Mahomet Aquifer facts for kids
The Mahomet Aquifer is a very important underground water source. It's found in central Illinois. This huge natural water storage is made of sand and gravel. It's part of a much older, buried river valley called the Mahomet Bedrock Valley. The aquifer stretches across 15 counties. It can be from 50 to 200 feet (15 to 60 meters) thick. Every day, it provides over 100 million US gallons (378,541 cubic meters) of groundwater. This water is used by cities, industries, and for watering crops.
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How the Aquifer Formed
The Mahomet Aquifer is made of sand and gravel. These materials were left behind by melting glaciers a very long time ago. Water from these glaciers flowed westward. It followed the path of the ancient Mahomet Bedrock Valley. This valley is part of a bigger system that reaches into Indiana. Most of the sand and gravel making up the aquifer is found deep underground. It's usually 100 to 200 feet (30 to 60 meters) below the surface.
The aquifer covers a huge area. It's about 1.26 million acres (5,100 square kilometers) in east-central Illinois. It spreads across 15 different counties. The Mahomet Aquifer is usually 4 to 15 miles (6 to 24 kilometers) wide. Its thickness varies, but it averages about 100 feet (30 meters). Most of the aquifer is "confined." This means it's trapped between layers of rock or clay. However, in some western counties, it's closer to the surface.
How We Use the Water
The Mahomet Aquifer provides water for about 850,000 people. Experts think this number might grow to 910,000 people by 2020. Around 100 million US gallons (378,541 cubic meters) of water are pumped from the aquifer daily. This water goes to cities, farms, businesses, and homes. About 45% of the water is used by the public. Industries use 29%, and commercial businesses use 18%. The rest is used for things like watering livestock and irrigation.
As more people move into the area, the need for water increases. This rising demand has led to concerns about using too much groundwater. Scientists are studying the aquifer to understand it better. The Illinois State Geological Survey and the Illinois State Water Survey have found that water levels are dropping in some parts of the Mahomet Aquifer. This information helps people plan for the future.
Water Quality and Safety
The water in the Mahomet Aquifer is generally good quality. It naturally contains some dissolved minerals and iron. This is common for groundwater and doesn't harm people. However, one natural substance that can be a concern is arsenic. Arsenic can leach, or slowly dissolve, from certain rocks like oxidized pyrite.
The amount of arsenic can sometimes be higher than the safe limit. The United States Environmental Protection Agency (EPA) set a new standard of 10 parts per billion (ppb). Some areas of the aquifer can have 20 to 70 ppb of arsenic. Water systems had to meet this new standard by January 23, 2006. Luckily, arsenic can be removed from the water. Special water treatment systems are available to make the water safe to drink.
Working Together for the Aquifer
The Mahomet Aquifer Consortium (MAC) was created in 1998. Its main goal is to study the aquifer and create a plan for managing it. This group has about 70 members. They come from many different areas. These include the public, water companies, and local, state, and federal governments.
The MAC wants to learn as much as possible about the aquifer. This way, they can make smart decisions. Their goal is to make sure there's enough water for everyone in the future. They also consider how population growth and extreme weather events might affect the water supply.