Thread: Water quality
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Old 03-26-2014, 01:54 PM   #1
jungpeter
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City: Everett
Country: US
Vessel Name: SPIRIT BEAR
Vessel Model: PACIFIC TRAWLER 40
Join Date: Mar 2013
Posts: 146
Water quality

There's a good thread running on 12VDC watermakers. So as not to hijack that thread, I'll pose a related question. Given that most folks recognize the luxury of making their own water while underway, what precautions are folks taking to ensure the biological quality of self-made water?

City water used to fill a water tank is typically safe to drink as it comes out of the tap. It has passed through multiple filtration systems, and is also typically routinely tested and chlorinated. That doesn't mean you can automatically trust dock water at a marina, although most of us do. That doesn't mean it stays safe in our water tanks, although many expect it to.

A watermaker will desalinate water to a drinkable level. Raw water filters for sediment and (less often) oil are typically used to preserve the membrane's health. However, no reverse osmosis water maker will remove the bacteria in the raw water being used to create fresh water. The bugs are just too small and will pass un-molested into your water tank.

My doctor went high-order on me last spring, and insisted I install a water sterilizer on the output from my fresh water tank. She immediately grasped the concept of making water, and listened carefully to my standard operating procedure of only making water when I was reasonably sure it was "clean". She then reminded me that one cannot assess the degree of "cleanness" of water by simply looking at it, smelling it, or tasting it! MAKE SURE THE WATER IS STERILIZED before you drink it, she yelled. OK, OK, I get it. I put in a 40W 110VAC sterilizer, and trust that it works!

By way of example, the City of Victoria, BC (population 78K as of 2006) was ordered to treat their raw sewage in 2006. They have yet to do so, and the projected date for their sewage treatment plant is 2018. This is an example of how tough it is to tell if the raw water you are using to make water aboard your boat is safe. Would you make water in the vicinity of Victoria, knowing they discharge their raw sewage (yeah, that's UNTREATED, RAW sewage) directly into the Straits of Juan De Fuca? Nope, not me. Ditto as I pass by the many small shoreside communities, marinas, fishing lodges, etc. in WA state, BC and Alaska.

I guess the overall point of this post is to suggest there's more to the water making issue than simply voltage, current, DC vs AC, gal per hour, etc. One cannot always make water when you need it! And, given the difficulty in actually measuring "consumability" of water, it can't be done with a salinity meter. Having said that, I have a watermaker aboard. I use it regularly. I use it judiciously, in what (I hope) is good water. And I sterilize it immediately prior to consumption. So far, so good. YMMV.

Regards,

Pete
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