Small Community Water Systems Research Articles

Arsenic in drinking water poses a threat to public health world-wide. In March 2001, the EPA revised the maximum contaminant level (MCL) for arsenic in drinking water downward from 50 µg/L to 10 µg/L and required all U.S. small community water systems (CWSs) and non-community water systems (NCWSs) to comply by 23 January 2006. Much of the financial burden associated with complying with and maintaining this new drinking water MCL was shouldered by local community governments. For example, the Walker River Paiute Tribe operated a CWS on the Walker River Paiute Indian Reservation that needed upgrading to meet the new arsenic MCL. In collaboration with the Walker River Paiute Tribe, we conducted a study to assess whether reducing the arsenic concentration in drinking water to meet the new MCL reduced the arsenic body burden in local community members who drank the water. Installing a drinking water treatment to remove arsenic dramatically reduced both the drinking water concentrations (to below the current EPA MCL of 10 µg/L) and the community members’ urinary concentrations of total As, AsIII, and AsV within a week of its full implementation. Additional assistance to small water systems to sustain new drinking water treatments may be warranted.

Abstract Very small drinking water systems in the United States can face challenges in complying with the Safe Drinking Water Act, resulting in a need to improve existing infrastructure. This study applied a triple bottom-line approach to compare modeled health, environmental, and economic impacts of improving existing centralized water treatment systems to using point-of-use/point-of-entry (POU/POE) devices in four very small community water systems (CWS) serving 40–450 people. We found that POU/POE systems could be implemented 1–3 years faster than centralized improvements and achieve higher removal efficiencies (up to 99% removal for arsenic, compared to 80% for some centralized options), resulting in larger decreases in human exposure to arsenic or nitrate. Treatment options using adsorptive media or ion exchange resins had larger overall environmental impacts than reverse osmosis devices, and the total 30 year cost of POUs/POEs were more expensive in 3 of the 4 modeled systems than centralized improvements due to high replacement frequencies and populations. An ‘ideal’ option in each CWS was not selected; rather, we contextualized our results as tradeoffs.

Motivating the formation of partnerships by small water systems

Manganese (Mn) is currently regulated as a secondary contaminant in California, USA; however, recent revisions of the World Health Organization drinking water guidelines have increased regulatory attention of Mn in drinking water due to increasing reports of neurotoxic effects in infants and children. In this study, Mn concentrations reported to California's Safe Drinking Water Information System were used to estimate the potentially exposed population within California based on system size. We estimate that between 2011 and 2021, over 525,000 users in areas with reported Mn data are potentially exposed to Mn concentrations exceeding the WHO health-based guideline (80 μg L-1), and over 34,000 users are potentially exposed to Mn concentrations exceeding the U.S. Environmental Protection Agency health-advisory limit (300 μg L-1). Water treatment significantly decreased Mn concentrations compared to intake concentrations for all system sizes. However, smaller water systems have a wider range and a higher skew of Mn concentrations in finished water than larger systems. Additionally, higher Mn concentrations were found in systems above the maximum contaminant levels for chromium and arsenic. The treatment of these primary contaminants appears to also remove Mn. Lastly, data missingness remains a barrier to accurately assess public exposure to Mn in very small, small, and medium community water system-delivered water.

In the United States (US), private-supply tapwater (TW) is rarely monitored. This data gap undermines individual/community risk-management decision-making, leading to an increased probability of unrecognized contaminant exposures in rural and remote locations that rely on private wells. We assessed point-of-use (POU) TW in three northern plains Tribal Nations, where ongoing TW arsenic (As) interventions include expansion of small community water systems and POU adsorptive-media treatment for Strong Heart Water Study participants. Samples from 34 private-well and 22 public-supply sites were analyzed for 476 organics, 34 inorganics, and 3 in vitro bioactivities. 63 organics and 30 inorganics were detected. Arsenic, uranium (U), and lead (Pb) were detected in 54%, 43%, and 20% of samples, respectively. Concentrations equivalent to public-supply maximum contaminant level(s) (MCL) were exceeded only in untreated private-well samples (As 47%, U 3%). Precautionary health-based screening levels were exceeded frequently, due to inorganics in private supplies and chlorine-based disinfection byproducts in public supplies. The results indicate that simultaneous exposures to co-occurring TW contaminants are common, warranting consideration of expanded source, point-of-entry, or POU treatment(s). This study illustrates the importance of increased monitoring of private-well TW, employing a broad, environmentally informative analytical scope, to reduce the risks of unrecognized contaminant exposures.

Small, low-income communities in the United States disproportionately lack access to safe drinking water (i.e. water that meets regulated quality standards). At a community level, the literature has broadly claimed that a major barrier to safe drinking water access is low technical, managerial, and financial (TMF) capacity. At a broader structural level, the environmental justice literature has shown that historical neglect of low-income communities of color has resulted in numerous water systems without the financial and political resources to meet water quality standards. This study investigates the contemporary processes by which distributive injustices persist in California’s Central Valley. The study uses key informant interviews with a range of stakeholders, including employees at the state, county and community, non-profit organizations, and engineers, to understand why sustainable water quality solutions for small low-income communities remain such a challenge. The interviews are structured around a decision chain, which builds out the specific steps needed to go from a maximum contaminant level violation to remediation. The resulting decision chain makes visible the multiple steps at multiple stages with multiple actors that are needed to arrive at a solution to substandard water quality. It shows the numerous nodes at which progress can be stalled, and thus functions as a behind-the-scenes look at the (re)production of persistent inequalities. The complexity of the process shows why having the TMF capacity needed to get to a safe water system is not a reasonable expectation for most small community water systems. Inequalities are continually being produced and cemented, often by the very steps aimed towards remediation, thus making persistent disparities in safe drinking water access a de facto state-sanctioned process that compounds a discriminatory historical legacy.

BACKGROUND AND AIM: Louisiana faces risks of an oncoming water crisis that will be intensified by both man-made and natural threats. Climate models predict an increase in the frequency and magnitude of storms, precipitation, and flooding in Louisiana in the upcoming decades; while gaps in regulatory oversight and enforcement, weaknesses public health recommendations, and corrosion of drinking water infrastructure threatens delivery of clean water to vulnerable communities. METHODS: Results are presented from several independent investigations of private well or small community water systems throughout Louisiana. RESULTS:Several cases of private, small or rural water systems were uncovered which pose public health threats, despite the fact that they have historically complied with regulatory requirements, or conformed to public health recommendations for water system maintenance. In New Orleans, while water lead levels met regulatory requirements, prevailing recommendations for reducing exposures through flushing and partial line replacements were not only inconsistently effective, but could also inadvertently increase exposures. In Louisiana, an estimated 400 water systems have excess iron, a largely unregulated nutrient; but monitoring of two compliant systems with high iron revealed conditions which can impact public health, including mobilization of trace inorganics like lead, depletion of free chlorine residual, interference with disinfection, and propagation of water pathogens. Finally, monitoring of wells in the aftermath of historical floods, revealed water pathogen contamination, despite shock chlorination, and failures in pathogen detection using conventional water testing practices. CONCLUSIONS:The facts presented, support the need to address vulnerabilities in water regulations, oversight, infrastructure, testing, treatment, and exposure reduction strategies. Ultimately, vulnerable communities that are served by private wells or small rural water systems need low­cost autonomous water treatment solutions in order to prepare for threats they will inevitably face from anticipated climate impacts and infrastructure failures. KEYWORDS: Drinking water, climate change, iron, lead, water pathogens, infrastructure

BACKGROUND AND AIM: The US Environmental Protection Agency (EPA) sets maximum contaminant levels (MCLs) for 9 metals/metalloids in public drinking water systems. Beyond arsenic, no nationwide exposure estimates for public drinking water currently exist for these contaminants. Our objective was to estimate exposure to metals in community water systems (CWSs) across the US, to determine if sociodemographic or regional inequalities in these exposures exist, and to identify patterns of exposure for these metals as a mixture. METHODS: We evaluated routine compliance monitoring records for antimony, barium, beryllium, cadmium, chromium, mercury, selenium, thallium, and uranium collected from 2006-2011 (2000-2011 for uranium) by the US EPA in support of the Third Six Year Review for 37,915 CWSs. We focused our analysis on barium, chromium, selenium, and uranium (as arsenic has been reported previously and other metals were mostly undetected), comparing the mean contaminant concentration and the percent of CWSs with MCL excedances across subgroups (US region, sociodemographic county-cluster, size of population served, source water type, and correctional facilities). We evaluated patterns in metal exposure profiles via hierarchical cluster analysis, which also included published CWS arsenic estimates. RESULTS:The percentage of CWSs exceeding the MCL was highest for uranium (3.1% MCL of 30 µg/L, nationwide mean 4.37 µg/L), but lower than previously reported arsenic (2.6%). 75th, 95th percentiles for uranium, chromium, barium, and selenium concentrations were highest for CWSs serving {Semi-Urban, Hispanic} communities, small CWSs, CWSs reliant on groundwater, and those located in the Southwest, similar to previous CWS arsenic findings. Hierarchical cluster analysis revealed four clusters, including an arsenic-uranium-selenium cluster. CONCLUSIONS:{Semi-Urban, Hispanic} communities experience higher average concentrations of metal contaminants, including uranium and arsenic, in public drinking water. Uranium is an under-recognized contaminant in CWSs. Cluster analyses revealed that arsenic and uranium may co-occur in groundwater sources serving CWSs. KEYWORDS: exposure, environmental justice, environmental disparities, water quality

According to the US Environmental Protection Agency, there are about 35,000 small community water systems (defined as serving fewer than 10,000 people) and another 105,000 noncommunity water systems that serve transient and workplace populations. Although these systems face most of the same challenges as larger water utilities, they generally have fewer resources to successfully address them. For the noncommunity systems especially, drinking water isn't usually even the principal reason they exist.

Maria made a landfall in Puerto Rico on September 20, 2017 as a category 4 hurricane, causing severe flooding, widespread electricity outages, damage to infrastructure, and interruptions in water and wastewater treatment. Small rural community water systems face unique challenges in providing drinking water, which intensify after natural disasters. The purpose of this study was to evaluate the functionality of six very small rural public water systems and one large regulated system in Puerto Rico six months after Maria and survey a broad sweep of fecal, zoonotic, and opportunistic pathogens from the source to tap. Samples were collected from surface and groundwater sources, after water treatment and after distribution to households. Genes indicative of pathogenic Leptospira spp. were detected by polymerase chain reaction (PCR) in all systems reliant on surface water sources. Salmonella spp. was detected in surface and groundwater sources and some distribution system water both by culture and PCR. Legionella spp. and Mycobacteria spp. gene numbers measured by quantitative PCR were similar to nonoutbreak conditions in the continental U.S. Amplicon sequencing provided a nontarget screen for other potential pathogens of concern. This study aids in improving future preparedness, assessment, and recovery operations for small rural water systems after natural disasters.

Shiga toxin (Stx), one of the most potent bacterial toxins known, can cause bloody diarrhea, hemolytic uremic syndrome, kidney failure and death. The aim of this pilot was to investigate the occurrence of Shiga toxin-encoding genes, stx (stx1 and stx2) from total coliform (TC) and E. coli positive samples from small community water systems. After aliquots for TC and E. coli analyses were removed, the remnant volume of the samples was enriched, following a protocol developed for this study. Fifty-two per cent of the samples tested by multiplex PCR were positive for the presence of the stx genes; this percentage was higher in raw water samples. The stx2 gene was more abundant. Testing larger volumes of the samples increase the sensitivity of our assay, providing an alternative protocol for the detection of Shiga toxin-producing E. coli (STEC) that might be missed by the TC assay. This study confirms the presence of Stx encoding genes in source and distributed water for all systems sampled and suggests STEC as a potential health risk in small systems.

Access to safe and clean drinking water is necessary for ensuring good health and the well-being of human societies by reducing the burden of water-related diseases associated with dependence on unsafe water sources. To this end, most communities are provided with boreholes or small community mechanised systems where a centralised water treatment plant is absent. However, issues relating to the sustainability of these systems has become a big challenge to most of these communities mainly due to poor management. This research assessed the operation and maintenance (O&M) schemes of these water facilities within the Navrongo Municipality of the Upper East Region of Ghana. Structured and semi-structured questionnaires were administered in twenty (20) beneficiary communities to elicit information regarding the involvement of the community members in the general process leading to the provision of the water facility and its management. In addition, the providers of these facilities were interviewed to assess their level of involvement in their maintenance. The survey revealed that community members contributed towards the provision of the facilities, with 68% of the contributions being in the form of labour. Although 90% of the respondents admitted to the existence of Water and Sanitation Management Teams (WSMTs), 81% of them felt that the team members lacked good management skills. 63% agreed to the need for an upward review of the tariffs in order to meet the cost of O&M. In addition to providing requisite skills and capacity in community mobilization, WSMTs should be incentivised to ensure effective tariff mobilisation. Keywords : Water systems, small communities, sustainable management, operation and maintenance. DOI : 10.7176/JEES/9-10-11 Publication date :October 31 st 2019

This report describes the available drinking water quality monitoring data on the Centers for Disease Control and Prevention (CDC) National Environmental Public Health Tracking Network (Tracking Network). This surveillance summary serves to identify the degree to which ten drinking water contaminants are present in finished water delivered to populations served by community water systems (CWS) in 24 states from 2000 to 2010. For each state, data were collected from every CWS. CWS are sampled on a monitoring schedule established by the Environmental Protection Agency (EPA) for each contaminant monitored. Annual mean and maximum concentrations by CWS for ten water contaminants were summarized from 2000 to 2010 for 24 states. For each contaminant, we calculated the number and percent of CWS with mean and maximum concentrations above the maximum contaminant level (MCL) and the number and percent of population served by CWS with mean and maximum concentrations above the MCL by year and then calculated the median number of those exceedances for the 11-year period. We also summarized these measures by CWS size and by state and identified the source water used by those CWS with exceedances of the MCL. The contaminants that occur more frequently in CWS with annual mean and annual maximum concentrations greater than the MCL include the disinfection byproducts, total trihalomethanes (TTHM), and haloacetic acids (HAA5); arsenic; nitrate; radium and uranium. A very high proportion of exceedances based on MCLs occurred mostly in very small and small CWS, which serve a year-round population of 3,300 or less. Arsenic in New Mexico and disinfection byproducts HAA5 and TTHM, represent the greatest health risk in terms of exposure to regulated drinking water contaminants. Very small and small CWS are the systems’ greatest difficulty in achieving compliance.

Despite amendments and financial investment, noncompliance with the Safe Drinking Water Act persists in portions of the United States. This study hypothesizes that rural and urban U.S. residents are exposed to different patterns of drinking water violations and contaminants. Violations (n > 9,500) for 1,133 Virginia community water systems (CWSs) from 1999 to 2016 were analyzed to (1) evaluate the effects of size and rurality on compliance, (2) identify patterns in contaminant prevalence, and (3) identify gaps in consumer protection. Results indicate that very small CWSs had significantly more monitoring and reporting (MR) violations than large systems, while medium CWSs had significantly more maximum contaminant‐level violations. Isolated rural area CWSs had significantly high MR noncompliance compared with town and urban centers. This study highlights chronic MR noncompliance across rural regions of the state, which may mask consumer health concerns. Further work directly linking health records and noncompliance is recommended to quantify this risk.

A US Environmental Protection Agency project proved solar energy's viability for small community water systems in Puerto Rico and other remote areas.

Gastrointestinal illness (GI) has been associated with heavy rainfall. Storm events and periods of heavy rainfall and runoff can result in increased microbiological contaminants in raw water. Surface water supplies are open to the environment and runoff can directly influence the presence of contaminants. A time-stratified bi-directional case-crossover study design was used to estimate associations of heavy rainfall and hospitalizations for GI. Cases of GI were identified as in-patient hospitalization with a primary diagnosis of infectious disease associated diarrhea [ICD-9 codes: specified gastrointestinal infections 001–009.9 or diarrhea 787.91] among the residents of New Jersey from 2009 to 2013 resulting in a final sample size of 47,527 cases. Two control days were selected on the same days of the week as the case day, within fixed 21-day strata. Conditional logistic regression was used to estimate odds ratios controlling for temperature and humidity. To determine potential effect modification estimates were stratified by season (warm or cold) and drinking water source (groundwater, surface water, or ‘other’ category). Stratified analyses by drinking water source and season identified positive associations of rainfall and GI hospitalizations in surface water systems during the warm season with no lag (OR = 1.12, 95% CI 1.05–1.19) and a 2-day lag (OR = 1.09, 95% CI 1.03–1.16). Positive associations in ‘Other’ water source areas (served by very small community water systems, private wells, or unknown) during the warm season with a 4-day lag were also found. However, there were no statistically significant positive associations in groundwater systems during the warm season. The results suggest that water systems with surface water sources can play an important role in preventing GI hospitalizations during and immediately following heavy rainfall. Regulators should work with water system providers to develop system specific prevention techniques to limit the impact of heavy rainfall on public health.

In Puerto Rico, about 3% of the population gets its drinking water from 250 small community water systems. The simplicity of design, remote location and the threat of natural disasters requires a vulnerability assessment to minimise damage in the eventuality of these and terrorism acts. The objective of this study was to assess the vulnerability of 40 community water systems using a methodology developed for these aqueducts. The purpose was to determine the degree of vulnerability and the steps to minimise it in the event of natural or manmade disasters. An emergency response plan was developed for each system. The results showed that the majority of the systems had a high risk level value. An analysis of the results showed that the methodology failed to take into account factors such as requirement vs. necessity, which may have flawed the absolute value of the criticality and vulnerability of each system.

Waterborne illness related to the consumption of contaminated or inadequately treated water is a global public health concern. Although the magnitude of drinking water-related illnesses in developed countries is lower than that observed in developing regions of the world, drinking water is still responsible for a proportion of all cases of acute gastrointestinal illness (AGI) in Canada. The estimated burden of endemic AGI in Canada is 20·5 million cases annually - this estimate accounts for under-reporting and under-diagnosis. About 4 million of these cases are domestically acquired and foodborne, yet the proportion of waterborne cases is unknown. There is evidence that individuals served by private systems and small community systems may be more at risk of waterborne illness than those served by municipal drinking water systems in Canada. However, little is known regarding the contribution of these systems to the overall drinking water-related AGI burden in Canada. Private water supplies serve an estimated 12% of the Canadian population, or ~4·1 million people. An estimated 1·4 million (4·1%) people in Canada are served by small groundwater (2·6%) and surface water (1·5%) supplies. The objective of this research is to estimate the number of AGI cases attributable to water consumption from these supplies in Canada using a quantitative microbial risk assessment (QMRA) approach. This provides a framework for others to develop burden of waterborne illness estimates for small water supplies. A multi-pathogen QMRA of Giardia, Cryptosporidium, Campylobacter, E. coli O157 and norovirus, chosen as index waterborne pathogens, for various source water and treatment combinations was performed. It is estimated that 103 230 AGI cases per year are due to the presence of these five pathogens in drinking water from private and small community water systems in Canada. In addition to providing a mechanism to assess the potential burden of AGI attributed to small systems and private well water in Canada, this research supports the use of QMRA as an effective source attribution tool when there is a lack of randomized controlled trial data to evaluate the public health risk of an exposure source. QMRA is also a powerful tool for identifying existing knowledge gaps on the national scale to inform future surveillance and research efforts.

Community water system regionalization (CWSR) provides small community water systems with a solution to the conundrum of large fixed costs and a small rate base. In practice, however, very few systems actually regionalize. Applying social welfare theory, this article estimates stakeholder benefits from CWSR. Results are reported for three New Mexico communities as case studies in which CWSR was hypothetically imposed. Benefits for consumers are non‐negative across price scenarios, but in some cases producer benefits are negative. The findings suggest that reluctance to regionalize is not in consumers' economic interest, but it may be for producers. Depending on the water price that follows CWSR and savings achieved by economies of scale, consumers gain at producers' expense. The results shed light on issues that policymakers should consider when evaluating the merits of CWSR. Producers' historic reluctance to adopt CWSR may in fact be driven by economics.

In some way or another, all levels of government in Canada and First Nations share responsibility to implement multi-barrier protection of drinking water. The goal is to protect water from source to tap to minimize risk so that people have access to adequate and safe drinking water. The federal government has committed to assist First Nations achieve comparable levels of service standards available to non-First Nation communities. However, several recent reports on the status of drinking water services standards in First Nations indicate that people in these communities often experience greater health risks than those living off reserves. Using the federal drinking water risk evaluation guidelines, the capacities of First Nations and non-First Nations in Ontario to implement multi-barrier protection of their drinking water systems are compared. The Risk Level Evaluation Guidelines for Water and Wastewater Treatment in First Nation Communities rank drinking water systems as low, medium, or high risk based on information about source water, system design, system operation, reporting, and operator expertise. The risk evaluation scores for First Nations drinking water systems were obtained from Aboriginal Affairs and Northern Development Canada. A survey based on the federal Risk Level Evaluation Guidelines was sent to non-First Nation communities throughout Ontario with 54 communities responding. The capacity among First Nations was variable throughout the province, whereas all of the municipalities were in the low risk category, even small and northern non-First Nation community water systems. It is clear that the financial and technological capacity issues should be addressed regardless of the legislative and regulatory regime that is established. The current governance and management structure does not appear to be significantly reducing the gap in service standards despite financial investment. Exploring social or other underlying determinants of risk may provide alternative solutions to the ongoing water crisis in many First Nations.