Project head technician Marlon Castro (right) with a water committee member demonstrating a completed Manual Chlorinator before installation. La Amanacia, Matagalpa, 2021.

There is no other device like The Manual Chlorinator. It works with very low flow water systems and we have found no other non electrical water decontamination device that does this. It is virtually indestructible made of thick (schedule 40) PVC. It requires almost no maintenance. It is owned, constructed, and maintained by communities thus insuring its continuing existence. It is the only device of its kind to be adaptable to communities from as small as 30 inhabitants to as many as 5,000. The Manual Chlorinator is economical as it is less expensive than other manual (non-electrical) chlorine dispensing devices. It costs a community around $150 US to install, and costs from $5 to $15 US/month for chlorine tablets depending on the volume and size of the water system. It is simple to construct, maintain and operate.Over twenty years and 450 Chlorinator installations that supply uncontaminated drinking water to over 400,000 people have proven it works as designed.

TASCA extends no interest long term loans for payment and all communities have honored their commitment to pay. Each community has an existing fund from volunteer donations from each household for repair of their water system, and the Chlorinator and chlorine tablets are supported under this community system. We never have to advertise the Chlorinator as communities request it through word of mouth from positive comments from other communities with chlorinators installed.


While Fred Jacob was the Operations Manager for TASCA from 1995 to 2000 one of his responsibilities was testing drinking water in rural water systems. Fred realized after hundreds of tests that most rural water systems were contaminated with bacteria harmful to humans and there was no existing adequate system of decontaminating the water in Nicaragua. Looking for a solution Fred turned to a Minnesota NGO Compatible Technologies International (CTI), as they had engineers working on improving technologies in developing countries. Fred did not have the expertise to invent the device he imagined, but CTI was able to connect him with water engineer, Charlie Taflin.

Charlie Taflin inspecting the first chlorinator installation. Chilamate, Matagalpa. 2002.

In 1998 Charlie Taflin, a retired water engineer who had been head of the Minneapolis, Minnesota water plant for forty years was a recent volunteer with CTI. After Fred’s request for engineering support, CTI put Fred and Charlie in touch and the result of this partnership was in the invention of a device using solid chlorine tablets to decontaminate drinking water. Charlie tried eight different prototypes that he tested in the municipal water plant in St. Paul, Minnesota. With constructive analysis from Fred, Charlie decided after almost three years that he had invented an apparatus that met the criteria for a non-electrical, low maintenance, inexpensive device that worked 24/7. That device was originally called the CTI 8.

This invention is now called The Manual Chlorinator as TASCA has assumed responsibility for its promotion and name as CTI decided to not be involved with the chlorinator project.

There is available statistical evidence from the Nicaragua Ministry of Health of reductions in intestinal disorders in communities with chlorinated water. There is also anecdotal evidence from communities with a Chlorinator that The Manual Chlorinator improves the health of those with access to uncontaminated drinking water.


The Manual Chlorinator is an inexpensive, low-maintenance, non-electrical, appropriate technology instrument. It can deliver a controlled dosage of chlorine to water sufficient to inactivate most pathogens that cause disease in humans and are found in contaminated potable water systems. The Chlorinator accomplishes disinfection by directing water flow over solid chlorine tablets placed in a simple configuration of PVC pipe. Experience demonstrates that the chlorinator can be built in two hours or less using basic hand tools.

Developing the Manual Chlorinator involved three years of research plus three additional years of field-testing in twenty-one rural water systems in Nicaragua. The data gathered from testing these twenty-three systems demonstrate that properly constructed and with appropriate chlorine tablets, The Manual Chlorinator is capable of delivering constant and appropriate doses of chlorine in low to medium flow water systems supplying uncontaminated drinking water for rural populations and limiting intestinal disorders.

The Use of Chlorine

Chlorine has been chosen as the method to disinfect drinking water in the Manual Chlorinator because it is efficient, widely available and cost effective even in rural areas of developing countries. Chlorine has the advantage of leaving a residual in the distribution system that provides long-term protection from bacterial contamination.

Chlorine is currently the only practical method of disinfection that will accomplish this, given the criteria of creating a low cost, widely available, and effective method of drinking water disinfection. Chlorine is a potentially toxic oxidant therefore it must be handled properly, and the chlorinated water must be tested frequently to ensure that the required dose is not exceeded.

Right above: Chlorinator to be installed on top of a water storage tank. Community Limixto, Matagalpa, 2021.

The Manual Chlorinator: The Details

The chlorinator is built entirely from schedule 40 PVC pipe, fittings, and ¼-inch (6 mm) sheet PVC. The parts are easily constructed with simple tools and assembled with standard PVC cement and stainless-steel screws or PVC pegs. The body of the unit is a 4-inch (100 mm) PVC tee, with a 9-cm nipple and coupling on each end. A 4-inch (100 mm) riser, 30-cm long, is fitted into the branch of the tee, and is closed on top by a cap.

Figure 5 details the basic components of the manual chlorinator.

A tube containing the chlorine tablets is placed inside the riser. Inside the tee a ¼-inch (6 mm) plate supports the tablet tube. On the inlet end of the tee, between the nipple and the coupling is a baffle that directs the water flow. At the outlet end is a weir plate that regulates the depth of flow through the chlorinator.

Figure 6…

Below: Slide show of the areas in rural Matagalpa and Jinotega Departments where Manual Chlorinators were installed, 2020 & 2021. These photos give a good view of the people in the mountains and valleys where we work, and insight into the communities.

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