The EIS addresses the cumulative effects of constructing and operating three conveyance tunnel systems which are part of the total Tunnel and Reservoir Plan (TARP) proposed by MSDGC. These three tunnel systems are: Mainstream (59th Street to Addison Street), Calumet, and Lower Des Plaines. The subject of these statements is confined to the tunnel systems and their associated components because EPA is now considering whether to grant funds to construct these tunnels under its water pollution control authority. Other components of TARP, including the reservoirs, flood relief tunnels, instream aeration, and wastewater treatment plant improvements, are either ineligible for EPA funding or are not now under consideration for construction grants. Therefore, these other components are not considered to be part of the proposed action under review. The effects of these other components on water quality and the likelihood of their being financed is analyzed in this EIS in order to provide a context for evaluating the significance of the water quality improvements expected from the three tunnel systems.