Pot chlorination of shallow wells in a peri-urban community in Kenya: an effectiveness trial

2013 ◽  
Vol 3 (4) ◽  
pp. 564-571
Author(s):  
Krista Vandermeer ◽  
Robert Dreibelbis ◽  
Daniel Obote Akoko ◽  
Richard D. Rheingans

The effectivenss of pot chlorination to continously treat shallow wells in a peri-urban community in Kisumu, Kenya, was evaluated. A total of 30 shallow wells used by local residents were identified. Half were randomly allocated to be treated by pot chlorination, while the remainder served as the control group. Residual free chlorine (RFC) and the presence of Escherichia coli (E. coli) were measured in all wells before chlorination and at repeated intervals over a 14-day period. Although there was a reduction in E. coli levels in the intervention wells post-chlorination, there was no difference in the percentage of wells in each group meeting WHO drinking water guidelines of 0 E. coli CFUs/100 ml on day 7 (p = 0.444) or day 14 (p = 0.188). While the intervention was associated with a statistically significant improvement in the percentage of chlorinated wells meeting the WHO guidelines for RFC of at least 0.5 mg/l (41.7%) compared to control wells on day 7 (p = 0.010), by day 14 there was no detectable difference between the two groups (p = 0.444). Pot chlorination of the shallow wells in this study did not improve the microbiological quality of well water to WHO drinking water standards and was not effective in maintaining the recommended RFC required for continuous disinfection.

Author(s):  
Kaboré Aminata ◽  
Savadogo Boubacar ◽  
Jacques Sawadogo ◽  
Kafando Haoua ◽  
Tarnagda Grissoum ◽  
...  

Microbiological quality of drinking water in market gardening sites was assessed to understand the persistence of diarrhoeal diseases and malnutrition among children under five. Households with children under five (5) were selected in Dassa, Nebia, Nariou and Tanguin-wobdo located in centre-ouest region in Burkina Faso. A total of 140 water samples were collected from storage containers in households (n=108), boreholes (n=7) and hand dug wells (n=25) during the month of February 2018. Faecal coliforms, Escherichia coli (E. coli) and faecal streptococci were isolated and enumerated according French standard methods. WHO standards guidelines for drinking water were used to assess water quality. Results showed that 100% of hand dug well water were contaminated with faecal bacteria whereas all water from boreholes were potables. 72% of hand dug well water were contaminated with E. coli, 96.3% with faecal coliforms and 96% with faecal streptococci. In households, 95.9% of drinking water from boreholes were contaminated with faecal bacteria versus 100% of water from hand dug wells. This situation is related to the lack of safe drinking water infrastructures, unimproved sanitation and lack of hygiene in households. In fact, 78.12% of water infrastructures were hand dug wells located mostly in gardens. In these areas, contaminated hand dug well water are used for both irrigation and consumption. Regarding these results, a reinforcement of safe drinking water infrastructures such as boreholes, improved hygiene and sanitation and health education are necessary to improve the quality of drinking water to reduce diarrhoeal diseases and malnutrition among market gardeners’ children.


Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 392 ◽  
Author(s):  
Sabir Nurtazin ◽  
Steven Pueppke ◽  
Temirkhan Ospan ◽  
Azamat Mukhitdinov ◽  
Timur Elebessov

The thinly populated Balkhash District of Kazakhstan’s Almaty Region lies in the lower reaches of the Ili-Balkhash basin, which is shared by China and Kazakhstan. The district is arid and heavily dependent on inflows of surface water, which are threatened by the effects of upstream population growth, economic development, and climate change. The quality of drinking water from centralized water systems and tube wells in nine villages of the district was analyzed, and the organoleptic properties of water from these sources was also assessed by an expert and via surveys of local residents. Although most samples met governmental standards for the absence of chemical impurities, high concentrations of mineralization, chlorides, boron, iron, and/or uranium were present in some well water samples. Levels of these pollutants were as much as 4-fold higher than governmental maxima and as much as 16-fold higher than concentrations reported previously in surface water. All centralized water samples met standards for absence of microbial contamination, but total microbial counts in some well water samples exceeded standards. Organoleptic standards were met by all the water from five villages, but centralized water from one village and well water from four villages failed to meet standards based on expert judgment. Residents were, for the most part, more satisfied with centralized rather than well water, but there was no obvious relationship between the failure of water to meet standards and the locations or populations of the settlements. This is the first comprehensive assessment of groundwater used for drinking in the lower Ili-Balkhash basin, and although it relies on a limited number of samples, it nevertheless provides evidence of potentially serious groundwater contamination in the Balkhash District. It is thus imperative that additional and more detailed studies be undertaken.


2021 ◽  
Vol 8 (1-2) ◽  
pp. 11-16
Author(s):  
Sanja Furmeg ◽  
Lana Feher Turković ◽  
Ana Mojsović-Ćuić ◽  
Vesna Jaki Tkalec ◽  
Maja Kiš

In this study, microbiological quality of drinking water deriving from the private wells from Koprivnica-Križevci County was investigated. A total of 287 samples from different locations were collected during 2018 and analysed for the following microbiological parameters: total coliforms, Escherichia coli, Enterococcus spp., Clostridium perfringens, Pseudomonas aeruginosa, and the number of aerobic heterotrophic bacteria at 36 °C and 22 °C. The results showed that 24 % of the analysed water samples were of unsatisfactory microbiological quality, with high incidence of faecal contamination. Well water is still the main source of drinking water for many residents of this County, especially in its rural parts, so continuous monitoring and disinfection of drinking water deriving from private wells is of exceptional importance for the public health.


Author(s):  
Francesca Rubino ◽  
Yahaira Corona ◽  
José Guadalupe Jiménez Pérez ◽  
Charlotte D. Smith

In many regions where drinking water supply is intermittent and unreliable, households adapt by storing water in cisterns or rooftop tanks. Both intermittent supply and stored water can be vulnerable to contamination by microorganisms with deleterious health effects. The Guadalajara Metropolitan Area is a rapidly growing urban center with over five million residents where household storage is nearly ubiquitous. This pilot study was conducted in July 2018 to examine the microbiological quality of drinking water in Guadalajara. Samples were tested for free available chlorine residual, total coliform bacteria, and E. coli. A survey on access to water and public perspectives was also conducted. Water exiting rooftop tanks exceeded regulatory limits for total coliform levels in half of the homes studied. Piped water arriving at two homes had total coliform levels that far exceeded regulatory limits. No E. coli were detected in any of the samples. Only 35% of homes had a chlorine residual between the recommended 0.2 and 1.5 mg/L. Many homes reported unpleasant odors and colors. Only 7% of residents drank the piped water. Future studies are needed, especially during April and May when many homes reported a higher disruption to water service.


Author(s):  
Francesca Rubino ◽  
Yahaira Corona ◽  
José Guadalupe Jiménez Pérez ◽  
Charlotte Smith

In many regions where drinking water supply is intermittent and unreliable, households adapt by storing water in cisterns or rooftop tanks. Both intermittent supply and stored water can be vulnerable to contamination by microorganisms with deleterious health effects. The Metropolitan Zone of Guadalajara is a rapidly growing urban center with over five million residents where household storage is nearly ubiquitous. This pilot study was conducted in July 2018 to examine the microbiological quality of drinking water in Guadalajara. Samples were tested for free available chlorine residual, total coliform bacteria, and Escherichia coli. A survey on access to water and public perspectives was also conducted. Water exiting rooftop tanks exceeded regulatory limits for total coliform levels in half of the homes studied. Piped water arriving at two homes had total coliform levels that far exceeded regulatory limits. No E. coli were detected in any of the samples. Only 35% of homes had a chlorine residual between the recommended 0.2 and 1.5 mg/L. Many homes reported unpleasant odors and colors. Only 7% of residents drank the piped water. Future studies are needed, especially during April and May when many homes reported a higher disruption to water service.


2020 ◽  
Vol 10 (2) ◽  
pp. 202-208
Author(s):  
Asli Aslan ◽  
Haresh Rochani ◽  
Oghenekpaobor Oyibo ◽  
J. Edward Dotherow ◽  
Kendall W. Anderson ◽  
...  

Abstract Sachet water is one of the primary sources of drinking water in rapidly growing countries. A study to assess the microbiological quality of sachet water in 21 different brands was conducted in Ghana. Culturable total coliform was positive in 87% of the samples collected, where Escherichia coli colonies were absent. The analysis of quantitative polymerase chain reaction results indicated the presence of E. coli genes in 44.6% of the samples, with the highest concentration up to 3,166 CCE/100 ml. Microbial source tracking analyses showed that the source of E. coli genes did not originate from sewage contamination because the human-associated HF183 marker was not detected. Of the 175 samples tested, 71% did not mention any water treatment before filling the packages. These results suggest non-human sources of contamination, such as biofilm formation in the pipelines used to fill these packages due to poor disinfection. Our study shows an urgent need for increased regulation and standardized manufacturing of sachet water to ensure safe drinking water.


2014 ◽  
Vol 13 (2) ◽  
pp. 340-352 ◽  
Author(s):  
Andrée F. Maheux ◽  
Vanessa Dion-Dupont ◽  
Sébastien Bouchard ◽  
Marc-Antoine Bisson ◽  
Michel G. Bergeron ◽  
...  

The MI agar, Colilert®, Chromocult coliform® agar, and DC with BCIG agar chromogenic culture-based methods used to assess microbiological quality of drinking water were compared in terms of their ubiquity, sensitivity, ease of use, growth of atypical colonies and affordability. For ubiquity, 129 total coliform (representing 76 species) and 19 Escherichia coli strains were tested. Then, 635 1-L well water samples were divided into 100 mL subsamples for testing by all four methods. Test results showed that 70.5, 52.7, 36.4, and 23.3% of the non-E. coli total coliform strains and 94.7, 94.7, 89.5, and 89.5% of the 19 E. coli strains yielded a positive signal with the four methods, respectively. They also yielded a total coliform positive signal for 66.5, 51.7, 64.9, and 55.0% and an E. coli positive signal for 16.1, 14.8, 17.3, and 13.4% of the 635 well water samples tested, respectively. Results showed that Colilert® is the most expensive method tested in terms of reactants, yet it is the easiest to use. Large numbers of atypical colonies were also often observed on Chromocult coliform® and DC with BCIG, thereby challenging the target microorganism count. Thus, the MI agar method seems to be the best option for the assessment of drinking water quality.


2008 ◽  
Vol 54 (6) ◽  
pp. 495-500 ◽  
Author(s):  
B. Lévesque ◽  
D. Pereg ◽  
E. Watkinson ◽  
J.S. Maguire ◽  
L. Bissonnette ◽  
...  

Bermuda residents collect rainwater from rooftops to fulfil their freshwater needs. The objective of this study was to assess the microbiological quality of drinking water in household tanks throughout Bermuda. The tanks surveyed were selected randomly from the electoral register. Governmental officers visited the selected household (n = 102) to collect water samples and administer a short questionnaire about the tank characteristics, the residents’ habits in terms of water use, and general information on the water collecting system and its maintenance. At the same time, water samples were collected for analysis and total coliforms and Escherichia coli were determined by 2 methods (membrane filtration and culture on chromogenic media, Colilert kit). Results from the 2 methods were highly correlated and showed that approximately 90% of the samples analysed were contaminated with total coliforms in concentrations exceeding 10 CFU/100 mL, and approximately 66% of samples showed contamination with E. coli. Tank cleaning in the year prior to sampling seems to protect against water contamination. If rainwater collection from roofs is the most efficient mean for providing freshwater to Bermudians, it must not be considered a source of high quality drinking water because of the high levels of microbial contamination.


Author(s):  
Francesca Rubino ◽  
Yahaira Corona ◽  
José Guadalupe Jiménez Pérez ◽  
Charlotte Smith

In many regions where drinking water supply is intermittent and unreliable, households adapt by storing water in cisterns or rooftop tanks. Both intermittent supply and stored water can be vulnerable to contamination by microorganisms with deleterious health effects. The Guadalajara Metropolitan Area is a rapidly growing urban center with over five million residents where household storage is nearly ubiquitous. This pilot study was conducted in July 2018 to examine the microbiological quality of drinking water in Guadalajara. Samples were tested for free available chlorine residual, total coliform bacteria, and E. coli. A survey on access to water and public perspectives was also conducted. Water exiting rooftop tanks exceeded regulatory limits for total coliform levels in half of the homes studied. Piped water arriving at two homes had total coliform levels that far exceeded regulatory limits. No E. coli were detected in any of the samples. Only 35% of homes had a chlorine residual between the recommended 0.2 and 1.5 mg/L. Many homes reported unpleasant odors and colors. Only 7% of residents drank the piped water. Future studies are needed, especially during April and May when many homes reported a higher disruption to water service.


2014 ◽  
Vol 13 (1) ◽  
pp. 67-72
Author(s):  
Andrée F. Maheux ◽  
Vanessa Dion-Dupont ◽  
Marc-Antoine Bisson ◽  
Sébastien Bouchard ◽  
Éric Jubinville ◽  
...  

MI agar and Colilert®, as well as mFC agar combined with an Escherichia coli-specific molecular assay (mFC + E. coli rtPCR), were compared in terms of their sensitivity, ease of use, time to result and affordability. The three methods yielded a positive E. coli signal for 11.5, 10.8, and 11.5% of the 968 well water samples tested, respectively. One hundred and thirty-six (136) samples gave blue colonies on mFC agar and required confirmation. E. coli-specific rtPCR showed false-positive results in 23.5% (32/136) of cases. In terms of ease of use, Colilert was the simplest method to use while the MI method provided ease of use comparable to all membrane filtration methods. However, the mFC + E. coli rtPCR assay required highly trained employees for confirmation purposes. In terms of affordability, and considering contamination rate of well water samples tested, the Colilert method and the mFC + E. coli rtPCR assay were at least five times more costly than the MI agar method. Overall, compared with the other two methods tested, the MI agar method offers the most advantages to assess drinking water quality.


Sign in / Sign up

Export Citation Format

Share Document