We are an elderly couple. We use water from a well. We live in a fairly remote area, lots of woods and trees, not densely populated. We had our well water tested when we first moved and though e coli were present the count was low, and since anything that has a gut is an e coli host we didn't treat the water. No ill effects.

Then a couple of years ago I bought a little UV water sterilizer. It's for outdoorspersons, campers, hikers and the like. Runs on 4 AA's and will sterilize either .5 liters (16 ounces) or double that volume. Then I filter the drinking water through a carbon filter. The result is delicious sparkling clear water.

In December my husband went on chemotherapy and I started boiling the drinking water. This is not energy efficient and is a bit of a nuisance.

I plan to test a sample of the UV treated water but have to wait till I can take a sample to the city. No testing facilities in our town. The lab will only accept water that has been freshly collected and kept cool, so I can't mail or courier a sample.

Is UV treatment sufficient for sterilization?

Babs, I know that UV treated water can be very effective, but I don't know what system you are using or how you are using it. These things matter very much toward the overall effectiveness.

Here is a PDF file that discusses UV treatment and how it works.

Besides that, you will have to provide a little more specific information.

Very interesting article, Sher. I wondered about how deeply uv penetrates water but they explain that the water usually passes through teflon tubes during irradiation. They claim up to 99.9% reduction in bacterial count at the point of sterilization, but they recommend periodic lab testing and periodic sanitization of the equipment.

Babs, I'd worry about your battery-operated unit not having the wattage to handle the flow. The article also points out that mineral deposits (common with well water) may further reduce the effectiveness of the system. And some organisms, like Giardia, are resistant to uv.

Is store-bought bottled water sterile, or nearly so?

Another possibility: Hospitals use large bottles of Sterile Water for Irrigation. Perhaps a clinic or distributor in your area could sell you a few cartons? Unfortunately that would probably be more expensive than boiling your well water.

Before I posted the question I tried to figure out the wattage. But on the accompanying documentation there were no specifications.

Here's their website.

Sher, your website mentioned that UV is not suitable for killing the bigger 'bugs' e.g. protozoa, because the UV doesn't penetrate larger objects -- it can't reach their DNA -- but it can sterilize viruses and bacteria.

The site for SteriPen claims it does destroy the larger organisms. This is the sort of claim I'd like to check with an independent source.

Meantime I think I'd better keep boilig water!
Perf, there have been cases where bottled water is polluted, unfortunately. And bottled water is very cheap. It's just that I'm quite the energy nut, using low-energy-consumption products on principle. But when you compare bottled water vs. home-boiled water, I wouldn't be surprised if the latter is more efficient, when everything is factored in.

But rechargeables are more efficient yet.

The instructions for the care of the steri-pen do include cleaning the stirring rod of particles or deposits.

Thank you both for your help.