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)

Minnesota’s Well and Water System Disinfection Fact Sheet

Written by Steve Wilson, Groundwater Hydrologist at the Illinois State Water Survey

When I first started working on the Private Well Class materials, we made the decision to use existing, publicly available resources from the web for images because we had no budget for creating original figures and diagrams. It required us to search the web, and quickly we discovered that there was a lot of redundancy and “reinventing of the wheel” for many of the guides and fact sheets available to well owners.  It was the right decision because so many people before us, extension, health departments, and universities, had created vast libraries of materials available for well owners. For instance, I literally looked at dozens of documents on well disinfection. Initially this was annoying, but in the end was a good thing, it allowed me to pick what I felt were the best materials to provide through our class.

The Minnesota Department of Health is a very well managed and funded state agency that provides a number of exceptional materials freely available to well owners. Their well disinfection fact sheet is no exception.  It was the one I settled on. I felt it was thorough, well written, and covered all of the important information a well owner would need to know when disinfecting their well. 

But a year or so ago, their fact sheet changed.  It went from 10 pages down to 6, and though still well written, they removed a number of details that made it clear and more comprehensive.  I was a little disappointed.  None-the-less, because we work hard to give credit to the groups that develop the wonderful materials we have available to us, we linked to the new version and suggested it to well owners.  Then, as fate would have it, I was at a meeting where a colleague brought up the manual.  He mentioned that he felt the old version was a better document.  I used that as validation, and because I had retained a copy of the previous version, I decided to go back to offering the previous version as a resource on our website.

I wanted to write something about this fact sheet because I think it is the approach everyone should be using when a well owner asks them about disinfecting their well. It includes step by step instructions, explains why taking these steps are necessary, and has pictures to clearly show you what things look like.  

• You can download the fact sheet here.

We welcome your feedback, and if you have any resources that are specific to a topic that you believe are exceptional, please share them with us at info@privatewellclass.org.