A water treaty has survived three wars between India and Pakistan. Now the agreement is in trouble, but some say a new is treaty needed for both political and environmental reasons.

Oil refineries release billions of pounds of pollution into waterways each year, according to regulatory data. NPR found that pollution is concentrated near places where people of color live.

Oxygen levels, necessary for fish, are up and dangerous phosphorus levels are down in the historically polluted waterway. But a new report points to climate change as a possible wildcard.

Studies based on private health data are crucial to understanding dangers posed by pollution. A new rule makes it harder for the EPA to consider many studies when setting safeguards.