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The occurrence, spatiotemporal changes, and health hazard of antibiotics in source water and finished water in the Wuhan section of the Yangtze River are not well understood. In this study, 43 source water and finished water samples were collected from 11 water plants in Wuhan in August 2021 and May 2022. Fifty-one antibiotics from eight categories were measured. A total of 41 antibiotics were detected in the source water samples, and 24 in the finished water samples. The total antibiotic concentration in source water ranged from 1.68 to 437.18 ng/L, which is significantly higher than that in finished water (2.04–87.25 ng/L). Sulfonamides and lincosamides were predominant, accounting for nearly 80% of the total antibiotic concentration. Lincomycin constituted nearly 30% of the total antibiotic concentration in the source water. In August 2021, the average total antibiotic concentration in source water was 107.12 ng/L, higher than in May 2022 (63.13 ng/L). Spatially, the total antibiotic concentrations in samples collected from the Han River, a tributary of the Yangtze River, were higher than those in the main stream of the Yangtze River. Ecological risk assessment indicated that the hazard posed by most antibiotics were negligible. Lincomycin potentially posed a high health hazard, and clarithromycin and roxithromycin posed a moderate hazard to infants. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) have been found in both surface water and groundwater, which are sources of drinking water. Since one of the most important routes for MPs to enter the human body is through drinking water, the enormous buildup of MPs in waterbodies and the resulting effects on human health have caused social concern. However, our knowledge of drinking water treatment plant (DWTP) treatment techniques affects the removal of MPs, and there aren't any standardized or efficient quality assurance and quality control (QA/QC) measures for sampling and analysis. The current state of MPs in drinking water sources is described in this review, which also provides the most recent data on MPs removal by various DWTP units. Lastly, we propose practical QA/QC techniques to ensure the accuracy of MP analysis. This review intends to present the most recent data on MPs in drinking water and the effectiveness of MPs removal by DWTP units. It also advises that further research into the mechanisms of MPs removal be done in the future. [ABSTRACT FROM AUTHOR]

ObjectiveThe purpose was to understand the background level of environmental radioactivity in the surrounding area of Qinshan Nuclear Power Plant and accumulate historical monitoring data of radioactivity in the environment， in order to detect and deal with radioactive risk in water sources earlier.MethodsAccording to the requirements of the "Shanghai environmental radioactivity background monitoring plan"， the area 1 closest to the Qinshan Nuclear Power Plant was selected as the monitoring point， and the area 2 far from the nuclear power plant was selected as the blank control point. Considering the seasonal characteristics of high water， low water， and normal water periods， the establishment of sampling points， and population density and other comprehensive factors， a model of sampling from the disease control centers in these two regions was established， with the supervision and quality control by Shanghai disease control center. The water samples were collected once a quarter， with a sampling volume of 5 L each time， and the samples were sent to Shanghai Municipal Center for Disease Control and Prevention for processing and measurement. Since 2012， water samples from the two sources have been collected for more than ten years for the total α and total β monitoring of radioactive levels.Results2012‒2022 Area 1 total α radioactivity， total β radioactivity concentration ranges were 1.83×10-2‒3.93 ×10-2 Bq·L-1 and 6.05×10-2‒23.73 ×10-2 Bq·L-1， respectively. Total α radioactivity and total β radioactivity concentration ranges in Area 2 were 1.63×10-2‒4.46 ×10-2 Bq·L-1， and 9.60×10-2‒25.33 ×10-2 Bq·L-1，respectively.ConclusionThe radioactive levels in the source water of Area 1 and Area 2 are within the normal background range， which meets the requirements of the "Standard test methods for drinking water - radioactive indicators" （GB/T 5750.13‒2006）.

Source water challenges can add complexity to water treatment decisions, but operators must be educated and prepared to meet these challenges. [ABSTRACT FROM AUTHOR]

When a US Marine Corps training facility decided to add a second aquifer to its existing groundwater supply, it designed a treatment plant that would successfully blend the two source waters and meet strict water quality goals. [ABSTRACT FROM AUTHOR]

Increased wildfire activity in the western United States can lead to detrimental cascading effects to water quality. After fires, burned areas may experience significant runoff‐induced erosion and sediment transport into rivers and reservoirs, which could rapidly overwhelm existing drinking water treatment plants. This paper couples an assessment of wildfire risk with an evaluation of water utility preparedness to understand where key fire‐related drinking water vulnerabilities exist. Wildfire risk assessments were constructed and expanded from a commonly used methodology co‐developed between researchers and water managers (Edel et al., 2002), to understand drinking water impacts on water quality after wildfires. A water utility preparedness index was created for this study using publicly available information to contextualize how well utilities may be able to respond to water quality degradation after fires. Results indicate that 22% of utilities studied (10% of the population served) were underprepared for fire and 11% of watersheds used were at greater risk of wildfire (9% of the population served). However, nearly three‐quarters of utilities (76% of the population served) showed a moderate risk of fire and some need for improved fire preparedness. Information developed here could provide a useful framework from which utility managers can better assess their likely wildfire risk and preparation plans. [ABSTRACT FROM AUTHOR]

Safe, good-quality drinking water is a foundation of public health. Its provision relies on multiple barriers, the first being the protection of source water. Source water refers to the bodies of water (aquifers, rivers, lakes, springs, reservoirs) from which communities and individuals take their drinking water. A large waterborne campylobacter outbreak in 2016 spurred the New Zealand government to make a suite of legislative and policy reforms to strengthen the country's drinking water supply system. However, the nitrate contamination of a municipal drinking water source, and its subsequent breach of drinking water standards, should bring renewed attention to the protection of source water. This article presents a case study of the exceedance and a review of legislation and policy governing drinking water sources. It finds that while important steps have been made since 2016, weaknesses in responsibility and accountability remain in Aotearoa's drinking water supply system. [ABSTRACT FROM AUTHOR]

Contaminated source water for cities contributes to negative human health impacts and rising water treatment costs. Nutrient pollution is the primary source of surface water quality impairment in the United States and agriculture is the largest source of nutrient pollution (specifically nitrogen or nitrate) entering waterways. Solutions to source water contamination have historically centered on nutrient removal at the drinking water plant, which often requires additional investment. Pollution prevention through watershed management may be more cost-effective in some contexts and has greater co-benefits, and some drinking water managers and agricultural stakeholders have collaborated to create successful prevention programs. However, drinking water managers must balance several service requirements and regulatory standards, and may lack the resources or capacity needed to effectively engage in or initiate regional collaborations. This paper serves as an introduction to nutrient contamination of source waters and protection measures in the United States and provides a discussion of watershed-scale collaboration, particularly the engagement of municipal drinking water managers. This article is categorized under: Human Water > Water Governance Water and Life > Conservation, Management, and Awareness Science of Water > Water Quality [ABSTRACT FROM AUTHOR]

• A data processing platform, HDPairFinder, was developed to automatically recognize H/D isotope labeled chemicals in HPLC-HRMS data. • Cross-correlation was proposed to address the RT shift caused by the deuterium isotopic effect. • A suite of bioinformatic algorithms was incorporated to effectively remove false positive features. • AMINES, a library of over 38000 amino-containing chemicals, was constructed to facilitate compound annotation. • Over 1000 highly confident H/D-labeled amino-containing compounds can be identified from the data of environmental water samples. The combination of hydrogen/deuterium (H/D) formaldehyde-based isotopic methyl labeling with solid-phase extraction and high-performance liquid chromatography–high resolution mass spectrometry (HPLC-HRMS) is a powerful analytical solution for nontargeted analysis of trace-level amino-containing chemicals in water samples. Given the huge amount of chemical information generated in HPLC-HRMS analysis, identifying all possible H/D-labeled amino chemicals presents a significant challenge in data processing. To address this, we designed a streamlined data processing pipeline that can automatically extract H/D-labeled amino chemicals from the raw HPLC-HRMS data with high accuracy and efficiency. First, we developed a cross-correlation algorithm to correct the retention time shift resulting from deuterium isotopic effects, which enables reliable pairing of H- and D-labeled peaks. Second, we implemented several bioinformatic solutions to remove false chemical features generated by in-source fragmentation, salt adduction, and natural 13C isotopes. Third, we used a data mining strategy to construct the AMINES library that consists of over 38,000 structure-disjointed primary and secondary amines to facilitate putative compound annotation. Finally, we integrated these modules into a freely available R program, HDPairFinder.R. The rationale of each module was justified and its performance tested using experimental H/D-labeled chemical standards and authentic water samples. We further demonstrated the application of HDPairFinder to effectively extract N-containing contaminants, thus enabling the monitoring of changes of primary and secondary N-compounds in authentic water samples. HDPairFinder is a reliable bioinformatic tool for rapid processing of H/D isotopic methyl labeling-based nontargeted analysis of water samples, and will facilitate a better understanding of N-containing chemical compounds in water. [Display omitted] [ABSTRACT FROM AUTHOR]

BackgroundChina is a big country in the production and use of antibiotics. The abuse of antibiotics enables bacteria in water environment to acquire resistance, and promotes the generation and spread of antibiotics resistance genes (ARGs). The problem of antibiotic-resistant bacteria is increasingly serious and has become a public security issue of global concern. Water environment is a huge reservoir of antibiotics and ARGs. It is of great significance to study the pollution of antibiotics and ARGs in water to protect water sources and optimize the biosecurity of drinking water.ObjectiveTo evaluate the detection of antibiotics and ARGs in typical water sources, and to explore the relationship between antibiotics and ARGs. MethodsWater samples were collected in Heilongjiang, Liaoning, and Hubei provinces during the wet season (from August to October) in 2020. Ten water samples were collected from each of the three places, and a total of 30 water samples were collected in this study. Five kinds of antibiotics, including macrolides, quinolones, sulfonamides, tetracycline, and β-lactam, were detected by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The integron (Intl1), 16S rRNA, and 6 kinds of ARGs were detected by quantitative real-time PCR (qPCR). The ARGs include one macrolide ARGs (ermB), one β-lactam ARGs (blaTEM), two tetracycline ARGs (tetC, tetQ), and two sulfonamide ARGs (sul1, sul2). ResultsThe types of detected antibiotics varied by the three regions, and the concentration ranges of the same antibiotics varied by the three regions (P

Key Takeaways: Source water quality monitoring programs benefit from sampling efforts that address data needs on different spatial and temporal scales. The cost of monitoring programs is more than offset by real savings, avoided costs, and increased support for decision makers. Loveland Water and Power has derived diverse and sometimes unexpected benefits from its monitoring program. [ABSTRACT FROM AUTHOR]

Key Takeaways: Regular monitoring of particle concentration in conjunction with turbidity analysis provides supplementary data that can provide important water quality information. Particle analysis using flow imaging microscopy (FIM) can help operators better understand various treatment processes and algae growth in source waters. Specific size ranges can be monitored using FIM for target pathogens such as Cryptosporidium and Giardia. [ABSTRACT FROM AUTHOR]

Key Takeaways: The effectiveness of powdered activated carbon (PAC) at removing cyanotoxins depends on the specific toxin(s), water pH, and PAC source. A study showed that wood–lignite PAC adsorbed more cyanotoxin than bituminous coal–based PAC, and cyanotoxin removal was more effective at a higher pH. In this study, removal costs decreased as toxin concentration increased, and saxitoxin removal was less expensive when it was present with microcystin‐LR. A decision tree that balances treatment costs with toxin removal efficiency was developed to help water utilities. [ABSTRACT FROM AUTHOR]

After seven years in the making, a state‐of‐the‐art microfiltration membrane facility and new source water intake is being celebrated by the City of Sitka, Alaska. [ABSTRACT FROM AUTHOR]

Alert levels can be established using baseline data to trigger action in source water management and/or water treatment. [ABSTRACT FROM AUTHOR]

Water and wastewater laboratories have many similarities, but they also have unique differences that allow them to generate data that protect public health and the environment. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Effect‐based methods (EBMs) using in vitro bioassays and well plate–based in vivo assays are recommended for water quality monitoring because they can capture the mixture effects of the many chemicals present in water. Many in vitro bioassays are highly sensitive, so an effect in a bioassay does not necessarily indicate poor chemical water quality. Consequently, effect‐based trigger values (EBTs) have been introduced to differentiate between acceptable and unacceptable chemical water quality and are required for the wider acceptance of EBMs by the water sector and regulatory bodies. These EBTs have been derived for both drinking water and surface water to protect human and ecological health, respectively, and are available for assays indicative of specific receptor‐mediated effects, as well as assays indicative of adaptive stress responses, apical effects, and receptor‐mediated effects triggered by many chemicals. An overview of currently available EBTs is provided, and a simple approach is proposed to predict interim EBTs for assays currently without an EBT based on the effect concentration of the assay reference compound. There was good agreement between EBTs predicted using this simplistic approach and EBTs from the literature derived using more robust methods. Finally, an interpretation framework that outlines the steps to take if the effect of a sample exceeds the EBT was developed to help facilitate the uptake of EBMs in routine water quality monitoring and water safety planning for drinking water production. Environ Toxicol Chem 2023;42:714–726. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Key Takeaways: Des Moines Water Works' (DMWW's) source water faces significant water quality challenges from decades of agricultural nutrient pollution in Iowa. Lackluster results in regulating nutrient pollution, along with population growth and effects of climate change, add urgency to DMWW's drive to improve source water quality. To protect its source water, DMWW has collaborated with groups outside of its typical scope, building relationships with those who have the same values and vision. [ABSTRACT FROM AUTHOR]

Several factors may impact bacterial diversity in drinking water distribution systems (DWDSs) including the origin of the raw water, the water treatment technologies, and the disinfection practices applied. 16S rRNA metabarcoding was used for the in-depth characterization of bacterial communities in the four studied Croatian DWDSs (A, B, C, D) two of which had residual disinfectant (A, B) and two were without (C, D), while only B utilized the conventional water treatment technology. Significantly higher diversity and species richness were evidenced in non-disinfected DWDSs (P <0.05) compared to disinfected DWDSs. The phylum Proteobacteria was the most abundant in all the DWDSs, being proportionately higher in non-disinfected systems (P <0.05). The most abundant genera in DWDS-A Mycobacterium and Sphingomonas both positively correlated, whereas Lactobacillus negatively correlated with the concentration of disinfection by-products (DBPs) as a sum of haloacetic acids (HAAs). Conversely, the genus Ralstonia positively correlated with the individual DBP dichloroacetic acid. These results indicate that genera Sphingomonas, Mycobacterium, Lactobacillus , and Ralstonia could have an effect on promoting the formation of DBPs, in a similar manner to how negatively correlated taxa may influence their degradation. [ABSTRACT FROM AUTHOR]

Key Takeaways: Cyanobacteria can, but do not always, produce toxins that may be found in algal blooms, which can pose a public health threat even at low levels in water. The US Environmental Protection Agency, the World Health Organization, and Health Canada have taken varying approaches to establishing guidances for monitoring and managing algal toxins. Although based on different assumptions and interpretations, with somewhat different outcomes, all of the assessments provide appropriate safeguards for drinking water, with different water system impacts and at different treatment costs. [ABSTRACT FROM AUTHOR]

Understanding different types of drinking water sources is key for operators to provide effective treatment. [ABSTRACT FROM AUTHOR]

Key Takeaways: The concentration and composition of per‐ and polyfluoroalkyl substances (PFAS) in source water and treated water goals are the main drivers affecting PFAS management. Separately or together, granular activated carbon and ion exchange media are effective treatment options when trying to minimize PFAS in finished water. Requirements for ultimate disposal or destruction of PFAS and process residuals significantly affect operating costs, which in turn play a critical role in treatment process selection. [ABSTRACT FROM AUTHOR]

To explore the occurrence, source, and risk of 16 priority polycyclic aromatic hydrocarbons (PAHs) in urban source water at the tidal reach of the Yangtze River, eighty-nine surface water samples were collected in 8 field campaigns from July 2018 to November 2019. Fifteen of 16 PAHs except for dibenz(a,h)anthracene (DBA) were found in the water. Detection frequencies were observed between 53 and 72% for PAHs with 4 rings, while most of other PAHs were less detected, e.g., benzo(a)pyrene (BaP) in 31% of samples. The total concentrations of 16 priority PAHs reached up to 2.8 µg·L−1 and increased during the tidal transitions from flood to ebb. The average concentrations of PAHs in ebb tides were higher than those in flood tides. PAH concentrations and compositions showed great variation with different sampling campaigns, and higher levels and more components were observed in the rainy months and cold months. Those priority PAHs in the tidal water source are mainly from combustion activities (especially fossil fuel combustion), but the contribution from oil spills/leakage is also important in rainy months. High-molecular-weight PAHs in this tidal water source may pose risks to aquatic life, while they pose no carcinogenic risk to human health via ingestion of drinking water. [ABSTRACT FROM AUTHOR]

A novel underground reservoir was constructed in an abandoned tunnel for preserving the water in a remote island. The microbial community, potential opportunistic pathogens (OPs) and antibiotic resistance genes (ARGs) of water were analyzed over a year. Results demonstrated that the culturability of the total bacteria and coliforms were both sensitive to the temperature, and the total bacteria culturability had significantly positive relationship with temperature over a year. The ∑ARGs abundance sharply decreased from September to January, but bounced back in July, which was strongly related with phylum Proteobacteria, genera Methylophilus and Methylotenera. The potential OPs almost carried a variety of ARGs, especially in genera Pseudomonas, Enterobacter, Klebsiella, Escherichia with more than 40 ARGs types, which resulted in ARGs enrichment and transfer in the water system. The ∑ARGs of potential OPs variation was extremely significantly related with ARGs subtypes of MacB (r = 0.980, p < 0.05), AcrB (r = 0.997, p < 0.01), AcrA (r = 0.986, p < 0.05) and genus Klebsiella (r = 0.962, p < 0.05).Article Highlights: Significantly positive relationship between total bacteria number and temperature. ∑ARGs strongly related with phylum Proteobacteria, genera Methylophilus/Methylotenera. OPs of Pseudomonas, Enterobacter, Klebsiella, Escherichia with > 40 ARGs subtypes. ∑ARGs of potential OPs extremely significantly related with genus Klebsiella. [ABSTRACT FROM AUTHOR]

Extended drought in the twenty-first century has led to loss of volume for lakes and reservoirs across the globe. In the Colorado River Basin, USA, Lakes Powell and Mead have experienced a 68 and 71% decline in volume, respectively, since 2000. Lake Mead is important to the Las Vegas Valley as it accounts for 90–100% of the source water used to serve the 2.2 million residents and 43 million annual tourists. Lake Powell is also vital to maintaining water quality in Lake Mead as it is located upstream and provides 97% of the water entering Mead. As Lakes Powell and Mead are projected to continue decreasing in volume over the next 5 years, it is important to understand the effects of loss of lake volume on water quality in this highly-managed system. Here, the effects of lake drawdown on water quality parameters that affect disinfection byproduct (DBP) formation in the source water for the Las Vegas Valley are projected over the next 5 years using Federal flow projections, regression modeling to project influent temperature from Lake Powell into Lake Mead, and a three-dimensional hydrodynamic and water quality model for Lake Mead. Results from these modeling efforts include projections for changes in values of water temperature, bromide, and total organic carbon (TOC) at the modeled cell that contains the Las Vegas Valley's urban drinking water intake. Raw water bromide was found to have little change across modeled scenarios; however, raw water temperature is projected to increase because of falling lake surface elevations. Raw water TOC is projected to increase three-fold in the simulated scenario that includes the most loss of volume but remains close to historic values in the remaining simulated scenarios. With these raw water quality projections, water managers can better plan for alterations to the water treatment processes, including mitigation of DBP formation.

Source-water switching can lead to instability in drinking water distribution systems. In estuarine cities using surface water as source water where salt tide occasionally happens, the influence can be particularly complex due to changes of Larson Index (LI). The objective of this study was to investigate the effects of different switching patterns on the stability of water in an estuarine city. Fluctuated LI was found in the current distribution system. LI of the new source water was lower and more stable. Susceptible areas with a high frequency of over standard water quality were identified and pipe scales there were mainly composed of relatively stable iron oxides with dense crystal structures (Fe3O4 and α-FeOOH). Two old pipe sections were used to simulate different switching patterns. The microbial risk did not increase significantly when the original and new water sources were combined in different ratios (2∶8, 5∶5), when multiple water sources were used (3∶3∶4) or when salinity increased. The better water quality, lower LI of the new source water, and stability of the current distribution system together contributed to the biostability. Total iron increased after switching, then declined and stabilized for most switching patterns. Salt tide can lead to sharp iron release. The results provided insightful information for distribution systems that have cast iron pipes and that might encounter source-water switching patterns. [ABSTRACT FROM AUTHOR]

Key Takeaways: In 1972, Congress overrode a presidential veto to pass the Clean Water Act in the interest of restoring the environmental integrity of US waters. History reveals prevailing attitudes and concepts that did not consider a need for source water protection and human accountability. One component of the Clean Water Act's continued progress in addressing current and emerging threats to source water quality is a strong relationship with the Safe Drinking Water Act. [ABSTRACT FROM AUTHOR]

Various measures are available to help utilities mitigate drought as well as support water supply, quality, and reliability. [ABSTRACT FROM AUTHOR]

Key Takeaways: For years, geosmin was causing taste and odor (T&O) issues for the residents of Tulsa, Okla. With the application of algaecide at the pipe's intake, the median geosmin concentration was reduced by 83%. While utilities should focus on source water quality, the application of algaecide can help provide immediate relief for T&O issues related to geosmin. [ABSTRACT FROM AUTHOR]

We estimate a cost function for a water treatment plant in Ohio to assess the avoided‐treatment costs resulting from improved source water quality. Regulations and source water concerns motivated the treatment plant to upgrade its treatment process by adding a granular activated carbon building in 2012. The cost function uses daily observations from 2013 to 2016; this allows us to compare the results to a cost function estimated for 2007–2011 for the same plant. Both models focus on understanding the relationship between treatment costs per 1,000 gallons (per 3.79 m3) of produced drinking water and predictor variables such as turbidity, pH, total organic carbon, deviations from target pool elevation, final production, and seasonal variables. Different from the 2007–2011 model, the 2013–2016 model includes a harmful algal bloom toxin variable. We find that the new treatment process leads to a different cost model than the one that covers 2007–2011. Both total organic carbon and algal toxin are important drivers for the 2013–2016 treatment costs. This reflects a significant increase in cyanobacteria cell densities capable of producing toxins in the source water between time periods. The 2013–2016 model also reveals that positive and negative shocks to treatment costs affect volatility, the changes in the variance of costs through time, differently. Positive shocks, or increased costs, lead to higher volatility compared to negative shocks, or decreased costs, of similar magnitude. After quantifying the changes in treatment costs due to changes in source water quality, we discuss how the study results inform policy‐relevant decisions. Key Points: Estimate how drinking water treatment costs change due to changes in source water quality following a plant upgradeUse time series analysis to understand short‐ and long‐run effects on treatment costsRaw water total organic carbon and harmful algal bloom toxin detections are important drivers in drinking water treatment costs [ABSTRACT FROM AUTHOR]

• The pollution of Taihu Lake source water shaped the DBP distribution. • Taihu Lake source water is polluted with phenolic compounds. • Formulas of ninety-one unknown DBPs were identified. • The occurrence of 5 aromatic and heterocyclic brominated DBPs was confirmed. • Nineteen possible precursors of the discovered DBPs were detected. Although disinfection byproducts (DBPs) in drinking water have been suggested as a cancer causing factor, the causative compounds have not yet been clarified. In this study, we used liquid chromatography quadrupole-time-of-flight spectrometry (LC-QTOF MS) to identify the unknown disinfection byproducts (DBPs) in drinking water produced from Taihu Lake source water, which is known as a convergence point for the anthropogenic pollutants discharged from intensive industrial activities in the surrounding regions. In total, 91 formulas of DBPs were discovered through LC-QTOF MS nontarget screen, 81 of which have not yet been reported. Among the 91 molecules, 56 only contain bromine, 15 only contain chlorine and 20 DBPs have both bromine and chlorine atoms. Finally, five DBPs including 2,4,6-tribromophenol, 2,6-dibromo-4-chlorophenol, 2,6-dichloro-4-bromophenol, 4-bromo-2,6-di-tert-butylphenol and 3,6-dibromocarbazole were confirmed using standards. The former three compounds mainly formed in the predisinfection step (maximum concentration, 0.2-2.6 µg/L), while the latter two formed in the disinfection step (maximum concentration, 18.2-33.6 ng/L). In addition, 19 possible precursors of the discovered DBPs were detected, with the aromatic compounds being a major group. 2,6-di-tert-butylphenol as the precursor of 4-bromo-2,6-di-tert-butylphenol was confirmed with standard, with a concentration of 20.3 µg/L in raw water. The results of this study show that brominated DBPs which are possibly formed from industrial pollutants are relevant DBP species in drinking water produced form Taihu source water, suggesting protection of Taihu Lake source water is important to control the DBP risks. [Display omitted] [ABSTRACT FROM AUTHOR]

Copyright of Journal: American Water Works Association is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Source and raw water quality may deteriorate due to rainfall and river flow events that occur in watersheds. The effects on raw water quality are normally detected in drinking water treatment plants (DWTPs) with a time-lag after these events in the watersheds. Early warning systems (EWSs) in DWTPs require models with high accuracy in order to anticipate changes in raw water quality parameters. Ensemble machine learning (EML) techniques have recently been used for water quality modeling to improve accuracy and decrease variance in the outcomes. We used three decision-tree-based EML models (random forest [RF], gradient boosting [GB], and eXtreme Gradient Boosting [XGB]) to predict two critical parameters for DWTPs, raw water Turbidity and UV absorbance (UV254), using rainfall and river flow time series as predictors. When modeling raw water turbidity, the three EML models (r RF − Tu 2 = 0.87 , r GB − Tu 2 = 0.80 and r XGB − Tu 2 = 0.81) showed very good performance metrics. For raw water UV254, the three models (r RF − UV 2 = 0.89 , r GB − UV 2 = 0.85 and r XGB − UV 2 = 0.88) again showed very good performance metrics. Results from this study suggest that EML approaches could be used in EWSs to anticipate changes in the quality parameters of raw water and enhance decision-making in DWTPs. [Display omitted] • Decision-tree-based ensemble machine learning models were tested to predict quality parameters of raw water supplying DWTP. • Random forest and eXtreme Gradient Boosting techniques yielded the highest metrics for predicting raw water quality. • Decision-tree-based ensemble machine learning techniques may be used in the modelling component early warning systems. [ABSTRACT FROM AUTHOR]

Assessing the odor risk caused by volatile organic compounds (VOCs) in water has been a big challenge for water quality evaluation due to the abundance of odorants in water and the inherent difficulty in obtaining the corresponding odor sensory attributes. Here, a novel odor risk assessment approach has been established, incorporating nontarget screening for odorous VOC identification and machine learning (ML) modeling for odor threshold prediction. Twenty-nine odorous VOCs were identified using two-dimensional gas chromatography-time of flight mass spectrometry from four surface water sampling sites. These identified odorants primarily fell into the categories of ketones and ethers, and originated mainly from biological production. To obtain the odor threshold of these odorants, we trained an ML model for odor threshold prediction, which displayed good performance with accuracy of 79%. Further, an odor threshold-based prioritization approach was developed to rank the identified odorants. 2-Methylisoborneol and nonanal were identified as the main odorants contributing to water odor issues at the four sampling sites. This study provides an accessible method for accurate and quick determination of key odorants in source water, aiding in odor control and improved water quality management. Water odor episodes have been persistent and significant issues worldwide, posing severe challenges to water treatment plants. Unpleasant odors in aquatic environments are predominantly caused by the occurrence of a wide range of volatile organic chemicals (VOCs). Given the vast number of newly-detected VOCs, experimental identification of the key odorants becomes difficult, making water odor issues complex to control. Herein, we propose a novel approach integrating nontarget analysis with machine learning models to accurate and quick determine the key odorants in waterbodies. We use the approach to analyze four samples with odor issues in Changsha, and prioritized the potential odorants. [Display omitted] • Nontarget analysis and machine learning were integrated for odor risk assessment. • GC×GC-TOFMS was employed to identify the odorous compounds in water. • Machine learning models were developed to accurately predict odor thresholds. • 2-MIB and nonanal were prioritized as the potential key odorants. [ABSTRACT FROM AUTHOR]

• Non-targeted toxicity testing and chemical analysis to identify tap and source water effects and key toxicants. • Toxic effects are highest in downstream of the Yangtze River. • Chemical analysis combined with retention time prediction removes >70 % of low confidence structures. • Developing models for linking non-targeted toxicity testing and chemical analyses and further identifying key toxicants. • 103 key toxicants were elucidated in the Yangtze River. Many organic pollutants were detected in tap water (TW) and source water (SW) along the Yangtze River. However, the potential toxic effects and the high-concern organics (HCOs) which drive the effect are still unknown. Here, a non-targeted toxicity testing method based on the concentration-dependent transcriptome and non-targeted LC-HRMS analysis combining tiered filtering were used to reveal the overall biological effects and chemical information. Subsequently, we developed a qualitative pathway-structure relationship (QPSR) model to effectively match the biological and chemical information and successfully identified HCOs in TW and SW along the Yangtze River by potential substructures of HCOs. Non-targeted toxicity testing found that the biological potency of both TW and SW was stronger in the downstream of the Yangtze River, and disruption of the endocrine system and cancer were the main drivers of the effect. In addition, non-targeted LC-HRMS analysis combined with retention time prediction results identified 3220 and 631 high-confidence compound structures in positive and negative ion modes, respectively. Then, QPSR model was further implied and identified a total of 103 HCOs, containing 35 industrial chemicals, 30 PPCPs, 26 pesticides, and 12 hormones in TW and SW, respectively. Among them, the neuroactive and hormonal compounds oxoamide, 8-iso-16-cyclohexyl-tetranor prostaglandin E2, E Keppra, and Tocris-0788 showed the highest frequency of detection, which were identified in more than 1/3 of the samples. The strategy of combining non-targeted toxicity testing and non-targeted LC-HRMS analysis will support comprehensive biological effect assessment, identification of HCOs, and risk control of mixtures. [Display omitted] [ABSTRACT FROM AUTHOR]

Objective: To establishe an analysis and identification method for 2-methylisoborneol(2-MIB) and geosmin(GSM) in water using purge and trap-gas chromatography-mass spectrometry., Methods: The samples were enriched and analyzed using a purge and trap system, followed by the separation on a DB-624(30 m×0.25 mm, 1.4 μm) chromatographic column. Quantification was performed using gas chromatography-mass spectrometry with the selected ion monitoring and internal standard calibration., Results: The calibration curves for 2-MIB and GSM showed an excellent linearity in the range of 1 to 100 ng/L with R~2 values greater than 0.999. The detection limit and quantification limit for both 2-MIB and GSM were 0.33 ng/L and 1.0 ng/L, respectively. Spike recovery experiments were further carried on the source water and drinking water at three concentration levels. It showed that the average recoveries were from 82.0% to 111.0% for 2-MIB while 84.0% to 110% for GSM. Additionally, the test precision of 2-MIB and GSM ranged from 1.9% to 7.3% and 1.9% to 5.0%(n=6), respectively. The analysis of multiple samples including the local source water, treated water and distribution network water confirmed the existence of 2-MIB and GSM., Conclusion: Compared to the national standard(GB/T 5750.8-2023), the proposed method enables fully automated sample introduction and analysis without the extra pre-treatment. It provides the advantages of simplicity, good repeatability and high accuracy.

Utilities, Water Systems, Utility Management, Water Conservation, Water Quality, Earthquakes, Water Industry, AWWA, Leak Detection, Nonrevenue Water, Monitoring, Infrastructure, Natural Disasters, State Regulations, Federal Regulations, Compliance, Environment, Hamilton, Ontario, Canada, Planning, Source Water, Source Water Protection, Disaster Response, Public, Public Opinion Keywords: Utilities; Water Systems; Utility Management; Water Conservation; Water Quality; Earthquakes; Water Industry; AWWA; Leak Detection; Nonrevenue Water; Monitoring; Infrastructure; Natural Disasters; State Regulations; Federal Regulations; Compliance; Environment; Hamilton, Ontario, Canada; Source Water Protection; Planning; Source Water; Disaster Response; Public Opinion; Public EN Utilities Water Systems Utility Management Water Conservation Water Quality Earthquakes Water Industry AWWA Leak Detection Nonrevenue Water Monitoring Infrastructure Natural Disasters State Regulations Federal Regulations Compliance Environment Hamilton, Ontario, Canada Source Water Protection Planning Source Water Disaster Response Public Opinion Public 1 1 1 11/03/23 20231101 NES 231101 Water is everywhere, and while we are all connected by the natural world, the water industry connects us even more. Utilities can use similar long-term monitoring programs to better detect and respond to water quality problems, and through these efforts, gain a detailed understanding of their specific water quality challenges and potential solutions. [Extracted from the article]

• A GC–MS method for 10 bisphenols(BPs) and 12 natural estrogens(NEs) were developed. • Ten BPs and twelve NEs in eight drinking water treatment plants (DWTPs) were studied. • The far-less studied NEs were found both in the source and finished drinking water. • Residual BPs and NEs in drinking water may pose estrogenic effects on human. Bisphenol analogues (BPs) and natural estrogens (NEs) as two important groups of endocrine-disrupting compounds (EDCs) in drinking water treatment plants (DWTPs) have been hardly investigated except bisphenol A (BPA) and three major NEs including estrone (E1), 17β-estradiol (E2) and estriol (E3). In this study, a GC–MS analytical method was firstly established and validated for trace simultaneous determination of ten BPs and twelve NEs in drinking water, which included BPA, bisphenol B (BPB), bisphenol C (BPC), bisphenol E (BPE), bsiphenol F (BPF), bsiphenol P (BPP), bisphenol S (BPS), bisphenol Z (BPZ), bisphenol AF (BPAF), bisphenol AP (BPAP), E1, E2, E3, 17α-estradiol (17α-E2), 2-hydroestrone (2OHE1), 16hydroxyestrone (16α-OHE1), 4-hydroestrone (4OHE1), 2-hydroxyesstradiol (2OHE2), 4-hydroxyestradiol (4OHE2), 17-epiestriol (17epiE3), 16-epiestriol (16epiE3) and 16keto-estraiol (16ketoE2). This investigation showed that eighteen out of twenty-two targeted compounds were detected in drinking source waters of eight DWTPs with concentrations ranging from not detected to 142.8 ng/L. Although the conventional treatment process of DWTP could efficiently remove both BPs and NEs with respective removal efficiencies of 74.1%-90.9% and 74.5%-100%, BPA, BPS, BPE, BPZ, E1, 2OHE1, and 2OHE2 were found in the finished drinking waters. Chlorination could remove part of BPs and NEs, but the efficiency varied greatly with DWTP and the reason was unknown. In the finished drinking waters of eight DWTPs, the highest chemically calculated estrogen equivalence (EEQ) derived from BPs and NEs was up to 6.11 ngE2/L, which was over 22 times that could do harm to zebrafish, indicating a potential risk to human health. Given the fact that many chlorination products of BPs and NEs likely have higher estrogenic activities, the estrogenic effect of BPs and NEs in finished drinking water should be accurately examined urgently with the inclusion of BPs, NEs as well as their main chlorinated by-products. This study shed new light on the occurrence, removal, and potential estrogenic effects of BPs and NEs in DWTPs. [Display omitted] [ABSTRACT FROM AUTHOR]

• The non-fluorescent group of DOM contributed to the formation of HKs, HANs and HNMs. • Lower ratios of UTOX/TOX obtained in UV-LED/chlorine process than chlorination. • The formation and toxicity of N-DBPs and Br-DBPs increased at high UV fluence. Ultraviolet light-emitting diode (UV-LED) is a promising option for the traditional low-pressure UV lamp, but the evolutions of DOM composition, the formation of disinfection by-products (DBPs) and their toxicity need further study in raw water during UV-LED/chlorine process. In UV-LED (275 nm)/chlorine process, two-dimensional correlation spectroscopy (2DCOS) analysis on synchronous fluorescence and UV–vis spectra indicated the protein-like fractions responded faster than the humic-like components, the reactive sequence of peaks for DOM followed the order: 340 nm→240 nm→410 nm→205 nm→290 nm. Compared to chlorination for 30 mins, the UV-LED/chlorine process enhanced the degradation efficiency of three fluorescent components (humic-like, tryptophan-like, tyrosine-like) by 5.1%-46.1%, and the formation of carbonaceous DBPs (C-DBPs) significantly reduced by 43.8% while the formation of nitrogenous DBPs (N-DBPs) increased by 27.3%. The concentrations of C-DBPs increased by 17.8% whereas that of N-DBPs reduced by 30.4% in 24 h post-chlorination. The concentrations of brominated DBPs increased by 17.2% during UV-LED/chlorine process, and further increased by 18.5% in 24 h post-chlorination. According to the results of principal component analysis, the non-fluorescent components of DOM might be important precursors in the formation of haloketones, haloacetonitriles and halonitromethanes during UV-LED/chlorine process. Unlike chlorine treatment, the reaction of DOM in UV-LED/chlorine treatment generated fewer unknown DBPs. Compared with chlorination, the cytotoxicity of C-DBPs reduced but the cytotoxicity of both N-DBPs and Br-DBPs increased during UV-LED/chlorine process. Dichloroacetonitrile had the highest cytotoxicity, followed by monobromoacetic acid, bromochloroacetonitrile and trichloroacetic acid during 30 mins of UV-LED/chlorine process. Therefore, besides N-DBPs, the more toxic Br-DBPs formation in bromide-containing water is also not negligible in the practical applications of UV-LED (275 nm)/chlorine process. [Display omitted] [ABSTRACT FROM AUTHOR]