In 1992, the government passed several pieces of legislation to prevent water pollution. The laws primarily limit industrial water contamination:
Enhancement and Conservation of National Environment Quality Act (NEQA) of 1992
Factories Act of 1992
Navigation in Thai Waterways Act (Volume 14 ) as amended in 1992
Public Health Act of 1992
Cleanliness and Tidiness of the Country Act of 1992
The government continues to invest in wastewater treatment plants. In 2000, enough treated water was available to support 29% of the population, with more treatment plants under construction. Upon completion, treated water will support 65% of the population. The most common water treatments are inexpensive to build and maintain. They include oxidation ditches, aerated lagoons, and stabilization ponds. The government is also investigating more effective and modern techniques such as constructed wetlands.