a small activated sludge plant was constructed on the site in 1916, one of the septic tanks was converted between 1918 and 1921 to provide a larger test bed, and a permanent installation was built at withington sewage works, in south manchester. all proved to be successful, but a full-scale plant was not built at davyhulme until more than ten years later. a second main intercepting sewer, which would link various districts in southern manchester to davyhulme had been authorised by act of parliament in 1911, and construction began soon afterwards, but it took years to complete. it was extended by further acts in 1914, 1920 and 1924, and sewage finally entered the works on 22 november 1928. to cope with the new flows, the size of the inlet works detritus tanks and screening chamber was quadrupled, and a decision was made to feed half of the output from the screening plant to a new activated sludge plant.