An exciting new in-line chlorination program from Evidence Action’s Accelerator is ready to launch. A real-life example of one of Evidence Action’s core values, “Iterate, again,” in-line chlorination is a next-generation water treatment technology that builds on our highly successful Dispensers for Safe Water program. This intervention will enable us to reach new communities and significantly deepen the impact of our safe water work.

Over 2 billion people lack access to water that is safe to drink and unsafe water is responsible for more than 1.2 million deaths each year. Evidence Action’s dispensers are an easy-to-use and effective solution, providing communities with the correct dose of chlorine to disinfect water collected at water sources. Our team has iterated on product design over the years to reduce costs, improve functionality, increase scalability, and boost adoption rates.

A key failure point in the theory of change for many water treatment programs is getting community members to use the treatment method, and do so consistently.

Dispensers for Safe Water has been successful because its core innovations were designed to drive product adoption and reduce barriers to use. Dispensers themselves, which are prominently placed and highly visible, provide a daily reminder to community members to treat their water. Their simple design and instructions allow for easy dosing and a network of over 54,000 community promoters engaged in community education as of 2022.

However,  as we all know from the February status of our New Year’s resolutions on healthy diet and exercise, creating behavior change around preventative health is hard. There will always be a portion of the population that, for various reasons, does not treat their water or does not do so consistently due to a lack of knowledge, authority, or other challenges.

But what if we could trigger adoption without requiring widespread, sustained behavior change? If we could make the healthy choice the default choice, that’s an even bigger win. In-line chlorination provides a remarkable opportunity to do exactly this.

What is in-line chlorination?

In-line chlorination is a simple, cost-effective method of automatically treating water. An in-line chlorination device is a low-tech apparatus constructed from PVC piping that contains solid chlorine tablets. The term “in-line” indicates that the device is integrated into the existing water source infrastructure – typically, it is inserted into piping near the entrance to a water storage tank. Water flows through the piping of the device like it normally would through the rest of the water system, coming into contact with solid chlorine tablets as it passes through the device. That contact causes the tablets to slowly erode into the water, and as a result, the water is seamlessly treated and ready for the user to drink upon collection.

At its core, in-line chlorination is not a different intervention from dispensers, sharing the same core goal and metric of evaluation: chlorinating households’ water, a sign that the water is safe to drink. In-line chlorination is a different delivery mechanism for chlorine, and critically, one that addresses the key challenges of behavior change and product adoption.

Because chlorination is automatic, so is adoption. Users do not have to make a daily choice to take the extra step of treating their water. Rather, the water is treated by default, as it is in most major utility systems around the world.

Testing an evidence-backed, cost-effective, and scalable solution

Over the past two years, Evidence Action has completed stages one through four of our Accelerator process for in-line chlorination: screening; rapid review; deep dive; and scope and design. This has allowed us to deepen our knowledge of the intervention, grade it against our Accelerator’s criteria (including evidence, scale, and cost-effectiveness), carefully craft a path to test our assumptions, and better understand its strengths and weaknesses.

The three main activities across these stages were device testing, water point surveying, and program piloting.

To understand the technology’s suitability and ensure the devices’ effectiveness, we tested six different in-line chlorination devices. We assessed the devices on metrics such as durability, ease of installation and refilling, ability to adjust chlorine dose, and consistency of dosing.

Next, it was important to explore the target market for in-line chlorination. We designed and administered a water point survey to collect key insights into water point users, management, and infrastructure at more than 2,500 water points across Kenya, Uganda, and Malawi. At these water points, we documented existing infrastructure, tested water samples for pre-existing chlorine, and engaged with local stakeholders to understand their level of interest and existing systems and behaviors.

Most recently, we made strides through a program pilot in western Kenya, installing in-line chlorination devices on 67 water points that serve an estimated 13,000 people across three counties. In these communities, prior to the pilot, water treatment practices were extremely low (11%) and diarrhea prevalence in children under five was high (16%-18%), indicating enormous potential benefits of a water treatment program. After device installation, community acceptance was predominantly positive and chlorine was detected in water samples at 88% of collection points and 78% of household samples.

Launching and learning

Based on these positive results, we are continuing to increase our investment in in-line chlorination and have moved the program to stage five – launch. Thanks to generous funding recommended by GiveWell, we are leveraging insights from the pilot and our existing Dispensers for Safe Water infrastructure to implement in-line chlorination in seven districts in southern Malawi. This will amplify our reach in the region and provide the opportunity to test the program model at scale.

In addition to beginning to scale this program, we continue to focus on Evidence Action’s value of iteration. As with any new tool, we are aware of many areas where we can experiment to improve efficiency and impact, and also expect many unknown challenges as we move to scale. Our learning agenda focuses on improving all aspects of the delivery model from community engagement, to device installation, to follow-up and maintenance. This requires the ability to quickly address challenges and continuously optimize structures to best address the needs of communities.

We will use the model we refined to engage communities on dispensers in community education meetings and volunteer community promoters. But, the concerns and questions will be different, so as we roll out the program we will continue to track community response and adapt our staff training and community engagement accordingly. We are also creating digital tools to assist our staff with chlorine dose tracking and adjustment of in-line chlorination devices to reduce the required frequency of water point visits. 

In-line chlorination has emerged as another promising, high-impact tool in Evidence Action’s water treatment toolbox. Dispensers and in-line chlorination are unique and complementary tools well-suited to serve specific communities. While in-line chlorination has a key advantage in the potential for increasing adoption rates, dispensers are near-universally applicable. In-line installation requires a certain level of infrastructure, such as the presence of a water storage tank, and many water points are not suitable for this intervention. Fortunately, this program launch and test with new populations will further fuel our ability to iterate, improve, and accelerate cost-effective safe water programming to reach many more.