Those of us living in Terre Haute get our water supply from Indiana American Water. The source for this water is ground water. Between 60 to 72 percent of Indiana's population relies on groundwater for drinking and household uses. People sometimes imagine groundwater to be an underground lake or river, but actually in most places including Terre Haute, a groundwater aquifer is a sand and gravel deposit saturated with water. In Terre Haute, four deep wells and one radial collector well owned by Indiana American Water pump water from a sand-gravel aquifer to the surface.

In general, groundwater is safe to drink in Indiana. Natural constituents such as iron, manganese, sulfate, and hardness are common nuisances, but do not pose health threats. Groundwater, however, can be contaminated by human activities. Contaminants may include: industrial chemicals, nitrates from agricultural applications and waste water disposal, salt from salt piles and road applications, and gasoline and other petroleum products.

The Indiana Department of Environmental Management (IDEM) administers the Wellhead Protection Program, which is designed to protect Indiana groundwater drinking supplies from pollution. The greatest danger of pollution to our drinking supply comes from "nonpoint sources" (NPS), which are so named because the pollutants do not originate from single point sources such as industrial or municipal waste discharge pipes. Instead, NPS pollutants are usually chemicals deposited on the ground surface, such as agricultural fertilizer, road salt, herbicides, motor oil and pesticides, which enter our river and groundwater through rainwater or snowmelt. Thus, to protect the water supply in Terre Haute, we need to be careful about what chemicals are applied to the ground immediately above our aquifer.

Where is our aquifer located? Roughly, the aquifer is located beneath the Time-of-Travel (TOT) boundaries illustrated below, in the northwest portion of Terre Haute, roughly centered east-west between US 41 and Lafayette Avenue, and north-south between Locust St. and Maple Avenue. The areas above our aquifer which are most sensitive to pollution and contaminants are found within the 1-year TOT and 5-year TOT boundaries. TOT represents the time it takes for a surface pollutant to reach our ground water supply. Thus if you live within the boundaries of these TOT areas, any chemical you apply to your lawn or spill in your backyard will make its way into our water supply within 1-5 years. Please help us protect the TH water supply. Through voluntary management, our community may prevent future contamination of our water supply.

Note: There is a listed U.S. Environmental Protection Agency (EPA) Superfund site, Elm Street Groundwater Contamination located within the 1-year TOT of our water supply. This may or may not be a reason for concern within the community.

Top 10 Ways You Can Help Protect Our Ground Water

1.    Dispose of chemicals properly. Do not pour dangerous chemicals down drains!
2.    Take used motor oil to an automotive repair center. 
3.    Limit the amount of fertilizer and pesticides used on gardens and lawns. 
4.    Properly abandon unused wells or cisterns. 
5.    Dispose of household hazardous waste properly. 
6.    Remove abandoned fuel oil and gasoline tanks properly. 
7.    Keep septic systems well maintained.
8.    Report illegal dumping. 
9.    Minimize the use of de-icers. 
10.  Get involved in water education programs.