Many applications, from source to point of use

In comparison with other safe water treatment options, chlorine has a major advantage as it can be added at different stages of delivery, involving different people, and depending on the context. Below, you will find a description of possible applications from chlorination at source (water supply network, rain water harvesting, cleaning of wells), at pipeline level (water supply system), at points of sale (chlorination agents, kiosks, fountains) and, finally, point of use to the end of the chain (at household level through dissemination of flasks).

At source: Water supply network

Because success in effectively killing unwelcome organisms is a function of contact time, the chlorine solution should be injected into the water as close to the source as possible.

Continuous chlorination is a necessity for surface water supplies such as ponds, springs, lakes or cisterns. You can use feed pumps to inject chlorine into your system.

Example of city of Djibouti

Six Maxi WATA devices were purchased by the national department of water of Djibouti in 2009. Since then, 600 litres of chlorine have been produced every day and injected directly into the water supply network through a dosing pump, allowing the supply of clean water in six cities with 2,000 m3 production per day.

At supply system: Pipeline level

The function of water supply systems, composed of boreholes, storage tanks and water pipe networks, is to deliver water to people through a drinking fountain or a private branch pipe. The quality of water at start is good but its transportation through the pipeline alters it and generates recontamination. To avoid this, water is chlorinated at several key points, following WHO recommendations.

Example of AEP Mali

The training NGO Formations sans frontières is coordinating a project for the national water directorate (DNH) of Mali to assess the potential of WATA at pipeline level. Over 40 devices are being used to produce chlorine, which is added through dosing pumps. Benefits:

- Low-cost production of chlorine thanks to solar energy
- Complementary production based on power supply
- Possibility to adapt quantity to needs
- Locally-based produced systems
- Maintenance is ensured locally

At source: Disinfection of wells

WHO endorses the disinfection of drinking water in emergency situations. There are various ways of doing this but the most common is chlorination as it leaves a residual disinfectant in the water after chlorination.

Example of Pakistan

In the Pakistan flood emergency of 2010, and the response by the Swiss Agency for Cooperation and Development (SDC), the 70 WATA devices distributed were used for the disinfection of wells, boreholes, handpumps and bladder and other water storage tanks in the camps for Internally Displaced Persons (IDP). They were appreciated by all users as it offered a low-cost solution for water disinfection. Moreover, the local production of chlorine is essential when no chlorine is available (especially in remote areas) and the quality of local chlorine is unsatisfactory.

At source: Rainwater harvesting

Rainwater harvesting has been used around the world for thousands of years. Rainwater as it falls on house roofs is soft, clear and largely free of micro-organisms. During collection and storage however, there is a potential for microbiological contamination. Tanks must also be regularly flushed and cleaned. Disinfection is used to reduce the growth of microbes in the tank. Disinfection of tank water is essential if the water is to be used for drinking purposes. Chlorine is also effective in removing odours from rainwater because chlorine is an oxidizing agent and oxidises the chemicals involved. To achieve effective disinfection, it is necessary to add sufficient chlorine to provide a free chlorine residual of around 0.5 mg/L after a contact time of 30 minutes.

Example of RAIN programme in Burkina Faso

WaterAid has trained 16 chlorination agents from local NGOs in Burkina Faso in the local production of chlorine with 7 WATA devices. This has enabled the treatment of harvested rainwater (336,000 litres of safe water, if run on a 12 hours daily basis) and keeping it safe from recontamination.

At point of use: POU Syringe injection

Where production is centralised and the population is too widely spread out to organise a simple and effective dissemination of chlorine in flasks, one option is to bring the chlorine to a point of collection where people come with their containers to get their daily water. At this stage, chlorine can be added directly in the bucket.

Example of chlorinators agents at Lake Kivu in DRC

Chlorinators agents are present on the shores of Lake Kivu every day, where they hold out their syringes and inject very precise doses of active chlorine into water containers held out to them by people passing with the water they have collected to use at home.

At point of use: Flasks at household level

Locally-produced chlorine can be stored in bottles or flasks and disseminated to people at household level. The main challenge at this late stage is to ensure very good information and training on the precise dilution aspects, as it leaves this major responsibility to the end-user. Antenna has developed a quality control tool to check the presence of free residual chlorine in drinking water.s which can be a great support to check the right dilution.

Example of WATASOL in Guinea Conakry

Production of chlorine is centralised in Dabola where Tinkisso NGO produces 600 litres per day with three Maxi WATA. Chlorine is then stored in flasks of 250 ml and disseminated through the following channels:
Health centres and hospitals: Chlorine is prescribed by doctors in Dabola hospital and in 45 health centres of Faranah.

Weekly markets: chlorine is sold during market days through agents who promote hygiene awareness messages using megaphones.

Door-to-door: door-to-door sale allows direct response to the concerns of users and ensures the right use of chlorine.

Pharmacies: Various pharmacies have requested stocks of chlorine from Tinkisso for resale. This has increased the overall credibility of the product to consumers.

At point of use: Chlorinated water at kiosk

In some places, the dissemination of chlorine may not be the best option as dilution aspects may be complicated for end-users. There, chlorine produced is directly added to water containers making safe water the end product instead of chlorine.