Latest Testing Results

• Lead Levels: DWSD’s most recent testing cycle showed a 90th percentile lead result below the EPA action level of 15 ppb. However, the EPA’s revised Lead and Copper Rule Improvements (LCRI), finalised in 2024, lowers the action level to 10 ppb and requires accelerated lead service line replacement — placing greater pressure on Detroit’s programme to increase its annual replacement pace significantly.
• PFAS Status: The Great Lakes Water Authority continues to report no PFAS detected in treated drinking water. GLWA’s source water monitoring — drawing from the Detroit River — has not triggered exceedances under the EPA’s 2024 PFAS National Primary Drinking Water Regulation, though ongoing industrial discharge near Wyandotte remains under regulatory scrutiny.
• Testing Scope: DWSD conducts over 50,000 water quality tests annually, including enhanced lead monitoring at high-risk residential sites throughout the city. Results are published in the annual Consumer Confidence Report.
• Compliance Status: Detroit’s treated water meets all current federal and state drinking water standards. The utility is actively planning for compliance with the new LCRI lead requirements, which phase in through 2027–2030.

Great Lakes Water Source

• Detroit River Intake: Primary water source from the Detroit River, drawing from Lake Huron’s outflow before it enters Lake Erie, providing naturally soft, high-quality freshwater as a starting point for treatment.
• Source Water Protection: Comprehensive real-time monitoring and protection programmes safeguard intake areas, with continuous detection systems for potential threats including industrial discharge upstream. Ongoing regulatory action targets the BASF facility near Wyandotte, which discharges contaminated groundwater in proximity to local water intakes.
• Abundant Supply: Access to the Great Lakes system — holding roughly 21% of the world’s surface fresh water — ensures reliable long-term supply capacity. Detroit’s water security outlook compares favourably to drought-stressed cities like Phoenix or Los Angeles.

Treatment Excellence

• Modern Treatment Plants: Three major facilities — Water Works Park, Northeast, and Springwells — employ comprehensive treatment including coagulation, sedimentation, filtration, and advanced disinfection processes.
• UV Disinfection: State-of-the-art ultraviolet treatment provides additional protection against Cryptosporidium and Giardia without generating chemical byproducts, reducing the formation of disinfection byproducts overall.
• Corrosion Control: Optimised orthophosphate treatment minimises lead leaching from service lines and household plumbing, with careful pH and alkalinity management to protect distribution pipes and reduce consumer exposure.

Infrastructure Challenges and Solutions

• Lead Service Line Programme: Detroit has identified approximately 80,000 lead service lines and operates an ongoing replacement programme. The new EPA LCRI requires all systems to complete a full service line inventory by 2027 and replace all lead lines within 10 years. Detroit must substantially accelerate its current replacement pace to meet these requirements.
• Main Replacement Initiative: Over $500 million invested in water main replacements since 2020, prioritising areas with the highest leak rates and oldest pipe stock. Work is ongoing across multiple neighbourhoods.
• Smart Water Management: Advanced metering infrastructure provides real-time leak detection and consumption monitoring, improving system efficiency and enabling faster response to distribution issues.

Regional Water Quality Concerns

• PFAS in Metro Detroit: While GLWA’s treated water shows no PFAS detection, multiple southeast Michigan water systems have reported detectable levels, including systems near industrial sites and military installations across the region.
• Detroit River Industrial Discharge: Regulatory proceedings related to industrial discharge of PFAS and other chemicals into the Detroit River near community water intakes continued into 2026. Michigan EGLE and the EPA are actively monitoring and pursuing enforcement.
• Private Well Risk: Over 165,000 private wells in metro Detroit counties lack routine PFAS monitoring, leaving a significant portion of the suburban population without verified data on their water quality. See our Michigan state water quality guide for broader context on private well contamination across the state.

Regional Transformation

The Great Lakes Water Authority’s regional governance model has enabled significant capital investment — over $800 million in treatment plant upgrades and distribution improvements planned through 2030 — while allowing DWSD to focus on retail service quality and customer support. Detroit’s water quality programmes include comprehensive customer assistance, free lead testing and filters for residents, and community engagement efforts to maintain public trust. However, residents should stay informed about regional PFAS concerns, the status of their home’s service line, and the quality of their specific local provider if living outside Detroit proper. For related reading, see our guides for neighbouring cities including Cleveland, Chicago, and Toledo, all of which share Great Lakes source water with similar treatment profiles. Check the live boil water advisory tracker for any active notices in Michigan.