A few years back we started getting a bunch of questions from customers, especially commercial customers, concerned about the chlorine in the tap water killing the microbes in EM1 when trying to make Activated EM1. I have always used tap water and never had a problem with making Activated EM1, yet I didn't have a definitive answer about this for our customers. Naturally, I went to EMRO USA since they make EM1 for North America for EM America. Luckily, a researcher from EMRO was visiting during the summer and was able to run some experiments for us at their Tucson lab right away.
There are a few web sites out on the net that discuss making Activated EM1 and the need to use non-chlorinated water. The EPA limits the amount of chlorine in tap water to 0.1ppm. (This is not a post condoning the use of chlorine or other chemicals in water.) What we discovered about the tolerance of EM1 to chlorine was pretty impressive. EMRO also tested Activated EM1 at different ages. They found that EM1 can withstand up to 6ppm of chlorine for about 10 minutes of exposure time. Fresh Activated EM1 (4-5 days old) could withstand 4ppm and older Activated EM1 (15-20 days old) could withstand up to 2.5ppm.
These results let us know that the effects of chlorine in tap water on EM1 and Activated EM1 are likely to be so small that one shouldn't worry about it. Also, using tap water to mix with EM1 and Activated EM1 for applications should not be a concern.
This is just one more example of how simple it is to use EM1.