Why Sometimes Newer Isn’t Always Better: Minnesota Department of Health’s Well Disinfection Guide

We always receive questions from homeowners across the country on how to properly disinfect a private well. There are many different private well disinfection guides available for private well owners through many public health, extension and state organizations across the U.S. The Private Well Class has used the Minnesota Department of Health’s Well Disinfection guide in our 10-week class and in our Resource Library. After careful review of all of the information on well disinfection available, our opinion is that the MDH guide is one of the best and most complete available.

However, in 2015, MDH updated the 2012 “Well and Water System Disinfection for Private Wells,” with a newer, shorter “Well Disinfection” guide. Honestly, we were disappointed in the new guide because in making it shorter, they also took out some of the details that made their guide so complete. The bottom line is that we are still referring private well owners to the 2012 version of the document in our resource library and in our lessons. The step-by-step process hasn’t changed much between the two, but the supporting information has. The content in the 2012 version is not only more in-depth, but it provides more background information that tells you why you are doing something in the process instead of just how to do it. It clearly explains what disinfection is and what might cause contamination of the well and water system.

The 2012 version addresses two important questions about disinfection, “How Often Should a Well be Tested?” and “When Should a Well be Disinfected?” It provides sound advice, some of which is missing in the newer version. Understanding when to disinfect is an important issue, we often talk to private well owners who have/are disinfecting their well when it is not necessary.

The only time you should disinfect your well is after sampling indicates you have bacteria. Testing should be completed annually, as well as any time the well has been opened, or there has been an event that has impacted your well (after a flood, fire, repairs, etc.).

The Minnesota Department of Health’s Well Management Program stands out as a leader among their peers and we often refer well owners to their materials. We thought it worth noting that though we like the older version of their well disinfection guide better, we rely on many of their materials to support well owners all over the country. You can find their website at: http://www.health.state.mn.us/divs/eh/wells/

Well and Water System Disinfection for Private Wells (2012 version)

Well Disinfection (2015 version)