Testing your groundwater savvy

What’s underground, used daily by more than half the people of Maine? If you answered groundwater, you’re right! As individuals, we can make choices that will protect our groundwater resources from pollution and over use. Since we don’t see groundwater, it is easy to take it for granted. To get you thinking about this important resource, take this quiz to test your knowledge.     Where does our groundwater come from? A. Rainfall and melting snow. B. Underground rivers.
Where does groundwater flow when it comes out of the ground? A. Groundwater stays underground and does not come to the surface. B. Lakes, rivers, oceans, and streams.
A homeowner near Lewiston uses a well to provide drinking water. From where the water seeped into the ground, about how far did the groundwater travel before entering the well? A. Less than a mile away. B. 5 to 10 miles away. C. 20 miles away D. From Mt. Katahdin or the White Mountains depending on the well location.
How often should you pump out your septic system? A. Once a year. B. At least once every five years. C. When you see wet areas near the leach field. D. When you buy or sell the house.
What can you do to help protect groundwater? A. Recycle used waste oil. B. Limit the use of lawn chemicals. C. Don’t dump any chemicals or other household products on the ground. D. All of the above.
Which well-type is more susceptible to contamination? A. Dug wells B. Drilled wells.
Answers:
A. In Maine, we get about 42 inches of precipitation a year. Some of it evaporates or transpires through plants and never reaches water bodies. The rest runs off the land into lakes, streams, wetlands or rivers, or soaks into the ground to become groundwater.
B. Where the water table meets the land surface, a spring might bubble up or seep from the ground and flow into a lake, stream or the ocean. Groundwater helps keep rivers, streams, and wetlands flowing during dry summer months.
A. Less than a mile away. While there are some areas of the country where groundwater moves long distances underground, in Maine most of the groundwater travels short distances before coming to the surface.
B. Most experts recommend that septic systems be pumped every three to five years. If septic systems aren’t working right, they can contaminate your drinking water.
D. All of the above.
A. Dug wells. A review of statewide water test results reveal that dug wells are about twice as likely to show elevated bacteria counts compared to drilled wells. A dug well may allow surface water to enter through a poorly fitting lid, drilled wells tend to be more protected from direct entry of surface water into the well.
Groundwater is an important resource that needs our protection. Out of sight shouldn’t mean out of mind!
    This column was submitted by Marianne DuBois, a geologist with the Maine Department of Environmental Protection’s Bureau of Land and Water Quality. In Our Back Yard is a regular column of the Maine DEP. E-mail your environmental questions to infodep@maine.gov or send them to In Our Back Yard, Maine DEP, 17 State House Station, Augusta, ME 04333.