Bloomington sits in the heart of Indiana’s limestone country — rolling hills, Lake Monroe, Indiana University. It’s a beautiful place to live. But underneath that postcard scenery, the geology and industrial history create water quality challenges that most residents never think about.
The Superfund Legacy
Bloomington has an unusual distinction for a city its size: multiple EPA Superfund sites tied to PCB contamination, all tracing back to decades of electronics manufacturing.
Westinghouse Electric operated facilities in Bloomington from the 1950s through the 1980s, manufacturing capacitors and other electrical components that used polychlorinated biphenyls (PCBs). When these operations wound down, the contamination they left behind was staggering.
The EPA eventually designated several related cleanup sites:
- Neal’s Landfill — received PCB-contaminated waste from Westinghouse operations. Groundwater beneath the landfill showed PCB concentrations far exceeding safe drinking water standards.
- Lemon Lane Landfill — another disposal site for industrial waste, including PCB-laden materials. Listed on the National Priorities List in 1983.
- Bennett’s Dump — a third disposal location where PCB waste ended up, adding to the constellation of contaminated sites ringing the city.
The EPA has spent decades and hundreds of millions of dollars on remediation across these sites. Cleanup is ongoing. PCBs don’t break down easily in the environment — they persist in soil, sediment, and groundwater for generations.
Karst Geology: The Hidden Risk Factor
What makes Bloomington’s contamination problem worse than similar situations elsewhere is the geology. South-central Indiana sits on karst terrain — limestone bedrock riddled with sinkholes, caves, and underground channels.
In karst landscapes, surface contamination doesn’t get filtered through layers of soil and rock the way it does in other geologies. Instead, pollutants can travel rapidly through underground conduits directly into the aquifer. A chemical spill on the surface can show up in a well miles away within days or weeks.
This means:
- Groundwater is exceptionally vulnerable to surface contamination events
- Private wells in Monroe County face higher risk than wells in areas with more protective geology
- Septic systems — common in rural areas around Bloomington — can contribute bacteria and nitrates to groundwater more easily through karst pathways
The Indiana Geological and Water Survey has documented extensive karst features throughout Monroe County, including hundreds of mapped sinkholes and cave systems.
Lake Monroe: The City’s Lifeline
Bloomington’s municipal water supply comes primarily from Lake Monroe, Indiana’s largest reservoir. The lake was created in the 1960s by damming Salt Creek, and it provides water to roughly 100,000 people in the greater Bloomington area.
Surface water from a reservoir generally avoids the direct groundwater contamination risks from Superfund sites. But Lake Monroe has its own challenges:
- Agricultural runoff from farms in the watershed contributes nutrients that can fuel algal blooms
- Sedimentation from development and logging has been a long-term concern
- Emerging contaminants including pharmaceuticals and personal care products enter the watershed through various pathways
The City of Bloomington Utilities operates a modern water treatment plant that processes Lake Monroe water through conventional treatment plus granular activated carbon filtration. The utility’s annual water quality reports consistently show the treated water meeting all federal standards.
Emerging Contaminant Concerns
Like many communities nationwide, Bloomington faces questions about contaminants that weren’t regulated — or even tested for — in previous decades:
PFAS — Per- and polyfluoroalkyl substances have become a major concern across Indiana. While Bloomington hasn’t been identified as a PFAS hotspot on the scale of some military communities, testing is ongoing. The EPA’s 2024 PFAS drinking water standards of 4 parts per trillion for PFOA and PFOS are pushing utilities everywhere to test and potentially treat for these chemicals.
1,4-Dioxane — This industrial solvent and contaminant of concern has been found in groundwater at various Indiana sites. It’s particularly problematic because it’s highly mobile in groundwater and resistant to natural degradation.
Microplastics — Lake Monroe, like virtually all surface water bodies, contains microplastics. The health implications of microplastics in drinking water are still being studied, but their ubiquity in surface water sources is well-documented.
What Private Well Owners Should Know
If you’re on a private well in Monroe County or surrounding areas:
- Test annually for bacteria (coliform and E. coli) and nitrates at minimum
- Consider testing for VOCs (volatile organic compounds) if you’re within a few miles of any known contamination site
- Understand your karst risk — if your property has sinkholes or is near mapped cave systems, your well is more vulnerable to surface contamination
- Keep detailed records of your well construction, depth, and test results
The Monroe County Health Department can provide guidance on well testing and local contamination concerns.
What Residents Can Do
Whether you’re on city water or a private well, staying informed is the first step:
- Read your annual water quality report — Bloomington Utilities publishes this every year and it’s available online
- Consider a home water filter — activated carbon filters can address many taste, odor, and chemical concerns
- Report concerns — if you notice changes in your water’s color, taste, or odor, contact your utility or health department
- Stay informed about Superfund progress — EPA provides updates on the ongoing PCB remediation efforts at its Superfund site pages
If you’re concerned about your water quality, a certified water treatment professional can test your water and advise on solutions tailored to your specific situation and water source.