Wetlands as a solution to treating wastewater in southern Thailand

Johannes Kaltenbach, Malteser International - Germany, Reuters Alert 8 Aug 08;

Following the catastrophic tsunami in 2004, the rehabilitation of housing and the rebuilding of communities were the main focus of much of the relief and development work.

Malteser International piloted a wetland wastewater treatment plant in a relocated community on Koh Mook Island. The objective was to improve their sanitation facilities and offer a community based solution to environmental protection for a local fishing community by providing a wetland sewage treatment plant.

The lack of proper sanitation and hygiene facilities is a major concern for rural villages in southern Thailand. Coastal communities are suffering the consequences of pollution through untreated wastewater and solid waste. Diseases related to unhygienic conditions are widespread and harmful, particularly amongst children.

The sea has become polluted and therefore the source of income, marine products and tourism, are also in danger. The rehabilitation after the tsunami offered an ideal turning point.

By (re-) constructing settlements with a holistic concept, offering appropriate technology for waste treatment, the living conditions for the villagers could be made more sustainable in the areas of hygiene, sanitation and income generation.

A solution for the communities must be tailored to their requirements using simple and easily manageable techniques.

Wetland technology for treating waste water offers these requirements. Moreover, it provides an alternative for rural and small communities to treat sewage on a biological base with the outcome of a clean effluent according to international standards.

Thus, less pollution leads to better water quality in the shallow wells, no polluted run off into the sea, a clean environment, and fewer diseases.

The wastewater treatment plant is located on Koh Mook Island at a relocation site which covers 102 houses newly built by Safe Andaman Network and Malteser International. The construction area is located in a mangrove forest and therefore offers a real challenge for the constructors.

Wastewater (80 l per person per day) is collected from every household in a septic tank, where the sludge is separated. From here it is transported through pipes to pumping pits and finally pumped into the sub-terra reed beds.

In the beds it is evenly distributed through irrigation pipes. By percolating through a filter layer and treatment through the roots of the plants in the bed it is cleaned and the effluent is collected and drained as clean water into the mangroves.

However, the effluent can be used for agricultural and other purposes as e.g. flushing toilets. The whole system is easy to handle and runs automatically with a control unit switching pumps on and off.

A wastewater user group will be trained in the operation and maintenance of the system.