The filters described on this blog and the associated websites have been tested by 2 different EPA certified laboratories: AmTest in Kirkland Washington, and The city of Everett, Washington environmental lab
The test results can be found here
These links connect to the websites associated with this blog which are written by the same person who writes this blog. There have been over 60 separate tests done by the epa labs, in addition to 8 field tests (non epa certified – and 2 are yet to be posted) done on the filters described on this blog and the associated websites over a period of 6 and a half years:
shared source inititative dot com slash biosand water filter
Anyone with questions about these tests is encouraged to post them here. I am taking the risk of adding this post as a redundancy (I have written about this more than once), because of the numerous videos, and websites that continue to appear showing impressive versions of “slow sand filters” with no documentation of actual functionality or extended periods of operation through winter, spring, fall and summer conditions. Every filter is different because every situation is different. In each case, a new filter must be tested (we are talking about do it yourself filters here) and carefully monitored to be reasonably certain it works to purify water.