Evaluating In-line Chlorination in Nigeria

In-line Chlorination for Drinking Water Treatment in Nigeria

This study evaluates the implementation and effectiveness of in-line chlorination (ILC) for improving drinking water quality in rural Nigeria. Unsafe drinking water remains a major contributor to diarrheal disease, particularly among children under five. Inline chlorination is a passive water treatment approach that automatically doses chlorine at community water systems without requiring electricity or daily user action. Two cluster randomized controlled trials will be conducted in Kano State (North-West Nigeria) and Cross River State (South-South Nigeria). Communities will be randomized to either receive in-line chlorination installed at eligible communal water systems or serve as controls with no chlorination. The unit of randomization is a community or a cluster of communities that share water system for drinking water. The primary objective is to estimate the causal impact of in-line chlorination on household drinking water quality. Outcomes include the prevalence of Escherichia coli contamination in tap water and stored household water as well as the presence of free chlorine residual. Secondary objectives assess water source usage and adoption of chlorinated sources, as well as reduction in diarrheal disease. Implementation fidelity and operational performance of chlorination devices will also be monitored.

Study Overview

• Status: Not yet recruiting
• Conditions: Diarrhea; Adoption; Water Quality
• Intervention / Treatment: Device: In-line Chlorination (ILC) with Behavioral Change Communication (BCC)

• Study Type: Interventional
• Enrollment (Estimated): 2655
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Amy J Pickering; Phone Number: +1.510.410.2666; Email: pickering@berkeley.edu
• Study Contact Backup: Name: Elisa M Maffioli; Phone Number: +1.443.875.4930; Email: elisamaf@umich.edu

Study Locations

• Nigeria
  • Cross River State
    • Yala, Cross River State, Nigeria
      • Yala LGA
      • Contact: Gbenga Adedayo; Phone Number: +234.805.602.6845; Email: gadedayo@hanovialimited.com
  • Kano State
    • Makuda, Kano State, Nigeria
      • Makoda LGA
      • Contact: Gbenga Adedayo; Phone Number: +234.805.602.6845; Email: gadedayo@hanovialimited.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adult (18+) or emancipated minor (15+) pregnant women and women with children under 5 years old who do not plan to permanently move in the next 12 months.
• Must be knowledgeable about the household's water collection and management practices

Exclusion Criteria:

• Non-age-eligible women. Men and non-emancipated minors. Women who do not consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Arm 1: Inline Chlorination (ILC) with Behavioral Change Communication (BCC); Communities randomized to this arm will receive inline chlorination installed at eligible communal drinking water systems, such as boreholes or handpumps, and behavioral change communication.	Device: In-line Chlorination (ILC) with Behavioral Change Communication (BCC); In-line chlorination devices will be installed on all compatible communal water systems within treatment communities. Devices automatically dose chlorine proportional to water flow without requiring electricity or daily user input. Technologies will include TuriTap liquid dosers installed at handpumps and CTI-8 tablet dosers installed at tanks or piped systems. Devices will be calibrated and routinely monitored to maintain chlorine residual within recommended ranges. In addition to device installation, communities will participate in behavior change communication (BCC) activities designed to support understanding and acceptance of chlorinated water. BCC activities will include community sensitization meetings conducted by the implementing partner. Meetings will provide information on the purpose of chlorination through the in-line chlorination devices, expected benefits and limitations, safe water handling practices, and guidance for addressing taste or odor concerns.
No Intervention: Arm 2: Control (No Chlorination); Communities randomized to this arm will not receive inline chlorination during the study period and will continue their usual water collection and treatment practices.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of water source samples with detectable free chlorine residual.	Measured as >0.1 ppm.	About 4-, 8-, and 12-month follow ups after device installations
Proportion of household stored drinking water samples with detectable free chlorine residual.	Measured as >0.1 ppm.	About 4-, 8-, and 12-month follow ups after device installations
Proportion of household stored drinking water samples positive for Escherichia coli.	Measured as >1 MPN/100 mL of water by culture-based assay	About 4-, 8-, and 12-month follow ups after device installations

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of water source samples with detectable total chlorine residual.	Measured as >0.1 ppm.	About 4-, 8-, and 12-month follow ups after device installations
Concentration of E. coli in water source samples	Concentration of E. coli (in log10 MPN/100ml) in water source samples by culture-based assay	About 4-, 8-, and 12-month follow ups after device installations
Concentration of E. coli in household stored water samples	Concentration of E. coli (in log10 MPN/100ml) in household stored water samples by culture-based assay	About 4-, 8-, and 12-month follow ups after device installations
Concentration of total coliform bacteria in water source samples	Concentration of total coliform bacteria (MPN/100mL) in water source samples	About 4-, 8-, and 12-month follow ups after device installations
Concentration of total coliform bacteria in household stored water samples	Concentration of total coliform bacteria (MPN/100mL) in household stored water samples	About 4-, 8-, and 12-month follow ups after device installations
Prevalence of caregiver-reported diarrhea among children under five years of age	Measured as the proportion of children under five reported by caregivers to have experienced diarrhea, defined as three or more loose or watery stools within a 24-hour period, during the 7 days preceding the survey.	About 4-, 8-, and 12-month follow ups after device installations
Prevalence of caregiver-reported diarrhea among household members, any age	Measured as the proportion of individuals surveyed in the household that have experienced diarrhea, defined as three or more loose or watery stools within a 24-hour period, during the 7 days preceding the survey. Measured for subset of available respondents.	About 4-, 8-, and 12-month follow ups after device installations
Prevalence of diarrhea among female caregivers	Measured as the proportion of respondents that have experienced diarrhea, defined as three or more loose or watery stools within a 24-hour period, during the 7 days preceding the survey.	Time frame - About 4-, 8-, and 12-month follow ups after device installations

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of households reporting an ILC-compatible water source as their primary drinking water source	Measured as the percentage of surveyed households identifying an ILC-compatible water system as their source of drinking water. ILC-compatible water systems (boreholes, piped systems, or handpumps have chlorinated water in treatment)	About 4-, 8-, and 12-month follow ups after device installations
Proportion of households switching away from ILC-treated water sources	Measured as the percentage of households that discontinue use of a chlorinated water system for drinking water compared to baseline.	About 4-, 8-, and 12-month follow ups after device installations
Proportion of households reporting any household-level water treatment	Measured as the percentage of households reporting treatment of drinking water prior to consumption (e.g., boiling, filtration, manual chlorination).	About 4-, 8-, and 12-month follow ups after device installations
Time spent on household-level water treatment	Time (minutes) reported by households per day on making water safer to drink (gender stratified)	About 4-, 8-, and 12-month follow ups after device installations

Collaborators and Investigators

• Sponsor: University of California, Berkeley
• Collaborators: University of Michigan; Bayero University Kano, Nigeria
• Investigators: Principal Investigator: Amy J Pickering, University of California, Berkeley; Principal Investigator: Elisa M Maffioli, University of Michigan; Principal Investigator: Adamu I Tanko, PhD, Bayero University Kano, Nigeria

Publications and helpful links

General Publications

• Lindmark M, Cherukumilli K, Crider YS, Marcenac P, Lozier M, Voth-Gaeddert L, Lantagne DS, Mihelcic JR, Zhang QM, Just C, Pickering AJ. Passive In-Line Chlorination for Drinking Water Disinfection: A Critical Review. Environ Sci Technol. 2022 Jul 5;56(13):9164-9181. doi: 10.1021/acs.est.1c08580. Epub 2022 Jun 14.
• Pickering AJ, Crider Y, Sultana S, Swarthout J, Goddard FG, Anjerul Islam S, Sen S, Ayyagari R, Luby SP. Effect of in-line drinking water chlorination at the point of collection on child diarrhoea in urban Bangladesh: a double-blind, cluster-randomised controlled trial. Lancet Glob Health. 2019 Sep;7(9):e1247-e1256. doi: 10.1016/S2214-109X(19)30315-8.

Study record dates

Study Major Dates

• Study Start (Estimated): May 26, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027

Study Registration Dates

• First Submitted: May 14, 2026
• First Submitted That Met QC Criteria: May 14, 2026
• First Posted (Actual): May 22, 2026

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 14, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Inline Chlorination, Safe Water, Water Practices, Behavior, Diarrhea, Children
• Additional Relevant MeSH Terms: Signs and Symptoms, Digestive; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Diarrhea; Behavior
• Other Study ID Numbers: 2025-08-18832

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No