Saturday, May 25, 2013

Low Tech Water Filtering with a Berkey / British Berkefeld Combination

After repeatedly coming close to, but not quite passing, our water tests, I finally became disillusioned with attempting to get our well to a zero bacteria level. We have managed to avoid e. coli, but there often seemed to be other coliforms that managed to infiltrate somehow.
Bleaching the well is always an option, but that didn't really sit well (get it? Well?) with me. So with that in mind, I returned to my camping roots and sought out options for filtering my own water as needed.
Having tried a number of different solutions as a backpacker, including MiOx systems, chlorine drops, and ceramic filters, I opted for the most cost efficient, lowest technology option. This was a ceramic filter. They last for thousands of gallons of water, are easy to care for (requiring occasional manual cleaning of the outer ceramic), and have a long track record of efficient, chemical-free filtering of potable water.
Not wanting to have to manually pump every drop of water though, I was very happy to find that gravity-fed solutions have been around for over a century now!
Online, the tubes of the internet seem to be saturated with the American "Big Berkey" canisters, which also heavily promote their "Black Berkey" filters.
Drilling a little deeper though, there seems to be some lingering questions as to whether or not the Big Berkey canisters and filters are actually made in the U.S. More importantly, though, quality control on the filters seems to be very questionable. Many, many reports of the filters coming apart without warning led me to worry about just how much they could be trusted. Of course, the Black Berkey filters don't appear to be ceramic - they seem to be straight up carbon with perhaps some other components. Having never seen one in person though, I can't really make a confirmed comment about them.
With these reports in mind, I opted instead to go for the original British Berkefeld system, which the Berkey system is a derivative of.
I couldn't get original an original Berkefeld cannister, but this didn't trouble me so much, as it is basically two stainless steel canisters which sit upon one another. Untreated water goes in the top, and filters though to the lower canister, from which a spigot dispenses it for drinking and toothbrushing. The canister isn't nearly as critical as the filter.
I did insist on original UK-made filters though, and wasn't disappointed. I purchased two, 9" ceramic Berkefeld filters. They seem to be very straightforward. Wipe off the ceramic dust with a wet rag, install in the upper chamber with a rubber washer above, and a plastic nut below, and then run one or two full tanks of water though before use.
At first I was going to only use one filter, but the time taken for the canister to empty was on the order of 10-12 hours, so I installed the second filter as well. This does not change the economy of the system - only the speed of filtering.
For a standard "Big Berkey" canister, 9" filters fit fine, but seem to me to be oversized. In future I would order the 7" filters. The top two inches of the 9" filter are no longer covered by water within an hour of filling the top canister, if you even DO fill it. We also noticed while filling that there is a significant risk of contamination if untreated water runs down the side of the upper canister, as it would drain down into the lower canister. To account for this, we placed a "garter" around the base of the upper canister - actually, one of Donna's unused hair bands.
On Friday I dropped off two water samples for testing. One is untreated well water, and the other is water that was run through the filter. Yesterday, Monday, I called for the results - 27 choliform in the well, and 14 after filtering. Disappointing, as that's three times the safe limit, and I expected the filter to be flawless! I will tighten up the fittings as best I can, and re-run the test.
As we use and experience this filter more, I will try to give updates.


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