The Great Lakes Basin is the source of drinking water for 48 million people - with drinking water coming from the Great Lakes themselves to inland rivers and lakes within the watershed and groundwater aquifers flowing beneath them. Many of these sources are shared across city, county, state/provincial, and even international borders. Blue Accounting details the strategies and investments - from the local to international level - to protect sources of drinking water.


of the Great Lakes population who rely on public water systems are protected from a source water protection plan


of US public water system users within the Basin drink water that periodically is tested for selected unregulated contaminants through a US EPA monitoring program


of inland drinking water sources draw from watersheds impaired by nutrients

Download the Source Water fact sheet here. 

Our goal is to protect sources of drinking water in the Great Lakes Basin as the first step to assuring a safe and sustainable supply of drinking water for all Great Lakes Basin residents. To that end, the Source Water Work Group has identified four main approaches to protect source water:

  • Prevent contamination

  • Planning and regional collaboration

  • Monitoring and research

  • Outreach and education

As stewards of the largest freshwater system in the world, the residents of the Great Lakes and St. Lawrence River Basin are rightfully proud of this shared natural resource, but struggle to find consistent ways to track progress toward a collective desire for a safe and sustainable drinking water supply. Blue Accounting’s Source Water issue works with water professionals from around the Basin to track progress on reducing multiple threats to drinking water including nutrients, spills, and contaminants of emerging concern, while also tracking preventative efforts like management strategies and planning.

More About Source Water

How we Work

Blue Accounting has identified strategies and investments to protect source water and is tracking progress on these efforts.

Who’s Involved

This work is guided by a diverse, binational work group of water professionals from across the Great Lakes region that reflects the breadth of interest and experience in source water protection.

Where We Work