Earthquakes

Private Wells and Onsite Sewage Systems Following the February 26, 2015, Earthquake

Following the February 26, 2015 earthquake, private well owners may notice changes in the appearance of their water supplies or may have concerns about the quality of their water supply. Well owners, especially those close to the epicenter, should inspect the structural integrity of their well and also the clarity of the water coming from the well. Owners of onsite sewage systems should check the structural integrity of system components, especially if you notice wet spots, sewage odors or, possibly, the sounds made by mechanical components of your system.

Private Wells
Discoloration, caused by sediment or minerals in the water, is not uncommon after an earthquake. Well owners who observe sediment in the water supply should use an alternate source of water until the water supply is clear. If in doubt regarding water quality, the water may be boiled before use or residents may consider using bottled water.
If your water is cloudy or muddy, the well and waterlines should be flushed until the water has cleared. Owners may also use “shock chlorination,” which is a process of disinfecting a private water supply and plumbing system by circulating a concentrated chlorine solution throughout the system.
The local health department can assist well owners with the chlorination and/or boiling procedures, which can also be found at the following links:

If the discoloration persists, or if well owners have concerns about bacterial contamination or structural integrity of the well they should contact a licensed professional to inspect the structure, test the water and treat if necessary.

Onsite Sewage Systems
Depending on your location and the type and construction of your onsite sewage treatment system, the recent earthquakes may have cracked one or more of your system’s tanks, damaged important mechanical components, shifted components out of proper level or alignment, or broken or crushed connecting pipes and electrical cables.
For all systems, look for changes in how your system functions, looks, sounds, or smells.  Be on the alert for a change in how well household toilets flush and drains drain,  the sudden appearance of wet or unusually green spots in your yard, and/or the emanation of different or more intense odors from your system.
For systems with mechanical components (blowers, pumps, etc.), look for activated alarm lights and buzzers and/or a change in how the mechanical components of your system sound.
One problem often reported following an earthquake is due to grit that enters a water well after an earthquake.  If that grit makes its way through your household plumbing to your toilet, it can jam in the float valve – keeping that valve from closing when the tank is full.  The extra flow of water can overload your onsite sewage treatment system, contributing to a failure long after the earthquake has passed.

Additional Information
For more information about specific concerns regarding private wells or onsite sewage systems, contact your local health department, your Water System Installer or your Onsite Sewage System Operator. Additional resources on private well water, onsite sewage systems and the earthquake are available at the following locations:

Last Updated: September 21, 2016