The safety of Indiana’s drinking water depends entirely on the source and specific location. For most residents served by public systems, the water is generally safe and consistently meets federal standards established to protect public health. However, Indiana’s diverse landscape, industrial history, and extensive agriculture create localized water quality challenges. These issues are most pronounced in older urban centers with aging infrastructure and in rural areas where well water is susceptible to agricultural runoff. Understanding the regulatory framework, the water’s origin, and local risks is necessary to determine the safety of the water coming from any individual tap.
Oversight of Drinking Water Safety
The safety of public drinking water is overseen by a regulatory partnership between federal and state agencies. The foundational legal structure is the federal Safe Drinking Water Act (SDWA), which grants the Environmental Protection Agency (EPA) the authority to set national standards for contaminants. These regulations apply to all Public Water Systems (PWS).
The Indiana Department of Environmental Management (IDEM) is the state agency responsible for implementing and enforcing the SDWA, a process known as receiving “primacy.” IDEM monitors, tests, and ensures compliance for the over 4,000 PWS across the state, ranging from large municipal utilities to small community systems. This oversight includes regular inspections and mandated testing for hundreds of potential contaminants.
PWS must demonstrate compliance by regularly submitting test results to IDEM, proving that contaminant levels do not exceed the EPA’s Maximum Contaminant Levels (MCLs). This framework ensures water leaving the treatment plant is safe for consumption. However, this oversight does not extend to the final segment of the delivery system, such as pipes on private property or private water wells.
Understanding Indiana Water Sources
Indiana draws its drinking water from two primary sources: surface water and groundwater. Groundwater, sourced from underground aquifers, supplies approximately 60% of the state’s population and is the main source for many smaller towns and rural areas.
Surface water, including rivers, reservoirs, and lakes, serves most of the state’s larger metropolitan areas, particularly in the central and northern regions. Major sources include the Wabash River system, the Ohio River along the southern border, and Lake Michigan in the far north.
A fundamental distinction exists between municipal systems and private wells. Municipal water is treated and tested continuously under IDEM’s strict monitoring protocols. Conversely, private wells, which tap into the same aquifers, are not regulated by IDEM or the EPA. The responsibility for testing and maintenance rests solely on the homeowner, creating significant variability in water quality across rural Indiana.
Common Water Quality Issues in the State
Several specific contaminants challenge Indiana’s water quality, often linked to aging infrastructure and dominant industries. One widespread concern in older municipalities is the presence of lead service lines (LSLs), the pipes connecting the water main to a home’s plumbing. The EPA estimates that Indiana has approximately 265,000 LSLs, with high concentrations in older cities like Indianapolis and in the northwest region.
Existing LSLs continue to corrode, allowing lead to leach into drinking water, which is particularly hazardous to children. Another significant challenge stems from Indiana’s extensive agricultural activity, which contributes to nonpoint source pollution. Runoff from the state’s farmland often carries fertilizers and pesticides, including nitrates and herbicides like atrazine and metolachlor, into surface water and groundwater.
Nitrate contamination is a major health concern, especially for infants, as high levels can cause methemoglobinemia, or “blue baby syndrome,” primarily affecting private wells in rural areas. Emerging contaminants like Per- and Polyfluoroalkyl Substances (PFAS) are also a growing issue, linked to industrial sites and military bases where they were historically used in firefighting foams.
Locations such as Grissom Air Force Base and Camp Atterbury have been identified as sites where PFAS has contaminated groundwater, requiring ongoing monitoring and remediation efforts. Finally, the proximity of coal ash disposal sites near waterways creates a risk of heavy metals leaching into nearby surface water and groundwater sources.
Steps to Check Your Home Water Safety
For residents served by a public water system, the first step for checking water safety is locating the annual Consumer Confidence Report (CCR). Federal law requires all Community Water Systems to prepare and distribute this report to customers by July 1st each year. The CCR details the water’s source, all detected contaminants, measured levels, and any violations of federal standards from the previous calendar year.
Consumers can find their CCR on their utility’s website or contact their local water provider. IDEM also maintains an online Drinking Water Viewer, which provides access to compliance data and testing results for public systems. Residents in older properties should consider a third-party lead test to check for contamination from internal plumbing or the service line owned by the property.
For private well owners, regular testing is strongly recommended. The Indiana Department of Health (IDOH) advises annual testing for total coliform bacteria and nitrates. Testing every five years is also recommended for lead, copper, and naturally occurring arsenic, or whenever the water’s taste, odor, or appearance changes. Homeowners can order certified testing kits from the IDOH lab or a state-certified private laboratory to ensure accurate results.