THE MANUAL CHLORINATOR–ORIGIN AND DEVELOPMENT
The Manual Chlorinator works with very low flow water systems which is an advantage over most other chlorination devices. It is made of thick (schedule 40) PVC and requires minimal maintenance. It is owned, constructed, and maintained by communities thus insuring its continuing existence. It is adaptable to communities from as small as 30 inhabitants to as many as 5,000. The Manual Chlorinator is economical as it costs a community around $150 US to buy and 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 communities honor their commitment to pay. Each community has an existing fund from donations from each household for repair of their water system, and the Chlorinator and chlorine tablets are supported under this community system.
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, Charles Taflin.
Charles Taflin inspecting the first chlorinator installation. Chilamate, Matagalpa. 2002.
In 1998 Charles 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 Charles in touch and the result of this partnership was in the invention of a device using solid chlorine tablets to decontaminate drinking water. Charles tried eight different prototypes that he tested in the municipal water plant in St. Paul, Minnesota. With constructive analysis from Fred, Charles 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.
DISINFECTING DRINKING WATER IN RURAL WATER SYSTEMS
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 details the internal components.
Below: Slide show of the areas in rural Matagalpa and Jinotega Departments where Manual Chlorinators were installed, 2020, 2021, and 2022. These photos give a good view of the people in the mountains and valleys where we work, and insight into the communities.