Drinking Water Quality Research Articles

Unveiling the transformation of 2,4,6-trihalophenols by active species in drinking water pipelines: The role of goethite

The long-term accumulated pipe scale in the water distribution system (WDS) is vital for ensuring the safety of drinking water delivery. This study revealed a novel positive role of pipe scale in triggering interface free radicals for aromatic substances degradation. The goethite (main constituents of pipe scale) converts from the trivalent state to the divalent state by withdraw electrons from aromatic phenolic compounds. Active free radicals such as hydroxyl radical (OH), Cl, and ClO were subsequently formed via a cascade of chain reactions under WDS conditions, among which OH was the dominate active species driving efficient transformation of 2,4,6-trichlorophenol (60.8%) and 2,4,6-tribromophenol (80.5%) and the corresponding toxicity attenuation. The goethite mediated chlorination is a surface reaction following Langmuir–Hinshelwood model. Our works revealed the presence of natural source of OH for disinfection byproducts transformation. Given the ubiquitous existence of iron scales inside ductile iron pipe, the finding renewed the understanding of the impact of WDS on drinking water quality.

Assessment of groundwater quality for human consumption and its health risks in the Middle Magdalena Valley, Colombia

Groundwater is the primary source of water for people living in rural areas, especially during seasons when surface water is contaminated or unavailable. In Colombia, people use groundwater as drinking water without additional treatment. In addition, there is no infrastructure for wastewater collection and sewage treatment in the region of the Middle Magdalena Valley. The current study aims to evaluate the quality of groundwater in this region to determine any potential health hazards associated with its consumption. To reach the objective, three (3) physicochemical and microbiological sampling campaigns were carried out during different hydrological periods. A total of 428 groundwater samples were analyzed for over 28 parameters. The results were compared with the water quality standards proposed by the US EPA and Colombian regulations for human consumption. The analysis revealed the presence of total and fecal coliforms in 89% and 58% of the analyzed samples, respectively, identifying them as the main contaminants in groundwater. Furthermore, the pH levels did not meet the standards set by the US EPA in 33.8% of the cases and by Colombian regulations in 31.02%. Additionally, 32.8%, 17.6%, 14.3%, and 10.9% of the samples failed to meet the established thresholds for apparent color, magnesium, iron, and nitrates, respectively, under both standards. Moreover, only the analyses of selenium, mercury, and zinc complied with the quality standards under both regulatory frameworks. Based on the Colombian Drinking-Water Quality Risk Index (CDWQRI-IRCA), the risk associated with water quality meant for human consumption was assessed. The results showed that over 84% of the samples analyzed posed a high risk to human health, 4.6% posed a medium risk, 5.5% posed a low risk, and only 5.7% posed no risk at all. Additionally, official mortality statistics for children under four years old were reviewed, which revealed two deaths in 2019 due to Acute Diarrheal Disease (ADD) caused by consumption of contaminated water. Therefore, it is crucial to implement water treatment systems, establish aqueducts in rural areas, and conduct rigorous and systematic monitoring of drinking water to ensure it is safe for human consumption. It is also important to track morbidity and mortality rates associated with water consumption.

Drinking Water Sources Feasibility Test Based On Escherichia Coli As an Indicator Of Pollutant In Sultan Village Stunting Locus Of

Introduction: Water quality parameters are indicated by the presence of E. coli bacteria. These bacteria come from human feces, warm-blooded animals, and non-fecal coliforms. Decree of the Health Minister of the Republic of Indonesia Number 907/MENKES/VII/2002 concerning requirements and supervision of drinking water quality states that good drinking water has a zero total coliform and fecal coliform. Methods: This research uses a descriptive approach with a cross-sectional design. It aims to determine the quality of water sources in Sulkatan village. Ten (10) water sources were used as the samples using total sampling method. The collected samples were then taken to the laboratory to be tested with a series of MPN tests Results and Discussion: The results show that the amount of Escherichia coli bacteria in water samples in Sulkatan Village is 0MPN/100 ml. It is owing to the location of the water source that is far from industrial activities, household waste and residential areas. Conclusion: The quality of the tested well-water samples is good and within normal limits in accordance with the Decree of the Health Minister of the Republic of Indonesia Number 907/MENKES/VII/2002

Release of lead, copper, zinc from the initial corrosion of brass water meter in drinking water: Influences of solution composition and electrochemical characterization

Corrosion of brass plumbing materials may lead to metal release and deteriorate the drinking water quality. In this study, the initial corrosion of brass coupon cut from commercially available water meter was investigated. High rates of Pb, Cu and Zn release from the brass coupon were found during the early stage of corrosion (0–5 d) due to general corrosion and galvanic corrosion. The corrosion current density (Icorr) increased and resistance (RF) decreased during this period indicating that severe corrosion had occurred. In a later stage (5–30 d), a decreased Icorr and an increased RF were observed due to the development of a denser layer of Pb and Cu corrosion products which regulated the release of soluble Pb and Cu. The release of Zn continued and no significant Zn precipitation was found. Overall, particulate Pb, particulate Cu and soluble Zn dominated in the metal release during the initial corrosion of brass. The release of Pb, Cu and Zn was enhanced by a lower pH. Free chlorine was found to slightly reduce the release of Pb but promote the release of Cu and Zn. The presence of Pb on the brass surfaces was found to alleviate the dezincification process. A conceptual model based on metal release profile and electrochemical characterization was proposed to describe the initial corrosion of brass in typical drinking water.

Shallow groundwater quality and health risk assessment of fluoride and arsenic in Northwestern Jiangsu Province, China

Assessing groundwater quality is critical to regional water resource conservation and human health safety, especially in areas with co-existence of toxic constituents fluoride (F−) and arsenic (As). In this study, fourteen groundwater samples were collected in Feng County, Northwestern Jiangsu Province to identify dominant contaminants and their spatial distribution and health risk. The composition and variation characteristics of major ions (K+, Na+, Ca2+, Mg2+, Cl−, SO42−, HCO3−, and NO3−) and trace elements (F−, As, and Mn) were analyzed. The hydrochemical results revealed that high F− groundwater was mainly distributed in the northern areas whereas As-riched groundwater was primarily distributed in southern areas. Notably, over 85.7% and 21.4% of the shallow groundwater samples exceeded the drinking water quality standard of 1.5 mg/L for F− and 10 µg/L for As, respectively. Based on the water quality index (WQI) appraisal result, 71.4% of the groundwater in the study area is classified as “poor”, and thus unsuitable for drinking directly. We assessed the human non-carcinogenic health risk of F− (HQFluoride) and As (HQArsenic) and the carcinogenic health risk of As (CRArsenic). The calculated hazard quotient (HQ) for F− indicated nearly all groundwater samples have an unacceptable risk (HQ > 1) for each age group. However, HQArsenic values revealed that 28.6%, 21.4%, 21.4%, and 21.4% of groundwater samples posed potential non-carcinogenic health risks for infants, children, females, and males, respectively. The calculated results of CRArsenic showed that 0%, 21.4%, 28.6%, and 28.6% of groundwater samples posed unacceptable health risks (CR > 1.0 × 10−4) to infants, children, females, and males, respectively. The groundwater irrigation suitability assessment results showed that 21.4% of samples were doubtful to unsuitable for irrigation, and 85.7% owed magnesium hazards. The findings of this study will assist policymakers in formulating proper remedial policies and mitigation strategies to ensure the safety of drinking and irrigation water.

A point-of-use drinking water quality dataset from fieldwork in Detroit, Michigan

Drinking water quality sensor technology has rapidly advanced, facilitating the collection of rich datasets and real-time analytics. However, sensors have not yet been widely applied to monitor drinking water quality in premise plumbing. Richer quality of data in premise plumbing offers an improved understanding of the quality of drinking water present at the point-of-use. In this paper, online drinking water quality sensor nodes were temporarily installed in twenty-four homes in Detroit, Michigan. The water quality sensor nodes took measurements of five drinking water quality parameters every five minutes for four weeks. Additionally, free chlorine and lead were sampled periodically within each home. Together, these data make up a dataset that captures drinking water quality over time in a legacy city with an oversized drinking water system. This dataset offers more frequent measurements amongst more sample homes than are typically available in premise plumbing or at the tap. The data can be used to investigate temporal trends in drinking water quality, including diurnal patterns and anomaly detection. Additionally, this dataset could be utilized to evaluate water quality in comparison with other cities.

Justification of Temporary Deviations in Drinking Water Quality Given New Scientific Data for Health Risk Assessment

Justification of Temporary Deviations in Drinking Water Quality Given New Scientific Data for Health Risk Assessment

Long-term pilot study on advanced treatment of lake water by ultrafiltration / nanofiltration

Advanced water treatment technologies, including ozone biologically activated carbon adsorption (O3-BAC), ultrafiltration (UF), and nanofiltration (NF), are essential for enhancing drinking water quality. O3-BAC and UF excel in pathogen, virus, and by-product removal, while NF promises enhanced contaminant elimination for high-quality water. However, the implementation of combined UF/NF dual-membrane treatment processes in large-scale water treatment facilities using surface water sources like lakes remains relatively novel. The lack of long-term operational data is the main reason for the limited widespread adoption. To address this, two pilot systems were established: one comprising ‘O3-BAC + pressure-driven UF(I) + NF(I) (Route 1 at 6.4m3/h)’, and the other ‘immersed UF(II) + NF(II) (Route 2 at 3.2m3/h)’, undergoing a year-long evaluation. The trials showed that the dual-membrane systems were effective and resistant to interference. Notably, they achieved removal efficiencies exceeding 98 % for turbidity, UV254 absorbance, fluorescence substances, and algae, alongside significant reductions in odor (80 %) and total dissolved solids (TDS) by 30 %. Both membrane systems display promising performance and O3-BAC is recommended as a pretreatment process. Analysis revealed that the primary constituents of membrane fouling on the NF membranes are aluminum silicate, SiO2, CaCO3 particles, and organic pollutants, which are typically formed through interactions between calcium ions and dissolved organic matter (DOM). The most effective cleaning protocol involves acidic-alkaline treatments. This study provides valuable operational insights into advanced treatment processes using dual-membrane combinations for water treatment plants that rely on lake water sources.

Assessment of water quality using entropy-weighted quality index, statistical methods and electrical resistivity tomography, Moti village, northern Pakistan

In this study, twenty-two water samples were collected from boreholes (BH), and streams to evaluate drinking water quality, its distribution, identification of contamination sources and apportionment for Moti village, northern Pakistan. An atomic absorption spectrophotometer (AAS) is utilized to determine the level of heavy metals in water such as arsenic (As), zinc (Zn), lead (Pb), copper (Cu), cadmium (Cd), manganese (Mn), and ferrous (Fe). Groundwater chemistry and its quantitative driving factors were further explored using multivariate statistical methods, Principal Component Analysis (PCA) and Positive Matrix Factorization (PMF) models. Finally, a total of eight electrical resistivity tomographs (ERTs) were acquired across i) the highly contaminated streams; ii) the villages far away from contaminated streams; and iii) across the freshwater stream. In the Moti village, the mean levels (mg/l) of heavy metals in water samples were 7.2465 (As), 0.4971 (Zn), 0.5056 (Pb), 0.0422 (Cu), 0.0279 (Cd), 0.1579 (Mn), and 0.9253 (Fe) that exceeded the permissible limit for drinking water (such as 0.010 for As and Pb, 3.0 for Zn, 0.003 for Cd and 0.3 for Fe) established by the World Health Organization (WHO, 2008). The average entropy weighted water quality index (EWQI) of 200, heavy metal pollution index (HPI) of 175, heavy metal evaluation index (HEI) of 1.6 values reveal inferior water quality in the study area. Human health risk assessment, consisting of hazard quotient (HQ) and hazard index (HI), exceeded the risk threshold (>1),indicating prevention of groundwater usage. Results obtained from the PCA and PMF models indicated anthropogenic sources (i.e. industrial and solid waste) responsible for the high concentration of heavy metals in the surface and groundwater. The ERTs imaged the subsurface down to about 40 m depths and show the least resistivity values (<11 Ωm) for subsurface layers that are highly contaminated. However, the ERTs revealed relatively high resistivity values for subsurface layers containing fresh or less contaminated water. Filtering and continuous monitoring of the quality of drinking water in the village are highly recommended.

A data‐driven predictive model for disinfectant residual in drinking water storage tanks

AbstractA data‐driven approach is developed and proven for ranking the risk of low disinfection residual in water distribution storage tanks, 1 month ahead. The forecasting methodology uses water quality data collected from drinking water treatment plants, storage tank outlets, and rainfall data as inputs. This methodology was developed and tested with data from a water utility serving more than 5 million people. Results show high‐risk category prediction accuracy of 75%–80%. Using a final year of unseen validation data, more than 90% of the storage tanks ranked in the top 20 by the forecasting methodology experienced low disinfectant residual in the following month. Storage tanks are critical water distribution system infrastructure that are currently managed reactively. The adoption of such readily transferable machine learning approaches enables direct proactive management strategies and efficient interventions that can help ensure drinking water quality.

Assessment of physicochemical, minerals and microbiological qualities of borehole and well water: A case study of Akure Metropolis, Nigeria

Groundwater constitutes a substantial reservoir of fresh water utilized for agricultural irrigation and drinking, emphasizing the critical importance of safeguarding its availability and quality. Contamination of groundwater can arise from chemical, physical, or microbiological sources, each contributing to various health-related issues. In the region of FUTA Southgate, Southwest Nigeria, an assessment was conducted on the physicochemical and microbiological characteristics of groundwater from hand-dug wells and boreholes to ascertain its suitability for human consumption. The analysis indicated that parameters such as BOD, DO TS, TH, and nitrate content were within the acceptable limits set by the World Health Organization (WHO) and the Nigerian Standard for Drinking Water Quality (NSDQ). However, the presence of heavy metals like Fe, Cu, Cr, Pb, Mn, Cd, and Zn was detected using an atomic absorption spectrometer, revealing a slight level of contamination in both water sources. Furthermore, microbiological examination identified Total Coliform Counts of 382 cfu and 159 cfu in hand-dug wells and boreholes, respectively, indicating fecal contamination. The findings suggest that inadequate sewage systems and improper waste disposal practices contribute to the compromised water quality and elevated nitrate levels in hand-dug wells, rendering the shallow aquifer groundwater unsafe for drinking purposes across all evaluated parameters. Consequently, appropriate treatment and disinfection measures are imperative before utilizing the contaminated borehole and groundwater wells for human consumption or industrial purposes.

Evaluation of coliform (E. coli) load of the drinking water collected from Kosti and Rabak Cities, White Nile State, Sudan

Microbial drinking-water quality testing plays an essential role in measures to protect public health. However, such testing remains a significant challenge where resources are limited. The aim of this study was to evaluate the coliform load of drinking water from White Nile State. Samples of the drinking water were collected from Kosti and Rabak, White Nile State, Sudan, in clean disposable plastic bottles from random sites. The estimation of E. coli bacterium test was performed in Microbiology Laboratory, University of Gezira. The results showed that, Rabak samples had high mean number (92 + 22.27) of colonies/plate than Kosti samples (29.33 + 14.11), and this denotes a significant difference between them during (March, 2022), but those samples collected during (October 2022) and (March 2023) showed non-significant differences in microbial count, although Rabak samples showed high mean number of colonies/plate than Kosti samples. It was also noticed that, the contamination of the drinking water increased gradually throughout the study periods and sites. This reflect the increase in the organic waste and decrease in treatment of pollutants in both Kosti and Rabak cities during the study period.

Risks to Human Health from Mercury in Gold Mining in the Coastal Region of Ecuador.

Artisanal and small-scale gold mining (ASGM) plays a crucial role in global gold production. However, the adoption of poor mining practices or the use of mercury (Hg) in gold recovery processes has generated serious environmental contamination events. The focus of this study is assessing the concentration of Hg in surface waters within the coastal region of Ecuador. The results are used to conduct a human health risk assessment applying deterministic and probabilistic methods, specifically targeting groups vulnerable to exposure in affected mining environments. Between April and June 2022, 54 water samples were collected from rivers and streams adjacent to mining areas to determine Hg levels. In the health risk assessment, exposure routes through water ingestion and dermal contact were considered for both adults and children, following the model structures outlined by the U.S. Environmental Protection Agency. The results indicate elevated Hg concentrations in two of the five provinces studied, El Oro and Esmeraldas, where at least 88% and 75% of the samples, respectively, exceeded the maximum permissible limit (MPL) set by Ecuadorian regulations for the preservation of aquatic life. Furthermore, in El Oro province, 28% of the samples exceeded the MPL established for drinking water quality. The high concentrations of Hg could be related to illegal mining activity that uses Hg for gold recovery. Regarding the human health risk assessment, risk values above the safe exposure limit were estimated. Children were identified as the most vulnerable receptor. Therefore, there is an urgent need to establish effective regulations that guarantee the protection of river users in potentially contaminated areas. Finally, it is important to continue investigating the contamination caused by human practices in the coastal region.

Gambaran Kualitas Air pada Depot Air Minum Isi Ulang di Kelurahan Tarus

Water is one of the absolute needs required by all living things, especially humans. The quality of refill water into drinking water in bulk from and sell directly to consumers. The quality of refill water that can be consumed is that has gone through a processing process startingfrom raw water which is pumped using a jet pump while being injected into the reactor tank, then pumped into a filter tube, to the disinfection process using ultraviolet. The purpose of this study was to determine the quality of refill drinking water in Tarus Vilage based on microbiological and chemical variable. The type of research used is descriptive methods. The population in this study were 5 depots. The data obtained will be analyzed according to the 2010 minister of health regulation on drinking water quality. The results of laboratory examinations of Escherichia coli parameters showed that the raw water quality was good in depots 2, 3, 4 and 5, while depot 1 had passed the threshold of 2 mg/L, which means it did not meet the requirements. Good quality drinking water is depot 1, 2, 3, 4, and 5. Based on the chloride and nitrite parameters, the results obtained are good quality raw water and drinking water are depot 1, 2, 3, 4, and 5. Required periodic checks by Public Health Center staff on water quality at 5 refill drinking water depots so that each depot has the latest license.

Spatial and seasonal groundwater quality assessment for drinking suitability using index and machine learning approach

Spatial and seasonal evaluation and monitoring of groundwater (GW) quality is essential for the sustainable management of this priceless resource and the provision of safe drinking water. Nevertheless, GW quality appraisal was not given due attention in the current study area (flat terrain part of the Tana sub-basin). This study sought to assess the seasonal and regional physicochemical GW quality parameters for drinking appropriateness using the drinking water quality index (DWQI) and support vector machine (SVM). The main cations in both the dry and wet study seasons were, in decreasing order, Na+, Ca2+, Mg2+, K+, and Fe2+, according to the results. Conversely, the main anions were HCO3−, CO32−, Cl− or NO3−, SO42− and PO43−, ordered from higher to lower. During the two research seasons, Ca–HCO3 and Na–HCO3 were the predominant water types based on Piper diagram results. Reverse ion exchange and evaporation were the principal hydrogeochemical processes that control the hydrogeochemistry identified by Durov and Gibbs diagrams, respectively. Excellent GW quality class for drinking was demonstrated by the majority of geographical and seasonal DWQI readings over the two seasons. Nevertheless, during the rainy season, there was a noticeable decline in the GW quality condition around the northern shores of Lake Tana. Therefore, it is advised to implement comprehensive GW quality protection measures and improve system management to mitigate pollution to reduce health hazards in the examined region.

Applying user-centered design to improve drinking water consumer confidence reports: A Baltimore case study

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.

Exploring the drinking water supply in Rwanda with panel data analysis.

This study in Rwanda offers a comprehensive analysis of water quality, reliability, and cost-effectiveness, departing from previous research by utilizing panel data analysis for a nuanced understanding of spatiotemporal dynamics. Unlike earlier studies focusing on specific aspects, this research adopts a holistic approach, examining factors crucial for water supply, quality, and cost, thus providing an integrated view of Rwanda's water sector. By analyzing data from various sources, including the Water and Sanitation Corporation (WASAC), the study evaluates the reliability, quality, and cost-effectiveness of drinking water. It identifies cost-effective water treatment plants and studies determinants such as production cost, raw water quality, and supply between 2017 and 2022, introducing novel metrics such as performance scores and a drinking water quality index. Despite an increase in lost water, WASAC notably improves water supply, resulting in a higher water access rate by 2022. The study highlights the influence of factors such as performance scores and raw water quality on water supply and quality. It emphasizes continuous monitoring, targeted interventions, and community engagement for sustainable water service delivery. The findings provide actionable insights for policymakers, stakeholders, and practitioners, aiming to enhance water management strategies and improve water access in Rwanda.

Addressing challenges of BiVO4 light-harvesting ability through vanadium precursor engineering and sub-nanoclusters deposition for peroxymonosulfate-assisted photocatalytic pharmaceuticals removal

In this study, we present a complex approach for increasing light utilisation and peroxymonosulfate (PMS) activation in BiVO4-based photocatalyst. This involves two key considerations: the design of the precursor for BiVO4 synthesis and interface engineering through CuOx sub-nanoclusters deposition. The designed precursor of ammonium methavanadate (NH4VO3, NHV) leads to reduction in particle size, better dispersion and improved light harvesting ability, confirmed by the calculations of the local volume rate of photon absorption (LVRPA) using the Six-Flux Radiation Absorption-Scattering model. The morphological changes result in a significant improvement in photocatalytic activity under visible light for the degradation of pharmaceuticals (naproxen and ofloxacin) compared to the commercial NH4VO3. Additionally, CuOx sub-nanoclusters were deposited on designed BiVO4 and characterised using X-ray absorption near edge structure (XANES). The presence of sub-nanoclusters enhanced charge carriers separation, resulting in an increase in the apparent rate constants of 1.60 and 3.32-times for photocatalytic NPX and OFL removal, respectively. The application of obtained Vis light active photocatalysts in the presence of 0.1 mM PMS resulted in remarkably more efficient degradation of NPX (100 % within 60 min) and OFL (98.2 % within 120 min). PMS/Vis420/CuOx/BiVO4 system exhibited high stability and reusability in the subsequent cycles of photodegradation. However, high PMS dosage induced Bi leaching which may cause the instability of the photocatalyst. Finally, to address the environmental implications of pharmaceutical removal and adhere to the Guidelines for drinking-water quality, toxicity assessments using Vibrio fischeri bacteria were performed and compared to a quantitative structure–activity relationship (QSAR) model.

Impact of operational conditions on drinking water biofilm dynamics and coliform invasion potential.

The revelation that even low concentrations of coliforms can infiltrate into mature drinking water biofilms highlights a potential public health concern. Nowadays, the measurement of coliform bacteria is used as an indicator for fecal contamination and to control the effectiveness of disinfection processes and the cleanliness and integrity of distribution systems. In Flanders (Belgium), 533 out of 18,840 measurements exceeded the established norm for the coliform indicator parameter in 2021; however, the source of microbial contamination is mostly unknown. Here, we showed that mature biofilms, are susceptible to invasion of Serratia fonticola. These findings emphasize the importance of understanding and managing biofilms in drinking water distribution systems, not only for their potential to influence water quality, but also for their role in harboring and potentially disseminating pathogens. Further research into biofilm detachment, long-term responses to operational changes, and pathogen persistence within biofilms is crucial to inform strategies for safeguarding drinking water quality.

Case-control study of drinking water quality in Yemen

Background: Water, sanitation and hygiene (WASH) activities collapsed in Yemen due to the 2015 war, causing acute safe water shortage, poor sanitation and hygiene, and degraded microbial water quality. The cholera outbreaks in 2016/2017 triggered emergency WASH interventions to improve water quality and reduce cholera and other water-borne disease incidence. Aim: This study aimed to assess the microbial water quality in Sana’a, Yemen, following cessation of the WASH activities. Methods: We collected and analysed water samples in 2022 from 64 out of the 381 mini water purification plants that benefitted from WASH interventions in Sana’a in 2018, 2019 and 2020. Face-to-face interviews with representatives of each mini water purification plant were conducted alongside observatory evaluations. We compared results of the 2022 analyses with those of 2018, 2019 and 2020. We analysed our data using Microsoft Excel 2010 and descriptive statistics and presented the results in tables and charts. Results: By 2022, one year after suspending the WASH interventions, the purification system rating had decreased slightly from 87.4% to 84.1%, and the water safety requirements rating had decreased significantly from 78.1% to 62.1%, compared to the 2018–2020 values. This caused a nearly double value, from 15.1% to 31.3%, for the microbial pollution, confirming an inverse relationship between microbial pollution and both purification system and water safety requirements. Conclusion: The microbial water quality of the plants was degraded due to the cessation of the WASH programme. It is important to consider sustainability issues when designing and implementing WASH programmes to ensure that they achieve their goals. It is also crucial to monitor WASH activities rigorously and invest in raising awareness of WASH benefits among operators and community members so they can become effective partners in preventing contamination and water pollution.