There remained the issue of co-operation between the Manhattan Project's Metallurgical Laboratory in Chicago and the Montreal Laboratory. At the Combined Policy Committee meeting on 17 February 1944, Chadwick pressed for resources to build a nuclear reactor at what is now known as the Chalk River Laboratories. Britain and Canada agreed to pay the cost of this project, but the United States had to supply the heavy water. Because it was unlikely to have any impact on the war, Conant in particular was cool about the proposal, but heavy water reactors were still of great interest. Groves was willing to support the effort and supply the heavy water required, but with certain restrictions. The Montreal Laboratory would have access to data from the Metallurgical Laboratory's research reactors at Argonne and the X-10 Graphite Reactor at Oak Ridge, but not from the production reactors at the Hanford Site; nor would they be given any information about the chemistry of plutonium, or of methods for separating it from other elements. This arrangement was formally approved by the Combined Policy Committee meeting on 19 September 1944.