From 1985 until 2010 only one area of concern in the Great Lakes, the largest freshwater system in the world, was delisted. Delisting occurs when the problem causing a concern, such as pollution or invasive species, is cleaned up. Since the Great Lakes Restoration Initiative (GLRI) was announced in 2010, five areas have been delisted.

On Wednesday, the The US Environmental Protection agency released an even more ambitious plan to restore the lakes. The action plan focuses on four key areas: Cleaning up areas of concern, preventing and controlling invasive species, reducing nutrient run off, and restoring habitat to the region’s native species. If the plan is successful, it will restore the lakes to a safe and usable condition by 2020.

“The new Great Lakes Restoration Initiative Action Plan lays out the steps we need to take to get us closer to the day when all Great Lakes fish will be safe to eat, all beaches will be safe for swimmers and harmful algal blooms will not threaten our drinking water supplies. During the next five years, federal agencies will continue to use Great Lakes Restoration Initiative resources to strategically target the biggest threats to the Great Lakes ecosystem and to accelerate progress toward long term goals,” said U.S. Environmental Protection Agency (EPA) Administrator Gina McCarthy in a statement.

Despite the successes of the last five years, the Great Lakes have primarily made the news in recent years for toxic algae blooms and invasive species such as zebra muscles and asian carp.

The plan also contains provisions which would double the acreage of agricultural conservation programs in watersheds. This program is designed to reduce phosphorous runoff, largely from farms, which nourishes algae blooms.

“We’re currently engaged in the largest conservation initiative in American history, with more farmers taking action to preserve clean land and water than ever before. As part of that historic effort, many farmers in the Great Lakes region are working hard to help improve water quality downstream. We’re proud to partner with farmers and the many others engaged in voluntary efforts to restore the health of the Great Lakes. Supporting sound conservation practices such as planting cover crops, rotating crops, installing filter strips and restoring wetlands not only helps keep our water clean, it can help create jobs and grow the economy in local communities,” said U.S. Agriculture Secretary Tom Vilsack.

Currently, more than 35 million people on both sides of the US-Canadian border live in the Great Lakes basin. The lakes provide those people with drinking water and recreation as well as water for farm irrigation. As climate change continues to cause drought in many parts of the US and the world, including agricultural regions, the large supply of fresh water available from the lakes will become increasingly important.