case study on water consumption

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

Preview improvements coming to the PMC website in October 2024. Learn More or Try it out now .

• Advanced Search
• Journal List
• HHS Author Manuscripts

Challenges to Sustainable Safe Drinking Water: A Case Study of Water Quality and Use across Seasons in Rural Communities in Limpopo Province, South Africa

Joshua n. edokpayi.

1 Department of Hydrology and Water Resources, University of Venda, Thohoyandou 0950, South Africa; [email protected]

2 Department of Civil and Environmental Engineering, University of Virginia, Charlottesville, VA 22904, USA; ude.qud@drelhak (D.M.K.); moc.liamg@320hlc (C.L.H.); ude.ainigriv@sm4rfc (C.R.); ude.ainigriv@e9saj (J.A.S.)

Elizabeth T. Rogawski

3 Department of Public Health Sciences, University of Virginia, Charlottesville, VA 22908, USA; ude.ainigriv@m5rte

4 Division of Infectious Diseases & International Health, University of Virginia, Charlottesville, VA 22908, USA; ude.ainigriv.ccm.liamcsh@v8dr

David M. Kahler

5 Center for Environmental Research and Education, Duquesne University, Pittsburgh, PA 15282, USA

Courtney L. Hill

Catherine reynolds.

6 School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA

Emanuel Nyathi

7 Department of Animal Science, University of Venda, Thohoyandou 0950, South Africa; [email protected]

James A. Smith

John o. odiyo, amidou samie.

8 Department of Microbiology, University of Venda, Thohoyandou 0950, South Africa; [email protected] (A.S.); [email protected] (P.B.)

Pascal Bessong

Rebecca dillingham.

Author Contributions: Conceived and designed the experiments: J.N.E., E.T.R., D.M.K., C.L.H. Performed the experiments: J.N.E., E.T.R., D.M.K., C.L.H., C.R., E.N. Contributed reagents/materials/analysis tools: P.B., E.N., A.S., R.D., J.A.S., J.O.O. Analyzed the data: J.N.E., E.T.R., D.M.K., C.L.H. Wrote the paper: J.N.E., E.T.R., D.M.K., C.L.H. Participated in the editing of the manuscript: J.N.E., E.T.R., D.M.K., C.L.H., P.B., A.S., R.D., J.A.S., J.O.O., E.N., C.R.

Associated Data

Table S2: Membrane-filtration results for E. Coli and total coliforms of water sources,

Table S3: Anion concentrations (mg/L) of water sources,

Table S4: Major metal concentrations (mg/L) of water sources,

Table S5: Trace metal concentrations μg/L) of water sources.

Consumption of microbial-contaminated water can result in diarrheal illnesses and enteropathy with the heaviest impact upon children below the age of five. We aimed to provide a comprehensive analysis of water quality in a low-resource setting in Limpopo province, South Africa. Surveys were conducted in 405 households in rural communities of Limpopo province to determine their water-use practices, perceptions of water quality, and household water-treatment methods. Drinking water samples were tested from households for microbiological contamination. Water from potential natural sources were tested for physicochemical and microbiological quality in the dry and wet seasons. Most households had their primary water source piped into their yard or used an intermittent public tap. Approximately one third of caregivers perceived that they could get sick from drinking water. All natural water sources tested positive for fecal contamination at some point during each season. The treated municipal supply never tested positive for fecal contamination; however, the treated system does not reach all residents in the valley; furthermore, frequent shutdowns of the treatment systems and intermittent distribution make the treated water unreliable. The increased water quantity in the wet season correlates with increased treated water from municipal taps and a decrease in the average contaminant levels in household water. This research suggests that wet season increases in water quantity result in more treated water in the region and that is reflected in residents’ water-use practices.

1. Introduction

Clean and safe drinking water is vital for human health and can reduce the burden of common illnesses, such as diarrheal disease, especially in young children. Unfortunately, in 2010, it was estimated that 1.8 billion people globally drank water that was not safe [ 1 ]. This scenario is most common in developing countries, and the problem is exacerbated in rural areas [ 1 ]. Significant amounts of time are spent by adults and school children upon water abstraction from various sources [ 2 , 3 ]. It is estimated that, in developing countries, women (64%) and girls (8%) spend billions of hours a year collecting water [ 1 ]. The erratic supply of safe drinking and domestic water often affects good hygiene practices. In most developing countries of the world, inadequate supplies of drinking water can contribute to the underage death of children in the region [ 4 – 10 ].

Storage of collected water from rivers, springs, community stand-pipes, and boreholes is a common practice in communities that lack potable water supplies piped into their homes. Even when water is piped into the home, it is often not available on a continuous basis, and water storage is still necessary. Water is stored in various containers which include jerry cans, buckets, drums, basins and local pots [ 11 – 13 ]. It has been reported that when collection of water from sources of high quality is possible, contamination during transport, handling and storage and poor hygienic practices often results and can cause poor health outcomes [ 11 , 13 – 15 ].

South Africa is a semi-arid country that has limited water resources, and the provision of adequate water-supply systems remains a great challenge. In some of the major cities, access to clean and safe drinking water is comparable to what is found in other developed cities, but this is not the case in some cities, towns and most villages where there is constant erratic supply of potable water, and in some cases, there is no water supply system [ 16 ]. Although access to clean and safe drinking water is stipulated as a constitutional right for all South Africans in the country’s constitution [ 17 , 18 ], sustainable access to a potable water supply by millions of South Africans is lacking.

Residents of communities with inadequate water supply are left with no alternative other than to find local sources of drinking water for themselves. Rural areas are the most affected, and residents resort to the collection of water from wells, ponds, springs, lakes, rivers and rainwater harvesting to meet their domestic water needs [ 19 – 24 ]. Water from such sources is often consumed without any form of treatment [ 12 , 19 , 21 ]. However, these alternative sources of drinking water are often vulnerable to point and non-point sources of pollution and are contaminated frequently by fecal matter [ 5 , 19 , 25 ]. A report by the South African Council for Scientific and Industrial Research clearly showed that almost 2.11 million people in South Africa lack access to any safe water infrastructure. The consumption of water from such unimproved sources without treatment constitutes a major public health risk [ 26 ].

Consumption of contaminated drinking water is a cause of diarrheal disease, a leading cause of child mortality in developing countries with about 700,000 deaths of children under the age of 5 reported in 2011 [ 10 , 27 ]. In South Africa, diarrhea is one of the leading causes of death among young children, and this problem is worst in children infected with HIV (Human Immunodeficiency Virus).

The health risks associated with the consumption of unsafe drinking water are not only related to infectious diseases but also to other environmental components such as fluoride, arsenic, lead, cadmium, nitrates and mercury. Excessive consumption of these substances from contaminated drinking water can lead to cancer, dental and skeletal fluorosis, acute nausea, memory lapses, renal failure, anemia, stunted growth, fetal abnormalities and skin rashes [ 16 , 28 ]. Groundwater contamination with high arsenic concentrations have been reported in Bangladesh, and high fluoride concentrations have been reported in the drinking water from various provinces in South Africa [ 28 – 34 ].

Temporary seasonal variations have been reported to influence the levels of contaminants in various water sources differently. The key environmental drivers across the wet and dry seasons include: volume of water, flow, frequency of rainfall events, storm run-off, evaporation and point sources of pollution [ 35 , 36 ]. An increase in storm-water run-off within a river catchment may increase the level of contaminants due to land-use activities. Increased water volume could lead to a decrease in the concentration of contaminants due to the dilution effect. A low incidence of rainfall and high evaporation can cause a contaminant to concentrate in water. Very few water-quality parameters such as turbidity are expected to be higher in the wet season. Other parameters can vary depending on the key environmental drivers. There is paucity of data on the effect of change across seasons on water-use practices among household in rural areas of developing countries.

The geographic area for this study is located 35 km north of Thohoyandou, in Limpopo Province, South Africa. The area is primarily agricultural, such that water contamination by nitrates is a potential concern. In addition, mining operations in the area may contaminate water sources with heavy metals.

The significance of this study lies in the broad characterization of water-quality parameters that could affect human health, which is not restricted to microbiological analysis. In a rural community, the primary concern of drinking water is the microbiological quality of the water and chemical constituents are often considered not as problematic. This study was designed to evaluate a broad spectrum of water-quality constituents of natural water sources and household drinking water used by residents of rural communities in Limpopo Province. We also aimed to determine how water sources and collection practices change between dry and wet seasons within a one-year sampling period.

2. Materials and Methods

2.1. study design.

A baseline census of 10 villages in the Thulamela Municipality of Limpopo Province was completed to identify all households in which there was at least one healthy child under 3 years of age in the household, the child’s caregiver was at least 16 years of age, and the household did not have a permanent, engineered water-treatment system. 415 households that met these eligibility criteria were enrolled for the purposes of a water-treatment intervention trial. The baseline assessment of water-quality and use practices is reported here. Caregivers of the child under 3 years of age were given a questionnaire concerning demographics, socioeconomic status, water-use practices, sanitation and hygiene practices, and perceptions of water quality and health. In addition, a sample of drinking water was taken from a random selection of 25% of the total enrolled households in the dry (June–August 2016) and wet seasons (January–February 2017). The participant population was sorted by community, as a surrogate for water supply, and one-third from each community was randomly selected by a random number generated within Microsoft Excel (Seattle, WA, USA), which was sampled. The protocol used was approved by the Research Ethics Committee at the University of Venda (SMNS/15/MBY/27/0502) and the Institutional Review Board for Health Sciences Research at the University of Virginia (IRB-HSR #18662). Written informed consent was obtained from all participants and consent documentation was made available in English and Tshivenda. The majority of the baseline surveys were conducted in the dry season (approximately April to October). Six-months later, follow-on surveys were conducted at the height of the wet season (approximately November to March; however, the height of the season in 2016–17 was January to March).

2.2. Regional Description of the Study Area

The communities are located in a valley in the Vhembe District of Limpopo Province, South Africa ( Figure 1 ). The valley surrounds the Mutale River in the Soutpansberg Mountains and is located around 22°47′34′′ S and 30°27′01′′ E, in a tropical environment that exhibits a unimodal dry/wet seasonality ( Figure 2 ). In recent years, the area has received annual precipitation between 400 mm and 1100 mm; more importantly, the timing of the precipitation is highly variable ( Figure 2 ). Specifically, in 2010, the annual precipitation was about 750 mm; however, the majority of the precipitation came in March while, traditionally, the wet season begins earlier, in September or October. The year 2011 had the highest precipitation in the six-year period and had the majority of the rainfall in November. The years 2012 and 2015 began with a typical precipitation pattern; however, the rainfall did not continue as it did in 2013 and 2014. Annual temperature of the area also varies, with the highest temperature always recorded in the wet season ( Figure 3 ). There has been much variability of temperature in past years; however, this is beyond the scope of this study. The abbreviations used in Figure 1 and other figures, including the supplementary data and the type of the various water sources used in this study, are shown in Table 1 .

Map of the study area. The communities are all located within the Mutale River watershed. The rivers are indicated in blue, villages outlined in purple, environmental samples in blue squares, tributaries in green circles (which have intermittent flow), watershed boundary in orange. This heavily agricultural area has cultivated areas along both sides of thee Mutale River for the vast majority of the region; the area is shown with green outlines. There are two identified brick-processing areas shown in brown rectangles. Unfortunately, some sites are so close that the markers overlap (as with CR and IR). The location of the community supplies (CA, CB, and CC) are not shown to protect the privacy of those villages. See supplemental information for Google Earth files.

Precipitation trends in the study area. ( a ) Annual precipitation by hydrologic year. Data quality are presented on a scale of zero to unity where the quantity shown represents the proportion of missing or unreliable data in a year; ( b ) Cumulative precipitation for the last five complete years; ( c ) Average monthly precipitation calculated for years with greater than 90% reliable data (bottom right). All data are presented by the standard Southern hemisphere hydrologic year from July to June numbered with the ending year. Data are from the Nwanedzi Natural Reserve at the Luphephe Dam (17 km from the study area) and fire available through the Republic of South Africa, Department of Water and Sanitation, Hydrologic Services ( http://www.dwa.gov.za/Hydrology/ ).

The mean monthly temperature in the region recorded at Punda Milia. ( a ) Mean monthly temperature based on the means from 1962–1984; ( b ) Mean monthly temperature record. Data are available from the National Oceanic and Aviation Administration (U.S.), National Climatic Data Center, Climate Data Online service ( https://www.ncdc.noaa.gov/cdo-web/ ).

Abbreviations, water sources and type.

Agriculture occupies tine greatest land cover in the valley. Mogt households are engaged in some level of farming. Crops cultivated include maize and vegetables, and tree fruits include mangos and citrus fruits. Livestock is prevalent in the area with chickens, goats, and cattle. Smaller animals typically remain closer to households and larger animals graze throughout the region without boundaries. There are several brick-making facilities in the valley that include excavation, brick-forming and drying.

2.3. Water Sources

Drinking water in the study communities is available from a number of municipal and natural sources. The primary source of drinking water for seven of the villages is treated, municipal water. Two of the villages have community-level boreholes, storage tanks, and distribution tanks. An additional village has a borehole as well; however, residents report that, since its installation, the system has never supplied water.

The water for the treatment facility is drawn from behind a weir in the Mutale River and pumped to a retention basin. The water then undergoes standard treatment that includes pH adjustment, flocculation, settling, filtration, and chlorine disinfection. Water is then pumped to two elevated tanks that supply several adjacent regions, including the study area. Specifically, Branch 1 supplies Tshandama, Pile, Mutodani, Tshapasha and Tshibvumo; Branch 2 supplies an intermediary tank that in turn serves Matshavhawe, Muledane and Thongwe. Households can pay for a metered yard connection for the water used; these yard connections can be connected to household plumbing at the household’s discretion. The treated municipal water service is intermittent. Service in Tshandama and Pile was observed to be constant during the wet season and for only about two to three days per week during the dry season. Service in the remaining communities is two to four days per week during the wet season and about two days per week during the dry season. Furthermore, for the past two years, major repairs in the dry season caused the treated municipal water to cease completely. Households typically stored water for the periods when the treated municipal water was off; however, when the municipal water was unavailable for longer periods or not on the anticipated schedule, households obtained water from natural sources. The community-level boreholes provided water almost constantly but were subject to failure and delays in repairs.

Aside from the municipal sources, many residents of three villages have access to a community installed and operated distribution system that delivers water from the adjacent ephemeral rivers throughout the community (CA, CB, and CC). These systems are constructed with 50 mm to 70 mm (5 to 7 × 10 −2 m) high-density polyethylene pipes. Even these community-level schemes provide water on a schedule and sometimes require repair. Another common source of water for the community is springs. These shallow groundwater sources are common in the valley; however, there are communities that do not have a nearby spring. Some springs have had a pipe placed at the outlet to keep the spring open and facilitate filling containers. Researchers did not observe any constructions around the springs to properly isolate them from further contamination, and they are, therefore, not improved water sources. Pit latrines are common in every household throughout the region. Source (TS) is located near these communities while other springs (OS, LS) are located in agricultural areas. Boreholes provide deep groundwater supplies but require a pump. Such systems provide water as long as there is power for the pump and the well is deep enough to withstand seasonal variations. The two clinics in the study area surveyed each relied on a borehole for their water supply. Some residents also collected water directly from the river. The Mutale River is a perennial river; however, the ephemeral rivers, the Tshiombedi, Madade, Pfaleni, and Tshala Rivers, do not flow in the dry season all the way to the floor of the valley. The Tshala River has a diversion to a lined irrigation canal that always carries water, but there is very little flow that remains in the natural channel.

2.4. Water Sampling

The team of community health workers (CHW) that had previously conducted the MAL-ED (Malnutrition and Enteric Diseases) study in the same region [ 37 ] were recruited to assist with the data collection for this study; specifically, the regional description and water sources. These CHWs have an intimate knowledge of the communities as they are residents and have conducted health research in the area. The CHWs provided information on the location and condition of the various water sources in the study communities.

Water sources were tested during two intensive study periods: one in the dry season (June–August, 2016) and the other in the wet season (January–February, 2017). Water sources for investigation were selected based on identification from resident community health workers. Single samples were taken from all 28 identified drinking water sources in the 10 villages and three days of repeated samples were taken from six sources, which represented a range of sources (e.g., surface, borehole, shallow ground, pond, and municipal treated) in the dry season. Single samples of 17 of the original sources and three days of repeated samples were taken from five sources in the wet season, six months later. Some sources were not resampled because the routes to the sources were flooded, and these sources were likely infrequently used during the wet season due to blocked pathways. The wet and dry season measurements gave two different scenarios for water-use behaviors and allowed the researchers to measure representative water-quality parameters.

2.5. Measurement of Physicochemical Parameters

Physicochemical parameters of source water samples were measured in the field by a YSI Professional Plus meter (YSI Inc., Yellow Springs, OH, USA) for pH, dissolved oxygen and conductivity. The probes and meter was calibrated according to the manufacturer’s instructions. Turbidity was measured in the field with an Orbeco-Hellige portable turbidimeter (Orbeco Hellige, Sarasota, FL, USA) (U.S. Environmental Protection Agency method 180.1) [ 38 ]. The turbidimeter was calibrated according to the manufacturer’s instructions. Measured levels were compared to the South African water-quality standards in the regulations [ 39 ], pursuant to the Water Services Act of 1997.

2.6. Microbiological Water-Quality Analysis

Escherichia coli ( E. coli ) and total coliform bacteria were measured in both source and household water samples by membrane filtration according to U.S. Environmental Protection Agency method 10,029 [ 40 ]. Sample cups of the manifold were immersed in a hot-water bath at 100 °C for 15 min. Reverse osmosis water was flushed through the apparatus to cool the sample cups. Paper filter disks of 47 mm (4.7 × 10 −2 m) diameter and 0.45 μm (4.5 × 10 −7 m) pore size (EMD Millipore, Billerica, MA, USA) were removed from their sterile, individual packages and transferred to the surface of the manifold with forceps with an aseptic technique. Blank tests were run with reverse osmosis dilution water. Two dilutions were tested: full-strength (100 mL sample) and 10 −2 (1 mL sample with 99 mL of sterile dilution water) were passed through the filters; this provides a range of zero to 30,000 CFU/100 mL (colony forming units) for both E. coli and total coliforms. The filter paper was placed in a sterile petri dish with absorbent pad with 2 mL (2 × 10 −6 m 3 ) of selective growth media solution (m-ColiBlue24, EMD Millipore, Billerica, MA, USA). The samples were incubated at 35 °C (308.15 K) for 23–25 h. Colonies were counted on the full-strength sample. If colonies exceeded 300 (the maximum valid count), the dilution count was used. In all tests, the dilution value was expected to be within 10 −2 of the full-strength value and the sample was discarded otherwise.

The distribution of the household bacteria levels was evaluated by the (chi square) χ 2 goodness-of-fit test for various subsets of the data. Subsets of the data were then compared by an unpaired Student’s t-test for statistical significance; specifically, wet versus dry season levels as well as any other subsets that could demonstrate differences within the data.

2.7. Major Metals Analysis

A Thermo ICap 6200 Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES, Chemetix Pty Ltd., Johannesburg, South Africa) was used to analyze the major metals in the various samples. The National Institute of Standards and Technology traceable standards (NIST, Gaithersburg, MD, USA) purchased from Inorganic Ventures (INORGANIC VENTURES 300 Technology Drive Christiansburg, Christiansburg, VA, USA) were used to calibrate the instrument for the quantification of selected metals. A NIST-traceable quality control standard from De Bruyn Spectroscopic Solutions, Bryanston, South Africa, were analyzed to verify the accuracy of the calibration before sample analysis, as well as throughout the analysis to monitor drift.

2.8. Trace Metals Analysis

Trace elements were analyzed in source water samples using an Agilent 7900 Quadrupole inductively coupled plasma mass spectrometer (ICP-MS) (Chemetix Pty Ltd., Johannesburg, South Africa). Samples were introduced via a 0.4 mL/min (7 × 10 −9 m 3 s −1 ) micro-mist nebulizer into a Peltier-cooled spray chamber at a temperature of 2 °C (275.15 K), with a carrier gas flow of 1.05 L/min (1.75 × 10 −5 m 3 s −1 ). The elements V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se were analyzed under He-collision mode to remove polyatomic interferences. NIST-traceable standards was used to calibrate the instrument. A NIST-traceable quality control standard of a separate supplier to the main calibration standards was analyzed to verify the accuracy of the calibration before sample analysis.

2.9. Anion Analysis

The anions were analyzed in source-water samples as stated in Edokpayi et al. [ 41 ]. Briefly, an Ion Chromatograph (Metrohm, Johannesburg, South Africa) was used to analyze the concentrations of fluoride, bromide, nitrates, chloride and sulfate. Calibration standards in the range of 1–20 mg/L were prepared from 100 mg/L stock solution containing all the test elements. Prior to analysis, the samples were filtered with a 0.45 μm (4.5 × 10 −7 m) syringe filter. Eluent for the sample run was prepared from sodium bicarbonate and sodium carbonate. A 50 mmol/L sulphuric acid with a flow rate of 0.5 mL/min (8 × 10 −9 m 3 s −1 ) was used as suppressant.

3.1. Socio-Demographic Characteristics of Enrolled Households

We included 405 enrolled households who completed the baseline questionnaire. The majority of caregivers were the mothers (n = 342, 84.4%, median age = 27 years) or grandmothers (n = 51, 12.6%, median age = 50 years) of a young child in the household. Almost all the caregivers had completed at least secondary school education (n = 371, 91.6%). Median monthly income for the entire household was USD$106 (interquartile range (IQR): 71–156). Access to improved sanitation was high. 373 (n = 92.1%) households used an improved pit latrine, and only 19 (n = 4.7%) reported open defecation. However, few households (n = 35,8.6%) reported having a designated place to wash hands near their toilet, and only 29% (n = 119) reported always using soap when washing hands.

Most households had their primary water source ( Table 2 ) piped into their or their neighbor’s yard (dry: n = 226, 62.3%; wet: n = 241, 67.5%) or used a public tap (dry: n = 69, 19.0%; wet: n = 74, 20.7%). A minority (dry: n = 40, 11.0%; wet: n = 19, 5.3%) collected their water directly from rivers, lined canals, or springs. Water was collected by adult women in most households, and it was reported to take a median of 10 min (IQR, both seasons: 5–30) to go to their water source, collect water, and come back in one trip. Three quarters (n = 270, 74.4%) reported that their water source was not continually available in the dry season and two-thirds (n = 234, 65.5%) in the wet season. Almost half (48.9%) reported interruptions in availability that lasted at least 7 days in the dry season and 32.8% in the wet season. Households stored water during interruptions and/or collected water from alternative sources (dry: n = 133, 36.6%; wet: n = 115, 32.2%), which were surface water or shallow groundwater sources (e.g., rivers, lined canals, or springs).

Primary drinking-water sources reported among 363 and 357 households in the study area in the dry and wet seasons, respectively.

Household water was most frequently stored in jerry cans or plastic buckets (n = 363, 89.7%), while 25 households stored water in large drums or plastic tanks (6.2%). Most households reported that their drinking water containers were covered (n = 329, 81.2%), but most used a cup with a handle (n = 281, 69.4%) or their hands (n = 93, 23.0%) for water collection ( Table 3 ). Only 13.3% (n = 54) households reported treating their water, mainly by boiling (n = 22), chlorine (n = 15), or letting the water stand and settle (n = 11).

Mode of water collection from storage containers.

Approximately one-third of caregivers (n = 114, 28.2%) perceived that one can get sick from drinking water (n = 114, 28.2%), and cited diarrhea, schistosomiasis, cholera, fever, vomiting, ear infections, malnutrition, rash, flu and malaria as specific illnesses associated with water. Despite these perceptions, the majority were satisfied with their current water source (n = 297, 73.3%). Those who were unsatisfied cited reasons of insufficient quantity (n = 75), shared water supply (n = 65), uncleanliness (n = 73), cloudiness (n = 47), and bad odor or taste (n = 38).

3.2. Physicochemical and Microbiological Characteristics of the Water Sources

pH and conductivity values ranged between 5.5–7.3 and 24–405 μS/cm in the wet season and 5.8–8.7 and 8–402 μS/cm in the dry season ( Table S1 ). Both pH and conductivity levels were within the recommended limits of the World Health Organization (WHO) for drinking water. The microbiological results and turbidity of the sources tested are presented in Figures ​ Figures4 4 and ​ and5, 5 , and Table S2 , respectively. Microbiological data show contamination with E. coli , a fecal coliform that is potentially pathogenic, and other coliform bacteria.

Membrane filtration results for ( a ) E. coli and ( b ) other coliforms. Data are presented for wet and dry seasons. The four ephemeral rivers (*) have no dry season data because they had no flow; all other sources have the results reported, some of which are zero or near-zero. South African National Standard (SANS 241:1-2015) set the limit of 0 CFU/100 mL for E. coli and 10 CFU/100 mL for total coliforms (CFU/10 −4 m 3 ). Ephemeral rivers that do not flow all the way into the valley are indicated (*) in the dry season.

Turbidity of the water sources in the study area. Two to three measurements were taken during an intensive study period from 13 January 2017 to 4 February 2017 in the wet season and three to four measurements from 5 June 2016 to 15 July 2016 in the dry season. The median measurement of the values is reported here. Ephemeral rivers that do not flow all the way into the valley are indicated (*) in the dry season.

Municipal treated water never showed any detectable colony-forming units (CFU) in a 100 mL sample for E. coli , which is within the Soufh African regulation [ 39 ]. In the wet season, other coliform bacteriaweae detected in the treated wtter (a median valueof 10 CFU/100 mL wac recorded).

Household sample of stored water ( Figure 6 ) show that bacterial contamination levels ranged from no detectable colonies lo the maximum detection level of our protocol of 30,000 CFU/100 mL. There is a trend that total colitorm levels ere lower (during the wet season than the dry season. In the wet season, some communities within the sturdy area had access to constant municipal treated water as monitored by researcher verification of public tap-watcr availebJlity. Othet communities had intermittent access to municipal treated water. Of these honseholds, those that had constant access to treated water at or near their household did have less total coliform in their stored water than those with intermittent services ( Figure 7 ). This neglects the communities that are outside of the municipal treated-water servic e area.

Box-and-whisker plot of total coliform measurements of stored, untreated water in study households in the wet (n = 95) and dry (n = 103) seasons. The box-and-whisker plot indicates the mean (diamond), first, second, and third quartiles (box), and minimum and maximum (whiskers).

Box-and-whisker plot of total coliform measurements of stored water in the wet season in study households in communities that had verified continuous access to municipal treated water versus verified intermittent access.

The total coliform from households in communities with verified continuous treated water had a log-normal distribution (verified by 99%, α = 1 significance level, χ 2 goodness-of-fit test) and were statistically significantly lower (α =1 significance level) than those from households in communities with verified intermittent treated water. Unfortunately, due to the low number of samples from intermittent households, a χ 2 goodness-of-fit test was not meaningful.

3.3. Anion Concentrations

Major anions investigated in the various water sources fell within the recommended guideline values from the WHO [ 42 ]. Fluoride concentrations ranged from below the detection limit (bdl) to 0.82 mg/L in the dry season and to 1.48 mg/L ( Table S3 ) in the wet season. Fluoride levels fell below the threshold limit for fluoride in drinking water from the WHO (1.5 mg/L). Nitrates were also observed within the limit of drinking water, between bdl–17.48 mg/L and bdl–9.72 mg/L in the dry and wet seasons, respectively. Chloride, sulfate and phosphate levels were also present in moderate levels in the various water sources; however, a relatively high concentration of chloride of 462.9 mg/L was determined in the Mutale River in the wet season.

3.4. Trace and Major Elements Composition

Major metals in the various water sources in both seasons complied with the recommended limits of SANS and WHO in drinking water [ 39 , 42 ]. Sodium concentrations in the range of 3.14–41.03 mg/L and 3.02–15.34 mg/L were measured in the wet and the dry seasons, respectively ( Table S4 ). Low values of potassium were measured. Calcium levels ranged between 0.66–33.91 mg/L and 0.53–27.39 mg/L, in the wet and dry seasons, respectively. Low levels of magnesium were also found. Most of the water sources can be classified as soft water owing to the low levels of calcium and magnesium. Aluminium (Al) concentration ranged between 39.18–438 μg/L ( Figure 8 ). Two of the water sources which are community-based water supply systems recorded high levels of Al which exceeded the aesthetic permissible levels of drinking water; others fell within this limit. Similarly, the levels of iron (Fe) varied between 37.30–1354 mg/L and 35.21–1262 mg/L in the wet and the dry seasons, respectively ( Figure 9 ). Some of the sources showed high Fe concentration which exceeded the aesthetic permissible limit of WHO in drinking water [ 42 ]. Two community-based water systems had higher levels of Fe in the wet season as well as the major river in the region (Mutale River) for which high Fe levels were observed in both seasons. One of the clinic boreholes also recorded high levels of Fe above the permissible aesthetic value of (300 mg/L) in both seasons. Temporary seasonal variation was significant only in the levels of Fe and Al. In the wet season, their levels were generally higher than in the dry season. Some other trace metals of concern like Pb, Hg, As, Cd, Cr, Ni, Cu, Mn, Sr were all present at low levels that were below their recommended limits in drinking water for both seasons ( Table S5 ).

Aluminum, measured by an inductively coupled plasma mass spectrometer (ICP-MS), concentration for natural sources in the study area in the wet and dry seasons. The SANS 241 standard is shown (an operational standard is intended for treated water). Sources marked with * are intermittent sources and had no dry-season sample. Other sources have measured concentrations; although they may be too low to plot.

Iron, measured by an ICP-MS, concentration for natural sources in the study area in the wet and dry seasons. The SANS 241 standard is shown. Sources marked with * are intermittent sources and had no dry-season sample. Other sources have measured concentrations; although they may be too low to plot.

4. Discussion

This study provides a comprehensive description of water quality and drinking-water use across seasons in a low-resource community in rural South Africa, including a variety of water sources, ranging from the municipal tap to natural sources and a combination of both when the municipal tap was intermittently available.

Water sources in the study area, aside from the municipal tap, were highly contaminated with E. coli in both the wet and dry seasons; that is, E. coli was above the South African standard (acute health) of 0 CFU/100 mL. It is particularly important to note that E. coli was detected in the boreholes used for water at the local clinics, implying inadequate access to potable water for potentially immunocompromised patients. While the municipal treated water met the E. coli detection limit, the municipal tap did not always fall within the standards of turbidity (≤1 NTU operational and ≤5 NTU aesthetic) and total coliform (≤10 CFU/100 mL) [ 39 ]. These are not direct health risks; however, both measurements can be used to judge the efficacy of the treatment process and suggest that treatment may not have removed other pathogens that were not directly tested, such as protozoan parasites.

While the microbiological contamination of the drinking-water sources was not acceptable, the chemical constituents fell within the South African guidelines [ 39 ]. Calcium, sodium, magnesium and potassium were present in low levels and their concentrations complied with regulatory standards of SANS [ 39 ] and WHO [ 42 ]. Some metals (cadmium, mercury, arsenic and lead) known to be carcinogenic, mutagenic and teratogenic, causing various acute and chronic diseases to humans even at trace levels in drinking water, were investigated and found to be present in very low concentrations that could be of no health risk to the consumers of the various water resources in the region. However, some other metals, such as Al and Fe, were higher in some of the water sources; yet these were still well below the health guidelines for the respective constituent (recommended health levels from SANS and WHO are given as Al < 0.9 mg/L, Fe < 2 mg/L). At these levels, they do not present a health risk but could impart color and significant taste to the water thereby affecting its aesthetic value. Water sources from the community water-supply systems and one of the clinic boreholes recorded higher levels of Al and Fe. The other metals evaluated (copper, zinc, nickel, chromium, Se and Mn) were present in low levels that complied with their recommended limits in drinking water [ 39 , 42 ].

Fluoridation of drinking water is a common practice for oral health in many countries [ 43 ]. The required level of fluoride to reduce incidences of dental caries is in the range of 0.6–0.8 mg/L; however, levels above 1.5 mg/L are associated with dental and skeletal fluorosis [ 43 – 45 ]. The likelihood of fluorosis as a result of high concentration of fluoride is low in these communities, but there could be a high incidence of dental caries since fluoride levels below 0.6 mg/L were measured and some of the water sources did not have fluoride concentrations detectable by the instrument. The National Children’s Health Survey conducted in South Africa showed that 60.3% of children in the age group of 6 years have dental caries. Approximately a third (31.3%) of children aged 4–5 years in Limpopo province have reported cases of dental caries [ 44 , 45 ].

Chloride levels in the water sources do not cause any significant risk to the users except imparting taste to the water for some of the sources that recorded chloride levels above 300 mg/L. Although the study area is characterized by farming activities, the nitrate concentrations measured do not present any health risks. Therefore, the occurrence of methemoglobinemia or blue-baby syndrome as a result of high nitrate levels is unlikely. Other anions were present in moderate levels that would also not constitute any health risks. The levels of all the anions determined in the various sources were lower than the recommended guidelines of WHO [ 42 ].

The microbiological analysis of environmental water sources revealed several trends. Without exception in these samples, bacterial levels in the wet season were higher than in the dry season. This may be caused by greater runoff or infiltration, which carries bacteria from contaminated sources to these water bodies. The upward trend in bacteria in the municipal treated water is not explained by an increase in runoff, but may be due to higher turbidity of the intake for the municipal treated water in the wet season. The treatment facility workers reported to the researchers that they were unable to monitor the quality of the treated water due to instrument failure during the wet season surveillance period.

Water stored in the household showed that the mean total coliform in the wet season was lower than that in the dry season. This trend is opposite to what was observed in the source, or environmental samples. This difference may be explained by the greater availability of treated water in the wet season versus the dry season for approximately 40% of the sampled households ( Figure 7 ). In addition, it is possible that families try to save water during the dry season and do not reject residual water, while the rainy season allows easier washing of the container and for it to be filled with fresh water more regularly.

In the wet season, two communities had consistently treated water available from household connections (usually a tap somewhere in a fence-in yard) or public taps. While the municipal treated water was of lower quality in the wet season than the dry season, the quality was significantly better than most environmental sources.

Another potential explanation is that residents stored their water within their households for a shorter time, which is supported by the use data that showed interruptions in supply were more common and for longer duration in the dry season. The quality of the water stored in households with continuous supply versus intermittent supply also suggests that water availability may play a role in household water quality. This is consistent with research that demonstrates that intermittent water supply introduces contamination into the distribution system in comparison with continuous supply [ 46 ]. Intermittent supply of water may also result in greater quantity and duration of storage at household level, which could increase the likelihood of contamination.

While it has been shown that the quality of water used for drinking in these villages does not meet South African standards, this problem is confounded by evidence from surveys indicating that residents believe they have high-quality water and, therefore, do not use any form of treatment. In the rare case that they do, it is by letting the water stand and settle or by boiling. In addition, even if treated water is collected, there is a risk of recontamination during storage and again when using a cup held by a hand to retrieve water from storage devices, which was common in surveyed homes. In addition, there was little to no detectable residual chlorine in the municipal tap water to prevent recontamination. A previous study performed in an adjacent community showed higher household treatment levels; however, this may have been due to intervention studies in that community (the community in question was excluded from this study because of previous interventions) [ 47 ]. The study also concurred that boiling was the most common method employed.

Given that most of the water from the various sources in this community is contaminated and not treated, there is a high risk of enteric disease in the community. Lack of access to adequate water and sanitation cause exposure to pathogens through water, excreta, toxins, and water-collection and storage pathways, resulting in immense health impacts on communities [ 48 ]. A large burden of death and disability due to lack of access to clean water and sanitation is specifically associated with diarrheal diseases, intestinal helminths, schistosomiasis and trachoma [ 49 ]. While it was found in this study that the study area has a high prevalence of improved sanitation, the likelihood of poor water quality due to intermittent supply and lack of treatment poses a risk of the adverse health effects described. In a previous longitudinal cohort study of children in these villages, most children were exclusively breastfed for only a month or less, and 50% of children had at least one enteropathogen detected in a non-diarrheal stool by three months of age [ 50 ]. Furthermore, the burden of diarrhea was 0.66 episodes per child-year in the first 2 years of life, and stunting prevalence (length-for-age z-score less than −2) in the cohort increased from 12.4% at birth to 35.7% at 24 months [ 50 ]. It is likely that contaminated water contributed to the observed pathogen burden and stunting prevalence in these communities. In summary, microbiological contamination of the drinking water is high in the study area, and risk from other chemical constituents is low. Therefore, engineered solutions should focus more on improving the microbiological quality of the drinking water.

The intermittent supply in municipal tap water, inadequate water quality from alternative sources, and the risk of recontamination during storage suggest a need for a low-cost, point-of-use water-treatment solution to be used at the household level in these communities. Access to clean drinking water will contribute to improving the health of young children who are at highest risk of the morbidity and mortality associated with waterborne diseases. Such an intervention may go beyond the prevention of diarrhea by impacting long-term outcomes such as environmental enteropathy, poor growth and cognitive impairment, which have been associated with long-term exposure to enteropathogens [ 51 ]. This is supported by a recent finding that access to improved water and sanitation was associated with improvements on a receptive vocabulary test at 1, 5 and 8 years of age among Peruvian, Ethiopian, Vietnamese and Indian children [ 52 ]. The implementation of point-of-use water treatment devices would ensure that water is safe to drink before consumption in the homes of these villages, improving child health and development.

5. Conclusions

This study was comprehensive in the assessment of all aspects of water quality and corresponding water-use practices in rural areas of Limpopo Province. The results obtained indicate that microbiological water quality is more likely to have adverse effect on the consumers of natural water without adequate treatment, as E. coli was determined in all the natural water sources. Local needs assessments are critical to understanding local variability in water quality and developing appropriate interventions. Interventions to ensure clean and safe drinking water in rural areas of Limpopo province should, first and foremost, consider microbiological contamination as a priority. Risk-assessment studies of the impact of water quality on human health is, therefore, recommended.

Supplementary Material

Tables s1 through s5.

Table S1: Physical characteristics of water sources. Two to three measurements were taken during an intensive study period from 13 January 2017 to 4 February 2017 in the wet season, and three to four measurements from 5 June 2016 to 15 July 2016 in the dry season. The median measurement of the values is reported here. Sites with missing samples, such as ephemeral rivers that do not flow all the way into the valley in the dry season, are indicated (*). Sites with missing data due to instrument failure are indicated (#). Values that were below the detection limit are indicated (bdl). South African regulation (SANS 241:1-2015) and the World Health Organization Recommended Guidelines for Drinking Water Quality (Fourth Edition) are listed; parameters not listed are indicated (nl),

Acknowledgments:

This project was funded by the Fogarty International Center (FIC) of the National Institutes of Health (NIH) (Award Number D43 TW009359), National Science Foundation (NSF) (Award Number CBET-1438619), the Center for Global Health at the University of Virginia (CGH), and the University of Virginia’s Jefferson Public Fellows (JPC) program. The content is solely the responsibility of the authors and does not represent the official views of the funders. The authors also acknowledge the tireless work of the community field workers who undertook interventions and collected all of the survey data. The authors also acknowledge A. Gaylord, N. Khuliso, S. Mammburu, K. McCain and E. Stinger, who performed much of the water-quality analysis and T. Singh, who supported the laboratory analysis for inorganic materials.

Supplementary Materials: The following are available online at www.mdpi.com/s1 ,

Conflicts of Interest: The authors declare no conflict of interest.

We want to hear from you! Let us know what you think about our website.

interstitialRedirectModalTitle

interstitialRedirectModalMessage

• Show search

Food & Water Stories

Solutions to Address Water Scarcity in the U.S.

More than half the nation has regularly experienced droughts since 2000.

February 13, 2020 | Last updated March 31, 2022

• Agriculture
• Groundwater

Freshwater is essential for all life on Earth. Yet, only 2.5 percent of Earth’s vast water resources are fresh, and less than 1 percent of that is easily accessible for people and nature. This limited resource must be man­aged wisely, particularly in the face of climate change, growing populations, and increasing demands from multiple sectors. To meet this challenge, The Nature Conservancy works to reduce demands for water among the biggest users, improve the flexibility of water governance and management, and advance financial incentives and tools that enable users—like irrigation districts and cities—to transfer water, which will provide water security for the environment as well.

The benefits of healthy, sustainable water resources:

• Supply clean drinking water.
• Grow our food and are used to raise livestock.
• Produce the goods we use.
• Drive economic and social benefits.
• Sustain healthy rivers, lakes, springs and associated habitats that support diverse wildlife.
• Provide for recreation and tourism. And can be harnessed to produce clean hydroelectric power.

Freshwater Challenges in the U.S.

More than half the continental U.S. has regularly experienced drought conditions over the past two decades.

Because of climate change, experts predict precipitation will likely decline 20 to 25 percent by 2100 in much of the West.

Since 2000, the Colorado River Basin— which supplies water to 40 million people—has experienced historic drought conditions.

Water scarcity isn’t limited to Western states. In 2014, 40 of 50 state water managers expected shortages in some portion of their states over the next 10 years.

Our Freshwater Conservation Strategies

Our approach to protecting freshwater involves a combination of water funds, promoting incentives, collaborating with water users, and advancing sound water policies and funding.

We invest in water markets and water transactions with cities, irrigation districts and other water users to demonstrate flexible water use and transfers that include water for environmental needs.

We promote and incentivize innovative approaches that reduce demands and improve infrastructure to move and store water more efficiently.

We collaborate with farmers, ranchers and corporations to reduce water use at all levels in the agricultural supply chain.

We advance local, state and federal policies that enable water managers to effectively meet the needs of people and nature. We also work to secure state and federal funding that supports sustainable water practices and agreements.

We demonstrate our work through more than 70 projects across the nation. Currently, approximately 90 percent of these are located in the western U.S., including TNC’s Colorado River Program . The remaining projects are located east of the Mississippi River in regions that are beginning to experience water scarcity more frequently and intensely.

Finding Solutions to Water Scarcity in  Agriculture

Agriculture accounts for 70 percent of the planet’s freshwater withdrawals annually. This presents a tremendous opportunity to work with farmers and agriculture supply chain companies to ensure the sustainability of the food we eat and the water upon which it relies. In the U.S., irrigation accounts for more than 80 percent of total water consumptive use and up to 94 percent of con­sumption in regions most prone to water scarcity. Below are two case studies that demonstrate how TNC is working with farmers to help reduce water use. 

Case Study 1: Saving Water, Securing the Nation's Food

Agricultural irrigation accounts for 90 percent of the consumptive water use in Nebraska. There are 7 million acres of irrigated land in the Platte River Valley alone. Here, The Nature Conservancy recognized a chance to conserve water at a large scale and reached out to land­owners interested in new water-saving irrigation technologies. These efforts evolved into a collaboration with Coca-Cola, John Deere, McDonalds and the World Wildlife Fund to launch the Western Nebraska Irrigation Project in 2014.

TNC connected 11 farmers who collectively manage 8,000 acres with tech­nology providers to install soil moisture probes, pivot telemetry and weather stations to help reduce water use. The farmers were then provided support that enabled them to micromanage irrigation and reduce the amount of water pumped from the underlying aquifer by 20 percent. The project site included quality historic water-use records, which enabled researchers to measure change. Over a three-year period, the farmers saved over a billion gallons of water—enough to fill more than 110,000 semi tanker trucks.

Less groundwater pumping not only helps secure the resiliency of the underlying aquifer, it also saves the farmers time and money. One participating farmer reported “the probes paid for themselves easily each year,” while another noted the technology saved time because he didn’t have to drive to his field to check conditions.

The project’s success spurred interest in Central Nebraska, where TNC teamed with Nestlé Purina and Cargill to launch a  second irrigation project  in 2018. Here, researchers estimated that 20 participating farmers saved at least 120 million gallons of water in the first year. In March 2020, the project reached its enrollment target of 50 farmers, with many reporting that the technology and training has helped them save time and money because of less pumping.

Case Study 2: Price River, Utah—Water Wise Solutions for People and Nature

TNC is working with a wide range of partners in the Price River watershed to enhance water use in ways that benefit agricultural operations while improving flows. Since 2016, TNC has worked with farmers to test water-saving methods that could inform drought contin­gency plans in the Colorado River’s Upper Basin. Working with farmers and other partners, TNC is exploring temporary, voluntary and compensated measures—like water banking—to help reduce the risk of water shortages for all.

Quote : Kevin Cotner

My family has farmed here for three generations. Working with TNC gives me a chance to help improve my agricultural operations and the wildlife habitat here that I care so much about.

Kevin Cotner

Agriculture uses about 80 percent of the water in the Colorado River Basin, with large flows moving from rivers to fields through irrigation ditches, canals and other structures. The infrastructure that moves irrigation water is often old, leaky and inefficient. To address this challenge, TNC works with water users to improve the delivery and timing of irrigation water through updated canal lining and piping. On the Price River, TNC has negotiated an innovative water-management agreement with a canal company to enhance flows and agriculture. The agreement upgrades the company’s infrastructure and benefits six rare fish species in the lower Price. Water that isn’t delivered to shareholders is stored in an adjacent reservoir for strategic releases in late summer when levels in the river typically drop. While these measures increase water for the environment, they can also benefit farm productivity and help enhance the security of water for agriculture.

Take Action

You can advance TNC’s efforts to secure clean fresh water around the world. Make a difference today!

More Water Stories

Groundwater: Our Most Valuable Hidden Resource

Though it's out of sight, groundwater is critical for biodiversity, growing food and other needs for a healthy planet. See what The Nature Conservancy is doing to safeguard this hidden resource.

Demand Management in the Colorado River Basin

State Drought Contingency Plans in the Colorado River Basin are using demand management to reduce water use at critical times and compensate users for saving water.

Western Nebraska Irrigation Project

A three-year pilot project with Nebraska farmers has yielded big water savings on the Platte River.

Reducing Carbon Footprint of Water Consumption: A Case Study of Water Conservation at a University Campus

• First Online: 01 January 2013

Cite this chapter

• Tammy E. Parece 3 ,
• Lawrence Grossman 3 &
• E. Scott Geller 4  

Part of the book series: The Handbook of Environmental Chemistry ((HEC,volume 25))

3246 Accesses

5 Citations

This chapter reports on a study to promote environmentally relevant behavior on a university campus. Ten residence halls at Virginia Tech were included in the study, and the project employed five different strategies, each with a different number of prompting strategies to determine which approach was most effective at influencing reductions in water use. Consumption reductions were observed in most of the residence halls participating in the study, but no one strategy was more effective than another. Even though reductions were not achieved in all residence halls, overall water consumption was reduced by 11.6%. Reducing the consumption of water also resulted in the reduction of energy used to treat and transport the water from the University’s water source – the New River. Therefore, the energy savings achieved resulted in a reduction of the University’s carbon footprint.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Subscribe and save.

• Get 10 units per month
• Download Article/Chapter or eBook
• 1 Unit = 1 Article or 1 Chapter
• Cancel anytime
• Available as PDF
• Read on any device
• Instant download
• Own it forever
• Available as EPUB and PDF
• Compact, lightweight edition
• Dispatched in 3 to 5 business days
• Free shipping worldwide - see info
• Durable hardcover edition

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Similar content being viewed by others

Every Drop of Water and Food Footprints Count for Humanity

Examining water conservation behaviors and attitudes: evidence from the city of Ada, Oklahoma, USA

Carbon Footprint of Water Consumption in Urban Environments: Mitigation Strategies

No responses were obtained for the Fall Survey, possibly resulting from a glitch in the email invitation sent out by the University.

Requests for additional information on the survey questions may be sent to the corresponding author at [email protected].

Knight JF, Voth ML (2012) Application of MODIS imagery for intra-annual water clarity 7 assessment of Minnesota Lakes. Rem Sens 4:2181–2198

Article   Google Scholar  

WHO (2012) World health organization water sanitation and health. http://www.who.int/water_sanitation_health/mdg1/en/index.html Accessed 9 June 2012

IPCC (2007) Climate change 2007: the physical science basis. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Contribution of working group I to the 23 fourth assessment report of the intergovernmental panel on climate change, Cambridge University Press, Cambridge and New York

Google Scholar  

Pickett STA, Cadenasso ML, Grove JM, Nilon CH, Pouyat RV, Zipperer WC, Costanza R (2001) Urban ecological systems: linking terrestrial ecological, physical, and socieoeconomic components of metropolitan areas. Annu Rev Ecol Syst 32:127–157

United Nations (2010) World urbanization prospects: the 2009 revision. Department of Economic and Social Affairs – Population Division. Available at http://esa.un.org/wpp/

Welker AL, Wadzuk BM, Traver RG (2010) Integration of education, scholarship, and service through stormwater management. J Contemp Water Res Educ 146:83–91

Geiger R, Aron RH, Todhunter P (2003) The climate near the ground, 6th edn. Rowman and Littlefield Publishers, Inc. Lanham

U.S. EPA (2012) Indoor water use in the United States http://www.epa.gov/watersense/pubs/indoor.html Accessed June 2012

Orange County Water District (2012) Water facts http://www.ocwd.com/ca-182.aspx Accessed 9 June 2012

McCalley LT, Midden CJH (2002) Energy conservation through product-integrated feedback: the roles of goal-setting and social orientation. J Econ Psychol 23(5):589–603

Kurz T, Donaghue N, Wakjer I (2005) Utilizing a social-ecological framework to promote water and energy conservation: a field experiment. J Appl Soc Psychol 35(6):1281–1300

Geller ES (1989) Applied behavior analysis and social marketing: an integration for environmental preservation. J Soc Issues 45(1):17–36

McKenzie-Mohr D (2000) Fostering sustainable behavior through community-based social marketing. Am Psychol 55(5):513–537

Lehman PK, Geller ES (2004) Behavior analysis and environmental protection: accomplishments and potential for more. Behav Soc Issues 13:13–32

Steg L, Dreijerink L, Abrahamse W (2006) Why are energy polices acceptable and effective? Environ Behav 38(1):92–111

Winkler RC (1982) Water conservation. In: Geller ES, Winett RA, Everett PB (eds) Preserving the environment: new strategies for behavior change. Pergamon, New York

Virginia Tech (2009) http://spec.lib.vt.edu/archives/125th/timeline.htm Accessed 13 February 2010

Commonwealth of Virginia (2002) GIS data. http://gisdata.virginia.gov/Portal/ Accessed 25 November 2009

Virginia Tech (2008) GIS layers provided by Virginia Tech facilities information system. Available for downloading at http://www.gis.lib.vt.edu/gis_data/Blacksburg/CDfiles.htm

Parece T, DiBetitto S, Sprague T, Younos T (2010) The Stroubles Creek watershed: history of development and chronicles of Research. VWRRC Special Report No. SR48-2010. Virginia Tech, Blacksburg. http://www.vwrrc.vt.edu/special_reports.html#2009

Abrahamse W, Steg L, Vlek C, Rothengatter T (2005) A review of intervention studies aimed at household energy conservation. J Environ Psychol 25(3):273–291

Younos T, Grady C, Chen T, Parece T (2009) Conventional and decentralized water supply infrastructure: energy consumption and carbon footprint. American Water Resources Association 2009 Spring Specialty Conference, Anchorage, May 4–6, 2009

Kloss C (2008) Managing wet weather with green infrastructure municipal handbook rainwater harvesting policies EPA-833-F-08-010

Cialdini RB (2003) Crafting normative messages to protect the environment. Curr Dir Psychol Sci 12(4):105–109

Schultz PW, Nolan J, Cialdini RB, Goldstein NJ, Griskevicius V (2007) The constructive, destructive, and reconstructive power of social norms. Psychol Sci 18(5):429–434

Van Raaij WF, Verhallen TMM (1983) A behavioral model of residential energy use. J Econ Psychol 3(1):39–63

Corral-Verdugo V, Frías-Armenta M (2006) Personal normative beliefs, antisocial behavior, and residential water conservation. Environ Behav 38(3):406–421

Stern PC, Dietz T, Abel T, Guagnano GA, Kalof L (1999) A value-belief-norm theory of support for social movements: the case of environmentalism. Res Human Ecol 6(2):81–97

Scherbaum CA, Popovich PM, Finlinson S (2008) Exploring individual-level factors related to employee energy-conservation behaviors at work. J Appl Soc Psychol 38(3):818–835

Geller ES, Erickson JB, Buttram BA (1983) Attempts to promote residential water conservation with educational, behavioral and engineering strategies. Popul Environ 6(2):96–112

Becker LJ (1978) Joint effect of feedback and goal setting on performance: a field study of residential energy conservation. J Appl Psychol 63(4):428–433

Stern PC, Gardner GT (1981) Psychological research and energy policy. Am Psychol 36(4):329–342

Brandon G, Lewis A (1999) Reducing household energy consumption: a qualitative and quantitative field study. J Environ Psychol 19(1):75–85

Seligman C, Becker LJ, Darley JM (1981) Encouraging residential energy conservation through feedback. In: Baum A, Singer JE (eds) Advances in environmental psychology, vol 3. A. Baum and J. E. Singer, Hillsdale

Palmini DJ, Shelton TB (1982) Residential water conservation in a noncrisis setting: results of a New Jersey experiment. Water Resour Res 18(4):697–704

Miller E, Buys L (2008) The impact of social capital on residential water-affecting behaviors in a drought-prone Australian community. Soc Nat Res 21:244–257

Lawrence K, McManus P (2008) Towards household sustainability in Sydney? Impacts of two sustainable lifestyle workshop programs on water consumption in existing homes. Geogr Res 46(3):314–332

Aronson E, O’Leary M (1983) The relative effectiveness of models and prompts on energy conservation: a field experiment in a shower room. Environ Syst 12(3):219–224

McClelland L, Cook SW (1980) Energy conservation in university buildings: encouraging and evaluating reductions in occupants’ electricity use. Eval Rev 4(1):119–132

Luyben PD (1980) Effects of informational prompts on energy conservation in college classrooms. J Appl Behav Anal 13(4):611–617

Article   CAS   Google Scholar  

Wodarski JS (1982) National and state appeals for energy conservation: a behavioral analysis of effects. Behav Eng 7(4):119–130

Howard GS, Delgado E, Miller D, Gubbins S (1993) Transforming values into actions: ecological preservation through energy conservation. J Counsel Psychol 21(4):582–596

Larson ME, Houlihan D, Goernert PN (1995) Brief report: effects on informational feedback on aluminum can recycling. Behav Interv 10(2):111–117

Ludwig TD, Gray TW, Rowell A (1998) Increasing recycling in academic buildings: a systematic replication. J Appl Behav Anal 31(4):683–686

Marcell K, Agyeman J, Rappaport A (2004) Cooling the campus: experiences from a pilot study to reduce electricity use at Tufts University, USA, using social marketing methods. Int J Sustain High Educ 5(2):169–189

Petersen JE, Shunturov V, Janda K, Platt G, Weinberger K (2007) Dormitory residents reduce electricity consumption when exposed to real-time visual feedback and incentives. Int J Sustain High Educ 8(1):16–33

Marans RW, Edelstein JR (2010) The human dimension of energy conservation and sustainability: a case study of the University of Michigan’s energy conservation program. Int J Sustain High Educ 11(1):6–18

Torres-Antonini M, Dunkel NW (2009) Green residence halls are here: current trends in sustainable campus housing. J Coll Univ Student Hous 36(1):10–23

Download references

Acknowledgments

We are grateful for the support of many officials at Virginia Tech and for the participation of numerous students. The Virginia Tech Graduate Student Assembly provided a Graduate Research Award which partially funded the purchase of intervention materials.

Author information

Authors and affiliations.

Geography Department, Virginia Tech, Blacksburg, VA, USA

Tammy E. Parece & Lawrence Grossman

Center for Applied Behavior Systems, Virginia Tech, Blacksburg, VA, USA

E. Scott Geller

You can also search for this author in PubMed   Google Scholar

Corresponding author

Correspondence to Tammy E. Parece .

Editor information

Editors and affiliations.

Plymouth Street 2502, Blacksburg, 24060-8256, Virginia, USA

Tamim Younos

Center Street 1422, Lafayette, 47905, Indiana, USA

Caitlin A. Grady

Rights and permissions

Reprints and permissions

Copyright information

© 2013 Springer-Verlag Berlin Heidelberg

About this chapter

Parece, T.E., Grossman, L., Geller, E.S. (2013). Reducing Carbon Footprint of Water Consumption: A Case Study of Water Conservation at a University Campus. In: Younos, T., Grady, C. (eds) Climate Change and Water Resources. The Handbook of Environmental Chemistry, vol 25. Springer, Berlin, Heidelberg. https://doi.org/10.1007/698_2013_227

Download citation

DOI : https://doi.org/10.1007/698_2013_227

Published : 20 March 2013

Publisher Name : Springer, Berlin, Heidelberg

Print ISBN : 978-3-642-37585-9

Online ISBN : 978-3-642-37586-6

eBook Packages : Earth and Environmental Science Earth and Environmental Science (R0)

Share this chapter

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

• Publish with us

Policies and ethics

• Find a journal
• Track your research

SustainCase – Sustainability Magazine

• trending News
• Climate News
• Collections
• case studies

Case study: How Mandarin Oriental Hotel Group reduces water consumption

As an international hotel investment and management group with deluxe and first-class hotels, resorts and residences, operating 29 hotels and eight residences in 19 countries and territories around the globe, Mandarin Oriental Hotel Group, realising that the availability of clean, accessible water is critical to the health and economic vitality of the communities where it operates, implements a series of water conservation strategies, including investing in water efficient technologies.

This case study is based on the 2016 Sustainability Report b y Mandarin Oriental Hotel Group published on the Global Reporting Initiative Sustainability Disclosure Database  that can be found at this link . Through all case studies we aim to demonstrate what CSR/ ESG/ sustainability reporting done responsibly means. Essentially, it means: a) identifying a company’s most important impacts on the environment, economy and society, and b) measuring, managing and changing.

Mandarin Oriental Hotel Group has set a goal to reduce water intensity per guest night by 20% from 2007 levels, by 2020.     Tweet This! In order to reduce water consumption Mandarin Oriental Hotel Group took action to:

• conduct water risk assessments
• implement water conservation measures
• recycle and reuse water

Subscribe for free and read the rest of this case study

Please subscribe to the SustainCase Newsletter to keep up to date with the latest sustainability news and gain access to over 2000 case studies. These case studies demonstrate how companies are dealing responsibly with their most important impacts, building trust with their stakeholders (Identify > Measure > Manage > Change).

With this case study you will see:

• Which are the most important impacts (material issues) Mandarin Oriental Hotel Group has identified;
• How Mandarin Oriental Hotel Group proceeded with stakeholder engagement , and
• What actions were taken by Mandarin Oriental Hotel Group to reduce water consumption

Already Subscribed? Type your email below and click submit

What are the material issues the company has identified?

In its 2016 Sustainability Report Mandarin Oriental Hotel Group identified a range of material issues, such as guest health and safety, human rights and diversity, supply chain management, biodiversity, information protection. Among these, reducing water consumption stands out as a key material issue for Mandarin Oriental Hotel Group.

Stakeholder engagement in accordance with the GRI Standards

The Global Reporting Initiative (GRI) defines the Principle of Stakeholder Inclusiveness when identifying material issues (or a company’s most important impacts) as follows:

“The reporting organization shall identify its stakeholders, and explain how it has responded to their reasonable expectations and interests.”

Stakeholders must be consulted in the process of identifying a company’s most important impacts and their reasonable expectations and interests must be taken into account. This is an important cornerstone for CSR / sustainability reporting done responsibly.

Key stakeholder groups Mandarin Oriental Hotel Group engages with:  

How stakeholder engagement was made to identify material issues

To identify and prioritise material topics Mandarin Oriental Hotel Group engaged with its stakeholders through a stakeholder panel, which integrated perspectives from various organisations such as Conservation International, the International Tourism Partnership, National Geographic Traveler , the United States Green Building Council and the World Wildlife Fund.

In its 2016 Sustainability Report Mandarin Oriental Hotel Group reports that it took the following actions for reducing water consumption:

• Conducting water risk assessments
• Mandarin Oriental Hotel Group carried out a Group-wide water risk assessment, using the World Resources Institute’s Aqueduct tool. Based on the properties’ location, Mandarin Oriental Hotel Group considered its exposure, on a site-by-site basis, to a series of risks that included baseline water stress, flood occurrence and drought severity. The assessment reviewed the current condition, as well as a projection for 2020. The water risk assessment identified 13 properties in Mandarin Oriental Hotel Group’s existing portfolio and seven development projects that were located in high water stressed areas, and its key findings were used to identify and prioritise target water conservation actions and programmes. For example, Mandarin Oriental, Bangkok ran a campaign to educate employees on water conservation during the 2016 drought in Central Thailand.
• Implementing water conservation measures
• Motion Sensors and Low Flow Fixtures: Mandarin Oriental Hotel Group continues to retrofit motion sensor and low flow fixtures in its properties’ common areas, back-of-house areas and guestrooms. In 2016, Mandarin Oriental, Bangkok, Singapore and Hong Kong installed new low flow toilets in their guestrooms.
• Process Improvements and Water Efficient Technologies: From Mandarin Oriental Hotel Group’s buildings’ heating and cooling systems to its kitchen, laundry and gardening operations, the stimulation of process improvements that conserve water has helped to support the Group’s progress toward its 2020 goal. Each of Mandarin Oriental Hotel Group’s hotels and residences are actively identifying and implementing water efficiency technologies and process improvements to conserve water. In 2016, Mandarin Oriental, Hong Kong introduced an alternative system for defrosting food, eliminating the traditional use of freshwater and Mandarin Oriental, Boston has begun to offer soakless pedicures to reduce water associated with spa services.
• Behavioural Change Initiatives: Due to behavioural change initiatives, Mandarin Oriental Hotel Group has been able to support a culture of conservation. At Mandarin Oriental, Hong Kong, overnight cleaning water consumption is monitored daily and water saving opportunities are reviewed with the kitchen team on a monthly basis. In 2016, employees at Mandarin Oriental, Marrakech began placing water conversation labels next to all back office water taps as a gentle reminder not to be wasteful when using water.
• Recycling and reusing water
• Mandarin Oriental, Sanya uses recycled treated grey water for irrigation throughout the resort’s extensive gardens. At Mandarin Oriental, Marrakech, ground water is used for irrigating its landscaping and vegetable garden.
• Mandarin Oriental, Milan is using groundwater for the chiller system rather than evaporative cooling towers. Mandarin Oriental, Bodrum engages in a similar process, using seawater instead.
• Mandarin Oriental, Hong Kong and The Excelsior, Hong Kong recycle water from the cooling towers for toilet flushing. Mandarin Oriental, Tokyo also uses recycled water for toilet flushing in part of the building.

Which GRI Standards and corresponding Sustainable Development Goals (SDGs) have been addressed?

The GRI Standard addressed in this case is: Disclosure 303-1 Water withdrawal by source

Disclosure 303-1  Water withdrawal by source corresponds to:

• Sustainable Development Goal (SDG) 6 : Ensure availability and sustainable management of water and sanitation for all
• Business theme:  Sustainable water withdrawals

78% of the world’s 250 largest companies report in accordance with the GRI Standards

SustainCase was primarily created to demonstrate, through case studies, the importance of dealing with a company’s most important impacts in a structured way, with use of the GRI Standards. To show how today’s best-run companies are achieving economic, social and environmental success – and how you can too.

Research by well-recognised institutions is clearly proving that responsible companies can look to the future with optimism .

7 GRI sustainability disclosures get you started

Any size business can start taking sustainability action

GRI, IEMA, CPD Certified Sustainability courses (2-5 days): Live Online or Classroom  (venue: London School of Economics)

• Exclusive FBRH template to begin reporting from day one
• Identify your most important impacts on the Environment, Economy and People
• Formulate in group exercises your plan for action. Begin taking solid, focused, all-round sustainability action ASAP. 
• Benchmarking methodology to set you on a path of continuous improvement

See upcoming training dates.

References:

1) This case study is based on published information by Mandarin Oriental Hotel Group, located at the link below. For the sake of readability, we did not use brackets or ellipses. However, we made sure that the extra or missing words did not change the report’s meaning. If you would like to quote these written sources from the original, please revert to the original on the Global Reporting Initiative’s Sustainability Disclosure Database at the link:

http://database.globalreporting.org/

2)  http://www.fbrh.co.uk/en/global-reporting-initiative-gri-g4-guidelines-download-page

3) https://g4.globalreporting.org/Pages/default.aspx

4) https://www.globalreporting.org/standards/gri-standards-download-center/

Note to Mandarin Oriental Hotel Group: With each case study we send out an email requesting a comment on this case study. If you have not received such an email please contact us .

The Environmental Impact of AI: A Case Study of Water Consumption by Chat GPT

• A. Shaji George Masters IT Solutions, Chennai, Tamil Nadu, India
• A. S. Hovan George Student, Tbilisi State Medical University, Tbilisi, Georgia
• A. S. Gabrio Martin Masters IT Solutions, Chennai, Tamil Nadu, India

As AI is becoming more a part of our lives, people are starting to worry about the negative consequences it might have on the environment. One of the major issues is its high water consumption. The water[21] consumption of AI models, including Chat GPT, is a major concern and must be managed effectively to reduce environmental harm. This document examines the amount[15] of water that is utilized by Chat GPT and other AI models and investigates the impact that it may have on the environment, as well as possible solutions to control their water usage. The study further considers the plausibility and usefulness of these approaches. The findings imply that although water usage of AI systems is significantly lower compared to other industries, it is still a matter of concern. AI models can have a significant water footprint, but this can be reduced by taking certain measures such as improving energy efficiency, utilizing renewable energy sources, optimizing algorithms and implementing strategies to conserve water. Despite the potential of these solutions, there are still issues to be addressed, such as the expense associated with implementation, and further research is required for optimum utilization. In conclusion, this document emphasizes the relevance of recognizing the water footprint caused by AI models, giving important details regarding potential solutions to minimize their environmental impact.

How to Cite

• Endnote/Zotero/Mendeley (RIS)

Current Issue

Make submission, publication information.

ISSN : 2583-9675

Publisher: PU Publications

Publication Format: Online

Language:  English

Establishment Year: January, 2023

Frequency: Bi-Monthly

eMail:  [email protected]

© Copyright 2023 - 2024 PUIIJ | PU Publications. All Rights Reserved.                                  WEB PARTNER: AUSOM DIGITAL 

Assessing the Consumption-based Water Use of Global Construction Sectors and its Impact to the Local Water Shortage

• Shuai, Chenyang
• Xiang, Pengchen
• Sun, Jingran

The trillion-dollar construction sector has exacerbated the significant challenge of global water scarcity. However, a notable gap exists in the availability of a comprehensive water footprint (i.e., water use through supply chain) map specific to the global construction sector and its impact on local water scarcity. Our study developed a water scarcity assessment model and linked it with the global environmental-extended multi-regional input-output model covering 120 sectors and 154 countries. With this, our study assessed the water footprints by final demands of the construction sector and their impact on local water shortages. Our findings indicate that the global construction sector's water footprint is approximately 61 billion tons, constituting 5.3% of global water withdrawal in 2020. Both building construction and civil engineering construction sectors exhibit similar water footprints. Notably, water-scarce countries experience a disproportionate impact, with higher-income nations more significantly affected by their construction water footprint compared to low-income countries. The novelty of the study lies in the detailed economy-by-economy WF estimation of global build and civil construction sector and linked it with local water scarcity. Our results underscore the urgency of implementing measures by water scarcity countries and key sectors to mitigate and reduce the water footprint of the construction sector, thereby contributing to global water sustainability.

• Water Scarcity;
• Sustainable Management;
• Trade System;
• Global Scale;

Demand for AI is driving data center water consumption sky high

The AI boom is fueling the demand for data centers and, in turn, driving up water consumption. (Water is used to cool the computing equipment inside data centers.) According to FT, in Virginia — home to the world’s largest concentration of data centers — water usage jumped by almost two-thirds between 2019 and 2023, from 1.13 billion gallons to 1.85 billion gallons.

Many say the trend, playing out worldwide, is unsustainable. Microsoft, a major data center operator, says 42% of the water it consumed in 2023 came from “areas with water stress.” Google, which has among the largest data center footprints, said this year that 15% of its freshwater withdrawals came from areas with “high water scarcity.”

Why can’t data centers recycle water in a closed-loop system? Many do, but much of what they consume is set aside for humidity control, meaning it evaporates. Especially in drier regions, air that’s not humidified can become a strong conductor of static electricity, which is usually bad news for computers.

More TechCrunch

Get the industry’s biggest tech news, techcrunch daily news.

Every weekday and Sunday, you can get the best of TechCrunch’s coverage.

Startups Weekly

Startups are the core of TechCrunch, so get our best coverage delivered weekly.

TechCrunch Fintech

The latest Fintech news and analysis, delivered every Tuesday.

TechCrunch Mobility

TechCrunch Mobility is your destination for transportation news and insight.

Telegram founder Pavel Durov reportedly arrested in France

Pavel Durov, founder and CEO of messaging app Telegram, was arrested on Saturday evening while leaving his private jet at France’s Bourget airport, according to French television network TF1. Reports…

Apple reportedly announcing iPhone 16 lineup and more on Sept. 10

Apple will be unveiling new products on September 10, with the announced phones going on sale on September 20, according to a report from Bloomberg’s Mark Gurman. That lineup will…

Featured Article

The fallout after Bolt’s aggressive fundraising attempt has been wild

After fintech Bolt surprised the industry with a leaked term sheet that revealed it is trying to raise at a $14 billion valuation, things got weird.

Starliner will return to Earth uncrewed, astronauts staying on ISS until February

Boeing’s Starliner mission is coming back to Earth — empty. After months of data analysis and internal deliberation, NASA leadership announced today that Starliner will be coming back to Earth…

Do you know where your children are? Maybe on X

A surprising number of “iPad kids” — aka Generation Alpha’s 7- to 9-year-old demographic — are using X, according to new data from parental control software maker Qustodio. The firm…

Google just made a $250M deal with California to support journalism — here’s what it means

This week, Google joined a $250 million deal with the state of California to support California newsrooms. While the deal offers a much-needed cash infusion for an industry that’s seen…

X shareholders as of June 2023 included funds tied to Bill Ackman, Binance, and Sean ‘Diddy’ Combs

A court order recently forced Elon Musk’s X to reveal its full list of shareholders, as of June 2023, to the public. Many of the recognizable tech industry names had…

VCs are so eager for AI startups, they’re buying into each others’ SPVs at high prices

VCs are increasingly buying shares of late-stage startups on the secondary market as they try to get pieces of the hottest ones — especially AI companies. But they are also increasingly doing so through financial instruments called special purpose vehicles (SVPs). Some of those SPVs are becoming such hot commodities…

The top AI deals in Europe this year

Cumulatively, there have been more than 1,700 funding rounds for AI startups in Europe so far in 2024.

The founder building a wealth-management product her grandmother would have loved

After two years of building the company, the company quietly launched its beta in June and is officially announcing it today, right here, in TechCrunch. 

These 74 robotics companies are hiring

From the looks of things, companies in the category — including Agility Robotics and Formlogic — can’t hire quickly enough.

Threads confirms it is experimenting with ephemeral posts

Automatically disappearing posts on social networks could be handy for users who have a habit of deleting their posts through third-party tools, or if the context of those posts is…

‘Disappointed but not surprised’: Former employees speak on OpenAI’s opposition to SB 1047

Two former OpenAI researchers who resigned this year over safety concerns say they are disappointed but not surprised by OpenAI’s decision to oppose California’s bill to prevent AI disasters, SB…

VC Neil Mehta, who’s quietly nabbing prized SF property, plans a “Y Combinator for restaurants”

Neil Mehta, the VC behind the acquisition of a string of properties on San Francisco’s tony Fillmore Street, made waves earlier this week for reportedly throwing long-established local restaurants to…

Justice Department sues RealPage over allegedly helping landlords collude to drive up rents

RealPage, which makes property management software, was sued Friday by the U.S. Justice Department and eight attorneys general for allegedly helping apartment and building managers around the country collude to…

Colorful Capital will stop trying to raise for a fund

Colorful Capital’s co-founders, William Burckart and Megan Kashner, declined to comment. 

Andrew Ng steps back at Landing AI after announcing new fund

Andrew Ng is stepping down from his role as CEO at Landing AI, the computer vision platform he founded in 2017. Dan Maloney, formerly the COO, will take the reins…

Piramidal’s foundation model for brainwaves could supercharge EEGs

AI models are being applied to every dataset under the sun, but are inconsistent in their outcomes. This is as true in the medical world as anywhere else, but a…

M&A can open up the playing field for the competition

No two businesses are the same, and that’s good news: As we saw again this week, it opens up space for companies to try opposite approaches, join forces or challenge…

Marc Andreessen’s family plans to build a ‘visionary’ subdivision near the proposed California Forever utopia city

Marc Andreessen’s family is planning to build a large housing development near the proposed California Forever city.

Canoo’s chief technology officer is out amid wider reorg

EV startup Canoo’s chief technology officer Sohel Merchant has left the company, two people familiar with his departure have told TechCrunch. Merchant was one of the members of Canoo’s founding…

Halliburton shuts down systems after cyberattack

A company spokesperson for the oil drilling and fracking giant declined to name the executive overseeing cybersecurity, if any.

Peloton adds $95 activation fee for used equipment

The move is an effort to squeeze additional revenue from second-hand products, over concerns that cheaper, slightly used bikes, treadmills and rowers could cannibalize used sales.

Last day for massive ticket savings to TechCrunch Disrupt 2024

Time is running out! These are the last hours to save up to $600 on TechCrunch Disrupt 2024 tickets — offer ends tonight at 11:59 p.m. PT. Join 10,000+ startup…

Meta and Spotify CEOs criticize AI regulation in the EU

Meta and Spotify are once again teaming up — this time, on the matter of open source (or to be precise, open-weight) AI which the companies claim are being hampered…

Tingit is building a marketplace for ‘zero-effort’ repairs, starting with fashion

Tingit, a startup out of Lithuania, wants to help people restore their used clothing to their former glory with its newly launched repairs marketplace.

After changing its license, Redis drops its biggest release yet

Redis, the company behind the popular in-memory data store, which is often used as a cache, vector database or streaming engine, today announced the launch of Redis 8. With this…

360 One lifts its valuation of India’s National Stock Exchange to $29.9B

360 One Asset, an investor in National Stock Exchange (NSE), has increased its valuation for India’s top stock exchange to $29.9 billion.

Get in on the ground floor with Tesla’s humanoid by pretending to be one for pay

Tesla is hiring individuals standing between 5’7 and 5’11 to carry up to 30 pounds for seven hours a day to train its Optimus robot.

DeepMind workers sign letter in protest of Google’s defense contracts

At least 200 workers at DeepMind, Google’s AI R&D division, are displeased with Google’s reported defense contracts — and according to Time, they circulated a letter internally back in May…

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

• View all journals
• Explore content
• About the journal
• Publish with us
• Sign up for alerts
• 15 August 2024

‘Unacceptable’: a staggering 4.4 billion people lack safe drinking water, study finds

• Alix Soliman

You can also search for this author in PubMed   Google Scholar

People gather around a roadside pipeline to collect drinking water in Bangladesh. Credit: Mamunur Rashid/NurPhoto/Getty

Approximately 4.4 billion people drink unsafe water — double the previous estimate — according to a study published today in Science 1 . The finding, which suggests that more than half of the world’s population is without clean and accessible water, puts a spotlight on gaps in basic health data and raises questions about which estimate better reflects reality.

That this many people don’t have access is “unacceptable”, says Esther Greenwood, a water researcher at the Swiss Federal Institute of Aquatic Science and Technology in Dübendorf and an author of the Science paper. “There’s an urgent need for the situation to change.”

The United Nations has been tracking access to safely managed drinking water, recognized as a human right, since 2015. Before this, the UN reported only whether global drinking-water sources were ‘improved’, meaning they were probably protected from outside contamination with infrastructure such as backyard wells, connected pipes and rainwater-collection systems. According to this benchmark, it seemed that 90% of the global population had its drinking water in order. But there was little information on whether the water itself was clean, and, almost a decade later, statisticians are still relying on incomplete data.

“We really lack data on drinking-water quality,” Greenwood says. Today, water-quality data exist for only about half of the global population. That makes calculating the exact scale of the problem difficult, Greenwood adds.

Crunching numbers

In 2015, the UN created its Sustainable Development Goals to improve human welfare . One of them is to “achieve universal and equitable access to safe and affordable drinking water for all” by 2030. The organization updated its criteria for safely managed drinking-water sources: they must be improved, consistently available, accessible where a person lives and free from contamination.

The world faces a water crisis — 4 powerful charts show how

Using this framework, the Joint Monitoring Programme for Water Supply, Sanitation and Hygiene (JMP), a research collaboration between the World Health Organization (WHO) and the UN children’s agency UNICEF, estimated in 2020 that there are 2.2 billion people without access to safe drinking water. To arrive at this figure, the programme aggregated data from national censuses, reports from regulatory agencies and service providers and household surveys.

But it assessed drinking-water availability differently from the method used by Greenwood and her colleagues. The JMP examined at least three of the four criteria in a given location, and then used the lowest value to represent that area’s overall drinking-water quality. For instance, if a city had no data on whether its water-source was consistently available, but 40% of the population had uncontaminated water, 50% had improved water sources and 20% had water access at home, then the JMP estimated that 20% of that city’s population had access to safely managed drinking water. The programme then scaled this figure across a nation’s population using a simple mathematical extrapolation.

By contrast, the Science paper used survey responses about the 4 criteria from 64,723 households across 27 low- and middle-income countries between 2016 and 2020. If a household failed to meet any of the four criteria, it was categorized as not having safe drinking water. From this, the team trained a machine-learning algorithm and included global geospatial data — including factors such as regional average temperature, hydrology, topography and population density — to estimate that 4.4 billion people lack access to safe drinking water, of which half are accessing sources tainted with the pathogenic bacteria Escherichia coli .

The model also suggested that almost half of the 4.4 billion live in south Asia and sub-Saharan Africa (see ‘Water woes’).

Source: Ref 1.

‘A long way to go’

It’s “difficult” to say which estimate — the JMP’s or the new figure — is more accurate, says Robert Bain, a statistician at UNICEF’s Middle East and North Africa Regional Office, based in Amman, Jordan, who contributed to the calculation of both numbers. The JMP brings together many data sources but has limitations in its aggregation approach, whereas the new estimation takes a small data set and scales it up with a sophisticated model, he says.

The study by Greenwood and her colleagues really highlights “the need to pay closer attention to water quality”, says Chengcheng Zhai, a data scientist at the University of Notre Dame in Indiana. Although the machine-learning technique used by the team is “very innovative and clever”, she says, water access is dynamic, so the estimation might still not be quite right. Wells can be clean of E. coli one day and become contaminated the next, and the household surveys don’t capture that, Zhai suggests.

“Whichever number you run with — two billion or four billion — the world has a long way to go” towards ensuring that people’s basic rights are fulfilled, Bain says.

doi: https://doi.org/10.1038/d41586-024-02621-0

Greenwood, E. E. et al. Science 385 , 784–790 (2024).

Article   Google Scholar  

Download references

Reprints and permissions

Related Articles

• Water resources
• Public health

Groundwater-dependent ecosystem map exposes global dryland protection needs

Article 17 JUL 24

How do you make salty water drinkable? The hunt for fresh solutions to a briny problem

News Feature 04 JUL 24

How to address agriculture’s water woes

Spotlight 19 JUN 24

Extreme heat is a huge killer — these local approaches can keep people safe

News 22 AUG 24

First biolab in South America for studying world’s deadliest viruses is set to open

News 21 AUG 24

Hopes dashed for drug aimed at monkeypox virus spreading in Africa

News 16 AUG 24

Senior Researcher-Experimental Leukemia Modeling, Mullighan Lab

Memphis, Tennessee

St. Jude Children's Research Hospital (St. Jude)

Assistant or Associate Professor (Research-Educator)

The Center for Molecular Medicine and Genetics in the Wayne State University School of Medicine (http://genetics.wayne.edu/) is expanding its high-...

Detroit, Michigan

Wayne State University

Postdoctoral Fellow – Cancer Immunotherapy

Tampa, Florida

H. Lee Moffitt Cancer Center & Research Institute

Postdoctoral Associate - Specialist

Houston, Texas (US)

Baylor College of Medicine (BCM)

Postdoctoral Associate- CAR T Cells, Synthetic Biology

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Quick links

• Explore articles by subject
• Guide to authors
• Editorial policies

--> AGU