The Massachusetts Water Resources Authority (MWRA) has proposed a new $764 million plan to reduce future sewage overflows in Greater Boston, which could fall short if predictions by climate change are accurate. The proposal includes improvements to zero overflows from combined sewers by 2050, assuming a "typical year" of precipitation. However, environmental groups argue that these measures are inadequate due to climate change. The current plan involves building storage tanks, "micro tunnels" and green infrastructure, separating some of the combined sewer overflow pipes, at three to four times the cost. The state Department of Environmental Protection and federal Environmental Protection Agency are reviewing the draft draft. Despite these improvements, the MWRA is still exceeding current compliance with a current sewage discharge plan.