Drinking Water Utility-Level Understanding of Climate Change Effects to System Reliability.

Climate change hazards, including increased temperatures, drought, sea level rise, extreme precipitation, wildfires, and changes in freeze-thaw cycles, are expected to degrade drinking water utility system infrastructure and decrease the reliability of water provision. To assess how drinking water utility manager perceptions of these risks affect utility planning, 60 semistructured interviews were conducted with utilities of various sizes, source water supplies, and United States geographical regions. This study analyzes these interviews (1) to evaluate which climate hazards are of primary concern to drinking water managers, (2) to develop a mental model framework for assessing utility-level understanding of climate change risks to system reliability, and (3) to examine the status of current water utility adaptation planning.

Assessment of Lead in Drinking Water from Multiple Drinking Water Sampling Programs for a Midsize City.

Following an exceedance of the lead action level for drinking water in 2016, the Pittsburgh Water and Sewer Authority (PWSA) undertook two sampling programs: the required biannual Lead and Copper Rule (LCR) compliance testing and a home sampling program based on customer requests. The LCR sampling results, at locations expected to be elevated when corrosion is not well controlled, had higher concentrations than customer-requested homes, with 90th percentile values for the LCR sites exceeding the action level through 2019 (except for June 2018). Customer-requested concentrations showed greater variability, with the median lead concentration for customer-requested samples below detection for each year of sampling, suggesting only some homes show elevated lead when corrosion control is not fully effective.

Modeling Trihalomethane Increases Associated with Source Water Bromide Contributed by Coal-Fired Power Plants in the Monongahela River Basin.

Increases in source water bromide concentrations are challenging for drinking water utilities since bromide contributes to the formation of disinfection byproducts (DBPs) that have negative human-health effects. The present work evaluates the role of coal-fired power plant wet flue gas desulfurization (FGD)-associated bromide loads on in-stream bromide concentrations in the Monongahela River Basin in the water year (WY) 1998 (during a nationwide study) and over a five-year period from WYs 2013 through 2017. Under mean flow conditions in the lower Monongahela River for the WYs of interest, the median-estimated wet FGD bromide discharges are modeled to represent a significant fraction (27-57%) of observed bromide concentrations with the range representing the change in load conditions across WYs.

Fluorescence characterization of organic matter and fouling: Case study in a full-scale reverse osmosis membrane treatment plant.

Membranes used for water treatment are subject to organic fouling, caused by organic matter in source water. Characterizing organic matter has the potential to improve fouling prediction since the development of an organic fouling layer on the membrane is dependent on the specific characteristics of the organic matter. A field study was performed at a full-scale reverse osmosis water treatment plant that treats secondary wastewater effluent for industrial reuse at a power plant.

Reduction in sulfate inhibition of microbial dechlorination of polychlorinated biphenyls in Hudson and Grasse River sediments through fatty acid supplementation.

Microbial dechlorination of polychlorinated biphenyls (PCBs) in aquatic sediments may reduce the need for dredging for remediation. To better understand this biotransformation route under different geochemical conditions, the influence of sulfate on dechlorination in sediments from the Hudson River and the Grasse River spiked with two PCB mixtures (PCB 5/12, 64/71, 105/114 and 149/153/170 in Mixture 1 and PCB 5/12, 64/71, 82/97/99, 144/170 in Mixture 2) was investigated. The results showed that PCB dechlorination was partially inhibited in the sulfate-amended sediment microcosms.

Biogenic Cyanide Production Promotes Dissolution of Gold Nanoparticles in Soil.

Gold nanoparticles (Au NPs) are often used to study the physiochemical behavior and distribution of nanomaterials in natural systems because they are assumed to be inert under environmental conditions, even though Au can be oxidized and dissolved by a common environmental compound: cyanide. We used the cyanogenic soil bacterium, Chromobacterium violaceum, to demonstrate that quorum-sensing-regulated cyanide production could lead to a high rate of oxidative dissolution of Au NPs in soil. After 7 days of incubation in a pH 7.

Coal-Fired Power Plant Wet Flue Gas Desulfurization Bromide Discharges to U.S. Watersheds and Their Contributions to Drinking Water Sources.

Wet flue gas desulfurization (FGD) wastewater discharges from coal-fired power plants may increase bromide concentrations at downstream drinking water intakes, leading to increased formation of toxic disinfection byproducts (DBPs). Despite this, bromide was not regulated in FGD wastewater in the 2015 Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category (ELGs). Case-by-case management was recommended instead, depending on downstream drinking water effects.

Effects of Ferric Oxyhydroxide on Anaerobic Microbial Dechlorination of Polychlorinated Biphenyls in Hudson and Grasse River Sediment Microcosms: Dechlorination Extent, Preferences, Removal, and Its Enhancement.

Microbial reductive dechlorination of polychlorinated biphenyls (PCBs) has been observed in many PCB-impacted sediments. However, this biodegradation is relatively site-specific and can be affected by PCB compositions and sediment geochemical conditions. To better understand the influence of a common competing electron acceptor, ferric oxyhydroxide (FeOOH), on dechlorination, two sediments (Hudson River and Grasse River sediments), and two PCB mixtures (PCB 5/12, 64/71, 105/114, and 149/153/170 in and PCB 5/12, 64/71, 82/97/99, 144/170 in ) were used for this microcosm study.

Quorum Sensing Signals Form Complexes with Ag and Cu Cations.

Quorum sensing (QS) regulates important bacterial behaviors such as virulent protein production and biofilm formation. QS requires that molecular signals are exchanged between cells, extracellularly, where environmental conditions influence signal stability. In this work, we present a novel complexation between metal cations (Ag and Cu) and a QS autoinducer signal, N-hexanoyl- L-homoserine lactone (HHL).

Power Plant Bromide Discharges and Downstream Drinking Water Systems in Pennsylvania.

Coal-fired power plants equipped with wet flue gas desulfurization (FGD) systems have been implicated in increasing bromide levels and subsequent increases in disinfection byproducts at downstream drinking water plants. Bromide was not included as a regulated constituent in the recent steam electric effluent limitations guidelines and standards (ELGs) since the U.S.

Disinfection byproduct regulatory compliance surrogates and bromide-associated risk.

Natural and anthropogenic factors can alter bromide concentrations in drinking water sources. Increasing source water bromide concentrations increases the formation and alters the speciation of disinfection byproducts (DBPs) formed during drinking water treatment. Brominated DBPs are more toxic than their chlorinated analogs, and thus have a greater impact on human health.

Microbial-Catalyzed Reductive Dechlorination of Polychlorinated Biphenyls in Hudson and Grasse River Sediment Microcosms: Determination of Dechlorination Preferences and Identification of Rare Ortho Removal Pathways.

Biodegradation of polychlorinated biphenyls (PCBs) is an important transformation and detoxification route in the environment. To better understand the influence of PCB congener compositions on dechlorination, sediments from two rivers, Hudson and Grasse, and two PCB mixtures (PCB 5/12, 64/71, 105/114, and 149/153/170 in Mixture 1 and PCB 5/12, 64/71, 82/97/99, and 144/170 in Mixture 2) were used for this microcosm study. The Grasse River sediment microcosms exhibited more extensive dechlorination than the Hudson River sediment microcosms.

Current and Potential Future Bromide Loads from Coal-Fired Power Plants in the Allegheny River Basin and Their Effects on Downstream Concentrations.

The presence of bromide in rivers does not affect ecosystems or present a human health risk; however, elevated concentrations of bromide in drinking water sources can lead to difficulty meeting drinking water disinfection byproduct (DBP) regulations. Recent attention has focused on oil and gas wastewater and coal-fired power plant wet flue gas desulfurization (FGD) wastewater bromide discharges. Bromide can be added to coal to enhance mercury removal, and increased use of bromide at some power plants is expected.

Impacts of PCB analytical interpretation uncertainties on dechlorination assessment and remedial decisions.

Laboratory analyses of polychlorinated biphenyls (PCBs) often do not quantitate the 209 individual PCB congeners, thereby requiring analyst interpretation to determine individual congener concentrations. Error introduced during this interpretation is subsequently propagated to calculated surrogate variables, such as the number of chlorines per biphenyl (CPB), and the molar dechlorination product ratio (MDPR), which are used to assess the extent of dechlorination and inform remedial decisions. The present work applies a Monte Carlo (MC) analysis to assess current methods for quantitating co-eluting congeners and the errors that could occur in individual congeners and derived CPB and MDPR estimates.

The effect of sampling strategies on assessment of water quality criteria attainment.

Sample locations for large river studies affect the representativeness of data, and thus can alter decisions made regarding river conditions and the need for interventions to improve water quality. The present study evaluated three water-quality sampling programs for Total Dissolved Solid (TDS) assessment in the Monongahela River from 2008 to 2012. The sampling plans cover the same 145 km of river but differ in frequency, sample location and type (e.

Life cycle water consumption and wastewater generation impacts of a Marcellus shale gas well.

This study estimates the life cycle water consumption and wastewater generation impacts of a Marcellus shale gas well from its construction to end of life. Direct water consumption at the well site was assessed by analysis of data from approximately 500 individual well completion reports collected in 2010 by the Pennsylvania Department of Conservation and Natural Resources. Indirect water consumption for supply chain production at each life cycle stage of the well was estimated using the economic input-output life cycle assessment (EIO-LCA) method.

Source water changes and energy extraction activities in the Monongahela River, 2009-2012.

Fossil fuel wastewaters disposed of to surface waters used as sources for potable water supply have the potential to affect finished drinking water quality since these produced waters contain high concentrations of constituents that are of concern to drinking water providers (including dissolved solids, sulfate, chloride, and bromide). A 3-year field study in the Monongahela River was conducted to determine how constituent concentrations and associated loads changed in the river basin, and whether these changes were caused by surface discharges associated with shale gas extraction. Low flow during the dry summer of 2010 contributed to increases in bromide concentrations at drinking water intakes; however, similar low flow conditions in summer of 2012 did not, indicating bromide loads discharged to the river decreased from 2010 to 2012.

Multivariate distributions of disinfection by-products in chlorinated drinking water.

Drinking water disinfection by-product (DBP) occurrence research is important in supporting risk assessment and regulatory performance assessment. Recent DBP occurrence surveys have expanded their scope to include non-regulated priority DBPs as well as regulated DBPs. This study applies a Box-Cox transformed multivariate normal model and data augmentation methods for left-censored and missing observations to US EPA Information Collection Rule (ICR) drinking water data to describe the variability in the trihalomethane (THM4), trihaloacetic acid (THAA), dihaloacetic acid (DHAA), and dihaloacetonitrile (DHAN) DBP classes, the relationship between class-sum and the occurrence of individual DBPs within these classes.

Raman spectroscopic discrimination of cell response to chemical and physical inactivation.

Raman spectroscopy was applied to study Escherichia coli and Staphylococcus epidermidis cells that were inactivated by different chemicals and stress conditions including starvation and high temperature. E. coli cells exposed to starvation conditions over several days lost viability at the same rate that spectral bands assigned to DNA and RNA bases decreased in intensity.

Expanded thermodynamic true yield prediction model: adjustments and limitations.

Bacterial yield prediction is critical for bioprocess optimization and modeling of natural biological systems. In previous work, an expanded thermodynamic true yield prediction model was developed through incorporating carbon balance and nitrogen balance along with electron balance and energy balance. In the present work, the application of the expanded model is demonstrated in multiple growth situations (aerobic heterotrophs, anoxic, anaerobic heterotrophs, and autolithotrophs).

Bacterial growth yields on EDTA, NTA, and their biodegradation intermediates.

Ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) are widely used anthropogenic chelating agents for control of metal speciation and are ubiquitous in natural waters and wastewaters. This is the first report of systematic measurement of the growth yields of a mixed culture (BNC1-BNC2) on EDTA and its biodegradation intermediates, and of Aminobacter aminovorans (aka Chelatobacter heintzii) ATCC 29600 on NTA and its biodegradation intermediates. The yields measured for BNC1-BNC2 co-culture were 75.