On 1 May 1983 the minor district Thap Khlo was established as a subordinate of Taphan Hin District, from which four tambon were split off. On 13 August 1987 it was upgraded to a full district.
Economy
Khao Chet Luk in the Thap Khlo District is the site of Thailand's largest gold mine, the Chatree Mining Complex. Akara Resources PCL, a Thai-Australian firm, owns and operates the mine. Akara is a subsidiary of Australian company, Kingsgate Consolidated Ltd. The complex includes the Chatree South ore field, which began commercial production in November 2001, and the Chatree North ore field, which began production in November 2008. The complex also includes processing plants. In 2015, the mine produced and exported four tonnes of gold. In May 2016, the Thai government announced that the Chatree mine would be closed at the end of 2016 due to environmental concerns. The mine has long been accused by local residents of poisoning residents, crops, and livestock. In January 2015 a government investigation team said that more than 300 neighboring villagers had tested positive for arsenic and manganese. Akara has asked the government to review its decision. The company was surprised that the cabinet adopted the resolution to close the mine given that a panel set up by the Ministry of Industry has not yet completed its investigation into pollution and health complaints. The panel, set up in 2015, is composed of state agencies, affected villagers, academics, environmentalists, and Akara representatives. The company claims that there is no conclusive link between the heavy metals and illnesses claimed by some villagers. Blood tests on 1,004 residents in 14 communities living around the mining sites in 2014 and 2015 found that 42 percent of residents had high levels of manganese in their blood. In July 2018, the committee looking into the case confirmed that toxic leaks have emanated from tailing storage at the mine. Evidence of leakage into nearby rice fields and an observation well were also confirmed. Kingsgate will seek a settlement through arbitration procedures under the Australia-Thailand Free Trade Agreement "in order to recover the substantial losses that it has suffered, and continue to suffer, as a result of the measures taken by the Thai government."
Administration
The district is divided into four sub-districts, which are further subdivided into 57 villages. There are two townships, Thap Khlo and Khao Sai. Both cover parts of their respective tambons. There are a further four tambon administrative organizations.
