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Indianapolis Water Quality City View of Downtown Next to River

January 2024

Looking Under the Hood of Indianapolis Water Quality

Indianapolis is known as the racing capital of the world, but Indiana's capital city offers more than the iconic roar of the Indy 500. Situated at the 'Crossroads of America,' the city celebrates its serene canals and walkways as much as its famous speedways and sporting events. Indy’s blue-collar grit and Midwestern charm create a unique cultural and historical identity that is held in place by its many monuments.

As strong as Indianapolis’s identity is, the city continues to grow and evolve. Indianapolis is attracting about 65 new residents per day with its expanding job market and affordable living. Industries like life sciences, advanced manufacturing, and tech are flourishing here, which is great for the economy but stressful on the city’s infrastructure. Managing water quality is becoming a complex challenge.

In this article, we're shifting the spotlight from the Speedway to Indianapolis water quality. We'll explore where your water comes from, the challenges in keeping it clean, and what you can do to ensure that what flows from your tap is always high quality.

Where Does Indianapolis Water Come From?

Indianapolis and surrounding Morgan County draw water from a network of surface water and groundwater sources, with the bulk coming from the White River.

To keep water quality standards high, the Citizens Energy Group operates multiple water treatment plants, including the White River and the White River North Plants. These plants draw upon the steady flow maintained by Morse Reservoir.

Another key contributor is Fall Creek, with the Geist Reservoir and Citizens Reservoir sending supply to both Fall Creek and White River treatment plants. This is augmented by a network of strategically placed groundwater wells that are utilized intermittently, boosting the water supply to the White River and Fall Creek plants when necessary.

The waters of Eagle Creek Reservoir also play a significant role, being the main supply line to the T.W. Moses treatment plant. Beyond these, Indianapolis benefits from a series of six groundwater treatment plants that address the needs of smaller portions of its service area. These include White River North, Geist Station, Harding Station, South Well Field, Harbour, and Ford Road.

The city of Westfield has three dedicated water treatment plants, while South Madison has one of its own. All four of these are supplied with groundwater from deep aquifers.

How Is Indianapolis Water Treated?

Indianapolis water quality is maintained through a multi-step treatment process that differs based on the source of the water. Groundwater undergoes aeration and filtration to remove any dissolved minerals, like iron and manganese. Surface water treatment is a little more involved. It includes:

  • Coagulation: Chemicals are added to surface water to clump smaller particles together into larger particles.
  • Flocculation: These larger particles are combined into a mass called floc that can be more easily removed.
  • Sedimentation: The floc settles to the bottom due to its weight, separating from the clean water.
  • Filtration: The clear water is filtered to remove any remaining particles.
  • Disinfection with Chlorine: Chlorine is added to eradicate bacteria and maintain a disinfectant level in the distribution system.
  • Ultraviolet (UV) Light: UV light is employed for additional disinfection.
  • Fluoridation: Fluoride is added to prevent cavities.
  • Ammonia Treatment: Ammonia is used to reduce disinfection by-products and help chlorine remain effective longer in the system.

Water quality data is collected through extensive water testing. Over 11,000 water samples are tested, starting with the source water and continuing through every step of the treatment process. This ensures Hoosiers enjoy safe drinking water as defined by local and national drinking water standards.

Is Indianapolis Water Clean?

Indianapolis manages much of its stormwater and sewage using a combined sewer system. While this was the pinnacle of sanitation engineering when it was built over a century ago, it's woefully inadequate today. During heavier rains, combined sewage overflow events send raw sewage into the city's waterways, including the White River and Eagle Creek.

While billions of federal dollars are being sent to Indiana to try to address these problems with new tunnel systems and updates to wastewater treatment plants, the Indiana Department of Environmental Management (IDEM) has other water pollution worries. Indiana has more miles of impaired rivers[1]  than any other state. That means water that is too contaminated for drinking, fishing, or swimming.

Indiana water quality, including the watersheds Indianapolis relies on, suffers from pollutants such as E.coli from human and animal waste, toxic algae, industrial contaminants like PFAS, and more. Indiana is working hard on cleanup efforts, but they still have a long way to go.

Is It Safe to Drink the Tap Water in Indianapolis?

According to the Indianapolis Water Quality Report and the U.S. Environmental Protection Agency (EPA), Indianapolis tap water is safe to drink. It’s important to note that meeting regulatory standards doesn’t always mean water is safe, though.

Since the enactment of the Clean Water Act in 1972, the EPA has set minimum standards for drinking water quality for all public water suppliers. Currently, there are enforceable standards for over 90 pollutants commonly found in U.S. tap water.

While these standards are vital, there are thousands of contaminants that utilities don’t test for. Contaminants like microplastics, which are found in water supplies across the world, have no limits placed on them.

PFAS, known as forever chemicals because they don’t break down in nature, have been a known carcinogen for over 20 years. It’s taken until 2023 for the EPA to suggest enforceable limits in your drinking water.

According to the Environmental Working Group (EWG), a D.C.-based water watchdog, if these new standards become law, it will be the first change to national water regulations in 20 years.

Regulation is often behind science, and the scientific community learns more about water contaminants every year, leaving water regulations out of date.

Let’s dive into some of the dangers found in Indianapolis’s water that are within legal limits but are causing concern to scientists.

Which Chemicals Are Hurting Indianapolis Water Quality?

One problem Indianapolis water quality faces is disinfection by-products (DBPs). When chlorine and chloramines interact with organic matter, cancer-causing DBPs are formed. There are also problems with elevated levels of arsenic, chromium, radium, nitrates, and pesticides like atrazine.

Haloacetic Acids (HAA5)

There are five haloacetic acids that make up HAA5: monobromoacetic acid, dibromoacetic acid, monochloroacetic acid, dichloroacetic acid, and trichloroacetic acid. These disinfection by-products result from chlorine and other disinfectants interacting with organic matter in water, and they can lead to cancer with long-term exposure.

Levels of HAA5 in Indianapolis water have exceeded what the EWG recommends for safety by 381 times:

  • EPA maximum allowance: 60 parts per billion (ppb)
  • EWG recommended maximum: 0.1 ppb
  • Indianapolis maximum contaminant level: 38.1 ppb

Haloacetic Acids (HAA9)

HAA9 includes all of the contaminants from HAA5 but adds bromochloroacetic acid, bromodichloroacetic acid, chlorodibromoacetic acid, and tribromoacetic acid. These are also cancer-causing disinfection by-products.

Levels of HAA9 in Indianapolis water have exceeded what the EWG recommends for safety by 555 times:

  • EPA maximum allowance: No legal limit
  • EWG recommended maximum: 0.06 ppb
  • Indianapolis maximum contaminant level: 33.3 ppb

Total Trihalomethanes (TTHMs)

Like HAA5, TTHMs form when the organic compounds in drinking water interact with chlorine. They are also known to be carcinogenic. Four chemicals make up TTHMs: chloroform, bromoform, bromodichloromethane, and dibromochloromethane.

Levels of TTHMs in Indianapolis water have exceeded what the EWG recommends for safety by 324 times:

  • EPA maximum allowance: 80 ppb
  • EWG recommended maximum: 0.15 ppb
  • Indianapolis maximum contaminant level: 48.6 ppb

Chromium (Hexavalent)

Chromium is another common contaminant found in U.S. water supplies. It can occur naturally, but it's also an industrial pollutant. Although it’s known to be a carcinogen, this contaminant is still unregulated by the EPA.

Chromium levels in Indianapolis water have exceeded what the EWG recommends for safety by 4 times:

  • EPA maximum allowance: No legal limit
  • EWG recommended maximum: 0.02 ppb
  • Indianapolis maximum detected level: 0.08 ppb


Nitrates usually end up in water supplies through stormwater runoff from fertilizers, but they can also come from septic tanks. They can cause oxygen deprivation in infants and increase the risk of certain cancers.

Nitrate levels in Indianapolis water have exceeded what the EWG recommends for safety by 6.3 times:

  • EPA maximum allowance: 10 parts per million (ppm)
  • EWG recommended maximum: 0.14 ppm
  • Indianapolis maximum detected level: 0.885 ppm


Arsenic is carcinogenic and is known to cause damage to the brain, central nervous system, skin, and blood vessels. It's a common contaminant in U.S. public drinking water because it can occur naturally in groundwater.

Arsenic levels in Indianapolis water have exceeded what the EWG recommends for safety by 41 times:

  • EPA maximum allowance: 10 ppb
  • EWG recommended maximum: 0.004 ppb
  • Indianapolis maximum detected level: 0.163 ppb


Radium, a radioactive heavy metal, is a by-product of oil and gas production, but it's also found in nature. Radium is a carcinogen, and its legal limits are measured in picocuries per liter (pCi/L).

Radium levels in Indianapolis water have exceeded what the EWG recommends for safety by 20 times.

  • EPA maximum allowance: 5 pCi/L
  • EWG recommended maximum: 0.05 pCi/L
  • Indianapolis maximum detected level: 1.01 pCi/L


Atrazine is an herbicide used in agricultural and residential areas. It’s been banned in the European Union and several other regions since 2003. In North America, it’s used for treating crops like corn, sugarcane, and sorghum, and it's used in home gardens, as well. When present in municipal water systems and individual wells, atrazine has been associated with hormonal imbalances, fertility problems, and an increased risk of cancer in both humans and wildlife.

Atrazine levels in Indianapolis water have exceeded what the EWG recommends for safety by 3.1 times:

  • EPA maximum allowance: 3 ppb
  • EWG recommended maximum: 0.1 ppb
  • Indianapolis maximum detected level: 0.305 ppb

Does Indianapolis Have Hard Water?

Indianapolis water quality is plagued by hard water minerals. With concentrations between 200 and 425mg/L, Indianapolis water is considered extremely hard.

Water hardness is a measure of dissolved minerals like calcium and magnesium in water. The more dissolved minerals in water, the harder it is considered to be. As water passes through soil and rock in nature, it breaks off small mineral particles that it then carries with it until depositing them elsewhere. This is usually in your pipes and on your surfaces.

While hard water is not dangerous to ingest, it can wreak havoc on your home and skin, even causing eczema. Not only does it build up as limescale on your surfaces, but hard water minerals combine with soap to create soap scum on your skin, so you never get fully clean.

To rid your home of hard water, you’ll either need to use a water softener or a salt-free water conditioner.

Does Indianapolis Add Fluoride to Drinking Water?

Like in many other major American cities, water utilities in Indianapolis fluoridate their water as a public health initiative. Fluoride is a naturally occurring mineral that has been proven to protect and even rebuild tooth enamel in children and adults.

While some people are very happy to have the added protection from dental cavities, others would like to control their fluoride intake. If you’d rather remove fluoride from your tap water, you should know that most filters don’t remove fluoride. For that, you’ll need a high-quality reverse osmosis water filtration system.

Quality Water Women Under Faucet

Get the Best Quality Water in Your Indianapolis Home

Indianapolis is attracting new people and industries every day. Unfortunately, this is presenting challenges to Indianapolis water quality. The century-old infrastructure is struggling to keep up, and throughout the state, water pollution is plaguing the rivers and lakes. While Federal grant money is flowing into Indiana, it could take many years to see results.

If you want the best-tasting clean water straight from your tap no matter what, HomeWater can help. HomeWater's UPSTREAM 4-Stage Whole Home Water Filter improves your water quality by removing impurities like sediment, chloramines, DPBs, PFAS, microplastics, chromium, and more.

Elevate your Indianapolis water experience with HomeWater.

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