CTI has developed a device capable of disinfecting water in gravity-fed potable water systems. The device, called the CTI 8 Chlorinator is an inexpensive, low-maintenance, non-electrical, appropriate-technology apparatus. It is capable of delivering a controlled dosage of chlorine sufficient to inactivate most pathogens (disease-causing organisms) found in most rural potable water systems. The CTI 8 accomplishes disinfection by directing water flow over solid chlorine tablets in a simple configuration of PVC tubing. A CTI 8 chlorinator can be built and installed for around $100.00 US per unit. For a typical community of 200 people, monthly operational costs including chlorine can be expected to be between $5 and $10 US, depending on various factors such as temperature, level of contamination and quantity of water flow.
The chlorinator is constructed of 3-inch and 4-inch PVC pipe and fittings, and ¼-inch PVC plate. The CTI 8 can be built in a matter of hours using basic hand tools. It uses chlorine in the form of calcium hypochlorite or trichloro-s-triazinetrione tablets approximately 2 ½ inches / 6.35 cm in diameter.
The development of the CTI 8 involved three years of research and development, plus two years of field-testing in fifteen rural water systems in Nicaragua.
- Designed for rural areas w/gravity fed water systems w/a flow rate between 2 and 20 gallons per minute.
- Will treat water systems serving a population of approximately 100-1,000 people.
- Requires a clean water source with little organic material.
- Requires a closed system from the water source to the end user. Or with an open system, the system must have a functioning filtration system, sedimentation system, or both. (See MSSF water treatment plant design)
- Turbidity levels should be less than 10 units
- Disinfectant used: Chlorine tablets (Calcium hypochlorite or Trichloro-s-triazinetrione—It’s important to note that the tablets must be approved for human consumption)
- Requires testing and record keeping, and regular monitoring by someone trained in its operation. Chlorine levels measured with an approved chlorine comparator at the holding tank and at least 1 other point in the distribution system. Measurements must be taken 3-4 times per week initially and at least 1 time per week ongoing.
CTI Evaluation Form: (Here are the questions you need to answer.)
Design Manual: (Detailed construction manual)