Water companies of Thailand

The Metropolitan Waterworks Authority (Abrv: MWA; Thai: การประปานครหลวง, kan prapa nakhon luang) is a Thai state enterprise under the Ministry of Interior. Its mission is to produce, distribute, and sell treated water in Bangkok, Nonthaburi, and Samut Prakan, and engage in related businesses synergistic with waterworks.

The Provincial Waterworks Authority (PWA) (Thai: การประปาส่วนภูมิภาค) is a Thai state enterprise under the Ministry of Interior. The PWA is responsible for the production and distribution of potable water that meets WHO standards to 74 provinces throughout Thailand—all except Bangkok, Samut Prakan, and Nonthaburi)—which are served by the Metropolitan Waterworks Authority.

Thai Tap Water Supply Public Company Limited (TTW) is tap water producer and distributor in Nakhon Pathom and Samut Sakorn areas for the Provincial Waterworks Authority (PWA), to replace tap water production from the PWA's groundwater wells and to increase tap water production volume to accommodate consumers demand so as to help alleviate land subsidence problems and saltwater penetration in accordance with the governmental policy. Pathum Thani Water Co., Ltd. (PTW), the company's subsidiary, is engaged in the same business in Pathum Thani Province.