The Atascosa Lookout lava flow is a mid-Tertiary trachyandesite flow that caps the rhyolitic to dacitic volcanic sequence exposed in the Atascosa Mountains of southern Arizona. The flow erupted near the beginning of extension in the southern Basin and Range following the floundering of the Farallon plate and during the development of the San Andreas fault. The flow hosts a variety of disequilibrium crystals and textures including resorbed and overgrown feldspar phenocrysts with inclusion-rich zones, quartz-bearing enclaves, and clusters of plagioclase +/- chromium diopside, magnesian augite, quartz, hornblende, and orthopyroxene crystals and envelopes of contrasting composition with both the groundmass and the enclaves. Current evidence suggests that magma generation and differentiation commonly take place mainly in the lower crust and batches of magma are emplaced and equilibrate across a range of crustal levels. Crystallization depths and temperatures of various phases in the flow were obtained with new and revised geothermometers and geobarometers to examine the petrogenesis of the lava flow. Major elements of parental melts for most of the mineral phases were estimated using thermobarometry equilibrium tests and rare earth and trace element concentrations of parental melts of hornblendes and clinopyroxenes were calculated using known partition coefficients elements. Thermobarometry shows distinct ranges of temperatures and pressures for each component of the flow and calculated parental melts of various phases are distinct from one another. Orthopyroxenes crystallized at depths greater than 25 km, at the highest temperatures from the most mafic parent, estimated to be a picro-basalt. Clinopyroxenes crystallized at 11.5 – 30 km, lower temperatures and a more evolved parent of basalt or trachybasalt composition. Plagioclase crystallized throughout the crust from a range of intermediate melts and hornblendes crystallized 12 – 13 km from a parental melt similar in composition to the groundmass. This study demonstrates the lava flow hosts minerals that crystallized from different parent melts at various crustal levels. Extension and previous magmatism provided a rapid path for magma to ascend, subduing crustal assimilation and enhancing the probability of a diverse crystal cargo that retains the record of the plumbing system beneath a volcanic complex.

Although challenges in water and sanitation access are often assumed to be issues of low- and middle-income nations, over 400,000 homes in the United States still lack access to complete indoor plumbing. Previous research has demonstrated that the remaining plumbing challenges are more prevalent in communities with high Black and brown populations. This study hypothesizes that the 1930s practice of redlining by the Home Owners' Loan Corporation (HOLC), which systematically denied loans to minority populations, is linked to present-day inadequate plumbing access (i.e. defined as incomplete plumbing above the national average). Digitized HOLC maps for 202 urban areas across the country and US Census data from the 2016-2020 American Community Survey were combined to interpolate the modern-day plumbing access for historic neighborhoods (n=8871 communities). Analysis via binomial logistic regression demonstrated that nationally, redlined communities (HOLC Grade "D") are significantly more likely to have a rate of incomplete plumbing above the national average as compared to greenlined communities (HOLC Grade "A") (0.1352; CI= +0.036). This finding was also observed for three of the nation's four census sub-regions (Northeast, Midwest, West). Slight differences by region in relationships between the proportion of specific racial/ethnic populations on rates of incomplete plumbing demonstrate the need for targeted place-based interdisciplinary examinations of exclusionary practices. The demonstration of the present-day impacts of redlining after nearly 90 years emphasizes the need to intentionally mitigate past injustices to ensure modern-day equity. / Master of Science / Access to water is a prevailing issue in underserved communities. Over 400,000 homes in the United States still lack access to complete indoor plumbing. This condition is called incomplete plumbing which is defined by the US Census Bureau as not being able to use running water, or flush a toilet, or bath. Redlining is the historical practice of denying loans to homeowners in a certain area based on their race or economic status. Our study sought to discover whether redlining has negatively affected the presence of plumbing in homes. To do this we examined whether incomplete plumbing in 2020 was above the national average in areas that were previously redlined. We found that redlined communities are significantly more likely to have a rate of incomplete plumbing above the national average as compared to greenlined communities. The same trend was found in three of the nation's four census sub-regions (Northeast, Midwest, and West). These findings show that racist practices such as redlining have had a lasting effect on modern-day infrastructure such as plumbing.

Nitrification is increasingly of concern in US potable water systems, due to changes from chlorine to chloramine as a secondary disinfectant in order to comply with new regulations for disinfectant by-products. The ammonia that is released from the chloramine decay supports nitrification. A comprehensive literature review systematically examined the complex inter-relationships between nitrification, materials corrosion and metals release. That analysis suggested that nitrification could accelerate decay of chloramine, enhance corrosion of water distribution system materials, and increase leaching of lead and copper to potable water under at least some circumstances. Moreover, that certain plumbing materials would inhibit nitrification, but that in other situations the plumbing materials would enhance nitrification. Experiments verified that nitrification could affect the relative efficacy of chlorine versus chloramine in controlling heterotrophic bacteria in premise plumbing. Without nitrification, chloramine was always more persistent and effective than chlorine in controlling biofilms. But with nitrification and in pipe materials that are relatively non-reactive with chlorine, chloramine was much less persistent and less effective than chlorine. In materials that are reactive with chlorine such as iron pipes, the relative efficacy of chloramine versus chlorine depends on the relative rate of corrosion and rate of nitrification. High rates of corrosion and low rates of nitrification favor the use of chloramine versus free chlorine in controlling bacteria. Plumbing materials had profound impacts on the incidence of nitrification in homes. Effects were due to toxicity (i.e., release of Cu⁺²), recycling of nitrate back to ammonia substrate by reaction (zero-valent iron, lead or zinc materials), or release of nutrients that are essential to nitrification by leaching from concrete or other materials. As a general rule it was determined that concrete and iron materials encouraged growth of nitrifiers in certain oligotrophic waters, materials such as lead, PVC/plastic pipe, glass and surfaces of other materials were readily colonized by nitrifiers, and materials such as copper and brass were very toxic and relatively resistant to nitrifier colonization. Dependent on circumstance, nitrification had no effect, increased or decreased aspects of materials corrosion. Nitrification markedly increased lead contamination of low alkalinity potable water by reducing the pH. In some cases nitrification dramatically decreased leaching of zinc to potable water from galvanized iron, because of lowered dissolved oxygen and reduced pH. Nitrification did not affect copper solubility in low alkalinity water, but is expected to increase copper solubility in higher alkalinity waters. Finally, nitrification in homes plumbed with PVC or plastics can drop the pH and increase leaching of lead from downstream brass materials in faucets. This can explain why some modern homes plumbed with PVC can have more lead in water when compared to homes plumbed with copper pipe. Phosphate had profound impacts on the incidence of nitrification and resulting effects on water quality. While phosphate levels below about 5 ppb could strongly inhibit nitrification due to a nutrient limitation, nitrifiers can obtain sufficient phosphate from plastic, concrete, copper and iron pipe materials to meet nutritional needs. High levels of phosphate inhibitor can reduce the concentration of Cu⁺² ions and make nitrification more likely, but phosphate can also sometimes lower the corrosion rate and increase the stability of disinfectant and its efficacy in controlling nitrifiers. Phosphate plays a key role in determining where, when and if problems with nitrification will occur in a given water distribution system. This work provides some new fundamental and practical insights to nitrification issues through a comprehensive literature review, lab experiments, solubility modeling and field studies. The results and practical tools developed can be used by utilities and consumers to predict nitrification events and resulting water quality problems, and to make rational decisions about practices such as inhibitor dosing, plumbing material selection and use of whole house filters. / Ph. D.

This thesis provides a comprehensive look at water hammer with an emphasis on home plumbing systems. The mathematics of water hammer are explained, including the momentum and continuity equations for conduits, system construction, and the four-point implicit finite difference scheme to numerically solve the problem. This paper also shows how the unsteady momentum and continuity equations can be used to solve water distribution problems instead of the steady-state energy and continuity equations, along with the examples problems which show that an unsteady approach is more suitable than the standard Hardy-Cross method. Residential plumbing systems are examined in this paper, household fixtures are modeled for their hydraulic functions, and several water hammer simulations are run using the Water Hammer and Mass Oscillation program (WHAMO). It is determined from these simulations that the amount of air volume in the system is a key factor in controlling water hammer. Abnormal pump operation is clearly explained including a description of the four quadrants and eight zones of operation as well as the mathematics and a numerical scheme for computation. Low pressures caused by transients can lead to intrusion and contamination of the drinking water supply. Several scenarios are simulated using the WHAMO program and cases are provided in which intrusion occurs. From the intrusion scenarios, key factors for intrusion to occur during transients include the starting energy in the system, the magnitude of the transient, the hydraulics of the intrusion opening, and the external energy on the pipe (the level of the groundwater table). A primer for using WHAMO is provided as an appendix as well. / Master of Science

Potable water distribution systems are broken into major and minor distribution networks. Major water distribution networks refer to large-scale municipal pipe systems extending from the treatment plant to the upstream node of the water service line for buildings. Minor water distribution systems, also referred to as plumbing water distribution systems, run from the upstream node of the water service line to all interior plumbing fixtures and demand nodes associated with the building. Most texts and research papers focus on major systems, while only a small number of documents are available concerning the design and analysis of minor systems. In general, the available minor system documents are quite prescriptive in nature. This thesis presents a comprehensive evaluation of contemporary plumbing water distribution system design. All underlying theory is explained and advantages and drawbacks are discussed. Furthermore, contemporary methods for designing minor distribution systems have come under recent scrutiny. Issues have been raised regarding the accuracy of water demand estimation procedures for plumbing systems, namely, Hunter's method. Demand estimates are crucial for designing minor piping systems. The formulation and application of a pressure-driven design approach to replace Hunter-based design methods is presented. EPANET, a commonly used hydraulic modeling software package, is utilized to evaluate network behavior. Example applications are presented to illustrate the robustness of a pressure-driven approach, while also allowing the evaluation of plumbing water distribution system performance under worst-case loading conditions. / Master of Science

Legionella pneumophila (Lp) and nontuberculous mycobacteria (NTM) are opportunistic pathogens that can be transmitted via drinking water, when tiny droplets containing the bacteria are aerosolized and inhaled during activities such as showering. The resulting respiratory illnesses, Legionnaires' Disease and NTM lung disease, are among the leading sources of drinking water associated disease in the United States and other parts of the world. Lp and NTM are both difficult to control, because they establish as part of natural biofilms that form within the interiors of pipes and fixtures that deliver drinking water to the point of use. These pathogens are especially problematic within premise (i.e., building) plumbing, where intermittent use throughout the day leads to long periods of stagnation, increased water age, warmer temperatures, and depleted disinfectant residuals that exacerbate bacterial growth. The recent advent of high throughput DNA sequencing has led to the discovery that drinking water microbiomes are diverse, complex, and largely comprised of non-pathogenic microbes. This has further led researchers to hypothesize that the microbial ecology of this diverse microbiome could be harnessed as a natural means to control Lp and NTM, i.e., a "probiotic" approach, but such an approach has not yet been demonstrated. The objective of this study was to assess this hypothesis by utilizing biologically active granular activated carbon (GAC) filters, which are already a widely used drinking water treatment both at the municipal and household scale, as a means to naturally shape the microbial ecology of downstream premise plumbing and inhibit Lp and NTM proliferation. GAC has an extremely high surface area that aids removal of organic carbon via adsorption but also provides an ideal habitat for establishment of biofilms, which removes organic carbon from the water via biodegradation. Convectively-mixed pipe reactors (CMPRs) were used for replicable simulation of premise plumbing distal taps. The CMPRs consisted of four-foot-long closed polyvinyl chloride (PVC) pipe segments with the sealed bottom portion resting in a ~48 °C water bath and with the top portion plugged and exposed to the cooler, ambient atmosphere (25 °C in this study), inducing convective mixing and resulting in an internal water temperature of 37 °C. PVC was chosen because it is common in premise plumbing and generally leaches the least organic carbon among the different types of plastic pipe. Four different influent water conditions were implemented in the experimental design: 1) Untreated, dechlorinated municipal tap water with high organic carbon and low biomass; 2) GAC-treated tap water with low organic carbon and elevated, viable biomass; 3) GAC-treated + 0.22-m pore size membrane-filtered tap water to remove both nutrients and biomass; 4) GAC-treated tap water pasteurized at 70 °C with low nutrients and elevated, killed biomass. The 0.22-m pore size membrane filter simulated the use of a building scale particle filter, while pasteurization simulated water passing through a hot water heater at an elevated temperature recommended for pathogen thermal disinfection. To understand the influence of these experimental conditions on older pipes containing mature biofilms versus new pipes that leach more organics and are being freshly colonized, a set of older pipes colonized with mature ~4-year-old biofilms were compared to newly purchased pipes. Each set of pipes was tested in triplicate for the four different experimental conditions with the full volume replaced three times a week for eight months, simulating infrequently used taps containing warm, continuously mixing water thought to create conditions at a very high risk for opportunistic pathogen growth. In the aged CMPR bulk water effluents, droplet-digital-polymerase-chain-reaction measurements showed a one-log reduction of Lp and NTM when receiving GAC-treated or GAC-treated + particle-filtered influent water versus receiving dechlorinated municipal tap water or GAC-treated + pasteurized water. These findings suggest that decreased biodegradable dissolved organic carbon achieved by GAC filtration acted to suppress Lp and NTM growth, while the additional step of biomass removal by particle filtration provided a more modest benefit. In the CMPRs consisting of new pipes, concentrations of Lp and NTMs in the effluent bulk water were similar among the experimental conditions, except that the CMPRs receiving the GAC-treated + particle-filtered influent water experienced a two-log reduction in NTMs. These results demonstrate that the colonization and proliferation of NTM within premise plumbing can be significantly controlled by limiting nutrients and biomass in the influent water. This work demonstrates the potential of harnessing GAC-treatment as a means to Control Lp and NTM in premise plumbing via nutrient removal. In scenarios where chemical disinfectants have been depleted, off-the-shelf GAC-treatment used as point-of-entry treatment to large buildings with recirculating plumbing could provide benefits that have previously been unrecognized. Alternatively, pasteurization in very hot water heaters could provide a short-term disinfection benefit, but eventually the nutrients embodied in the dead biomass undermine the positive influence of the nutrient removal provided by the GAC-treatment. Improved mechanistic understanding of probiotic strategies to opportunistic pathogen control would be needed to overcome inherent limitations to the approaches examined herein, if more effective control is desired in the absence of thermal or chemical disinfection. / Master of Science / Legionella pneumophila (Lp) and nontuberculous mycobacteria (NTM) are bacterial pathogens that are the leading source of drinking water-associated disease in the US. Unfortunately, they are not effectively controlled by protections put in place by the US Safe Drinking Water Act (SDWA). Firstly, they cause respiratory infections, which are spread when tiny droplets of water are inhaled during activities such as showering, whereas the SDWA is specifically designed to protect against ingested pathogens. Secondly, unlike fecal-derived organisms (e.g. E. coli) that are the focus of the SDWA, Lp and NTM grow naturally in drinking water distribution systems, especially in premise (i.e., building) plumbing, where water is warmer and more stagnant. Therefore, even if water leaving the treatment plant is devoid of Lp or NTM, this does not guarantee that the consumer's tap water will be Lp- or NTM-free. Also, even though chlorine or other chemical disinfectant is required by the SDWA to be added to the water leaving the treatment plant to control downstream microbial growth, the disinfectant can be depleted or absent within the premise plumbing itself. Additionally, both Lp and NTM tend to more naturally resist chemical disinfectants than fecal-derived organisms. This research is aimed at overcoming these challenges, opening the door to new approaches to controlling Lp and NTM in premise plumbing. Historically, any microbial growth occurring in drinking water has been viewed as problematic, as it usually indicates the chemical disinfectant is inadequately protecting consumers. However, this work explores whether having an abundant community of beneficial bacteria could improve microbial water quality by competing against pathogens for limited space for attachment and nutrients. Such an approach would be analogous to the use of probiotics in humans, to establish a beneficial gut flora that is less susceptible to pathogen invasion. Granular activated carbon (GAC) filters are often used at drinking water treatment plants and by consumers as a point-of-use (e.g., installed on the kitchen tap or in a refrigerator) or whole-house treatment to remove any contaminants of concern and improve the taste and odor of tap water. The granules within GAC filters have a high surface area that helps remove contaminants, but also provides an environment where microbes can live and thrive. As water enters the filter, beneficial microbes can break down any remaining nutrients in the water (e.g., organic carbon and nitrogen). Additionally, the water leaving the filter carries high levels of microbes that grow on the GAC filter that are shed as water passes through. The resulting water with reduced nutrients and higher concentrations of potentially beneficial microbes could create a competitive environment that alters growth of harmful bacteria, like Lp and NTM, in downstream portions of plumbing. The incoming cold water is also warmed by the building envelope, which increases bacterial growth rates. Thus, the underlying hypothesis of this research is that GAC treatment could provide a combination of reduced nutrients and competitive microbes as water enters downstream premise plumbing and reduce the growth of Lp and NTM. However, GAC-treated water within a building can be further altered by other treatments, like a very hot water heater, which would heat and kill the microbes flowing through it, or a particle filter, which could remove the microbes in the water. This work also seeks to understand how these additional treatments might improve or interfere the nutrient reduction and addition of competitive microbes provided by GAC treatment. This research explores how all these different scenarios affect the growth of Lp and NTM using a lab-scale simulated premise plumbing system constructed out of polyvinyl chloride (PVC) pipe that is a common plumbing material used in homes. Water that was added to the pipes was prepared in four different ways to test the probiotic control hypothesis across distinct experimental conditions that replicate the different influent water scenarios. The four conditions were implemented over the course of eight months with regular chemical and biological analyses conducted to understand the effects of the different influent waters on Lp and NTM. It was discovered that premise plumbing with mature biofilms receiving GAC-treated water or GAC-treated + particle-filtered water contained ~90% less Lp and NTM than premise plumbing receiving non-filtered municipal tap water. However, if the GAC-treated water passes through a water heater, the capacity to limit Lp or NTM growth was lost. While GAC filters are currently thought of as an instantaneous treatment that removes contaminants from water, this work demonstrates how GAC treatment might provide prolonged benefits to water, after it has passed through the filter on its journey to a shower head or faucet. Increased understanding of the exact mechanisms of limited pathogen growth gained by this research can lead to new and effective approaches to protect people from contracting diseases caused by Lp and NTM.

Master of Science / Department of Architectural Engineering and Construction Science / Thomas Logan / Typical building sanitary lines are sloped at a minimum of 1/8” to utilize gravity and prevent liquid separation from solid waste. The purpose of this research is to analyze how a lesser amount of water from a 1.6 gallon per flush water closet affects drainage in a four inch diameter pipe at 1/4" slope. Low flow water closet manufacturers ensure that waste clears the bowl, but there is no significant research following the flushed water further down the pipe line. This research utilizes a 1.6 gallon per flush floor-mounted water closet connected to 30 feet of sloped four inch PVC Drain Waste Vent piping. Data presented from 25 flush trials indicates that further research needs to be conducted at a smaller pipe diameter. Four-inch piping is too large, causing the 1.6 gallons of water to quickly lose the required force over the course of 30 feet, resulting in pipe line clogs. An average of four additional water-only flushes are necessary to completely clear the test media and toilet paper from the pipe. This research references previously published research and focuses on test results presented by the Plumbing Efficiency Research Coalition. Two case studies of city wide replacements of old water closets are presented to discuss the viability of city wide mandates in relation to water conservation.

Lead exposure poses as a risk factor for various adverse health effects including intellectual delays, reduced IQ, and behavioural problems in children, as well as cognitive decline in adults. Lead enters drinking water through corrosion of leaded materials such as lead pipes, solder, and brass devices. Three rounds of residential and non-residential lead monitoring were conducted to evaluate the corrosion control implemented by Halifax Water, and to identify sites with elevated lead concentrations. Follow-up testing was conducted at several sites to determine the sources of lead, and the factors that contributed to high lead release. Finally, a bench scale experiment was conducted to determine the impacts of plumbing flux on metal release. The lead action level for residential testing was exceeded only in the round that was conducted during the winter. Lead concentrations were also higher in the winter rounds than the fall round of non-residential sampling. The seasonal lead variation was likely caused by fluctuations in aluminum residuals in the water leaving the plant. Frequency of use, age, and outlet manufacturer were factors that were associated with elevated lead levels. Follow-up studies were conducted at several fountains to determine the source of elevated lead levels. These fountains typically contained several leaded components and received infrequent use. Fountains with leaded components that received high, regular usage had often provided samples with low lead levels. Drinking fountains that were banned and recalled in the US for potentially containing lead lined cooling tanks were found at eight locations throughout the study area. It was found that three of the eight likely contained the lined cooling tanks. High lead levels were present in samples collected from these fountains, even at sites with frequent usage. Low-use sites with the lead lined tank produced the highest lead levels in this study. Fountains suspected of containing lead lined tanks were removed and replaced, and the lead levels were significantly reduced at these sites. The impact of plumbing flux on metal concentrations was relatively short in duration, lasting only a week for most metals, with the exception of tin. Lead levels were found to stabilize under all flux conditions following roughly 40 L of flushing. Flux type was the main factor contributing to the elevated metals. The traditional petroleum flux was much more resistant to flushing than the water soluble flux, as it caused elevated tin levels for several weeks and a tacky flux deposition in the copper pipe remained even three months after the start of the experiment. The high amount of chloride from the flux was aggressive towards the copper corrosion, but it is unclear if this would have led to copper pitting corrosion.

No description available.

Knots and links $L\subset S^3$ carry a wealth of data. Spanning surfaces $F$ (1- or 2-sided), $\partial F=L$, especially {\bf checkerboard} surfaces from link diagrams $D\subset S^2$, help to mine this data. This text explores the structure of these surfaces, with a focus on a gluing operation called {\bf plumbing}, or {\it Murasugi sum}. First, naive classification questions provide natural and accessible motivation for the geometric and algebraic notions of essentiality (incompressibility with $\partial$-incompressibility and $\pi_1$-injectivity, respectively). This opening narrative also scaffolds a system of hyperlinks to the usual background information, which lies out of the way in appendices and glossaries. We then extend both notions of essentiality to define geometric and algebraic {\it degrees} of essentiality, $\underset{\hookrightarrow}{\text{ess}}(F)$ and $\text{ess}(F)$. For the latter, cutting $S^3$ along $F$ and letting $\mathcal{X}$ denote the set of compressing disks for $\partial (S^3\backslash\backslash F)$ in $S^3\backslash\backslash F$, $\text{ess}(F):=\min_{X\in\mathcal{X}}|\partial X\cap L|$. Extending results of Gabai and Ozawa, we prove that plumbing respects degrees of algebraic essentiality, $\text{ess}(F_1*F_2)\geq\min_{i=1,2}\text{ess}(F_i)$, provided $F_1,F_2$ are essential. We also show by example that plumbing does not respect the condition of geometric essentiality. We ask which surfaces de-plumb uniquely. We show that, in general, essentiality is necessary but insufficient, and we give various sufficient conditions. We consider Ozawa's notion of representativity $r(F,L)$, which is defined similarly to $\text{ess}(F)$, except that $F$ is a closed surface in $S^3$ that contains $L$, rather than a surface whose boundary equals $L$. We use Menasco's crossing bubbles to describe a sort of thin position for such a closed surface, relative to a given link diagram, and we prove in the case of alternating links that $r(F,L)\leq2$. (The contents of Chapter 4, under the title Alternating links have representativity 2, are first published in Algebraic \& Geometric Topology in 2018, published by Mathematical Sciences Publishers.) We then adapt these arguments to the context of spanning surfaces, obtaining a simpler proof of a useful crossing band lemma, as well as a foundation for future attempts to better classify the spanning surfaces for a given alternating link. We adapt the operation of plumbing to the context of Khovanov homology. We prove that every homogeneously adequate Kauffman state has enhancements $X^\pm$ in distinct $j$-gradings whose traces (which we define) represent nonzero Khovanov homology classes over $\mathbb{Z}/2\mathbb{Z}$, and that this is also true over $\mathbb{Z}$ when all $A$-blocks' state surfaces are two-sided. A direct proof constructs $X^\pm$ explicitly. An alternate proof, reflecting the theorem's geometric motivation, applies our adapted plumbing operation. Finally, we describe an interpretation of Khovanov homology in terms of decorated cell decompositions of abstract, nonorientable surfaces, featuring properly embedded (1+1)-dimensional nonorientable cobordisms in (2+1)-dimensional nonorientable cobordisms. This formulation contains a planarity condition; removing this condition leads to Khovanov homology for virtual link diagrams.