Saltwater Intrusion: Protect Your Well

Saltwater intrusion, a byproduct of sea level rise, is a growing issue in Delaware. Here are some things you can do to protect your wells.

Photo of a drinking water well located next to a canal

How Can I Prevent Salt Water from Getting Into My Well?

Reduce water use. During prolonged dry periods don’t water your lawn, wash your car or fill your swimming pool. These activities require a large amount of water and will increase the time your well is pumping.

Do not place wells near saltwater bodies. Many canals along coastal communities are salty and wells located too close can draw saltwater in if conditions are right.

If your well must be located near a saltwater body, construct the portion of the well that allows water to be drawn to the surface in the shallowest part of the aquifer or into a deeper aquifer known as a confined aquifer.

In flood prone areas, make sure the well is finished above ground level higher than the flood level. The current regulation for wells located in flood prone areas is 24 inches above the land surface. The part of the well that sticks up above the ground has a vent to allow the well to connect with the atmosphere, typically covered by a screen. If the top of the well is submerged by flooding, water can flow down into the well and contaminate it with salt water.

Maintain the well stick-up. If the well casing becomes damaged (hit by a car or lawnmower), have a licensed well driller repair the casing as soon as possible. Cracks in a casing can allow saltwater to flow into the well. If any settling is noticed around the well contact the Division of Water at 302-739-9944 or a well driller.

What Can I Do If My Well Becomes Contaminated with Saltwater?

A worker samples water from a drinking water wellReduce pumping. If this does not help, alternatives would be to wait for the saltwater concentration to decrease or have a new well installed at a shallower depth or in a confined aquifer.

Homeowners with wells near saltwater bodies may detect a “salty” taste in their water during the hotter, dryer months, when the water table is at its lowest and the transition zone advances inland. The water table typically becomes higher during the winter and early spring, moving the transition zone seaward, resulting in a decline of salt concentrations.

Saltwater cannot be removed using the typical water softener most homeowners use.

Can I Sample My Own Water?

You can also sample your water yourself to get an accurate chloride and sodium concentration from a laboratory.

Sampling kits are available through the Department of Public Health’s Office of Drinking Water for a nominal fee.

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