The impact of communal tap stands on drinking water quality at point of use

Last registered on December 03, 2021


Trial Information

General Information

The impact of communal tap stands on drinking water quality at point of use
Initial registration date
November 30, 2021

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
December 03, 2021, 6:04 PM EST

First published corresponds to when the trial was first made public on the Registry after being reviewed.


Primary Investigator

Ghent University

Other Primary Investigator(s)

PI Affiliation
Ghent University

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Many people, especially in Sub Saharan Africa, lack access to safe drinking water. Drinking water from unprotected sources causes diarrhoea and other waterborne diseases, which are a threat in the developing world. Improving access to safe drinking water is part of SDG6. Many NGOs and governments are involved in providing access, which facilitates clean water use, but research has pointed out that this does not always lead to improved drinking water quality at point of use. There are several reasons for this. One reason might be that beneficiaries don't take the water from the tap stand as they find it too expensive, while water from a stream or a lake is for free. The beneficiaries might also lack trust in the organisation realising the infrastructure or to the individuals exploiting the tap stand. Another reason could be that beneficiaries use the water from the tap stand, but as they trust this water too much, they pay less attention to hygiene and good sanitation practices after receiving the intervention. For instance if clean water and good sanitation practices are substitutes, then providing access to safe drinking water might worsen the situation. Drinking water might be carried or stored in dirty containers or mixed with water from other sources. Water from tap stands might also take longer to collect, if the tap stand is further away from the house than the existing water source.
This study investigates the impact of the provision of communal tap stands on point of use drinking water quality in Western Uganda (Kitagwenda District). In the area the inhabitants use mostly lake water, water from shallow wells or hand dug wells for their water provision. The intervention involves the construction of two extensions of an existing water pipeline, finished by the end of November 2021. Collective tap stands will provide access to safe drinking water to around 2400 people (around 500 households). Enumerators (students from a local university) will visit a total of 361 households. They will let several household members take a survey and collect drinking water samples POU (at the household level) before and after intervention in treatment and control villages. These samples will be analysed on a number of characteristics (E.coli, total coliforms and turbidity), but our main focus is E.coli.
Data collection will take place twice, once in September-October 2021 (before installation) and once in January-February 2022 (when treatment villages received the intervention and control villages did not yet).
External Link(s)

Registration Citation

Defloor, Bart and Femke Maes. 2021. "The impact of communal tap stands on drinking water quality at point of use." AEA RCT Registry. December 03.
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Experimental Details


The intervention consists of the prolongation of an existing pipeline towards five villages in Western Uganda. This leads to the installation of 6 public tapstands and 1 water kiosk within villages, providing drinking water to communities that did not have access previously. They relied on water from hand dug wells, shallow wells, lakes or streams. The pipeline will serve around 2400 individuals (around 500 households). There are three treatment villages that will receive the intervention by the end of November 2021, the two control villages will receive the intervention after January 2022. The aim of the research is to evaluate whether providing access to drinking water via public tapstands influences water quality at point of use.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
The outcome variable is a dummy variable: whether or not point of use water quality (at the household level) contains E.coli. The dummy takes the value 1 if no E.coli are found (<1 cfu/100ml) and 0 otherwise.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
The secondary outcome is time gain due to the intervention.
Secondary Outcomes (explanation)
Time gain will be measured in two ways. The first one is reported time gain based on the answers the respondents provide to the survey question "How long does a roundtrip take", expressed in minutes. The second one is based on the observed distance between the respondents' homes and the drinking water point before and after intervention. The distance is based on GPS coordinates of the house and the different water points.

Experimental Design

Experimental Design
A total of five villages will receive the intervention (pipeline and tapstands). It is a phase-in design: three villages will receive access to the pipeline early (in November/December 2021), these are the treatment villages. The other two villages will receive access to the pipeline later (after March 2022), they will serve as control villages.
Experimental Design Details
Randomization Method
All five villages are similar in characteristics, some villages get the intervention earlier than others (phase in). The needs of all these villages have been assessed and all five villages fulfil the requirements in terms of lack of access to water and in terms of distance to the closest tap stand with safe drinking water. The three treatment villages are decided upon by the current project planning, based on the fact that they are positioned on the trajectory of the pipeline. The two other control villages are not on that trajectory. One control village is located at the side of the trajectory, the other control village is not on the trajectory, but is located close to a village that is already connected. Both villages will be connected after March 2022, one as an extension of the new pipeline and one as an extension from the village that is currently already connected.
Randomization Unit
The village is a cluster.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
5 clusters (5 villages).
Sample size: planned number of observations
361 households / water samples, observed twice (before and after the intervention).
Sample size (or number of clusters) by treatment arms
3 treatment villages, 53 + 95 + 75 = 223 water samples, observed twice (before and after the intervention)
2 control villages, 39 + 99 = 138 water samples, observed twice (before and after the intervention)
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
The main outcome is a discrete variable. With 361 observations out of which 61% are treated (223 out of 361). With currently 11,29% of households using safe sources for drinking water (and treating the water) realising in 0 E.coli, this amounts to an MDE of 14,03%-points. These calculations are based on McConnell and Vera-Hernandez (2015). McConnell, Brendon; Vera-Hernández, Marcos (2015) : Going beyond simple sample size calculations: A practitioner's guide, IFS Working Papers, No. W15/17, Institute for Fiscal Studies (IFS), London,

Institutional Review Boards (IRBs)

IRB Name
Faculty of Economics Ethical Commission
IRB Approval Date
IRB Approval Number
FEB 2021-N


Post Trial Information

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Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials