How Does Heavy Rain Affect the Water Quality from a Well?


Many homeowners who rely on a private well often ask how environmental factors such as rain affects the quality of water they use in their house. In general, as long as your well is well-built and in good operational condition, you do not need to worry too much about how rain will affect your groundwater. However, the water quality can change dramatically during a period of heavy rain. If you find water in your house to be brown or cloudy, you shouldn’t dismiss it as simply “cloudy water” caused by rain. Anytime your water changes colour or tastes different, you must take it seriously. In this blog, we discuss how heavy rainfall affects private wells and what can be done to ensure high-quality water in the house at all times.

Rainfall & Water Quality

Discoloured water after it rains can be caused by a few different issues, some more serious than others. There are a few issues you should rule out first.
  1. Is only one tap running discoloured water or is it every tap? If it’s just one tap, it could be rust from the plumbing and fixture.
  2. Has the water recently been turned on after being turned off for a while? If so, it could be caused by some rust and debris that would stop after a while of running the water.

If you have eliminated those issues, you’re seeing discoloured water coming out of every tap after heavy rains. This is likely caused by surface water leaking into your well. This is dangerous because the runoff from surface water could have pesticides, fertilisers, or animal waste — especially if you live on a farm. Another potential source of dangerous bacterial contamination is yours or your neighbours’ leaky septic system overwhelmed by the rain. Coliform and E. Coli are two harmful bacteria that can cause severe illness, especially in children and the elderly.

How to Diagnose and Fix the Problem?

Brown or discoloured water is a sign of possible contamination. Finding out the cause of the problem is key to getting the right solution. A water test will tell you a lot about what may be causing the discoloured water. It very well may be water is leaking into your well from the surface due to heavy rain. Rain would reach inside the casing only if the grouting is damaged or the well cap isn’t sealed properly. If rainwater enters your well, bacteria could also get in. Older wells were often installed without grout surrounding the pipe, and even older wells are often shallow enough to experience these types of issues more often. It’s important to fix the root problem and disinfect the well after you do. If you do have higher levels of bacteria in your well, you may need to engage in chlorination to kill off some of them and install a UV treatment system to kill the remaining bacteria present in your water. It is in your best interest to work with a team of water well technicians to complete this so you do not over-chlorinate your well water. Read More: How to remove bacteria from drinking water?

Ensure High-Quality Water with Regular Water Testing

Environmental Protection Agency (EPA) recommends that all household wells in Ireland be tested at least once a year to check for contamination. The best time to test a well is after heavy rainfall, as this is when contamination is likely to be at its highest. Any change in smell, taste or colour of the water is a strong indication that contamination has taken place. In that case. it is critical to get your water tested for E. coli and Coliform bacteria. The need for other tests depends on the location of your well and the appearance of your water. For example, if your well is in an agricultural area you may need to get it tested for nitrate or if it is slightly discoloured you may also want to get it tested for iron and manganese.

Get the Best Advice

The quality of water from your private well may vary throughout the year. The best way to ensure you are using safe water in your house is to get your water tested regularly and take corrective measures to safeguard your well. If your home relies on a private well, it is highly recommended to get a specialist well treatment system installed that will eliminate any contaminants present in your water. Celtic Water Solutions offers customised water treatment solutions based on your water test results. Our water experts would go through the test results with you and offer the best solution to treat the problem of water. Our team has over 20 years of experience treating private wells and has helped thousands of households improve their water quality. Contact us for a free consultation.