The Risca & Pontymister Gas Co. was formed by Special Act in 1867. The original gas works (at Pontymister) was designed and built by George Bower of St. Neots. In 1883 The Risca and Pontyminster Gas Company, had authorised capital of £8,000, and had in produced 3.4m cu.ft. of 14 cp gas from 429 tons of coal. (The Cardiff Times 20th January 1883), Joseph Firbank was the Chairman, T. Dyne Steel C.E. the Engineer. There were Special Acts, in 1891 and 1892. In 1900 the Western Valleys (Mon.) Water & Gas Co. Annual gas production was 9m cu.ft. of 15cp gas from 900 tons of coal with 6 miles of mains. Col. G. Wilkinson was chairman, Guy S. Davies was Manager & Secretary. Supplies Risca and Pontymister, Cross Keys and Pontywain, Mon. (GD&S). The gas company was Acquired by Risca UDC in 1909. In 1912 Mynyddislwyn UDC sought powers in the 1913 Session to purchase part of the gas undertaking of the Risca UDC (and parts also of the Bedwellty UDC and Blackwood Gas Co.). In 1914 the annual gas production was 30.6 m cu.ft. of 15.16 cp gas from 2,980 tons of coal, with 18 miles of mains. Also supplied Cross Keys and Pontywain. Bulk sales to Mynyddislwyn. In 1949 arrangements were in hand for a bulk supply from the Pontypool system, which had been provided by October. Vested in the Wales Gas Board from the Risca UDC. In 1952 the “Gas World Year Book”, showed that Risca purchased 61m cu.ft. of gas town gas and J. F. Rust. was the engineer and manager. The gasworks were visible on the 1882 to 1986 OS maps.
