in an attempt to deal with river pollution, the council created the river medlock improvement committee on 1 april 1863. such problems were not limited to manchester, and two pieces of legislation were introduced nationally to address the issues. the first was the public health act 1875, and the second was the rivers pollution prevention act 1876. in the following year, the river medlock improvement committee became the rivers committee, and proposed a combined drainage scheme for the city and 15 other authorities with responsibility for the areas around the city. all pulled out of the scheme because of the likely cost, but in 1888, the city of manchester decided to proceed on its own. two deep level sewers were authorised, which intercepted the existing sewers before they discharged into the rivers. when the first sewer reached davyhulme, further progress was impeded by the manchester ship canal, then being built, and the site became the location of the sewage treatment works. it had the advantage that treated water could be discharged into the ship canal to maintain water levels.