Groundwater system painting by Glenn Wolff
Over half the U.S. population, including 99 percent of the rural population, relies on groundwater for its drinking water supply. In Michigan, 45 percent of the population has a drinking water supply of groundwater. Groundwater is also used in crop irrigation and industrial processes. But many citizens are generally unaware of the nature and critical importance of groundwater.
Groundwater is water found underground in cracks and spaces in soil, sand, and rock. These underground stores of water are called aquifers. Aquifers consist of permeable materials like gravel, sand, sandstone, or fractured rock, like limestone, that allow water to flow through. Groundwater can be found almost anywhere: the area where water fills the aquifer is called the saturation zone, and the top of the saturation zone is referred to as the water table. The water table may be located a foot below the ground’s surface, or it can be hundreds of feet down.
Groundwater can be extracted from aquifers naturally or artificially. Springs naturally bring groundwater to the surface and discharge it into lakes and streams (surface water bodies). Wells drilled into the aquifer can also pump groundwater to the surface.
Groundwater supplies are recharged or replenished by rain and snow melt. There can be shortages if groundwater supplies are used up faster than they are naturally recharged, or if supplies are polluted by human activities.
Groundwater is critically important to daily living. Of all the Earth’s water that is usable by humans, 98 percent is groundwater. A 2005 U.S. Geological Survey found that groundwater is used for 37 percent of agricultural water use, primarily in irrigation. Consider the fact that Americans, collectively, drink more than one billion gallons of tap water every day, and that 40 percent of the world’s food supply is grown on irrigated cropland, and the crucial importance of clean groundwater becomes clear.
Most people do not realize the impact they can have on groundwater. Anything poured or spilled onto the ground’s surface can end up in the groundwater supply, even years later, and contaminated groundwater can ruin human and animal health. Overuse can lead to shortages in the water supply. The average American uses 100 gallons of water every day. If the rate of use exceeds the rate of natural recharge, a shortage may occur. With the level of public and industrial dependence on groundwater, such a shortage could be devastating.
Every individual has a responsibility to protect groundwater, because every individual is impacted daily by the quality and quantity available.
How to Protect Your Groundwater
Test your well
If your drinking water comes from a private well, have the water tested. Spring is a great time to test well water, particularly for health-related concerns like bacteria and nitrate. Check out this fact sheet on water well testing by the Michigan Department of Environment, Great Lakes and Energy (EGLE).
Properly fill and seal an unused well on your property
Wells that are no longer in use represent a direct conduit for pollutants to contaminate the groundwater aquifer. If you have an unused well on your property, take steps to ensure that it is abandoned properly and will not contaminate groundwater in the future. Here is information you need to know from EGLE.
Take steps to reduce your water use
About 45% of Michigan residents rely on groundwater as their primary water supply. Reducing water use conserves groundwater, since most groundwater used in homes is discharged to lakes and streams and not returned to the aquifer. Some quick and easy solutions to reduce your water use include buying more efficient appliances, faucets, and toilets. Planting less water-intensive landscaping and using rain barrels to collect rainfall for watering the garden can also help to conserve groundwater. Often times, reducing water use results in lower water bills and energy savings as well. Read more here.
Do a spring cleaning of hazardous materials around your home
Old motor oil, unused or old paint/varnish or other cleaning products often build up in and around our homes. Take an opportunity during this week to do a spring cleaning of hazardous materials so that they do not end up contaminating groundwater or surface waters. Dispose of them properly — that means not down the storm sewer, and not down your septic system either.
Learn about water quality for your community water supply
Many “city” water supplies in Michigan use groundwater. About 12,000 public wells service 1.7 million citizens. Contact your local water utility and ask them for the most recent water quality data or learn about how your community’s water supply is protected.