By Alec Janis M.S. – Connecticut Institute of Water Resources
In 1718, in what is now Franklin, Connecticut, a well was dug as an all-purpose public source of water for the community. In about 1755, the people began to complain about the water’s quality, saying it stained clothes and remained tainted until 1794, when an earthquake shook the town. After the earthquake, it was found that the well had been restored to its original quality. Although this is a more extreme example, the quality of your well water can change at any time, which means that just because it was safe to drink when it was installed, that may not be the case today.
The Connecticut Department of Public Health recommends that all residents test their wells every two to five years. If you’re struggling to remember the last time you tested your well, you’re not alone. We estimate that 96% of Connecticut well owners do not follow these guidelines.
So how does your well work? When it rains, some water is absorbed by the plants in the landscape, but they can’t uptake all that water. After water travels past the plant roots, it continues until it reaches an area where all the spaces in the soil have been saturated. This is known as the water table. Think of the soil like a sponge; as you add water, the water fills all the holes and space inside until it’s completely soaked through. If you have a shallow well, your water is being pulled directly from this water table.
If you have a drilled well, your water comes from much further underground. Below the saturated layer of soil, there’s solid stone called bedrock. Throughout the bedrock, there are small cracks, called fractures, where water moves. You can see an example of this when passing a rocky cliff face along the highway that seems to be randomly covered in ice. The ice you see has formed from water that has made its way through soil on top of the ledge, into the fractures in the stone and eventually drips out of small cracks where it freezes in the cold air. A drilled well is a bored hole in the bedrock, intersecting many fractures. Instead of following the original path, water now pours out of the fractures and pools in the newly formed hole.
Now that we know how water travels, let’s consider everything the water is interacting with on its way down. Consider the animal waste on your lawn from a pet or a passing deer, the fertilizers or pesticides you may use on your lawn, or even the de-icing salts you put on walkways during the winter. Precipitation, in the form of rain or snow, pulls everything underground. However, not all of this will end up directly in your well water. The dirt acts as a filter stopping some contaminants while letting others through. Depending on the chemical make-up, certain compounds will remain in the soil while others will break down and continue to travel through.
When this water reaches the bedrock, it will continue to pick up and lose different chemicals. This process will slowly erode these cracks, causing the paths to change over time. As the stone erodes, metals and minerals will be picked up with the traveling water and occasionally end up in your drilled well.
This is why it is important to routinely test your well water quality every few years. As water erodes fractures in the bedrock, new cracks and pathways form, changing the contaminants that are entering your well. We currently don’t have a simple method to track how groundwater is moving, so testing is the best way to understand what’s happening in your well.
To get your well tested visit a local or lab participate in the UConn Extension well testing program. We are hosting a collection event at the UConn Extension - Middlesex County Extension Center (1066 Saybrook Rd, Haddam, CT 06438) on May 3rd from 10:00am – 1:00pm. These tests test for coliform bacteria, lead, arsenic, uranium, nitrates, sodium, chloride, fluoride, pH, hardness, sulfate, turbidity, iron, and manganese. These tests, normally valued at $350, are being offered for a reduced cost of $200.
We will mail a sample kit to participants who have signed up in advance of the collection event. Sample kits will also be available at the collection event on May 3rd as well as at the Old Saybrook Environmental Fair (Old Saybrook Middle School, 60 Sheffield St, Old Saybrook, CT 06475) on April 26th.
Participants can sign up online at https://s.uconn.edu/haddam-well-testing. The deadline to be mailed a sample kit is April 25th.
If participants cannot make the day above, we offer a walk in service year-round where participants can bring their water sample to the UConn main campus Monday through Thursday from 8 am – 5 pm. For more information on how to sign up, visit https://ctiwr.uconn.edu/walk-in/.
We support UConn Extension’s mission by providing answers you can trust with research-based information and resources. For home gardening questions, contact the UConn Home & Garden Education Center at homegarden.cahnr.uconn.edu, or reach out to your local UConn Extension center at cahnr.uconn.edu/extension/locations. For more information about the CT Institute of Water Resources and Well testing services, visit https://ctiwr.uconn.edu/