Columbus OH metro: water quality. Columbus draws most of its drinking water from three reservoirs – Hoover, O'Shaughnessy, and Griggs – supplemented by
Columbus draws most of its drinking water from three reservoirs – Hoover, O'Shaughnessy, and Griggs – supplemented by wells tapping the glacial aquifer that underlies central Ohio. The Division of Water serves about 1.2 million people across the city and surrounding suburbs. Toledo, on the western edge of this metro area, operates its own system from Lake Erie, a supply that gained national attention during the 2014 algal toxin crisis.
With 2.1 million people spread across this metro, the water picture varies. Columbus's reservoir-based system is relatively well protected. Toledo's Lake Erie intake faces seasonal algal bloom pressure. The two cities share a metro designation but almost nothing about water supply infrastructure.
Ohio's PFAS situation is shaped by decades of industrial and military activity. The DuPont Washington Works facility in Parkersburg, West Virginia – just across the Ohio River – contaminated the drinking water of communities in southeast Ohio with PFOA, a case that became the subject of a landmark class-action lawsuit and the 2019 film Dark Waters.
Closer to Columbus, Rickenbacker Air National Guard Base on the city's south side has been investigated for PFAS from AFFF use. Ohio EPA sampling in 2023 found PFAS compounds in groundwater near the base, though Columbus's reservoir supply is not directly connected to that aquifer.
Ohio adopted action levels for PFOA (70 ppt) and PFOS (70 ppt) in 2019, which were less stringent than the federal MCLs that followed. The state has been updating its approach since the EPA finalized federal limits. According to Ohio EPA data, 22 public water systems statewide reported PFAS above detection limits under UCMR5, with several in the Columbus and Toledo service areas.
Toledo's Lake Erie source faces a different emerging contaminant: microcystin from harmful algal blooms. The city invested over \$500 million in treatment upgrades after the 2014 crisis, but HABs remain an annual concern.
Columbus sits in a moderate position among Ohio metros. Cleveland and Cincinnati face heavier industrial legacy contamination. Toledo's algal bloom vulnerability is a challenge unique among major Ohio cities. Columbus's reservoir-based supply is better protected from both PFAS and HABs than surface water intakes on Lake Erie or the Ohio River.
Nationally, Ohio's industrial history puts the entire state on the higher end of PFAS risk, but Columbus specifically benefits from geography – sitting atop glacial deposits that provide relatively clean groundwater supplementation.
See our Ohio state page for statewide data.
Columbus and Toledo have very different water challenges. Start by identifying your system and its specific risk factors.
Check your water to see monitoring results for your area. If you're near Rickenbacker in south Columbus, or in Toledo where both PFAS and algal toxins are relevant, a certified filter addresses the compounds most likely in your supply. For long-term trend data, including Toledo's post-2014 improvements, pull a detailed report.