Pub Date : 2024-05-01DOI: 10.1371/journal.pwat.0000208
Holly A. Young, Korine N. Kolivras, L. H. Krometis, C. Marcillo, J. Gohlke
Through the Unregulated Contaminant Monitoring Rule (UCMR), the Environmental Protection Agency monitors selected unregulated drinking water contaminants of potential concern. While contaminants listed in the UCMR are monitored, they do not have associated health-based standards, so no action is required following detection. Given evolving understanding of incidence and the lack of numeric standards, previous examinations of health implications of drinking water generally only assess impacts of regulated contaminants. Little research has examined associations between unregulated contaminants and fetal health. This study individually assesses whether drinking water contaminants monitored under UCMR 2 and, with a separate analysis, UCMR 3, which occurred during the monitoring years 2008–2010 and 2013–2015 respectively, are associated with fetal health outcomes, including low birth weight (LBW), term-low birth weight (tLBW), and preterm birth (PTB) in Virginia. Singleton births (n = 435,449) that occurred in Virginia during UCMR 2 and UCMR 3 were assigned to corresponding estimated water service areas (n = 435,449). Contaminant occurrence data were acquired from the National Contaminant Occurrence Database, with exposure defined at the estimated service area level to limit exposure misclassification. Logistic regression models for each birth outcome assessed potential associations with unregulated drinking water contaminants. Within UCMR 2, N-Nitroso-dimethylamine was positively associated with PTB (OR = 1.08; 95% CI: 1.02, 1.14, P = 0.01). Molybdenum (OR = 0.92; 95% CI: 0.87, 0.97, P = 0.0) and vanadium (OR = 0.96; 95% CI: 0.92, 1.00, P = 0.04), monitored under UCMR 3, were negatively associated with LBW. Molybdenum was also negatively associated (OR = 0.90; 95% CI: 0.82, 0.99, P = 0.03) with tLBW, though chlorodifluoromethane (HCFC-22) was positively associated (OR 1.18; 95% CI: 1.01, 1.37, P = 0.03) with tLBW. These findings indicate that unregulated drinking water contaminants may pose risks to fetal health and demonstrate the potential to link existing health data with monitoring data when considering drinking water regulatory determinations at the national scale.
{"title":"Unregulated drinking water contaminants and adverse birth outcomes in Virginia","authors":"Holly A. Young, Korine N. Kolivras, L. H. Krometis, C. Marcillo, J. Gohlke","doi":"10.1371/journal.pwat.0000208","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000208","url":null,"abstract":"Through the Unregulated Contaminant Monitoring Rule (UCMR), the Environmental Protection Agency monitors selected unregulated drinking water contaminants of potential concern. While contaminants listed in the UCMR are monitored, they do not have associated health-based standards, so no action is required following detection. Given evolving understanding of incidence and the lack of numeric standards, previous examinations of health implications of drinking water generally only assess impacts of regulated contaminants. Little research has examined associations between unregulated contaminants and fetal health. This study individually assesses whether drinking water contaminants monitored under UCMR 2 and, with a separate analysis, UCMR 3, which occurred during the monitoring years 2008–2010 and 2013–2015 respectively, are associated with fetal health outcomes, including low birth weight (LBW), term-low birth weight (tLBW), and preterm birth (PTB) in Virginia. Singleton births (n = 435,449) that occurred in Virginia during UCMR 2 and UCMR 3 were assigned to corresponding estimated water service areas (n = 435,449). Contaminant occurrence data were acquired from the National Contaminant Occurrence Database, with exposure defined at the estimated service area level to limit exposure misclassification. Logistic regression models for each birth outcome assessed potential associations with unregulated drinking water contaminants. Within UCMR 2, N-Nitroso-dimethylamine was positively associated with PTB (OR = 1.08; 95% CI: 1.02, 1.14, P = 0.01). Molybdenum (OR = 0.92; 95% CI: 0.87, 0.97, P = 0.0) and vanadium (OR = 0.96; 95% CI: 0.92, 1.00, P = 0.04), monitored under UCMR 3, were negatively associated with LBW. Molybdenum was also negatively associated (OR = 0.90; 95% CI: 0.82, 0.99, P = 0.03) with tLBW, though chlorodifluoromethane (HCFC-22) was positively associated (OR 1.18; 95% CI: 1.01, 1.37, P = 0.03) with tLBW. These findings indicate that unregulated drinking water contaminants may pose risks to fetal health and demonstrate the potential to link existing health data with monitoring data when considering drinking water regulatory determinations at the national scale.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141053668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-25DOI: 10.1371/journal.pwat.0000162
M. Fox, Vidisha Agarwalla, Kayla R. Iuliano, J. H. Munroe, K. Nachman, Thomas A. Burke
The US Environmental Protection Agency is revising its policy on drinking water quality reports for consumers. These reports are intended to enhance the public’s “right to know” and to spur action to protect and promote safe water. However, these reports are known to be highly technical and difficult to access compromising their communication value. This study engaged a 10-person focus group to gather evidence on how these reports can be improved. We applied user-centered design principles to understand public drinking water consumer information needs and preferences and to develop new communication tools and methods. Through a set of in-depth interviews, we learned that most participants were unaware of the report until introduced to it during the study. The focus group participants voiced preferences for: better ways to convey technical information; more health information; a clearer understanding of costs and billing; and neighborhood or household level water quality information. Following the interviews, we convened two rounds of small group meetings to create new report designs and to review and refine the designs. The focus group developed a one-page summary statement, water contaminant trend charts, an interactive map, and other recommendations on ways to improve dissemination of the report. The project results, focus group recommendations and designs were submitted to the US Environmental Protection Agency for consideration as the policy for these reports is finalized. We believe these findings provide valuable insights into water quality communication challenges and that this approach is widely applicable and can be informative for water utilities as they prepare future reports.
{"title":"Applying user-centered design to improve drinking water consumer confidence reports: A Baltimore case study","authors":"M. Fox, Vidisha Agarwalla, Kayla R. Iuliano, J. H. Munroe, K. Nachman, Thomas A. Burke","doi":"10.1371/journal.pwat.0000162","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000162","url":null,"abstract":"The US Environmental Protection Agency is revising its policy on drinking water quality reports for consumers. These reports are intended to enhance the public’s “right to know” and to spur action to protect and promote safe water. However, these reports are known to be highly technical and difficult to access compromising their communication value. This study engaged a 10-person focus group to gather evidence on how these reports can be improved. We applied user-centered design principles to understand public drinking water consumer information needs and preferences and to develop new communication tools and methods. Through a set of in-depth interviews, we learned that most participants were unaware of the report until introduced to it during the study. The focus group participants voiced preferences for: better ways to convey technical information; more health information; a clearer understanding of costs and billing; and neighborhood or household level water quality information. Following the interviews, we convened two rounds of small group meetings to create new report designs and to review and refine the designs. The focus group developed a one-page summary statement, water contaminant trend charts, an interactive map, and other recommendations on ways to improve dissemination of the report. The project results, focus group recommendations and designs were submitted to the US Environmental Protection Agency for consideration as the policy for these reports is finalized. We believe these findings provide valuable insights into water quality communication challenges and that this approach is widely applicable and can be informative for water utilities as they prepare future reports.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"27 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140657919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-17DOI: 10.1371/journal.pwat.0000132
Britne Clifton, J. Viers
In this study, we examine a novel levee breach experiment that reconnected a floodplain along the Cosumnes River, California to determine the decadal impact of removing 250 meters of levee and assess the recruitment of large wood. This is the latest study in an ongoing series of investigations 40 years in the making along the largest river on the western slope of the Sierra Nevada without a major dam. We present the findings of this multi-modal investigation here by first measuring the geomorphic alteration of the floodplain surface to quantify the depletion and accretion of sediment across the excavated site. We then identify and quantify the deposition of large wood. Results indicate initiation of anastomosing channel formation and distinct areas of large wood recruitment supporting a naturally evolving lateral levee. Accretion resulted in more than 25,000 m3 of sediment deposition within the original excavation site, the development of multiple sand splays, and natural recruitment of native riparian tree species. We conclude by discussing implications following other approaches to floodplain restoration as a Nature-based Solution. In episodic flow regimes, like in California’s Mediterranean-montane hydroclimatic regime, restoring lateral hydrologic connectivity facilitates ecosystem function. Large flood pulse events drive sediment dynamics and geomorphic heterogeneity while enriching biodiversity through biogeochemical fluxes and habitat creation on reconnected floodplains that store floodwaters and reduce peak discharge. These findings support the importance of long-term monitoring efforts of floodplain restoration.
{"title":"Complex drivers of geomorphic response and habitat formation revealed in multiyear monitoring of Cosumnes River experimental floodplain reconnection","authors":"Britne Clifton, J. Viers","doi":"10.1371/journal.pwat.0000132","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000132","url":null,"abstract":"In this study, we examine a novel levee breach experiment that reconnected a floodplain along the Cosumnes River, California to determine the decadal impact of removing 250 meters of levee and assess the recruitment of large wood. This is the latest study in an ongoing series of investigations 40 years in the making along the largest river on the western slope of the Sierra Nevada without a major dam. We present the findings of this multi-modal investigation here by first measuring the geomorphic alteration of the floodplain surface to quantify the depletion and accretion of sediment across the excavated site. We then identify and quantify the deposition of large wood. Results indicate initiation of anastomosing channel formation and distinct areas of large wood recruitment supporting a naturally evolving lateral levee. Accretion resulted in more than 25,000 m3 of sediment deposition within the original excavation site, the development of multiple sand splays, and natural recruitment of native riparian tree species. We conclude by discussing implications following other approaches to floodplain restoration as a Nature-based Solution. In episodic flow regimes, like in California’s Mediterranean-montane hydroclimatic regime, restoring lateral hydrologic connectivity facilitates ecosystem function. Large flood pulse events drive sediment dynamics and geomorphic heterogeneity while enriching biodiversity through biogeochemical fluxes and habitat creation on reconnected floodplains that store floodwaters and reduce peak discharge. These findings support the importance of long-term monitoring efforts of floodplain restoration.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":" 34","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140691242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-16DOI: 10.1371/journal.pwat.0000165
Fazlul Karim, David J. Penton, Santosh K. Aryal, Shahriar Wahid, Yun Chen, Peter Taylor, Susan M. Cuddy
This paper presents results from a study on water yield assessment across five major river basins of Afghanistan. The study was conducted using GR4J and GR4JSG precipitation-runoff models. The river basins were divided into 207 subcatchments and each subcatchment was divided into multiple functional units. The model was calibrated using observed streamflow data from 2008 to 2015 and validated over the 2016 to 2020 period. Model parameters were calibrated for an unregulated subcatchment in each basin and calibrated parameters from the best-performing subcatchment were transferred to other subcatchments. Results show that modelled water yield across the five basins varies from 0.3 mm in the Helmand basin to 248 mm in the Panj-Amu basin, with an average of 72.1 mm for the entire country. In the period of 2008 to 2020, area averaged water yield in the five basins varies from 36 to 174 mm. For the same period, mean annual precipitation for the entire country is 234.0 mm, indicating a water yield of 30.8%. The nation-wide average water yield of 72.1 mm is equivalent to 46.3 billion cubic meters (BCM) of surface water for the country. In addition, about 28.9 BCM generates annually in the neighbouring Tajikistan and Pakistan from snow and glaciers of the Hindu-Kush mountains. The elevated northern parts of Afghanistan, including parts of neighbouring Tajikistan are the primary water source. Water yield across the country varies between years but there is no consistent increasing or decreasing trends. About 60 to 70% of flow occurs between March to June. The study identified the high water yield areas and investigated variability at monthly, seasonal, and annual time scales. An importance finding is the large spatial and temporal variability of water yield across the basins. This information is crucial for long-term water resources planning and management for agricultural development.
{"title":"Large scale water yield assessment for sparsely monitored river basins: A case study for Afghanistan","authors":"Fazlul Karim, David J. Penton, Santosh K. Aryal, Shahriar Wahid, Yun Chen, Peter Taylor, Susan M. Cuddy","doi":"10.1371/journal.pwat.0000165","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000165","url":null,"abstract":"This paper presents results from a study on water yield assessment across five major river basins of Afghanistan. The study was conducted using GR4J and GR4JSG precipitation-runoff models. The river basins were divided into 207 subcatchments and each subcatchment was divided into multiple functional units. The model was calibrated using observed streamflow data from 2008 to 2015 and validated over the 2016 to 2020 period. Model parameters were calibrated for an unregulated subcatchment in each basin and calibrated parameters from the best-performing subcatchment were transferred to other subcatchments. Results show that modelled water yield across the five basins varies from 0.3 mm in the Helmand basin to 248 mm in the Panj-Amu basin, with an average of 72.1 mm for the entire country. In the period of 2008 to 2020, area averaged water yield in the five basins varies from 36 to 174 mm. For the same period, mean annual precipitation for the entire country is 234.0 mm, indicating a water yield of 30.8%. The nation-wide average water yield of 72.1 mm is equivalent to 46.3 billion cubic meters (BCM) of surface water for the country. In addition, about 28.9 BCM generates annually in the neighbouring Tajikistan and Pakistan from snow and glaciers of the Hindu-Kush mountains. The elevated northern parts of Afghanistan, including parts of neighbouring Tajikistan are the primary water source. Water yield across the country varies between years but there is no consistent increasing or decreasing trends. About 60 to 70% of flow occurs between March to June. The study identified the high water yield areas and investigated variability at monthly, seasonal, and annual time scales. An importance finding is the large spatial and temporal variability of water yield across the basins. This information is crucial for long-term water resources planning and management for agricultural development.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"15 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140696343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-16DOI: 10.1371/journal.pwat.0000237
Lars K. Hallstrom
{"title":"Integrating data within watershed management and public health","authors":"Lars K. Hallstrom","doi":"10.1371/journal.pwat.0000237","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000237","url":null,"abstract":"","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"20 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140696318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-16DOI: 10.1371/journal.pwat.0000106
Kenneth W. Chapman, T. Gilmore, M. Mehrubeoglu, Christian D. Chapman, A. Mittelstet, John E. Stranzl
Imagery from fixed, ground-based cameras is rich in qualitative and quantitative information that can improve stream discharge monitoring. For instance, time-lapse imagery may be valuable for filling data gaps when sensors fail and/or during lapses in funding for monitoring programs. In this study, we used a large image archive (>40,000 images from 2012 to 2019) from a fixed, ground-based camera that is part of a documentary watershed imaging project (https://plattebasintimelapse.com/). Scalar image features were extracted from daylight images taken at one-hour intervals. The image features were fused with United States Geological Survey stage and discharge data as response variables from the site. Predictions of stage and discharge for simulated year-long data gaps (2015, 2016, and 2017 water years) were generated from Multi-layer Perceptron, Random Forest Regression, and Support Vector Regression models. A Kalman filter was applied to the predictions to remove noise. Error metrics were calculated, including Nash-Sutcliffe Efficiency (NSE) and an alternative threshold-based performance metric that accounted for seasonal runoff. NSE for the year-long gap predictions ranged from 0.63 to 0.90 for discharge and 0.47 to 0.90 for stage, with greater errors in 2016 when stream discharge during the gap period greatly exceeded discharge during the training periods. Importantly, and in contrast to gap-filling methods that do not use imagery, the high discharge conditions in 2016 could be visually (qualitatively) verified from the image data. Half-year test sets were created for 2016 to include higher discharges in the training sets, thus improving model performance. While additional machine learning algorithms and tuning parameters for selected models should be tested further, this study demonstrates the potential value of ground-based time-lapse images for filling large gaps in hydrologic time series data. Cameras dedicated for hydrologic sensing, including nighttime imagery, could further improve results.
{"title":"Stage and discharge prediction from documentary time-lapse imagery","authors":"Kenneth W. Chapman, T. Gilmore, M. Mehrubeoglu, Christian D. Chapman, A. Mittelstet, John E. Stranzl","doi":"10.1371/journal.pwat.0000106","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000106","url":null,"abstract":"Imagery from fixed, ground-based cameras is rich in qualitative and quantitative information that can improve stream discharge monitoring. For instance, time-lapse imagery may be valuable for filling data gaps when sensors fail and/or during lapses in funding for monitoring programs. In this study, we used a large image archive (>40,000 images from 2012 to 2019) from a fixed, ground-based camera that is part of a documentary watershed imaging project (https://plattebasintimelapse.com/). Scalar image features were extracted from daylight images taken at one-hour intervals. The image features were fused with United States Geological Survey stage and discharge data as response variables from the site. Predictions of stage and discharge for simulated year-long data gaps (2015, 2016, and 2017 water years) were generated from Multi-layer Perceptron, Random Forest Regression, and Support Vector Regression models. A Kalman filter was applied to the predictions to remove noise. Error metrics were calculated, including Nash-Sutcliffe Efficiency (NSE) and an alternative threshold-based performance metric that accounted for seasonal runoff. NSE for the year-long gap predictions ranged from 0.63 to 0.90 for discharge and 0.47 to 0.90 for stage, with greater errors in 2016 when stream discharge during the gap period greatly exceeded discharge during the training periods. Importantly, and in contrast to gap-filling methods that do not use imagery, the high discharge conditions in 2016 could be visually (qualitatively) verified from the image data. Half-year test sets were created for 2016 to include higher discharges in the training sets, thus improving model performance. While additional machine learning algorithms and tuning parameters for selected models should be tested further, this study demonstrates the potential value of ground-based time-lapse images for filling large gaps in hydrologic time series data. Cameras dedicated for hydrologic sensing, including nighttime imagery, could further improve results.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"4 17","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140695887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-04DOI: 10.1371/journal.pwat.0000143
B. Desta, Johanna Sanchez, Cole Heasley, Ian Young, J. Tustin
At many public beaches, routine monitoring of beach water quality using fecal indicator bacteria is conducted to evaluate the risk of recreational water illness. Results from water sample analysis can take over 24-hr, which may no longer accurately reflect current water quality conditions. This study aimed to assess which combination of environmental factors best predicts fecal contamination (E. coli) levels at two of the most popular beaches on Lake Winnipeg, Manitoba (Gimli and Grand Beach), by linking water quality data and publicly available environmental data from 2007 to 2021. We developed separate mixed effects models for each beach for two outcomes, linear (continuous log-transformed E. coli concentration) and categorical (200 CFU/100 ml threshold), to explore differences in the predictors of E. coli concentrations and exceedances of the provincial health risk threshold, respectively. We used a Directed Acyclic Graph to choose which predictor variables to include in the models. For both beaches, we identified clustering of the E. coli outcomes by year, suggesting year-specific variation. We also determined that extreme weather days, with higher levels of rainfall in the preceding 48-hr, previous day average air temperature, and previous day E. coli concentration could result in a higher probability of E. coli threshold exceedances or higher concentrations in the water bodies. In Grand Beach, we identified that days with lower average UV levels in the previous 24-hr and antecedent dry days could result in a higher probability of E. coli threshold exceedances or higher concentrations. The findings can inform possible trends in other freshwater settings and be used to help develop real-time recreational water quality predictive models to allow more accurate beach management decisions and warrant enhancement of beach monitoring programs for extreme weather events as part of the climate change preparedness efforts.
许多公共海滩都会使用粪便指示细菌对海滩水质进行例行监测，以评估娱乐用水患病的风险。水样分析结果可能需要 24 小时以上的时间，这可能不再能准确反映当前的水质状况。本研究旨在通过将 2007 年至 2021 年的水质数据和公开环境数据联系起来，评估哪种环境因素组合最能预测马尼托巴省温尼伯湖两个最受欢迎的海滩（Gimli 和 Grand Beach）的粪便污染（大肠杆菌）水平。我们为每个海滩分别建立了线性（连续对数变换的大肠杆菌浓度）和分类（200 CFU/100 ml 阈值）两种结果的混合效应模型，以分别探索大肠杆菌浓度和超过省健康风险阈值的预测因素的差异。我们使用有向无环图（Directed Acyclic Graph）来选择将哪些预测变量纳入模型。对于这两个海滩，我们按年份确定了大肠埃希氏菌结果的聚类，这表明了特定年份的变化。我们还确定，极端天气日（前 48 小时降雨量、前一天平均气温和前一天大肠埃希氏菌浓度较高）可能导致水体中大肠埃希氏菌阈值超标或浓度较高。在大海滩，我们发现前 24 小时平均紫外线水平较低的日子和前一天干燥的日子会导致大肠杆菌阈值超标或浓度升高的概率较高。这些发现可以为其他淡水环境中可能出现的趋势提供信息，并可用于帮助开发实时娱乐水质预测模型，从而做出更准确的海滩管理决策，并确保加强海滩监测计划，以应对极端天气事件，作为气候变化准备工作的一部分。
{"title":"Environmental factors associated with Escherichia coli concentration at freshwater beaches on Lake Winnipeg, Manitoba, Canada","authors":"B. Desta, Johanna Sanchez, Cole Heasley, Ian Young, J. Tustin","doi":"10.1371/journal.pwat.0000143","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000143","url":null,"abstract":"At many public beaches, routine monitoring of beach water quality using fecal indicator bacteria is conducted to evaluate the risk of recreational water illness. Results from water sample analysis can take over 24-hr, which may no longer accurately reflect current water quality conditions. This study aimed to assess which combination of environmental factors best predicts fecal contamination (E. coli) levels at two of the most popular beaches on Lake Winnipeg, Manitoba (Gimli and Grand Beach), by linking water quality data and publicly available environmental data from 2007 to 2021. We developed separate mixed effects models for each beach for two outcomes, linear (continuous log-transformed E. coli concentration) and categorical (200 CFU/100 ml threshold), to explore differences in the predictors of E. coli concentrations and exceedances of the provincial health risk threshold, respectively. We used a Directed Acyclic Graph to choose which predictor variables to include in the models. For both beaches, we identified clustering of the E. coli outcomes by year, suggesting year-specific variation. We also determined that extreme weather days, with higher levels of rainfall in the preceding 48-hr, previous day average air temperature, and previous day E. coli concentration could result in a higher probability of E. coli threshold exceedances or higher concentrations in the water bodies. In Grand Beach, we identified that days with lower average UV levels in the previous 24-hr and antecedent dry days could result in a higher probability of E. coli threshold exceedances or higher concentrations. The findings can inform possible trends in other freshwater settings and be used to help develop real-time recreational water quality predictive models to allow more accurate beach management decisions and warrant enhancement of beach monitoring programs for extreme weather events as part of the climate change preparedness efforts.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"12 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140741732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-04DOI: 10.1371/journal.pwat.0000187
G. Clayton, R. Thorn, B. Fox, Darren M. Reynolds
Two billion people lack access to safely managed drinking water services, many of these are in low/middle income countries where centralised systems are impractical. Decentralised point-of-use drinking water treatment systems offer alternative solutions in remote or resource constrained settings. The main aim of this study was to assess the long-term (3 year) operation and performance of a point-of-use drinking water treatment system (POU-DWTS). A biologically contaminated urban drainage pond was used as a water source and the quality of the produced drinking water was assessed over two independent trials. The decentralised POU-DWTS combined ultrafiltration membranes with disinfection from electrochemically generated hypochlorous acid (HOCl). The operational parameters, such as flow rate, free available chlorine and transmembrane pressure, were monitored in real-time and recorded via a remote monitoring system. Water quality from the source and treated water was assessed over two trial periods within the 3-year operational trial: an 11-week period at the start and a 22-week trial at the end. All water samples were assessed for a range of basic, chemical, microbiological and metal water quality parameters. The results demonstrate that the decentralised POU-DWTS is capable of continuously producing high quality drinking water when HOCl is continuously used to dose water prior to entering the ultrafiltration [UF] membranes. Over the 3-year operational study, the continuous dosing of HOCl pre-UF membranes resulted in stable permeability, indicating no occurrences of irreversible biofouling within the UF membranes and that good membrane ‘health’ was maintained throughout. As such, there was no need to replace the UF membranes nor undertake acid/alkaline chemical cleans at any point throughput the three-year study. The POU-DWTS continuously produced high quality drinking water, resulting in 6453 m3 of drinking water produced over the trial period, that met international water quality standards, at a community scale within the location studied.
{"title":"Long-term trial of a community-scale decentralized point-of-use drinking water treatment system","authors":"G. Clayton, R. Thorn, B. Fox, Darren M. Reynolds","doi":"10.1371/journal.pwat.0000187","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000187","url":null,"abstract":"Two billion people lack access to safely managed drinking water services, many of these are in low/middle income countries where centralised systems are impractical. Decentralised point-of-use drinking water treatment systems offer alternative solutions in remote or resource constrained settings. The main aim of this study was to assess the long-term (3 year) operation and performance of a point-of-use drinking water treatment system (POU-DWTS). A biologically contaminated urban drainage pond was used as a water source and the quality of the produced drinking water was assessed over two independent trials. The decentralised POU-DWTS combined ultrafiltration membranes with disinfection from electrochemically generated hypochlorous acid (HOCl). The operational parameters, such as flow rate, free available chlorine and transmembrane pressure, were monitored in real-time and recorded via a remote monitoring system. Water quality from the source and treated water was assessed over two trial periods within the 3-year operational trial: an 11-week period at the start and a 22-week trial at the end. All water samples were assessed for a range of basic, chemical, microbiological and metal water quality parameters. The results demonstrate that the decentralised POU-DWTS is capable of continuously producing high quality drinking water when HOCl is continuously used to dose water prior to entering the ultrafiltration [UF] membranes. Over the 3-year operational study, the continuous dosing of HOCl pre-UF membranes resulted in stable permeability, indicating no occurrences of irreversible biofouling within the UF membranes and that good membrane ‘health’ was maintained throughout. As such, there was no need to replace the UF membranes nor undertake acid/alkaline chemical cleans at any point throughput the three-year study. The POU-DWTS continuously produced high quality drinking water, resulting in 6453 m3 of drinking water produced over the trial period, that met international water quality standards, at a community scale within the location studied.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"18 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140741366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-02DOI: 10.1371/journal.pwat.0000191
Brendan J. Moran, D. Boutt, L. A. Munk, Joshua D. Fisher
Deciphering the dominant controls on the connections between groundwater, surface water, and climate is critical to understanding water cycles in arid environments. Yet, persistent uncertainties in the fundamental hydrology of these systems remain. The growing demand for critical minerals such as lithium and associated water demands in the arid environments in which they often occur has amplified the urgency to address these uncertainties. We present an integrated hydrological analysis of the Dry Andes region utilizing a uniquely comprehensive set of tracer data (3H, 18O/2H) for these environments, paired directly with physical hydrological observations. We find two strongly decoupled hydrological systems that interact only under specific hydrogeological conditions where preferential conduits exist. The primary conditions creating these conduits are laterally extensive fine-grained evaporite and/or lacustrine units and perennial flowing streams connected with regional groundwater discharge sites. The efficient capture and transport of modern or “contemporary” water (weeks to years old) within these conduits is the primary control of the interplay between modern hydroclimate variations and groundwater aquifers in these environments. Modern waters account for a small portion of basin budgets but are critical to sustaining surface waters due to the existence of these conduits. As a result, surface waters near basin floors are disproportionally sensitive to short-term climate and anthropogenic perturbations. The framework we present describes a new understanding of the dominant controls on natural water cycles intrinsic to these arid high-elevation systems that will improve our ability to manage critical water resources.
{"title":"Contemporary and relic waters strongly decoupled in arid alpine environments","authors":"Brendan J. Moran, D. Boutt, L. A. Munk, Joshua D. Fisher","doi":"10.1371/journal.pwat.0000191","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000191","url":null,"abstract":"Deciphering the dominant controls on the connections between groundwater, surface water, and climate is critical to understanding water cycles in arid environments. Yet, persistent uncertainties in the fundamental hydrology of these systems remain. The growing demand for critical minerals such as lithium and associated water demands in the arid environments in which they often occur has amplified the urgency to address these uncertainties. We present an integrated hydrological analysis of the Dry Andes region utilizing a uniquely comprehensive set of tracer data (3H, 18O/2H) for these environments, paired directly with physical hydrological observations. We find two strongly decoupled hydrological systems that interact only under specific hydrogeological conditions where preferential conduits exist. The primary conditions creating these conduits are laterally extensive fine-grained evaporite and/or lacustrine units and perennial flowing streams connected with regional groundwater discharge sites. The efficient capture and transport of modern or “contemporary” water (weeks to years old) within these conduits is the primary control of the interplay between modern hydroclimate variations and groundwater aquifers in these environments. Modern waters account for a small portion of basin budgets but are critical to sustaining surface waters due to the existence of these conduits. As a result, surface waters near basin floors are disproportionally sensitive to short-term climate and anthropogenic perturbations. The framework we present describes a new understanding of the dominant controls on natural water cycles intrinsic to these arid high-elevation systems that will improve our ability to manage critical water resources.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"220 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140751340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-02DOI: 10.1371/journal.pwat.0000188
Alyssa Schubert, Jacob Harrison, Linda Kent-Buchanan, Victor Bonds, S. Hughes, Shawn P. McElmurry, Matthew Seeger, N. Love
Understanding water users’ perceptions of drinking water quality and the water service provider are important to understand for effective communication with users. Traditionally, the primary means through which water users receive information about drinking water is via the annual Consumer Confidence Report, which summarizes water quality information at the water system-scale and not at the point-of-use. In this study, we recruited 24 water users from different homes in Detroit, Michigan to assess the effect of access to individualized data on perceptions related to their drinking water quality and service provider. Each participant had a water quality sensor node, which measured five different water quality parameters, temporarily installed in their home for four weeks. Entry interviews were completed at the time of sensor node installation. After four weeks, water quality reports summarizing the individual water quality data collected by the sensor nodes were prepared and shared with participants, after which the exit interviews were completed. We found that access to individualized water quality data positively affected participants’ perceptions of drinking water quality and safety, for example, 92% of participants rated the safety of water at the faucet as at least ‘Somewhat Safe’ in the exit interview compared to 46% in the entry interview. However, participants’ perceptions of the water service provider did not change significantly in response to this information (p > 0.05). Half of the study participants expressed interest in more frequent monitoring and communication, including actionable data that allowed participants to make more informed decisions about how to better manage their water quality at home. We saw evidence of long-term changes in response to access to individualized information with 50% reporting changes in behavior related to drinking water use. We conclude that access to localized water quality data provides actionable information that Detroit, Michigan water users value.
{"title":"Perceptions of drinking water: Understanding the role of individualized water quality data in Detroit, Michigan","authors":"Alyssa Schubert, Jacob Harrison, Linda Kent-Buchanan, Victor Bonds, S. Hughes, Shawn P. McElmurry, Matthew Seeger, N. Love","doi":"10.1371/journal.pwat.0000188","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000188","url":null,"abstract":"Understanding water users’ perceptions of drinking water quality and the water service provider are important to understand for effective communication with users. Traditionally, the primary means through which water users receive information about drinking water is via the annual Consumer Confidence Report, which summarizes water quality information at the water system-scale and not at the point-of-use. In this study, we recruited 24 water users from different homes in Detroit, Michigan to assess the effect of access to individualized data on perceptions related to their drinking water quality and service provider. Each participant had a water quality sensor node, which measured five different water quality parameters, temporarily installed in their home for four weeks. Entry interviews were completed at the time of sensor node installation. After four weeks, water quality reports summarizing the individual water quality data collected by the sensor nodes were prepared and shared with participants, after which the exit interviews were completed. We found that access to individualized water quality data positively affected participants’ perceptions of drinking water quality and safety, for example, 92% of participants rated the safety of water at the faucet as at least ‘Somewhat Safe’ in the exit interview compared to 46% in the entry interview. However, participants’ perceptions of the water service provider did not change significantly in response to this information (p > 0.05). Half of the study participants expressed interest in more frequent monitoring and communication, including actionable data that allowed participants to make more informed decisions about how to better manage their water quality at home. We saw evidence of long-term changes in response to access to individualized information with 50% reporting changes in behavior related to drinking water use. We conclude that access to localized water quality data provides actionable information that Detroit, Michigan water users value.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"79 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140752884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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