World Environmental and Water Resources Congress 2016: Environmental, Sustainability, Groundwater, Hydraulic Fracturing, and Water Distribution Systems Analysis

FAU has pioneered the advancement of landfill leachate treatment systems using advanced oxidation processes such as TiO₂ photocatalysis and electromagnetic oxygen/hydrogen (EMOH) technology at laboratory scale, which has led to the development of reactor prototypes for pilot scale testing. If a relatively inexpensive way to pretreat leachate and safely dispose of it onsite can be found, the potential for zero liquid discharge at certain landfills may be achievable. In this study, the highest performing reactor configuration was TiO₂ adsorption/settling pretreatment followed by the UV/TiO₂ falling film (150-W) + EMOH reactor, which achieved a process removal efficiency of 63% COD and 53% ammonia, in 8 hours of treatment. BOD tests indicate that complete mineralization is occurring, and kinetics testing results suggest simple process enhancements may achieve stringent surface water discharge targets.

A closed landfill site has still to be managed for several decades in aftercare operation. Current studies predict that for almost all landfill sites the aftercare operation has to be prolonged for several decades in contrast to previously made assumptions. This means higher costs and economic problems for owners as the provision made cannot cope. To minimize aftercare costs, owners require a decision support tool to define optimal solutions and measures. Due to the interconnections between the amount of leachate and its treatment and transportation only an integrated and interdisciplinary approach is able to cope with the different expectations to a solution. Therefore, a group of experts from different disciplines was assembled to enable integrated decision support in order to find an optimal solution for a demonstration case, ranking scenarios using a decision support framework. The robustness of this ranking was also tested with a sensitivity analysis. The result of this decision support process with the involvement of all necessary stakeholders showed that for this case study the solution of vehicle transport of the leachate to a nearby wastewater treatment plant and subsequent treatment there using a side stream deammonification plant is preferable.

The environmental exposure to heavy metals is a well-known risk factor for several gastrointestinal (GI) disorders. The present study was conducted at Maheshtala textile, bleaching dyeing industrial area for two consecutive years (2012–2013) to study the impact of bleaching and dyeing effluent discharge on accumulation of heavy metals in canal water, soil, fruits, and vegetable as a part of environment management of the area and ecological planning. During experiment, we investigated the levels of heavy metals (Pb, Zn, Ni) in effluent of small bleaching and dyeing units in soil, fruits, and vegetable samples of Maheshtala region of South 24-Pargana district of West Bengal, India, where gastrointestinal disorders have become an epidemic dimension among the people inhabiting that area. Heavy metals contents of the samples were determined by atomic absorption spectrophotometer. Three heavy metals (Pb, Cd, and Ni) were present in 2–40 fold higher concentrations whereas zinc level was present in 50 fold lower concentrations in vegetable and fruits. The higher concentrations of heavy metals in aquaphytes, vegetables, and fruit samples tested were found to be strongly correlated with the concentrations of metals present in soil or water matrix contaminated with effluents of bleaching and dyeing industries. The soil, fruits, and vegetable samples contained potentially toxic heavy metals in such high levels that these elements could be related to higher prevalence and/or vulnerability of GI disorder, ulcer, and cancer risks in Maheshtala region under study.

Autumn olive (Elaeagnus umbellata) is an exotic and invasive species that was used extensively as an erosion control plant along many highways in the Midwestern United States during the last century. Due to its invasive and strong nitrogen-fixing abilities, it aggressively spread outside its intended use area. Unfortunately, control management programs by many organizations have failed to control its spread. Currently, it exists in dense patches over vast areas in the Midwest. A by-product of its nitrogen-fixing is nitrate. Nitrate is regulated in drinking water for its known toxicity to human and animal infants. This study assesses the leaching of nitrate from autumn olive infested areas into its surrounding environment. Soil and groundwater samples were collected from areas infested with autumn olive and from paired nearby grass plots in Indiana and Michigan between 2009 and 2014. The samples were analyzed for nitrate, ammonia, and total nitrogen in addition to other relevant chemical and physical soil and water parameters.A matched pairs t-test indicates that the concentration of nitrate is significantly higher (p-value=0.0002) in the soil and groundwater beneath the autumn olive infested areas compared to their control areas. The nitrate concentrations in soil water of many infested areas exceeded the EPA’s MCL of 10 mg/L and were over ten times higher compared to their control areas. The data also showed varying seasonal nitrate leaching levels.

Clogging of leachate collection systems can cause catastrophic failures in landfill operation. The primary cause of clogging is calcium carbonate precipitation and formation of clog particles inside the pipe around a nucleus of silt, sand, and other particles, although the trigger mechanism is not known. This study focuses on quantifying the effectiveness of electronic scale control to reduce the clog formation within the pipe network. A field scale model (40 × 20ft) was constructed, featuring side-by-side flow of composite leachate treated electronically in one side and untreated leachate flow in the other side. Preliminary tests suggest that electronic scale control system does not have any statistically significant effect on water quality parameters. Therefore, long term leachate circulation tests using our field scale model to collect solids in the y-strainers and spool pieces will allow the researchers to quantify the amount of solids captured and compare the crystalline structures using XRD/XRF analysis, using pure crystal spectra of calcite and aragonite as a reference.

Fecal indicator organisms (FIOs) have been monitored in public near-shore Florida waters by Florida Department of Health (FDOH). This research used publicly-available FDOH data to characterize the incidences when FIOs exceeded federal health guidelines for 17 beaches, in nine counties distributed along Florida’s coast, collected weekly over about nine years (January 2004–October 2012). The research selected, in each county, two beaches with the greatest number of exceedances—not representative of the Florida coastline, but those where the presence of FIOs appears to have been most frequent. The objective was to determine whether, in Florida’s most-impacted waters, sampling strategies can be judged sufficient to reliably detect exceedances in time to warn beachgoers of potentially unhealthful conditions. Results showed great variation among beaches: 5 of 17 analyzed beaches showed exceedances in fewer than 8% of all weeks sampled; 3 others showed exceedances in more than 30% of weeks sampled. Most (9) were in the 10–20% range. For a few beaches, data allowed assessment of duration of high-FIO episodes, suggesting most (>60%) persist for two days or less. Conclusions suggest that, during this 9-year period, sampling may have failed to detect a substantial number of incidences when FIO concentration exceeded health-based guidelines.

Excess nutrients in stormwater runoff may lead to eutrophic areas, negatively impacting ecosystems, social, and economic well-being. A solution to remove nutrients such as nitrogen from stormwatermay be the use of bioretention, a low impact development (LID) technology. However, conventional bioretention systems are not designed specifically to remove or recover nitrogen. Nitrogen removal in a bioretention system can be improved by modifying the conventional system to include an internal water storage zone (IWSZ) that contains an electron donor (e.g., organic carbon source from wood chips) to enhance denitrification. This study provides evidence that modified bioretention systems are a promising LID technology for reducing nitrogen loads to downstream waters. The study demonstrates the nitrogen removal performance of field-scale conventional and modified bioretention systems in the subtropical climate of Tampa, FL. Both systems are similar in design except the modified system has an upturned elbow and is 0.3 mdeeper to accommodate the IWSZ. Initial results show greater total nitrogen mass removal in the modified (73%) compared to the conventional (62%) system. This is likely due to the enhanced denitrifying conditions and increased hydraulic detention time associated with the IWSZ. Furthermore, nitrogen removal in the modified system was observed to be greater during the initial period of a storm event compared to the final period. The results also demonstrate that careful attention to design considerations can reduce nitrogen removal performance variability, which has been observed in prior modified bioretention studies.

The purpose of this review paper is to summarize the literature on the behavior and performance of permeable asphalt (PA), examine the feasibility of applying PA to arterial streets in cold climates, and present recommendations to improve the success of PA in wider applications. The review presented here required examining existing data sources and scientific journal papers, along with interviewing professionals who have conducted studies or dealt with PA in a variety of locations. The conclusions and recommendations drawn from this evaluation are intended to be guidelines for agencies looking to potentially apply PA to arterial streets in cold climate regions. Literature selected for review included PA sites that had several of the following characteristics: high volume traffic, cold climate region, abundant annual snowfall and extreme average temperatures, used sand, salt, plows, and deicers in winter maintenance activities, and experienced studded snow tires. In addition, sites reviewed also had subgrade soils with adequate infiltration rates, deep groundwater, relatively little annual precipitation, and area frost depths of 24 in. below finished grade. It was not possible to have each case study reviewed address all criteria, but all of these factors were considered important to the review to provide accurate literature comparison, and they allowed us to ascertain and present general behavior and patterns regarding PA. In addition, a summary of recommendations on the application of PA to arterial streets in cold climates with respect to water quality treatment performance, hydrologic performance, materials and durability, and maintenance practices are also presented.

Substantial savings in operations can be achieved by reducing the amount of wastewater that must be pumped and treated in sewer collection systems. There are three components to wastewater flows: base flow of sewage, infiltration, and inflow. Utilities have long dealt with the infiltration and inflow (I and I) issues in their system by televising their pipes and identifying leak points, but this primarily addresses only infiltration. Inflow, which creates hydraulic issues during rain events, leads to sanitary sewer overflows and can subject the utility to fines from regulatory agencies, and create publicity and legal issues when houses are damages from sewage backing up into houses and businesses. As a result, dealing with the inflow portion of Iand I isimportant to controlling cost, wear, and risk. Inflow often can be identified and corrected easily, and removing the inflow portion from I and I, often leads to a more focused plan for infiltration correction program, thereby saving money. The intent of this paper is to provide a guideline on dealing with inflow identification and removal, using a pair of utility examples, and showing the resulting benefits on the infiltration correction that resulted.

Anaerobic polycyclic aromatic hydrocarbons (PAHs) biodegradation is highly important for treating PAHs-contaminated aquifers without oxygen. The aim of this study was to investigate the biodegradation characteristics of benzo(a) pyrene (BaP) in aqueous solution by C. cellulans CWS2 under anaerobic conditions. The degradation characteristics include different temperatures (20–35°C), different pH values (7.0–12.0), and different BaP concentrations (0, 2.5, 5.0, 10.0, 25.0, 50.0 mg/L). The behavior after adding other PAHs and an additional carbon source was also evaluated. C. cellulans CWS2 could degrade BaP at a concentration of 25.0 mg/L in the temperature range of 20–35°C, and approximately 58% of the biodegradation was achieved at 35°C within 10 days at a natural pH. The alkaline conditions of 7.0–10.0 favor biodegradation and reached their highest point at pH 10.0. A BaP concentration of 10.0 mg/L with an initial value of 1.85 at OD600 nm for degradation of the BaP system and a pH of 7.0 was the most ideal condition for obtaining the highest degradation ratio, which was above 80% or higher. C. cellulans CWS2 could degrade phenanthrene and pyrene at the same time, and a low concentration of phenanthrene and pyrene did not reduce BaP degradation. BaP metabolism by C. cellulans CWS2 under anaerobic conditions was the sole carbon and energy source even when there was an additional available carbon source.

On February 2, 2014, the failure of a storm water pipe under the primary coal ash pond of the Dan River Steam Station owned by the Duke Energy released an estimated 39,000 t of coal ash and 27 million gal.of pond water into the Dan River near Eden, NC. Together with the coal ash, a number of contaminants absorbed on the particles and dissolved in the pond water were also released into Dan River.One dimension numerical model, CCHE1D, developed by the National Center for Computational Hydroscience and Engineering, the University of Mississippi, was used to simulate the fate and transport of contaminants in Dan River and Kerr Reservoir. The entire study reach extends from the USGS Wentworth gauge on Dan River, about 22 km upstream of the spill location to the Kerr Dam, about 182 km downstream of the spill location. Transport and fate simulations in the water column and in the bed were carried out for arsenic (As), and selenium (Se). Good agreements were obtained by comparing the simulation results with EPA’s field observations. The simulation results show that concentrations of those selected contaminants in water column and bed sediment are below the EPA screening values after five months of the spill accident. It is also found that most of the chemicals released to the river will eventually deposit in the bed of Dan River and Kerr Reservoir. The simulation results provide useful information for water environment evaluation and water resource management.

Coal ash is the second largest industrial waste in the US with approximately 130 million t produced per year.Only about 45% of the coal ash is recycled. The remaining amount of coal ash waste is stored in containment cells and ponds, which are generally located at the proximity of rivers and other surface water resources. Accidental release of coal ash and associated toxic chemicals into water resources due to failure of containment structures may pollute the environment and harm the aquatic ecosystem. Numerical modeling can be a useful tool to predict the movement of the coal ash and associated chemicals in surface flows for mitigation, incident response and recovery efforts. This paper presents the two-dimensional modeling of the accidental spill of coal ash into the Dan River, NC, on February 2, 2014, using hydrodynamic, sediment transport and pollutant transport modules of the CCHE2D software developed at the National Center for Computational Hydroscience and Engineering, The University of Mississippi. The transport and fate of coal ash and the two associated contaminants, arsenic and selenium, during the first 32 days after the spill were modeled over a 24.2 mi-long (38.9 km) reach of the Dan River extending immediately upstream of the spill site to the Schoolfield Dam in Virginia. The simulations revealed what happened physically and chemically in the river channel immediately after the incident in the river channel. The results were validated using available data and field observations.

Silver nano particles (NPs) are the largest and fastest growing category of nanotechnology-based medicines and consumer products. Silver can be highly toxic to some aquatic organisms and as an antibiotic may also damage or alter the most abundant and vulnerable beneficial microbial communities in the environment, such as Gordonia sp. However, considering the complex chemical background of natural surface water, the silver NPs can have complicated processes with the background chemicals such as chloride, surfactants, and dissolved natural organic matters (NOM). The results show that the average particle size and dispersivity of silver NPs play an important role in the toxicity of silver NPs. Aggregation is signification for silver NPs in DI water. However, the presence of 3 mM sodium dodecyl sulfate (SDS) or 8 mg/L Suwannee river NOM reduced the aggregation of silver NPs apparently. Overall, the degree of aggregation increased in the order of 3 mM SDS < 8 mg/L NOM < DI water <10 mM NaCl <10 mM NaNO₃. When the silver NPs had an elevated concentration from 7.3 to 29.2 mg/L in DI water, the log inactivation of the Gordonia sp. increased from 0.16±0.04 to 0.45±0.13. However, the log inactivation rate increased to 1.40±0.26 and 0.87±0.12 in the presence of 3 mM SDS or 8 mg/L NOM, respectively with 29.2 mg/L silver NPs. On the other hand, 10 mMNaCl reduced the log inactivation rate to 0.07±0.07 due to causing moderate aggregation of silver NPs and forming likely less toxic silver chloride species.

A rising demand for electrical energy with a diminishing supply of fossil fuels as well as growing concern for the environment has led to an interest in renewable energy. Photovoltaics have grown in popularity as a renewable energy source and lots of research has been done to improve these systems. One of the ways to improve a photovoltaic system is to improve the inverter. A common inverter set-up with photovoltaic systems is a string inverter system, where panels are connected in a string to one or more inverters. One way to improve photovoltaic panels is to use micro inverters, which is a system of panels where each panel has its own inverter. Past research has shown that micro inverter systems are less negatively impacted by shading, and are safer, cheaper, and easier to install than string inverter systems. This paper investigates and compares the efficiency of these two inverters. The micro inverter was found to be approximately 5–8% more efficient than the string inverter.

Many of water conflicts or inefficiency arise by self-interest seeking behaviors of institutional stakeholders in water sector. While the major goal of these institutional stakeholders is to maximize their own revenues, they definitely prefer to consume water resources with less cost rather than more expensive ones. From the perspective of regional water management, water resources with less cost are not always the first priority to use, because of hydrological condition and regional heterogeneity. The water supply in Taipei metropolitan area, including, Taipei City, New Taipei City, and part of Taoyuan area, is a good example of this case. Two major reservoirs, Feitsui and Shihmen, supply water to this area. In this area, Taipei City Water Company cooperates with Feitsui Reservoir to be responsible for water supply of Taipei city. Taiwan Water Company is for New Taipei City and Taoyuan with water from Shihmen Reservoir. Comparing these two reservoirs, the ratio of water supply to reservoir capacity for Shihmen is around 4 to 5 while it is less than 1 for Feitsui. It implies the inefficient water allocation for this region. A new water transfer project, BanHsin Division Plan, has been constructed, which deliver water from Feitsui to Taiwan Water Company’s facility to reduce the loading of Shihmen. Although the capacity of BanHsin Diversion Plan is 530,000 t/day so far and will expend to 1,010,000 t/day within a few years, it has never been operated with full capacity. The reason is that water from Shihmen is cheaper for Taiwan Water Company. To solve this problem, one possible is to adjust the financial framework of water pricing. This study will try to review the institutional issues of water allocation in Taipei area. We will try to propose incentive strategies for the potential problem, which is expected to be more socio-politically acceptable comparing to traditional top-down, central control approaches. Besides, a water allocation model developed by WEAP, will be also used to evaluate the consequence of the strategies proposed by this study for the case of water supply in Taipei metropolitan area.

There are currently many knowledge gaps related to the role of food waste within the food-energy-water (FEW) nexus. Wasted food is a high-magnitude, energy- and nutrient-rich waste stream. Energy and water are consumed or contaminated both during production of wasted food and management of disposed food. Further, carbon and nutrients from landfilled food are potentially persistent and problematic contaminants that require intensive energy to treat, and/or large volumes of water to assimilate. Better understanding of potential water and energy costs underlying various alternative food waste treatments are necessary, for example, to inform decision making as communities implement ‘zero waste’ or the USEPA/USDA goal to halve food waste by 2030.Our approach towards FEW research is integrated through the energy and water footprints of wasted food, with particular attention to the uncharted and highly coupled water and energy impacts of food waste management.Herein, we present an approach to compare costs through the integrated FEW system related to several alternative pathways for food waste in the post-consumer phase. We consider food waste disposed in landfills, incinerated, digested for energy production, or composted. Our methods encompasses a conceptual methodology for characterizing interrelated water and energy impacts related to various alternative treatments for wasted food, evaluating potential magnitudes and directions of energy, water and nutrient transfer related to food waste, and feedbacks of human behavior. Through this approach, gaps in fundamental knowledge related to energy and water impacts of food waste are clearly identified.

Solar energy is emerging as a popular source of clean energy and represents a viable option to meet energy demands of Southwestern U.S., characterized with abundant sunshine. Technological advancements have made solar power efficient and economically competitive with the traditional thermoelectric power plants. Utility-scale solar plants may generate electricity by using the photovoltaic (PV) or concentrated solar power (CSP) systems. However, solar systems need water to wash the panels/mirrors to maintain their efficiency. Water use in CSP plants for wet or hybrid cooling processes is comparable to that in thermoelectric plants. Hence development of solar power may be curtailed in the semi-arid southwestern regions because of limited water resources and changing climate. This study used a system dynamics model to analyze water issues of the state of Nevada for development of solar power under the renewable portfolio standard (RPS). Water availability and use for different scenarios of PV and CSP were quantified to meet the RPS goals during the period 2010–2030. Land requirements and subsequent reduction in CO₂ emissions due to solar power development were also evaluated. Results showed that transitioning to solar technology from coal led to substantial reductions in CO₂ emissions during the period 2010–2030. CSP tower have the largest land requirements, whereas linear Fresnel have the smallest land requirements. Generating electricity using PV plants as well as using dry cooling methods for CSP plants was found to be better options for water stressed areas. This model can also be applied to other regions using appropriate datasets.

This paper (1) studies the adverse impacts on environmental and social aspects of the mining sectors beside its economic contribution, to emphasize an urgent task of sustainable assessment in APEC countries with two preventatives, Vietnam and Japan; (2) clarifies the strong points and drawbacks in sustainability assessment of fuzzy analytical hierarchy process; and (3) provides an evaluation for the mining sectors of Vietnam and Japan, based on the data obtained from APEC project in 2010. The results appropriately reflect the actual environmental, social, and economic situations of the industries. Both the economic performances have been toward sustainable development. The main factors for economic sustainability are export earning, the contribution of the mining sectors to GDP, FDI inflows, and the funds for mine close and reclamation. The environmental performances of Vietnamese mining sector have been gradually toward sustainable development. Japanese mining sector has been assessed as the good case study regarding environmental and social sustainability, while Vietnamese social one has been backward. The social sustainability has mainly depended on fatality variation. Both the mining sectors have been toward sustainable development based on the composite sustainability evaluations.

The South Florida Water, Sustainability, and Climate Project is a $5M interdisciplinary research project funded by the National Science Foundation to explore development of a decision-making framework for South Florida water management decision-makers. The project is in year four of a five-year duration, with a geographicallydistributed team representing 10 universities across the U.S. and collaborators including the South Florida Water Management District. The team is developing a hydro-economic optimization model and basic science and economic inputs to evaluate management scenarios and decision-making for South Florida water and environmental resources. Management of this complex interdisciplinary project requires strategies, approaches, and tools beyond conventional approaches, and specifically those that support high levels of communication, collaboration, and transparency. Team science skills in facilitation, dialogue, and conflict resolution are required, as relationships and interactions are as important to success as technical competency. Adaptive management approaches ensure iterative and adaptive development, frequent communication, and collaborative planning, and along with team science skills, build critical trust. The SFWSC adaptive management strategy, using a ‘people over process’ philosophy, incorporates agile management frameworks, team science understanding, and collaborative communication and planning tools. The effectiveness on integration and productivity is continuously analyzed through in-depth interviews, retrospectives, and surveys of team members and stakeholders. Team members rate effectiveness on integration favorably, and have received praise from external advisors on the level of integration thus far achieved compared to similar interdisciplinary research projects.

Of the three dimensions of sustainability—environmental, economic, and social—the social aspect is often the least well understood. However, social acceptance is a prerequisite to social sustainability: if a technology is rejected by a society or its members, it is not viable. Social acceptability can be studied using well-known survey techniques, and the information gathered can inform further efforts to understand the social sustainability of technologies. Eco-toilets (composting and urine diversion toilets) provide an excellent example of a technology that appears to be environmentally and economically sustainable, according to various measures, but might not be socially viable. In this research, preliminary analyses of some economic and environmental measures were followed by a household questionnaire to examine the social acceptability of eco-toilets. The questionnaire instrument was designed specifically for this purpose and queries attitudes, perceptions, and beliefs surrounding eco-toilets themselves as well as other related areas, such as risk and sensitivity to disgust. This instrument was implemented in a case study in coastal Massachusetts, where eco-toilets have been proposed as one potential solution to environmental pollution problems caused in large part by household sewage waste. Data collected with this questionnaire provide critical insight into factors influencing social acceptance of environmentally promising technologies. These insights can inform further efforts toward increasing social acceptance in the hope that eco-toilets could become a socially sustainable sanitation solution, or efforts toward inventing or selecting and evaluating alternative technologies that could sustainably meet household sanitation needs.

There are a multitude of significant ongoing efforts by universities, local governments and non-governmental organizations (NGOs) researching the issue of sea-level rise adaptation in Florida. Much of this work focuses on understanding the physical and economic vulnerability, as well as on developing adaptation strategies for the natural and built environments. Within these efforts, there has been very little attention given to the potential impacts of sea-level rise to human health. The National Climate Assessment, the Intergovernmental Panel on Climate Change (IPCC), the Centers for Disease Control (CDC) Building Resilience Against Climate Effects (BRACE) program, National Institutes of Health (NIH) Climate Change and Human Health program, and other nationally and internationally focused studies identify sea-level rise, human health effects of sea-level rise as a major component of understanding vulnerability and designing adaptation.

The current California drought has impacted freshwater availability for agricultural, industrial, commercial, and residential uses across the state. Due to the confluence of declining surface water deliveries, depleted streamflows and over-exploited groundwater wells, thousands of households across the state have reported water outages, and many now rely primarily on bottled water as a source of drinking water. At the same time, California is a large oil and natural gas producing state and generates large amounts of produced water from fuel extraction each year. In 2014, over 518 billion L of water were produced due tofossil fuel production in the state, yet the majority of this water was disposed of through Class II injection wells. There is growing interest in identifying alternative water sources, but to date, there have been limited attempts to assess the feasibility of using produced water in California for beneficial purposes in the residential and commercial sectors.This study addresses this gap and provides a geospatial assessment of the quantity and quality of produced water from California’s oil and gas activities in relation to water-stressed regions. A freshwater shortage risk metric isdeveloped, and the feasibility of water transfers are analyzed using produced water data. The outcomes of this study conclude that approximately 1.2 million people reside in high-risk areas that are within 24.14 km (15 mi) of a producing well with water that is clean enough to treat.

Why do you do what you do? Why are you in the decentralized wastewater industry? I joined the wastewater industry to interact directly with society and protect public health.I joined the decentralized wastewater industry because it is the most environmentally-sound, passive form of wastewater treatment and recycling. But what is truly saved by using decentralized wastewater treatment? And what can we do as an industry to help negate the growing environmental and fiscal problems facing society today? The environmental and economic benefits provided through the manufacture and construction of onsite (decentralized) wastewater systems versus centralized wastewater treatment plants were quantitativelyexamined through an analysis of embodied energy, embodied carbon, and the cost of each system type. The average decentralized system versus connecting to a sewer extension were found to reduce embodied energy, embodied carbon, and cost by 75%, 73%, and 68%, respectively. With the clear environmental and economic benefits associated with decentralized wastewater treatment systems, it is imperative that local, state, and national regulators shift the focus of wastewater treatment from centralized sewer systems to the more sustainable decentralized model. Doing so will greatly aid in the efforts to reduce the carbon footprint associated with development as well as reduce the cost of development for both government entities and end users. In addition, the environmental impacts of both a precast concrete septic tank and gravel/pipe drainfield (conventional) onsite systems and systems using recycled thermoplastics were evaluated. Water consumption, electricity consumption, fuel consumption, and carbon emissions were evaluated through raw material production, product manufacturing and transportation for both systems. It was determined that when transporting a recycled thermoplastic system 1,030 miand a conventional system only 30 mi, the recycled system reduced electricity consumption by 88%, fuel consumption by 67%, water consumption by 97%, and carbon emissions by 44%. Our everyday choices as members of the decentralized wastewater industry have an impact on the environment around us. What if we, as an industry, stood up through our local representatives and legislators to push for more funding of decentralized systems? What if we made daily choices that express our concern of the environment and chose to operate sustainably? We, as an industry, have the opportunity to lead–to build a sustainable and inspiring industry that gathers young, eager minds, ready to change the world. Let’s grasp the opportunity. Let’s start with why.  

As part of a co-curricular activity for students in the Home for Environmentally Responsible Engineering (HERE) program at Rose-Hulman Institute of Technology (RHIT), students conducted water taste tests to explore preferences of fellow students among various bottled and tap waters. The motivation behind this study stemmed from the high energy requirements and costs of producing bottled water when compared to the energy requirements and costs of producing tap water, as well as the plastic bottle waste added to landfills from water bottles that are not recycled. Here students administered a double-blind study in which participants tasted samples of four types of water: two bottled water samples (Aquafina and Ice Mountain) and two tap water samples (one of which underwent an additional filtration process post-tap). The samples were offered to the participants in random order. Participants completed a survey to answer questions regarding their typical water consumption (i.e. type of water they drink and their daily consumption amounts). They then chose their most and least preferred sample. Three trials of the taste test have been completed. Analyses show that there are statistically significant differences among most and least preferred samples. Chi-square analyses have been conducted to answer the question, “Is the true proportion of students most (least) preferring each type equal to 25%, or is the true proportion different than 25% for at least one type of water?” Additional testing was conducted to determine if most and least preferred water type is independent of stated preference for water type or amount of water consumed in a typical day. Finally, additional chi-square tests of independence were conducted to see if the most or least preferred sample is independent of the order in which the waters were tasted.

The purpose of this paper is to evaluate the process that Wake County government is utilizing to incorporate sustainability into the management of the county’s water resources. The process consists of evaluating and subsequently reducing the county’s environmental complexity factor (ECF) as it relates to sustainability and water resources. Threadcraft defined ECF as a relationship between project complexity and organizational action. “The more complex the analysis, the longer it takes an organization to make a decision. This is evident by many projects being placed on hold for an indefinite period of time in an effort for a political group to avoid the ramifications of the outcome independent of the pending impact to the environment.” In fiscal year 2013, the Wake County board of commissioners (BOC) approved an expansion request that authorized the hiring of a Hydrogeologist and the subsequent establishment of a contaminated groundwater program. This action was taken to address contaminated groundwater concerns in Wake County. Through the growth, land use, and environment committee, the BOC is currently evaluating the feasibility of a water partnership. Environmental services staff conducted research to evaluate the interest of stakeholders and define the scope of responsibility for the partnership to include the parameters that outline the requirements for its success. Simultaneously, the county is enhancing sustainability in areas consisting of water, energy, and waste. In summary, this paper will statistically evaluate the county’s actions to reduce its ECF as it relates to sustainability and water resources.

The Sarayan region situated on the edge of the Lut desert in central northeast Iran within the Southern Khorasanprovince, is an agricultural area with limited water resources almost exclusively from groundwater aquifers. Until two decades ago very limited information about the characteristics of the region’s aquifer and the sustainable yield and quality of the groundwater in the area existed. To get a better handle on the availability of groundwater and its quality, an extensive study of the region was initiated in the late 1980s. The study consisted of intensive water level monitoring and sampling for water quality (salinity of the aquifer water) for later analyses. The information collected was later used to develop a conceptual model of the basin and subsequently a mathematical model of the area to perform various simulations to look at scenarios for long term water resources management in the region. The basic hydro-meteorological data about the region include the mean annual temperature and precipitation within the basin that are 15.5ºC and 170 mm (60ºF and 6.7 in.), respectively. Precipitations mostly occur in late fall and winter seasons often in an intense short duration episodes. There are no perennial rivers in the area, though some floodway tracks run north to south draining the region’s northeastern hills with the Qasemabad saline floodway the most significant feature. In the southern part of the Sarayan region, the aquifer also provides some base flow to the Qasemabad desert that quickly evaporates leaving salt flats behind that could become airborne causing air quality issues periodically. Total basin area and perimeter are 2710 km² and 277.6 km, respectively. Groundwater in the Sarayan plain occur in an unconfined aquifer within an aerial extent of 748 km². Aquifer materials are composed of various alluviums such as coarse grain alluvial fan deposits, sand dunes and flat clay fine sediments. In general, the aquifer materials tend to be finer moving toward the south and hence hydrodynamic parameters such as hydraulic conductivity decrease in a southerly direction. The mean annual rate of drawdown in the past 30 years has been about 75 cm (~2.5 ft), which has reduced the aquifer extent (domain) continuously. This paper will provide the background on the project, the basis for conceptual model development and the construction of the mathematical model for aquifer assessment, and testing scenarios for sustainable exploitation of groundwater resources.

Biosand filters (BSF) are an effective point of use technology for drinking water treatment.However, drawbacks of BSFs include slow ripening and high head losses. This paper discusses two modifications that address these drawbacks: (1) use of pumice to enhance hydraulic performance, and (2) dosing of Moringa oleifera to expedite ripening. Three filter columns with sand, pumice, and a pumice/sand beds were studied for over 3 months. Headloss, filtration rate and water quality parameters were monitored. In the first few cycles, the pumice and the dual media columns had 2–3 times greater filter run lengths compared with the sand column. The pumice column consistently had the lowest product water turbidity (< 0.23 NTU). On the other hand, the sand column had the highest organic removal (about 14.7%). The study showed that pumice had better hydraulic performance while achieving better turbidity removal. M. oleifera dosed columns ripened faster, however, continuous dosing resulted in excessive growth of biofilms, which shortened filter run times. The improvements in hydraulic performance and ripening due to the modifications can help improve acceptability of the technology by users. Further studies are necessary to find optimum doses and duration of M. oleifera application. Hydraulic modelling of the BSF showed that the experimental results (headloss and filtration rate) from the sand BSF corresponded well with model results. For pumice; however, the experimental results did not fit the model curves. This may be explained by the fact that internal pore spaces in pumice are not accounted for in the model.

Groundwater seepages, along a vertical transect, were estimated below the Indian River Lagoon (IRL), a coastal estuary located on the east coast of Florida, using MODFLOW, which is an uncoupled model, and SEAWAT, which is a coupled model. In the longitudinal direction, the modeling domain, perpendicular to the estuary coastline, extended from the water table divide on the mainland to the Atlantic Ocean (9.74 km). Vertically, the domain extended 33.5 m to the top of the Hawthorn Formation, considered an impermeable boundary. The flow in the unconfined aquifer below the estuary is density-dependent since the brackish water in the IRL and the ocean water mix with the freshwater in the aquifer. The hydraulic head boundary conditions for the brackish water of the estuary and the ocean water were converted to freshwater hydraulic heads when using MODFLOW. The following four sets of results were compared over three sampling events: freshwater hydraulic head contours in the unconfined aquifer, groundwater flow directions in the unconfined aquifer, spatial distribution of submarine groundwater discharge (SGD) from the unconfined aquifer into the IRL along the transect, and total SGD into the IRL from the aquifer. Visual comparisons showed that the hydraulic head distributions, spatial distributions of the SGD, and the velocity vectors obtained from the two models were quite similar. The differences in the total SGDs predicted by the two models ranged from 1.8% to 4%. The results indicate that MODFLOW may be a viable option to a coupled model even when the groundwater flow is density dependent.

It is well-known that unstable flows occur when denser saltwater overlies lighter freshwater. One such situation occurs in the Indian River Lagoon (IRL), a coastal estuary, located on the east coast of Florida. The IRL water is brackish as it is a mixture of the saltwater from the Atlantic Ocean flowing through inlets and the freshwater flowing from canals, rivers and groundwater. This brackish water overlies the freshwater that flows in the unconfined aquifer below the IRL. All cases of unstable density stratification result in a rapid and erratic redistribution of the salt. The rate of salt movement is much different than predicted by ordinary molecular diffusion alone. The dynamics of this unstable flow was investigated using a physical model made of Plexiglas which is 1.83m high and has a base of 0.61m by 0.61m. The model was filled with 1.64m of sand and the part above the sand, the source area, was used to add seawater or brackish water. The model consisting of five ports located at 0.255, 0.560, 0.865, 1.170, and 1.474m from the source was filled with 40F sand which was saturated with freshwater. This paper shows breakthrough curves from two experiments, conducted over five days and over 28 days in which the source concentration was kept constant at 36,000 mg/L at a depth of 4.5cm. Results indicate that the flow was unstable in the beginning (did not yield smooth breakthrough curves) but stabilized after approximately 23 days. Measured breakthrough curves were compared with numerically simulated curves using SEAWAT. It was found that the salt concentrations, under unstable conditions, can be predicted with reasonable accuracy if (1) the selected molecular diffusion coefficients are several orders of magnitude higher than values obtained through traditional experiments and (2) the selected molecular diffusion coefficients are time-dependent.

The radial collector wells provide large quantity of filtered water when constructed in the alluvial riverbeds getting low flow from upstream but their construction cost is very high. Simulation/optimization model AEMPSO-OD is developed to find the optimum location of the well within the river bed for a synthetic problem to minimize the capital cost by using analytical element method and particle swarm optimization. The AEM model generates line-sinks for well laterals by using values obtained from each position vector generated by PSO model and also creates other elements such as aquifer, resistance specified line-sink for river channel and in-homogeneity to represent no-flow boundary. The objective is to minimize the total cost subject to constraints for minimum discharge, residence time, maximum discharge intensity in radial drain and maximum induced recharge from river. The optimum is solution obtained by model in terms of location, length of each lateral and water level to be maintained in the well. The result shows that well discharge is highly increased by proximity of stream. As the well is located away from stream to increase residence time for better filtration, the induced recharge rate is also decreased which helps controlling sedimentation. The model is successful in finding optimum location and design. AEM is preferred as other mesh based method involves change in mesh with different locations populated by optimization model.

A new method of silver application to porous ceramic water filters is being investigated in the laboratory and field. Fieldwork was performed at an existing ceramic water filter factory:the PureMadi Mukondeni Pottery Cooperative, in Limpopo, South Africa. Results show there is no statistical difference in E. coli and total coliform removal between filters made using the conventional method of paintingan aqueous suspension of silver nanoparticles onto the ceramic filter and a new method that applies a silver nitrate solution to the clay-sawdust-water mixture prior to pressing and firing the filter. Laboratory tests studied E. coli removal with the two silver application methods using ceramic disks in a flexible-wall permeameter. Silver amounts applied using the silver nitrate method were varied. Results show that the two methods of silver application and amounts performed similarly in regards to E. coli removal. The new method is less expensive because of the lower cost of silver nitrate relative to silver nanoparticles. The new method alsosimplifies the filter manufacturing process, as the labor-intensive painting step is omitted.Potentially, even more silver in the form of silver nitrate can be added to improve the performance of the filters without increasing filter cost compared to conventional methods of silver application.

Households in coastal Madagascar rely on locally manufactured pitcher-pump systems to provide water for drinking, cooking, and household use. These pumps typically include components made from lead (Pb). In a field study of 18 household pitcher pumps in the city of Tamatave, concentrations of Pb were frequently observed to exceed the World Health Organization (WHO) provisional guideline of 10 μg/L. Under first-draw conditions (after a pump had been inactive for 1 h), 67% of samples were in excess of 10 μg/L Pb, with a median concentration of 13 μg/L. Flushing the pump systems before collecting water resulted in a statistically significant (p < 0.0001) decrease in Pb concentrations: 35% of samples collected after flushing exceeded 10 μg/L, with a median concentration of 9 μg/L. We modeled the ingestion of Pb with the integrated exposure uptake biokinetic model (IEUBK) to predict blood lead levels (BLLs) in children, thereby characterizing potential health risks. We modified the IEUBK model to account for the use of contaminated water in preparation of the top three foods in the Malagasy diet (rice, corn, cassava). Results indicate that this route may contribute up to 60% of overall Pb uptake in children, and therefore we conclude that the IEUBK model should be modified when applied to a developing-world context. The modified IEUBK predicts that as high as 94% of children could experience elevated BLLs (> 5 µg/dL) in households or communities where the Pb concentration is at the high end of our field observations.

Pollution source identification in groundwater contaminant transport using limited concentration data of the contaminant plume is an inverse problem. In this paper, we develop a numerical-optimization approach that utilizes the green element method (GEM) and the shuffled complex evolutionary (SCE) technique to identify pollution source strengths and recover the concentration distribution of the plume for contaminant transport in groundwater systems. Two test cases are used to evaluate our proposed methodology: 1D transient case with an analytical solution and 2D transient hypothetical case that mimics a real life situation. The results indicate that the proposed methodology gives good estimates of the release history and the historical distribution of the plume even in the presence of observation and parameter errors.

Development initiatives designed to improve access to groundwater often introduce technologies to be owned and operated by rural communities. This research compares the groundwater quality, technical performance, and social implications of new hand augered wells fitted with bailers or EMAS hand pumps versus existing unimproved hand dug wells. It uses the following methods: water quality analysis, visual and manual inspection, user interviews, and a sustainability assessment applicable to developing communities. The research takes place in a coastal indigenous region of Panama disproportionately affected by a lack of improved access to water and challenges to the viability of piped gravity fed water systems that typically serve other rural areas across the nation. Results suggested that bailers and EMAS pumps yielded a mixed level of performance based on water quality measurements in the shallow wells of the study environment. The technologies generally satisfied international water quality guidelines for conductivity, TDS, and turbidity (with 57% of samples under 5 NTU). Water obtained from wells fitted with EMAS hand pumps demonstrated markedly better bacteriological water quality with all samples indicating undetectable levels of E.coli, while 83% of samples from bailers fell into a range signifying intermediate to no associated health risk. Interview data demonstrated that hand augered wells significantly improved household water access in the study area based on user considerations by providing a reliable drinking water alternative with adequate quantities of water perceived to be clean. A sustainability assessment determined the EMAS hand pump and bailer technologies to be cost effective and socially and environmentally appropriate, featuring fewer materials and simplistic designs.

The long-term effect of non-point source pollution on groundwater from agricultural practices is a major concern globally. Non-point source pollutants such as nitrate that occur through fertilizers and animal waste eventually make their way into the aquifer by infiltrating soil. The goal of this study is to characterize the probability distributions of non-point source locations and time release history of nitrate contamination into groundwater resources. A Bayesian framework using a Markov Chain Monte Carlo approach (MCMC) is developed to estimate posterior distributions of non-point sources by incorporating groundwater nitrate concentration data as well as geologic and hydrologic uncertainties. Hypothetical scenarios are used to test the approach and then apply it to a basin in North Carolina.The likelihood function computation involves a mechanistic model that simulates nitrate transport in groundwater from non-point agricultural sources and predicts nitrate concentrations at observation wells. Effectiveness of the proposed approach is tested through a convergence analysis of the MCMC algorithm. The Bayesian inference analysis methodology developed in this research will help decision makers and water managers identify potential source containment areas and to decide if further sampling is required.

At the seacoast in a coastal aquifer, freshwater from inland terrestrial sources discharges to the sea, flowing over denser seawater from marine sources that intrudes inland along the base of the aquifer. As the seawater flows inland, it mixes with the seaward flowing freshwater, is recirculated, and discharges back to the sea. The sum of the recirculated seawater and fresh groundwater discharge is called submarine groundwater discharge (SGD). Recirculated seawater can be a major component of SGD, affecting the salinity of the SGD discharged into coastal and estuarine systems. Based on dimensional analysis, three dimensionless ratios (L_D, R_D, and P_R) that represent saltwater intrusion, the recirculation of seawater, and the percent of recirculated seawater that is contained in the SGD can be considered dependent variables in this problem. Two additional dimensionless ratios (a_z and r_K) that represent the ratio of the freshwater inflow relative to the vertical density-driven buoyancy flux and the ratio of the vertical and horizontal hydraulic conductivities in the aquifer cross-section can be considered independent variables in this problem. Numerical experiments were conducted using SEAWAT to determine how L_D, R_D, and P_R are related to a_z and r_K over a wide range of values of a_z = 0.1 to 10.0 and r_K = 0.01, 0.1, and 1.0. Based on the results of this investigation, L_D, R_D, and P_R all increase as a_z and r_K are decreased, and L_D, R_D, and P_R all decrease to zero or near zero as a_z and r_K are increased. Maximum values of L_D, R_D, and P_R occur at a_z = 0.1 for r_K = 0.01, and minimum values of L_D, R_D, and P_R occur at a_z = 10.0 for r_K = 1.0. The maximum value of P_R = 74.1 % at a_z = 0.1 and r_K = 0.01 confirms the important contribution that recirculated seawater can make to SGD and its effect on increasing the salinity of SGD in a vertically anisotropic aquifer, particularly at relatively small values of a_z ~ 0.1. The minimum values for L_D, R_D, and P_R, which approach zero and occur at the larger values of a_z, indicate that saltwater intrusion and the recirculation of seawater are significantly reduced in both isotropic and anisotropic aquifers at relatively large values of a_z ~ 10.0. In natural settings, aquifer properties such as horizontal and vertical hydraulic conductivities, aquifer thickness, freshwater inflows, and other properties can be quite variable. However, based on the results of this investigation, saltwater intrusion, the recirculation of seawater, and the percent of recirculated seawater in submarine groundwater discharge in such field-scale aquifers can be investigated and even predicted by quantifying the two independent dimensionless ratios a_z and r_K.

Long-term groundwater monitoring (LTM) after active remediation is required to assess the concentration of residual contaminants and to protect human health and environment. As a monitored site becomes stable, the contamination extent diminishes and monitored parameters become more predictable, it may be feasible to reduce the monitoring frequency, locations, and analytical requirements while meeting monitoring goals and data sufficiency. LTM optimization offers an opportunity to reduce costs while assuring that monitoring network collects sufficient data. The optimization includes identifying the redundancy or insufficiency in the monitoring network, and recommending changes to protect against potential impacts to human health and the environment.This study develops an ant colony optimization (ACO) method, using ordinary kriging (OK), or inverse distance weighting (IDW) for data interpolation, to identify redundant wells in LTM networks while satisfying data accuracy requirements. ACO is a global stochastic search method inspired by the collective problem-solving ability of a colony of ants as they search for the most efficient routes from their nest to food sources.The performance of ACO combined with either IDW or OK interpolation is evaluated separately in two test cases for LTM network optimization. One is a synthetic data set generated from a groundwater transport simulation model with 73 data locations, and the other is a field site with 53 monitoring locations. Results of the test cases within the ACO-LTM optimization framework are discussed.

Groundwater is one of the important sources of water supply in Thailand especially in non-irrigated areas during dry season. Numerous groundwater contaminated sites have been reported from both natural and anthropogenic (i.e., man-made) activities with extent of plume migration, leading to a degrading quality of groundwater which is unacceptable for human consumption. Determination of contaminant transport parameters in the saturated zone is of great importance for groundwater risk assessment. For our study, a series of column experiments were conducted to obtain the transport parameters of 2-nitrophenol in natural soil which are collected from a contaminated site in Thailand. 26 porous media samples were randomly collected from the site from 1.5 m depth below ground surface and further analyzed for their grain size distribution using ASTM D422-63 standard method (standard test method for particle-size analysis of soils) to cluster the sample. Upward flow direction column setup was employed with 23.7 mM phosphate buffer containing 10 mg/L NaCl solution (as a conservative tracer) influent for at least five pore volumes (PV) at 30 mL/h constant rate injection, then switched to 10 mg/L of 2-nitrophenol in 23.7 mM phosphate buffer solution and the column was consecutively flushed for another 5 PVs. Effluents were systematically collected in every 0.25 PV and further analyzed for their Cl- and 2-nitrophenol contents by using a well-calibrated conductivity meter and gas chromatograph (GC), respectively. Natural soil from the study area could be clustered into three groups based on their D₅₀ values of 0.16 mm, 0.27 mm, and 1.08 mm, respectively. Cl- and 2-nitrophenol breakthrough curves were plotted and compared to assess the contaminant transport parameters, including its dispersivity and retardation factor in comparison to the conservative tracer. The dispersivity of 2-nitrophenol for three groups of sample is 0.41 cm, 0.34 cm, and 0.35 cm, respectively. For retardation factor, they were equal to 1.127, 1.086, and 1.086, respectively.

Water stress is rapidly increasing in many parts of Thailand, especially during drought season, due to expansion in agriculture and industry. This study is focusing in the Upper Chao Phraya river basin to assess the capability of using water stable isotope analysis (δD-δ¹⁸O) to refine the understanding on spatial and temporal distribution of precipitation as well as the surface water-groundwater interactions for the aquifer systems underneath the study area. Local precipitation, surface water, and groundwater are sampled along the main river courses and their tributaries. Massive precipitation isotopic composition database from IAEA existing monitoring network (GNIB) along with local Bangkok precipitation isotope signature are compared with precipitation from Chiang Mai province in the North of Thailand to better identify the rainfall isotopic compositions. In addition to the isotopic distinction of precipitation in the area, its impacts on isotopic signature of surface water and groundwater are additionally explored. LMWLs for local rainfall in Bangkok and Chiang Mai are generated with some seasonal variation of rainfall isotope signature due to rain out effect. Surface water in the study area is influenced by evaporation at some degree, revealing that rainfall may not be the primary source of surface water. Yom river’s isotope signal values are far more D and ¹⁸O-enriched compared to Ping’s and Nan’s, suggesting the mixing of groundwater into river water and/or the origin of surface water may come from dry-period precipitation. Stable oxygen and hydrogen isotope data in groundwater again fall on an evaporation line, and is thus indicative of the effects of high evaporation rates through the top surficial material. The isotopic similarity with the more depleted δD and δ¹⁸O of groundwater samples suggests the potential mixing of groundwater with river water by different mixing processes (54% from river water and 46% from rainfall). The results of stable isotope analyses show correlations in the isotope signature of shallow (i.e., < 50 m deep) and deeper aquifer (i.e., > 50 m deep) which may be associated with hydraulic connection and/or similar hydrogeological conditions. d-excess stable isotope analyses are beneficial to identify the relative contributions of the wet and dry seasonal sources to the groundwater recharge. The results indicate that groundwater sources in the area are composed of an average of approximately 71.4% wet seasonal sources and 28.6% dry seasonal sources.

MODFLOW is the U.S. Geological Survey modular finite-difference flow model, which is a computer code that solves the groundwater flow equation. The program is used by hydrogeologists over the world to simulate the flow of groundwater through aquifer systems.Compressible low permeable sediments in aquifer systems may occur as discontinuous interbeds or aquitards within aquifers or as extensive confining units adjacent to aquifers. Flow in the extensive confining units can be simulated by MODFLOW through taking the units as no-delay flow model layers. Flow delay was found by Terzaghi in 1925 through his 1D analytical consolidation solution. For a double-drainage confining unit adjacent to aquifers, consolidation degree reaches 99.4% while time factor value reaches 2. A 99.4% consolidation degree during one time step is employed in this paper to denote a no-delay flow model layer in MODFLOW simulation. An additional delay coefficient compared to Terzaghi’s flow delay in a low permeable confining unit was found in this paper to be in a range of 87.5 to 29 which depend on model layer number of the confining unit in MODFLOW simulation. No-delay option requires that the minimum time step used in MODFLOW is larger than a delay time length determined by a production of time factor of 2, time constant and additional delay coefficient of a confining unit. It is not appropriate to apply no-delay option to simulating flow in a confining unit if the minimum time step is less than a determined delay time length with a selected sub model layer number and drainage length of the unit.No-delay option can be only applied to very thin confining units in aquifer systems.

Groundwater is a critical water resource and accounts for the bulk of world drinking water supply. The quality of groundwater affects both human and animal health. While conventional groundwater treatment technologies work very well for many of the contaminants, there are more challenging new and emerging contaminants which need attention. Further, sustainability of groundwater water treatment technologies is important for them to be effective and acceptable to the public. The current drinking water treatment trains as practiced worldwide have been limited by availability of power, chemical requirements, and the use-of-technologies. New and effective drinking water treatment trains will be necessary to control the emerging contaminants, such as the endocrine-disruptors and pharmaceutical compounds, in addition to the regulated contaminants. Additionally, regulatory requirements dictate the constraints and boundaries for the existing technologies and technology development. The removal of currently removed contaminants (e.g., arsenic) could also be a challenge into the future as various government-bodies are developing new standards. Moreover, various organic compounds in groundwater warrant newer treatment trains/processes with new and effective technologies. This paper discusses these issues with reference to groundwater for use as potable water.

Environmental Protection Agency (EPA) established standards for different water quality constituents for surface and ground water. Understanding the behavior of the contaminating sources, the contamination movement with ground and surface waters are extremely crucial in keeping the environment clean and maintaining the ecosystem. Visualizing the solute transport through porous media is very essential in planning the remedial strategies with viable economic options. In this research work, an outreach and research modules were developed with simple user friendly immersive virtual 3D visualization concept. These modules will facilitate the users in understanding the complex process of contaminant movement with the ground water when an underground fuel pipeline failure occurs. When students/users enter the virtual environment, they can fly through the system and visualize and relate the issues. This will be extremely helpful to educate the public about the possible risks during such events.

The United States has seen a dramatic rise in the number of horizontal hydraulic fracturing wells drilled since 2009. Each well requires supporting infrastructure that includes a large well pad along with access roads and pipelines that result in the removal of vegetation and creation of bare ground or gravel conditions that can alter storm runoff patterns. The objective of this study was to explore the effects of land conversion for shale oil and gas development on storm flow characteristics of streams in Eastern Ohio. Using stream flow records, land cover type from satellite photos, and other publically available land data, the density of wells within a treatment watershed and the proportion of upland area used for oil and gas activities was compared with storm flow characteristics for the watershed before and after energy development and with a neighboring control watershed. Storm flow duration, peak flow and runoff volume significantly decreased in the treatment watershed after shale oil and gas development.

While there are anecdotal accounts of water pollution and much speculation of potential hazards, there are few quantitative accounts of actual impacts to the water resources caused by oil and gas production. This research demonstrates combining currently available information from the Oklahoma corporation commission (OCC), the Oklahoma water resources board (OWRB), and the Oklahoma department of environmental quality (DEQ), it is possible to quantify recent potential water impacts. The OCC records and addresses drilling complaints through their risk based data management system (RBDM). With the RBDM it was possible to locate 99 recent complaints with saltwater or oil spills. Those locations were then correlated with the OWRB mapping of vulnerable aquifers based on the DRASTIC model, and it was found that 24% occurred over very high vulnerable aquifers. Complaints were also compared to DEQ mapping of public water supply (PWS) intakes. Only one spill was located within three miles of a PWS intake. This analysis demonstrates that current oil and gas production does impact surface and groundwater resources, but that only a small percent of the recent spills had the potential for serious consequences. While specific to Oklahoma, most states will have similar data available.

The paper presents the equations for performing an energy balance on a water distribution system. It also discusses the meaning of the results and whether there is any application in practical design and operation of a water system.

Modern water distribution systems (WDSs) largely depend on computer networks and industrial control systems for monitoring and operational purposes. Although the adoption of these cyber-physical components has improved the reliability and quality of service, such progressive computerization may render WDSs vulnerable to cyber and cyber-physical attacks. The spectrum of potential threats is very broad, with several attacks able to cause the disclosure of critical information or service disruption at different levels—a water supply interruption, for instance. These attacks usually target the supervisory control and data acquisition (SCADA) system—i.e., the centralized computer system supervising the whole infrastructure—or the programmable logic controllers (PLCs) that locally operate pumps and valves. In this work, we introduce an EPANET-based toolbox that allows simulating the effects of cyber-physical attacks on a WDS. Plausible attack scenarios to network SCADA and PLCs are implemented in EPANET to simulate the response of a large WDS and assess how it diverges from normal operating conditions.

Water distribution system (WDS) complexity increases as its size increases. Not only size, but the configuration of the system also plays an important role in solving a water distribution system for its hydraulics and water quality. The flow pattern and the dynamics of the system heavily depend on the system configuration. A smaller change in parameter value in a loop configuration system would affect the system flow pattern and dynamics more than the branch configuration, as there are multiple paths to convey the required flow to a single node. On the other hand in a branch system a single path is typically used to convey the required flow to a node. Water distribution system model can predict the required and delivery heads, pressures, pumping energy, water quality, etc. Thus, the WDS model helps decision making in planning, design, operation, and management. The model input parameters can affect the model predictions. While some input parameters may affect the model outputs less, the others may affect significantly. The system configuration adds another complexity to it. The impacts of these input parameters may be different in different configuration systems. This paper considers a wide range of input parameters to observe their effects on model prediction uncertainties in nodal pressure, pumping energy requirement, and nodal water quality using Monte Carlo simulation (MCS). The effect of the system configuration on model prediction uncertainty is observed by applying the MCS to eight (8) water distribution systems of different configurations.

Both the Darcy-Weisbach and Hazen-Williams equations are used by water professionals in the analysis of flows and pressures in water distribution systems. Using a debate format, this paper will examine the history and original underlying assumptions of both equations and then debate which equation is most appropriate under what conditions. In particular, the paper will examine the question: With the advent of modern computers, should the Hazen-Williams equation no longer be used in water distribution system analysis? The debate will provide both affirmative and negative positions.

The ASCE Task Committee on Research Databases for Water Distribution Systems was formed in 2013 for the purpose of developing a database for use by the water distribution system community in developing and testing new algorithms for network design, analysis, and operations. This effort has led to the identification and collection of data files and supporting narratives for over 40 different distribution systems. This paper provides an overview of the database along with instructions for how the system data may be accessed for use.

Water systems (e.g., potable water, wastewater, and storm water systems) are regarded as “lifeline” infrastructure. Their disruption can cause cascading effects, influencing the economy of an entire region. Past hazard events show that water availability is crucial for minimizing the societal impact of such events and for recovery processes. To date, stochastic simulations of hazards events, and their direct and indirect physical damage to water system components, are typically not coupled with hydraulic simulations of functionality loss and restoration, including water quality, pressure, and flow throughout the network. This work presents a comprehensive approach to the modeling of water system resilience subject to a seismic event; however, the procedure is general and can be applied to other network systems and hazards. The model performs: (1) a baseline deterministic hydraulic analysis on an undamaged water system, focusing on meaningful functionality metrics, (i.e., water pressure, quantity, and quality); (2) a probabilistic analysis of the damaged system considering the damage state and the performance level of each component; (3) a probabilistic analysis of the water system functionality, considering the physical damage analysis and the recovery time of each component.

The EPANET package for modeling water distribution systems is widely used and several methods are available to interact with network data. These methods include commercial and freely available graphical interfaces, geographic information systems, and the programmer’s toolkit.Another approach is to use a technical computing platform such as the R environment to visualize and analyze simulation data. R is open source and freely available. epanetReader is an add-on package for reading files in EPANET’s ‘.inp’ and ‘.rpt’ formats into R. Basic summary information and plotting capability for the data contained in the input and report files is provided so that three lines of executable code are needed to (1) read a network file; (2) see the number of each type of element; and, (3) view a map of the network. Once information from EPANET exists within R, other add-on packages for graphics and animation can be used to interpret and visualize simulation results. epanetReader is freely available from GitHub or the comprehensive R archive network (CRAN). This paper provides further detail on the installation and usage of epanetReader, including several examples.

Optimal water system operation, including hydraulic and water quality constraints are complex problems to solve due to the nonlinear relationship of head-loss to flow and disinfectant-loss to time. A common approach used today is evolutionary algorithms (EA) such as genetic algorithms or others. For large problems with a large number of decision variables, ether over extended period or having several pumping units, the extended solution time of the EA approach may render the approach not relevant. The proposed method utilized the operation graph optimization (OGO) algorithm proposed previously by the authors, demonstrating high speed discrete minimal cost, optimization with hydraulic constraints. A minimal cost algorithm is proposed, including hydraulic and water quality constraints. The suggested algorithm raises the concentration of the residual chlorine in the network by optimally decreasing the operational volume of the water tanks, and by such increasing the pump switching frequency. The algorithm is demonstrated and compared to enumeration on a single pressure zone example network (1 water tank, 1 pumping unit), on a large example network (C-Town, 7 water tanks, 11 pumping units). The resulting pump schedule is not a global minimum when compared to the best enumeration result on a single pressure zone. However, the algorithm may serve, especially in large water systems, as a quick and feasible answer to system operators, regarding the water volume to maintain in the different tanks to provide minimal chlorine service concentration at near minimal cost.

Approaches in water distribution analyses are usually tested on one or a few benchmark systems (before they are applied to real systems). On the one hand, this makes findings comparable, but on the other hand, the results are usually very case-specific. Because of data availability and security reasons, models of water distribution systems are rarely published or available for research tasks. For that reason the idea of stochastically creating benchmark sets was established. Following that idea, automatic generators of numerous benchmark networks were developed and they increasingly find their way in the scientific community. Currently there are several software, algorithms, and generated virtual networks available. Each of them has its specific advantages and depending on the aim of a study serves the investigators purpose. This paper aims to summarize the research work on that topic from the past years to further establish the application of virtual networks and shows latest findings and the capability of recent approaches and their applications.

Water distribution systems are vulnerable of being intentionally or accidentally contaminated. In the case of a contamination event the contaminated section of the water distribution system should be located, isolated, and cleaned before it can be returned to regular service. Depending on the specific contaminant, the cleaning process mainly includes flushing and disinfection. All of the disinfection methods (e.g., tablet, continuous, and slug) require that the disinfectants will have minimal contact time (T) in a predefined concentration (C) with the pipes and the system’s apparatuses. The regulatory agencies, such as the Ministry of Health in Israel or the American Water Work Association, publishes procedures for the disinfection of water systems in which usually only a single water main is considered and no specific procedures are given for larger portions of the water system. This paper presents an optimal operation plan for the disinfection of water distribution systems using the slug feed method while considering the locations where the disinfectants should be injected into the network, injection times, flow rates, and drainage locations. The method is a two stage GA-EPANET procedure. It is demonstrated on a small real-world network section.

In this work, interacting small hydro power systems (SHPS) within a water distribution system with over capacities are investigated. Therefore, an excess water turbine (Pelton turbine–PT) is installed at the end of a supply zone, downstream of a pump as a turbine (PAT) which reduces the pressure for that supply zone. Different sizes of PT cause different flows and therefore also impact the energy production of the PAT. In addition, upcoming rehabilitation measure of the pipe feeding the PAT provides the chance to consider different rehabilitation strategies. The savings and additional costs for smaller or bigger pipe diameters also in combination with the consequential different feasible SHPS device sizes are analyzed. It was found that considering the interactions of the SHPS leads to an efficient overall solution, while the savings due to installing smaller diameter are more beneficial than less friction losses in a larger but more expensive pipe. Further, it is found that the impact of future demand scenarios (increase and decrease) is in relation to the sensitivities from costs assumptions insignificant.

Water quality in potable water distribution systems has been especially studied from the point of view of mixing processes in network junctions. Programs such as EPANET usually assume that there is complete mixing. However, researchers such as Romero-Gómez et al.have questioned this assumption and conducted a series of experiments which showed mixing within nodes isn’t actually complete. In the present research, we witnessed that mixture processes depend on contact as well as physical and temporal interaction between incident flows. This may vary according to entry flow relation but also according to the junction’s configuration type and its internal geometry. A physical modeling was conducted at a Hydraulic Laboratory in Universidad de los Andes, Bogotá, Colombia. A computational modeling was also done, and it used the computational fluid dynamics (CFD) methodology in order to simulate different node configurations. Qualitative and quantitative experiments were conducted for the physical modeling; for the first case, we used potassium permanganate as tracer and for the later we measured chlorine concentration in all pipes.

This project seeks to explore the way in which calibration of water quality models is made in WDS studying determinants such as water age and residual chlorine concentration. In this approach, we search for physical and chemical properties that help the calibration process, preventing it from being a simple numerical adjustment. There are two reasons why substance concentration varies throughout the network: reaction with bulk water and reaction with the conducts wall. These processes are associated with bulk coefficient (k_b) and wall coefficient (k_w), in each pipe. For the first one, kinetic models with constant decay coefficients have been applied for almost 30 years now. However, in recent times, these models have been considered inadequate due to their limited capacity to estimate residual chlorine decay with high precision. In this way, we take actual ideas of substance reaction in water to calibrate WDS based on models that are more rigorous in qualitative terms. It is used a variable bulk coefficient from Hua, Vasyukova and Uhl (2015), that contemplates water mixing from diverse sources. For k_w we consider pipe material and age. This way, the parameters to calibrate are α and β for each water source in the network and k_w for each coherent group of pipes. Initially, we use hypothetical networks with different calibration scenarios, and then, as case of study, it is performed a water quality model calibration in the trunk network from Bogotá, Colombia.