of the waste followed by ultrafiltration solids separation. An analysis of the equipment costs, utilities costs, and the net present value of installing such a system was performed. Other factors considered in the analysis were the beneficial byproducts of using the system–including biosolids bedding material, biogas for energy production, and cleaner effluent that can be used in a variety of ways.
The analysis found that while the costs of installing a thermophilic anaerobic digestion and ultrafiltration system are significantly higher than simply storing the waste until it is used, there are a variety of benefits that cannot be measured quantitatively. Some of these quantitative benefits are proactively meeting stricter waste storage and land application regulations, being self-sufficient on biogas energy and supplying surrounding areas with a renewable energy source. The high costs of the system may be minimized by installing the system in phases, starting with the anaerobic digestion and then adding the ultrafiltration process.
Abstract: The purpose of this project was to begin to address the following issue. The wastewater treatment plant (WWTP) in Waukesha, Wisconsin disinfects their effluent during summer months using ultraviolet (UV) radiation. This disinfection is a requirement as per their discharge permit issued by the Wisconsin Department of Natural Resources (WDNR). During exceptionally wet weather conditions, the capacity of the UV disinfection process is exceeded, and the plant must divert a portion of the flow around the UV process. That diverted portion of the water remains undisinfected as it is discharged to the neighboring Fox River. Diverting any portion of the plant’s effluent flow around the disinfection process during the disinfection season is a violation of the plant’s discharge permit. The plant has been issued a period of time to study the effects of the UV system and the effects their effluent has on Fox River water quality in order to make a determination as to the need to alter the UV system. The purpose of this project was to begin to address the above described situation.
The effectiveness of the UV system at Waukesha is based on the concentration of fecal coliform bacteria — fecal coliform being an indicator of human fecal pathogen pollution in water — in the effluent before it is discharged to the Fox River. This project involved the development of a fecal coliform monitoring program to analyze how the Waukesha plant is contributing fecal coliform contamination to the river. A series of locations — upstream of the plant, at the plant outfall, downstream of the plant, and the whole effluent — were sampled on 10 separate occasions, and tested as per standard water and wastewater examination method 9222 for fecal coliform colony counts. A laboratory was assembled in the MSOE CC-50 MSEV Laboratory, and the testing and analysis of the water samples were conducted there.
It was determined that the data collected were useful, but inconsistent with results that were expected. It was found that the Waukesha plant, on all occasions, was contributing fecal coliform pollution to the Fox River. It was found that there was little correlation between the flow of the river and concentrations of fecal coliforms. And it was found that photoreactivation and regrowth of pathogens may be occurring, but the data are too inconsistent, and additional sampling locations, tested during the disinfecting season, would likely be needed to make a more firm determination of this activity. The sampling and testing were all conducted during the nondisinfection season. Therefore, to make a determination of the necessity of alteration to the current UV system at Waukesha, a more extensive monitoring program much like the one employed by this study, with modifications, is needed to collect more concise data during both disinfecting and nondisinfecting seasons, and during a variety of flow conditions.
Abstract: In 2000, the Milwaukee Metropolitan Sewerage District (MMSD) chose the Caddy Vista Sanitary District (CVSD) and seven other municipalities to receive funds for demonstration projects aimed at reducing rain-derived infiltration and inflow (RDI/I in the sanitary sewer system. The CVSD project goals for Element 1 were to demonstrate the effectiveness of past sanitary sewer rehab projects in terms of annual maximum daily and annual average daily RDI/I reductions, and also to evaluate the cost-effectiveness of those rehab projects. Past sewer rehab projects included the work completed from 1995 to 1997, based on the 1994 Limited Sanitary Sewer Evaluation Survey (LSSES) recommendations. These projects included private sanitary lateral and public sewer main relay, and manhole and manhole cover replacements. To measure project effectiveness in terms of annual maximum daily RDI/I reductions, a pre- and post-rehab rainfall/RDI/I regression model was developed. When the models were compared to each other, approximately a fifty-percent reduction in annual maximum daily RDI/I was observed. Annual RDI/I volumes were reduced by 34 percent. This means two things: 1) Upgrades to the main line sewer and the lift station will not likely be required for annual maximum daily RDI/I. 2) Available capacity can be used for future growth of the CVSD.
Cost-effectiveness was based on comparing the initial investment of the sewer rehab projects to the benefits of RDI/I reduction. Results showed that peak-day RDI/I reductions warranted the sewer rehab costs during periods of 15-year rain events, or greater. While this may not seem significant, it is considering that the larger or less frequent rain events cause the most problems and damage. Future rehab projects will concentrate more on reducing average daily RDI/I, as well as the peak-day RDI/I for more frequent (or less than 15-year) rainfall return periods, and will be evaluated in terms of public versus private sources. In addition to these cost savings, the CVSD has already realized a 34 percent savings on annual operation and maintenance (O&M) costs associated with transporting and pumping RDI/I.
Abstract: Stormwater infiltration basins reduce stormwater runoff and recharge groundwater, in accordance with best management practices required by the Clean Water Act of 1987. Wisconsin Administrative Code NR 151 as well as guidance documents produced by the Wisconsin Department of Natural Resources suggest procedures for sizing stormwater infiltration basins. The purpose of this project is to model stormwater infultration at an existing rain garden, and use that data to evaluate and enhance current design methodologies.
Two storm events were modeled using a spreadsheet model developed for this project and RECARGA, which is a computer program developed by UW-Madison Civil and Environmental Engineering Department. The results from both models were used to redesign the rain garden so that all inflow would infiltrate into the subsurface. Basin sizes and costs were then compared.
The rain garden redesigned in accordance with RECARGA (default infiltration rates) showed the lowest design, construction, and overall total net present worth costs over a ten-year period. Darcy's Law showed the highest design and construction costs, but lowest maintenance net present worth costs over a ten-year period. RECARGA (Darcy's Law saturated hydraulic conductivities) showed the highest maintenance net present worth and overall net present worth costs. Overall, the rain garden designed in accordance with Darcy's Law from the spreadsheet model was smaller than those designed in accordance with RECARGA, and may become more cost effective if land prices increase.
Abstract: The overall goal of this study was to quantify costs and environmental impacts from a policy to require 100% of the households and businesses to process food waste through a Food Waste Disposer (FWD) for the City of Racine, WI. The current (baseline) situation is that approximately 60 per cent of Racine’s households have a FWD. The major objectives for this study were: to determine the impacts if the solid waste collection frequency was reduced to every other week from weekly; estimate the costs and or cost benefits to the City of Racine; determine the impacts of the additional food waste at the wastewater treatment plant; and compare the environmental effects if every home and business had a food waste disposer.
The city of Racine DPW Solid Waste and Wastewater Utility managers were contacted to obtain operational parameters and costs for the present situation in Racine. This data was compared to national data from other sources including Franklin Associates, US EPA, BioCycle and others. Hypothetically, if all of Racine’s homes had a food waste disposer installed, the solid waste collection frequency could be reduced from every week to every other week. The reduced collection frequency, employee reduction, reduced mileage and fuel costs would reduce the solid waste collection costs by $335,573 per year for the city. This reduced mileage would reduce truck emissions by 26 per cent, resulting in 429,868 pounds or 215 tons of reduced air emissions. Routing the additional food waste to the POTW, considering increased operational costs, which would be offset by increased biogas production, would result in a net cost increase at the POTW of $56,723. The overall resultant cost savings to the city of Racine would be $278,850 annually.
Abstract: Chlorinated solvent contamination was identified in the groundwater during a divestiture investigation at a former Allen-Bradley Company manufacturing site in Hato Rey, Puerto Rico. Currently, the site is operating under an approved Remediation Action Plan with the Puerto Rico Environmental Quality Board to clean up the site with a traditional pump-and-treat system. The system has been installed and began operation in January 1999. Due to the limitations of the treatment and the long time frame associated with pump-and-treat technology, alternative remediation approaches were investigated. This project focused on the investigation of Monitored Natural Attenuation (MNA) as an alternative remediation approach.
Capstone objectives are: 1. Analyze the potential for monitored natural attenuation to achieve the site-specific risk-based clean up goals for 1,1,1-Trichloroethane (TCA) and 1,1-Dichloroethene (1,1-DCE). One expected degradation pathway for TCA is: TCA > 1,1-DCE > Vinyl Chloride > CO2 2. Compare the cost difference between monitored Natural Attenuation and Traditional Pump-and-treat remediation strategies.
Capstone Conclusions are: Monitored natural attenuation is a technically feasible and cost effective remediation strategy for the Hato Rey, Puerto Rico site. 1. 1,1,1-Trichloroethane and its daughter products had reduced in mass and concentration prior to and as a result of active pump-and-treat remediation. 2. Detailed analyses and groundwater chemistry show that attenuation is occurring in the uppermost aquifer and is an effective remedial measure for impacted groundwater. 3. Transport modeling shows the nearest receptor cannot be impacted in the future. Proposed risk-based cleanup goals are protective. 4. Over the life of the project, monitored natural attenuation will potentially reduce the cost of remediation by $450,000.
Abstract: The Waukesha Wastewater Treatment Plant (WWTP) serves approximately 65,000 residents with an average daily flow of 11.0 million gallons per day. Wastewater is generated by residential, industrial, and commerical customers. The City also accepts wastes by truck through the Hauled Waste Program. Currently the Waukesha WWTP flares all of the biogas produced in the WWTP’s anaerobic digester except for the biogas produced during the winter months. In the winter, the plant utilizes a small portion of the biogas to directly power the plant’s boilers and produce heat. This biogas can be used to produce electricity and reduce pollution from an energy consumption standpoint. The WWTP could use its biogas either to power the wastewater treatment plant or to return electricity to the grid, and thus benefit from incentives offered for renewable power or to meet a state Renewable Portfolio Standard.
In this report, a Capstone CR65-ICHP Micro Turbine cogeneration system will be compared to the current, traditional process of flaring biogas. Biogas must be flared to meet the plant’s air permit, which is regulated by the Wisconsin Department of Natural Resources because of the biogas’ high methane content. Methane is a greenhouse gas that has an impact 21 times greater than an equivalent amount of carbon dioxide. Flaring the biogas converts the methane primarily into heat, light, and carbon dioxide. To further reduce greenhouse gas emissions, the biogas can be utilized to create energy when ignited. The energy produced from the previously wasted biogas will prevent pollution produced from the local utility, WE Energies, by lowering the energy demand of the community and reduce approximately 3.63 million pounds of emissions from their coal fired plants. The WWTP will produce electricity instead of continuing to be a customer that solely consumes energy.
Three microturbine cogeneration system alternatives were evaluated in this report. Alternative 1 utilizes a four microturbine system to operate 24 hours a day on the WWTP’s average of 142,000 ft3/day of biogas with a lower heating value of 579.9 BTU/ft3 from four anaerobic digesters. Alternative 2 consists of a larger, eight microturbine cogeneration system, operated only during on-peak hours to take full advantage of WE Energies buyback rate. This alternative would involve the installation of a 120,000 cubic foot membrane biogas storage system. Alternative 3 consists of a zero carbon, five microturbine system, which sequesters the microturbine exhaust with an algae growth-harvesting system. The algae biomass would be harvested several times a day and increase the amount of biogas produced in the digesters.
The most feasible option for the Waukesha WWTP was determined to be Alternative 1. This option costs approximately $1.3 million with a simple payback period of 14 years. When considering a 20 year facility plan, Alternatives 2 and 3 also generated a viable payback period of 17.3 and 14.5 years, respectively.
Abstract: The Menomonee River Valley (Valley) of Milwaukee, Wisconsin is undergoing a transition phase from a primarily industrial setting to a more diverse setting including entertainment, commercial, and industrial activities. The Valley’s subsurface is comprised of buried organic-rich estuarine deposits which have become a potential source for significant methane generation. As redevelopment continues in the Valley, the potential for methane accumulation at sites has become a safety concern and, therefore, a design consideration. The purpose of this paper is to 1) provide an evaluation of the methane concentrations and distribution in the Valley, 2) provide designs for the active methane abatement system and passive methane abatement systems as they apply to select sites in the Valley, and 3) provide a cost evaluation of each abatement system design. It is the author’s intent to have the work presented in this paper provide a general awareness and understanding of methane generation in the Valley and to facilitate the methane monitoring and mitigation process for future developers in the Valley.
A methane monitoring event was conducted at 40 monitoring points located throughout the Valley to evaluate the vertical and lateral distribution of methane. Methane concentrations were found ranging from zero percent to 100%; the area exhibiting detectable methane concentrations is primarily located in the eastern and central portion of the Valley, not on the bluffs surrounding the Valley. Additional field studies were also conducted to determine the methane generation rates and soil gas pressures within the Valley. Based on an evaluation of these data, two study sites were selected for the development of a design for a methane abatement system.
Several designs were considered including a passive methane abatement system; an active methane abatement system; the use of captured methane gas as an energy source; excavation of the methane-generating source; and innovative architectural designs. A site-specific design and cost evaluation for the passive and active methane abatement systems were completed for four building footprint dimensions. All other alternatives were evaluated qualitatively.
The active methane abatement system was determined to be the most expensive design and ranged in cost from $6.50 per square foot for smaller building dimensions (20,000 ft2) to $4.50 per square foot for larger building dimensions (50,000 ft2). The passive methane abatement system design was similar to the active system except no vacuum extraction equipment was necessary. Costs for the passive methane abatement system ranged from $5.00 per square foot for smaller building dimensions to $4.00 per square foot for larger building dimensions. Although the potential for methane accumulation beneath a building may pose a risk to human safety, engineered systems can be implemented to facilitate the development process. The costs of the engineered systems can be insignificant relative to the total development cost of a parcel (on the order of 4% to 6% of the total development cost).
Abstract: The purpose of this paper is to review what effect denying the presidential permit required to allow a border crossing between Canada and the United States (U.S.) for the Keystone XL (KXL) Pipeline had on potential life-cycle greenhouse gas (GHG) emissions from the West Canada Sand Basin (WCSB) crude oil. The focus of the evaluation is on the potential GHG emissions predicted if the KXL Pipeline were constructed and operated versus potential GHG emissions for other transportation routes without the KXL Pipeline. Current and projected WCSB crude oil production rates and exports are also reviewed and compared to rates and projections at the time of the presidential permit review in 2013. By comparing and contrasting the GHG emissions from alternative modes of transportation and reviewing WCSB crude oil production rates and exports, the paper evaluated the intended and unintended consequences of the decision to prevent construction of the KXL Pipeline as it related to GHG emissions and climate change.
The results of the evaluation determined that pipeline transport produces the least amount of GHG emissions for transporting WCSB crude oil from Canada to the Gulf Coast. However, the difference between GHG emissions of the different modes of transportation is small. Additionally the WCSB crude oil production rates and exports to the U.S. continued to increase in the near term despite lower costs per barrel of crude oil and the denial of the KXL Pipeline border crossing permit.