Groundwater and public waters, between past, present and future

Microbes that thrive in premise plumbing can have potentially important effects on human health. Yet, how and why plumbing-associated microbial communities vary across broad spatial scales remain undetermined. We characterized the bacterial communities in 496 showerheads collected from across the continental United States. The overall community structure, determined by 16S rRNA gene amplicon sequencing, revealed high levels of bacterial diversity. Although a large fraction of the observed variation in community composition could not be explained, differences in bacterial community composition were associated with water supply (private well water vs public municipal water), water source (groundwater vs surface water), and associated differences in water chemistry (pH and chlorine). Most notably, showerheads in homes supplied with public water had higher abundances of Blastomonas, Mycobacterium, and Porphyrobacter, while Pseudorhodoplanes, Novosphingobium, and Nitrospira were more abundant in those receiving private well water. We conducted shotgun metagenomic analyses on 92 of these samples to assess differences in genomic attributes. Public water-sourced showerheads had communities enriched in genes related to lipid and xenobiotic metabolisms, virulence factors, and antibiotic resistance. In contrast, genes associated with oxidative stress and membrane transporters were over-represented in communities from private well water-sourced showerheads compared to those supplied by public water systems. These results highlight the broad diversity of bacteria found in premise plumbing across the United States and the role of the water source and treatment in shaping the microbial community structure and functional potential.

As health-based drinking water standards for per- and polyfluorinated alkyl substances (PFAS) continue to evolve, public health and environmental protection decision-makers must assess exposure risks associated with all public drinking water systems in the United States (US). Unfortunately, current knowledge regarding the presence of PFAS in environmental systems is limited. In this study, a screening approach was established to: (1) identify and direct attention toward potential PFAS hot spots in drinking water sources, (2) prioritize sampling locations, and (3) provide insights regarding the potential PFAS sources that contaminate groundwater and surface water. Our approach incorporates geospatial data from public sources, including the US Environmental Protection Agency's Toxic Release Inventory, to identify locations where PFAS may be present in drinking water sources. An indicator factor (also known as "risk factor") was developed as a function of distance between potential past and/or present PFAS users (e.g., military bases, industrial sites, and airports) and the public water system, which generates a heat map that visualizes potential exposure risks. A binomial logistic regression model indicates whether PFAS are likely to be detected in public water systems. The results obtained using the developed screening approach aligned well (with a 76% overall model accuracy) with PFAS sampling and chemical analysis data from 81 public drinking water systems in the state of Kentucky. This study proposes this screening model as an effective decision aid to assist key decision-makers in identifying and prioritizing sampling locations for potential PFAS exposure risks in the public drinking water sources in their service areas. Integr Environ Assess Manag 2023;19:163-174. © 2022 SETAC.

During the last decade, the fuel oxygenate methyl tertiary butyl ether (MTBE) has received widespread attention as a potential threat to water quality, primarily due to leaking underground gasoline storage tanks and watercraft with two-stroke engines. In this article, we examine the annual detection frequency, number of new source detections, and concentration of MTBE detected in California's public drinking water groundwater and surface water sources from 1995 to 2002. This work builds on our previous evaluations of California's water quality monitoring database. However, it is unique in that it includes separate evaluations for groundwater and surface water sources that are of greatest concern to regulators, and which are likely being used for current public consumption. Our evaluations also include full-year data for 2002 (which have not been published previously) and an analysis of how the sampling and reported detections of MTBE vary by geographic location. We find that MTBE was generally detected (at any level) in approximately 0.5-0.9% and 0.2-0.4% of all groundwater sources assuming a one-detection and two-detection criterion, respectively. The overall detection frequency for MTBE in surface water sources is significantly higher than for groundwater sources, although these surface water detections appear to have substantially declined since 1996 (e.g., 7-9% for all surface water sources during 1996 to 1999 and 4% for all surface water sources during 2000 to 2002, assuming a one-detection criterion). The detection frequency of MTBE concentrations at or above the state drinking water standards in all drinking water sources (both groundwater and surface water sources) and the subset of drinking water sources that are likely to currently be delivered to consumers is markedly lower (and often zero). Despite the significant increase in water sampling over time, the number of new drinking water sources found to contain MTBE in California has not increased at the same rate and appears to have remained relatively stable or to have decreased since 1998. The data also show that nearly all of the 58 counties in California have routinely sampled at least some of their groundwater and surface water sources for MTBE over the last 8 years. Geographical evaluations show that MTBE has been detected (at least once) in groundwater sources in 34 counties and in surface water sources in 18 counties but has only been detected routinely (i.e., for 3 or more years) in 16 and 7 counties, respectively. Detected concentrations of MTBE are also generally below state drinking water standards, particularly for surface water sources. In short: (1) MTBE is rarely found in California groundwater or surface water sources that are of greatest concern to regulators or the public, and (2) drinking water detections of MTBE are expected to decline in the future due to the pending phase-out of MTBE and recent regulatory programs aimed at controlling gasoline releases from underground storage tanks and two-stroke-engine watercraft.

Efficacy of water treatment processes and endemic gastrointestinal illness – A multi-city study in Sweden

Introduction Outbreaks of acute gastrointestinal illnesses (AGI) have been linked to insufficient drinking water treatment on numerous occasions in the industrialized world, but it is largely unknown to what extent public drinking water influences the endemic level of AGI. This paper aimed to examine relationships between endemic AGI and pathogen elimination efficacy in public drinking water treatment processes. Methods From 20 cities in Sweden, time series data of all daily telephone calls to the Swedish National Healthcare Guide were obtained (75 months: 2007–2014). Calls regarding vomiting, diarrhea or abdominal pain (AGI calls) were separated from others (non-AGI calls). Information of which treatment processes these cities public drinking water plants have been used was achieved, together with the barriers efficacy (log reductions) to eliminate viruses, bacteria and protozoa. For each plant a weighted mean log reduction (WLR) was calculated, weighted by the rate these pathogen groups cause AGI. The association between different water treatments and the occurrence / seasonal patterns of AGI calls (relative non-AGI calls) was evaluated in regression models, adjusting for long term trends, population size, age distribution, and climate area. Results The data contained 546,169 AGI calls and 3,945,595 non-AGI calls. Populations delivered drinking water produced with higher log reduction had a lower relative number of AGI calls. In overall, AGI calls decreased by 4 % (OR = 0.96, 95 % CI: 0.96 – 0.97) per unit increase in the WLR (range WLR: 0.0 – 6.4 units). Stratifying on cities with surface water plants a larger protective effect with high WLR (>4 units) was observed: OR = 0.87, 95% CI: 0.85–0.88. Conclusions The occurrence of AGI was related to public drinking water treatment processes. The findings were valid in both groundwater and surface water sites, but were particularly evident between surface water sites during seasons when viruses are the main cause of AGI.

The paper presents the groundwater resources of Katowice and the results of studies conducted to identify prospective areas in aquifers with sufficient water resources for the location of public water intakes. The city of Katowice is the capital of Upper Silesia, the largest urban-industrial area in Poland, the region with a highly developed hard coal mining and many other different industries covering almost the entire scope of the economy. Due to long term drainage of mines causing the depletion and deterioration of groundwater and surface water resources, the main municipal water intakes have been located outside Katowice. Most of the pumped mine water is discharged into surface waters, causing significant salinity of water and disallow its use for municipal or industrial purposes in Katowice. The water collection and supply system is very extensive and covers a significant part of the Silesian agglomeration which is why Katowice is supplied with water from surface water intakes located outside the city. According to older published materials, such as the Hydrogeological map of Poland, there were no aquifers in the city that could have been used to supply the city with drinking water, however recent studies have shown that groundwater in the Quaternary aquifers in the western part of the city can be used to supply the city with public water. Less productive, Quaternary aquifers in north-eastern parts of the city may constitute the basis for drinking water supply in emergency situations, when surface intakes cannot be used, such as toxic, radiological or viral contamination or damage to the water supply network eg. as a result of an earthquake or warfare.

What's driving adoption of in‐season nitrogen application?

Access to drinkable water is essential to human life. The consequence of unsafe drinking water can be damaging to communities and catastrophic to human health. Today, one in five First Nation communities in Canada is on a boil water advisory, with some advisories lasting over 10 years. Factors contributing to this problem stretch back to colonial structures and institutional arrangement that reproduce woefully inadequate community drinking water systems. Notwithstanding these challenges, First Nation communities remain diligent, adaptive, and innovative in their efforts to provide drinkable water to their community members. One example is through the practice of source water protection planning. Source water is untreated water from groundwater or surface water that supplies drinking water for human consumption. Source water protection is operationalized through land and water planning activities aimed at reducing the risk of contamination from entering a public drinking water supply. Here, we introduce a source water protection planning process at Muskowekwan First Nation, Treaty 4, Saskatchewan. The planning process followed a community-based participatory approach guided by trust, respect, and reciprocity between community members and university researchers. Community members identified threats to the drinking water source followed by restorative land management actions to reduce those threats. The result of this process produced much more than a planning document but engaged multiple community members in a process of empowerment and self-determination. The process of plan-making produced many unintended results including human–land connectivity, reconnection with the water spirit, as well as the reclaiming of indigenous planning. Source water protection planning may not correct all the current water system inadequacies that exist on many First Nations, but it will empower communities to take action to protect their drinking water sources for future generations as a pathway to local water security.

Safe and adequate water supply is a challenging task in many developing cities like Pabna. People have been facing water supply problems e.g. odor, turbidity, iron, etc., thus leading to public health risk e.g. typhoid, skin disease, allergy, etc. This paper presents the existing water supply system of ward no. 5 of Pabna municipality. Primary data were collected from the householders through questionnaire and field visit to the study area during October, 2018 to April, 2019. The valuable information, ward map, etc. were collected from the respective officials of Pabna municipality. The collected data and information were then analysed. 19% householders use groundwater, 9% householders use public supply water and the rest use both. They use groundwater for drinking purposes and supply water for domestic purposes. 71% householders use water 80~100 lpcd and 29% householders use water 60~80 lpcd for their daily usages e.g. drinking, cooking, bathing, washing, defecation, etc. They use more water at morning and noon. 17% householders face occasionally and 32% householders face rarely the shortage of water. In supply water, odor is high at 46% houses, medium at 30% houses and low at 12% houses and turbidity medium at 10% houses and low at 76% houses. Supply water contains iron; high at 2% houses, medium at 39% houses and low at 46% houses. Arsenic is not present in both groundwater and supply water. Drinking water quality is very good at 12% houses, good at 15% houses and satisfactory at 73% houses. Some householders use filtered or boiled water for drinking. 90% householders use economic water closets. 20% householders are affected by water borne diseases e.g. skin disease, allergy, etc. The study helps understand the nature and type of water supply problems faced by the dwellers of Pabna municipality.

Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic compounds that are ubiquitous in many consumer and industrial products, including certain fire-fighting foams such as aqueous film-forming foam (AFFF) required by the Federal Aviation Administration (FAA) until 2024 for incident response and readiness. Recent regulatory changes, public health concerns and liability implications are likely to result in the discontinuation in the supply of AFFF; use of AFFF may also no longer be a tenable option for many airports based on its potential impact on public health via groundwater and public drinking water supplies. Transitioning from AFFF to a fluorine-free (F3) product involves assessment of liability, planning capital acquisitions and implementing the change successfully across airport lines of business. This paper specifically explores the successful PFAS management and transition strategy at Nantucket Memorial Airport.

Prevention and containment of outbreaks requires examination of the contribution and interrelation of outbreak causative events. An outbreak fault tree was developed and applied to 61 enteric outbreaks related to public drinking water supplies in the EU. A mean of 3.25 causative events per outbreak were identified; each event was assigned a score based on percentage contribution per outbreak. Source and treatment system causative events often occurred concurrently (in 34 outbreaks). Distribution system causative events occurred less frequently (19 outbreaks) but were often solitary events contributing heavily towards the outbreak (a mean % score of 87.42). Livestock and rainfall in the catchment with no/inadequate filtration of water sources contributed concurrently to 11 of 31 Cryptosporidium outbreaks. Of the 23 protozoan outbreaks experiencing at least one treatment causative event, 90% of these events were filtration deficiencies; by contrast, for bacterial, viral, gastroenteritis and mixed pathogen outbreaks, 75% of treatment events were disinfection deficiencies. Roughly equal numbers of groundwater and surface water outbreaks experienced at least one treatment causative event (18 and 17 outbreaks, respectively). Retrospective analysis of multiple outbreaks of enteric disease can be used to inform outbreak investigations, facilitate corrective measures, and further develop multi-barrier approaches.

Tsunamis are potential hazards in most of the world, (Figure 1), but risks are higher in areas associated with close and direct proximity to high seismic activity areas in marine and coastal areas, such as Indonesia, Japan, Chile, Peru, and SIDS (small island developing states) (UNISDR, 2009) (Figure 2). They generally hit in relatively limited areas: the coastal zone up to few kilometres inland from the shore. Tsunamis are short-term events, but impacts on human infrastructure and environment can be severe and enduring. Especially coastal freshwater resources, most often the source of public and private water supplies, are vulnerable to the imprint of saltwater that comes along with the tsunami flooding event. Safe, adequate, accessible, and socially acceptable water supply is of essential importance, both as a priority in the immediate aftermath of a disaster like a tsunami, but also in the longer term to ensure proper human health and prosperous livelihoods. Time horizon and severity of tsunami impacts on water resources and water supply systems depend on: magnitude and extent of the event, type of land mass hit (island vs. large mainland, low topography vs. rising coasts) and its natural protection (e.g. mangroves), population density, type and extent of freshwater resources present, and dependence on them for water supply. Often, alternative water supply solutions can be provided in the interim of a tsunami, from external sources and with external support because of the often limited geographical extent of the impacted areas. However, this is not always possible e.g. islands, and other aspects are relevant: recovery and sustainability of fundamental and primary freshwater resources, human health, optimal and efficient use of resources at any time of the disaster risk management cycle (Figure 3). Here, a distinction between groundwater and surface water systems is relevant. Groundwater systems are generally much slower in recovering due to longer internal residence times. However, since groundwater sometimes is the only freshwater resource available in coastal areas and on small islands, it is critical to assess the vulnerability and potential impacts. Since significant coastal populations around the world depend on groundwater for their water supply, either from decentralized, often small schemes and private wells, primarily in rural and peri-urban areas, or from larger centralized schemes, primarily in urban areas,

We provide a review and summary of methyl tertiary butyl ether (MTBE) water monitoring data that have been collected as part of national, multi-state, and state-wide assessments in the United States. Specifically, we summarize the key attributes of 24 publicly available studies or data sets and characterize the detection frequency and detected concentrations of MTBE for different water types based on these studies. The original sampling data from each study were obtained and independently analyzed wherever possible. For each study, the detection frequency of MTBE was calculated assuming any concentration above the reporting or analytical limit of detection and at three different concentrations (1, 5, and 20 μg/L). Detected concentrations of MTBE were based on all reported drinking water samples and were computed using summary statistics such as the median, mean, range, and distribution percentiles. The primary focus of this assessment is on MTBE detections in public drinking water served by groundwater or surface water, although several published studies also contain sampling data from domestic (private) drinking water wells. Some non-drinking water data sets (e.g., sampling data from ambient groundwater) are also included because it was not always possible to identify or separate these data by water type due to the manner in which they were coded or reported. These latter studies therefore contain some sampling data that are not informative for assessing MTBE drinking water exposures to consumers.

Land use in geographic areas that replenish groundwater and surface water resources is increasingly recognized as an important factor affecting drinking water quality. Efforts to understand the implications for health, particularly outcomes with long latency or critical exposure windows, have been hampered by lack of historical exposure data for unregulated pollutants. This limitation has hindered studies of the possible links between breast cancer risk and drinking water impacted by endocrine disrupting compounds and mammary carcinogens, for example. This paper describes a methodology to assess potential historical exposure to a broad range of chemicals associated with wastewater and land use impacts to 132 groundwater wells and one surface water body supplying drinking water to 18 public distribution systems on Cape Cod, MA. We calculated annual measures of impact to each distribution system and used the measures as exposure estimates for the residential addresses of control women in the Cape Cod Breast Cancer and Environment Study (Cape Cod Study). Impact was assessed using (1) historical chemical measurements of nitrate at the water supply sources (performed as required by the Safe Water Drinking Act) and (2) a geographic information system analysis of land use within the zones of contribution (ZOCs) delineated for each well in a state-mandated wellhead protection program. The period for which these impact estimates were developed (1972-1995) was constrained by the availability of chemical measurements and land use data and consideration of time required for groundwater transport of contaminants to the water supply wells. Trends in these estimates for Cape Cod suggest increasing impact to drinking water quality for land use over the study period. Sensitivity analyses were conducted to assess the effect on the distribution of controls' cumulative exposure estimates from (1) reducing the area of the ZOCs to reflect typical well operating conditions rather than extreme pumping conditions used for the regulatory ZOCs, (2) assuming residences received their drinking water entirely from the closest well or cluster of wells rather than a volume-weighted annual district-wide average, and (3) changing the travel time considered for contaminants to reach wells from land use sources. We found that the rank and distribution of controls' cumulative exposure estimates were affected most by the assumption concerning district mixing; in particular, assignment of exposure estimates based on impact values for the closest well(s) consistently produced a larger number of unexposed controls than when a district-wide average impact value was used. As expected, the results suggest that adequate characterization of water quality heterogeneity within water supplies is an important component of exposure assessment methodologies in health studies investigating impacted drinking water.

Making remediation and risk management decisions for widely‐distributed chemicals is a challenging aspect of contaminated site management. The objective of this study is to present an initial evaluation of the ubiquitous, ambient environmental distribution of poly‐ and perfluoroalkyl substances (PFAS) within the context of environmental decision‐making at contaminated sites. PFAS are anthropogenic contaminants of emerging concern with a wide variety of consumer and industrial sources and uses that result in multiple exposure routes for humans. The combination of widespread prevalence and low screening levels introduces considerable uncertainty and potential costs in the environmental management of PFAS.PFAS are not naturally‐occurring, but are frequently detected in environmental media independent of site‐specific (i.e., point source) contamination. Information was collected on background and ambient levels of two predominant PFAS, perfluorooctane sulfonate and perfluorooctanoate, in North America in both abiotic media (soil, sediment, surface water, and public drinking water supplies) and selected biotic media (human tissues, fish, and shellfish). The background or ambient information was compiled from multiple published sources, organized by medium and concentration ranges, and evaluated for geographical trends and, when available, also compared to health‐based screening levels. Data coverage and quality varied from wide‐ranging and well‐documented for soil, surface water, and serum data to more localized and less well‐documented for sediment and fish and shellfish tissues and some uncertainties in the data were noted. Widespread ambient soil and sediment concentrations were noted but were well below human health‐protective thresholds for direct contact exposures. Surface water, drinking water supply waters (representing a combination of groundwater and surface water), fish and shellfish tissue, and human serum levels ranged from less than to greater than available health‐based threshold values. This evaluation highlights the need for incorporating literature‐based or site‐specific background into PFAS site evaluation and decision‐making, so that source identification, risk management, and remediation goals are properly focused and to also inform general policy development for PFAS management.