The Great Lakes Water Authority (GLWA) and Detroit Water and Sewerage Department (DWSD) together operate one of the largest municipal water systems in the United States, treating and distributing Lake Huron water to approximately 3.8 million people across southeast Michigan — nearly 40% of the state’s population.
It’s a system of enormous scale and, for most customers, reliable quality. Detroit’s treated water consistently meets or exceeds federal drinking water standards. But the system has also been at the center of some of the most contentious water issues in America: mass residential water shutoffs, lead service line contamination, and the question of who deserves access to clean, affordable water.
The System
Detroit’s water comes from Lake Huron, drawn through intake pipes near Port Huron and treated at five water treatment plants with a combined capacity of over 1.7 billion gallons per day. It’s one of the best raw water sources in the country — deep lake water with relatively low contamination levels.
The treated water is distributed through approximately 3,300 miles of water mains within Detroit and an additional regional network serving 125 communities in eight counties. The system is so large that it was partially regionalized in 2016, with the creation of the Great Lakes Water Authority (GLWA) to manage regional wholesale operations while DWSD retained responsibility for Detroit’s retail distribution.
The Shutoff Crisis
Starting in 2014, DWSD launched an aggressive water shutoff campaign, disconnecting service to tens of thousands of Detroit households with unpaid water bills. In a single year, more than 27,000 accounts were shut off — a scale that drew international attention and condemnation.
The shutoffs hit Detroit’s most vulnerable residents hardest. In a city where nearly 35% of the population lived below the poverty line, many residents simply couldn’t afford their water bills, which had risen dramatically as the city raised rates to address billions of dollars in infrastructure debt.
Critics — including the United Nations, which sent investigators to Detroit in 2014 — argued that mass water shutoffs in a city surrounded by 20% of the world’s surface fresh water constituted a human rights violation. The city established income-based assistance programs in response, including the Water Residential Assistance Program (WRAP) and the Lifeline Plan, which provide reduced rates and payment plans for qualifying low-income residents.
The shutoffs slowed but never fully stopped. They were temporarily halted during the COVID-19 pandemic, and Detroit expanded its assistance programs. But the underlying tension between infrastructure costs and affordability remains unresolved.
Lead Service Lines
Like most Great Lakes cities built in the late 19th and early 20th centuries, Detroit has an extensive legacy of lead service lines — the pipes connecting water mains to individual homes. Estimates put the number at 80,000 to 125,000 lead service lines across the city, though the exact count is still being determined through the city’s ongoing inventory.
Detroit’s treated water includes corrosion control (orthophosphate) designed to build a protective coating inside lead pipes and prevent lead from leaching into drinking water. When applied correctly, this treatment keeps lead levels below the federal action level — which is exactly what failed in Flint when the city switched away from Detroit water without implementing corrosion control.
But corrosion control isn’t a permanent solution. The protective coating can be disrupted by:
- Water main breaks or repairs that change water chemistry or flow patterns
- Home plumbing work that disturbs pipe connections
- Changes in water treatment chemistry
- Extended periods of stagnant water in pipes
The EPA’s Lead and Copper Rule Revisions, finalized in 2024, require water systems to develop a complete inventory of service line materials and replace all lead service lines within 10 years. For Detroit, with potentially over 100,000 lead lines, that’s a massive undertaking — both logistically and financially.
The city has accelerated its replacement program, leveraging federal Infrastructure Investment and Jobs Act (IIJA) funding and state revolving funds. But at current replacement rates, meeting the 10-year deadline will be challenging.
Water Quality: What the Data Shows
Detroit’s drinking water quality is generally strong by national standards:
- Lead and copper: The system has consistently met the federal action level for lead (15 ppb) at the 90th percentile in routine monitoring, though individual homes with lead service lines can test higher.
- Disinfection: Detroit uses chloramine for secondary disinfection, which provides longer-lasting protection in the large distribution system but can form disinfection byproducts in areas with long water residence times.
- PFAS: Lake Huron has lower PFAS levels than many other Great Lakes water sources, and Detroit’s treatment processes further reduce concentrations. The system has met the EPA’s new PFAS drinking water standards.
- Bacteria: Routine monitoring shows consistent compliance with total coliform and E. coli standards.
The water leaving Detroit’s treatment plants is among the cleanest in the Midwest. The challenges emerge in the last mile — the aging distribution mains and service lines that carry water to homes.
Infrastructure Investment
Detroit’s water infrastructure needs are massive. The DWSD and GLWA face:
- Aging mains: Many water mains in Detroit are 80 to 100+ years old, with high break rates and water loss
- Combined sewer overflows (CSOs): Detroit’s combined sewer system (which carries both sewage and stormwater) overflows into the Detroit River and Rouge River during heavy rains — a major environmental and public health concern
- Treatment plant upgrades: Maintaining and modernizing treatment capacity for 3.8 million people requires sustained capital investment
- Lead line replacement: Potentially $1 billion+ to replace all lead service lines at an estimated $5,000-$10,000 per line
Federal infrastructure funding has provided a significant boost, but the long-term challenge is maintaining investment levels after one-time federal programs expire.
What Detroit Residents Should Know
- Your water is safe by federal standards. Detroit’s treated water consistently meets or exceeds all Safe Drinking Water Act requirements.
- If your home was built before 1960, there’s a meaningful chance you have a lead service line. Check the DWSD service line map or request an inspection.
- Run your tap for 30 seconds to 2 minutes before using water for drinking or cooking, especially first thing in the morning. This flushes water that may have been sitting in contact with lead pipes.
- If you’re struggling to pay your water bill, contact DWSD about assistance programs. The WRAP and Lifeline programs offer real help.
- NSF/ANSI 53-certified water filters can remove lead at the point of use — a practical precaution for homes with known or suspected lead lines while you wait for replacement.
- Get your water tested if you have concerns. DWSD offers free lead testing kits for Detroit residents.
If you’re concerned about lead or other contaminants in your drinking water, a certified water treatment professional can test your water and recommend the right filtration or treatment system for your home.