Has anyone had experience in using UV light to kill E. Coil bacteria in drinking water?

Question

Water test results show our water is contaminated with E. Coli bacteria. I'm considering installing a UV light filtration system, and wonder if anyone has had long term success in killing E.Coli bacteria. Our water source is a mountain stream running through our property it is fenced to keep stock out of the water. But becomes contaminated from pasture runoff. Our other option is chlorine treatment in the water tank. not my preferred option.

Answer 1

If you're avoiding chemical treatment because of the chlorine taste and smell, you also could consider using bromine.  I've seen UV treatment in meat packing facilities, but it's not 100% effective.  A slightly more costly, but very good system is reverse osmosis, and all of the excess water can be returned to the stream (only part of the inlet for RO units is actually purified, the rest is discharged to a drain).  Solar distillation is another option, however winter feesability could be an issue due to freezing temperatures in the mountians.  Heat treatment is generally not prefered for home use due to high energy usage.  

I'm most fimiliar with bromine treatment in an automatic feed system.  The bromine addition is done via a bromine cartrige with a metered feed rate.  Each cartriage typically is good for about 100,000 gallons (the ones we used), but i'm sure diferent manufacturers are different.  Bromine is nice because you really can't taste or smell it, and fumes are much less toxic.  For water used in the lawn, and garden, no sanitation would be required.  The company we used for water purification and distribution were Village Marine and Aquapro.

Answer 2

we live on a lake & the UV lighting is what is used, but i have no idea about how a person installs this, i know it's done under the water at the intake source, i don't  know how to go about putting in in a stream, i assume that you do, tho.

Answer 3

UV light is my vote. Bromine is very dangerous, expensive, and is harmful to many types of water pipes, over time causing leaks. Another option i didnt see listed is installing an "ozonanator" to purify your system, but that can only be used if all your plumbing pipes are plastic, specifically, PVC schedule 80. RO or "Reverse osmosis" is not an option for you because it is EXTREMELY expensive to have a whole house RO system installed, they are usually just good for under the sink drinking water etc. Ive had very good luck with UV light filtration, as have many of my customers whose plumbing ive worked on, customers including Armor Swift Eckridge, McDonalds, Pepsi, and Coca Cola, and BNSF railroad. Only done a few UV lights for residential units, but all have had very good results, below is a quotation taken directly from the EPA website and below that is the link you can check for yourself. Best of Luck.

"If my well is contaminated with E. coli, what can I do to protect myself?"

If your well tests positive for E. coli, do not drink the water unless you boil it for at least one minute at a rolling boil, longer if you live at high altitudes. You may also disinfect the well according to procedures recommended by your local health department. Monitor your water periodically after disinfection to make certain that the problem does not recur. If the contamination is a recurring problem, you should investigate the feasibility of drilling a new well or install a point-of-entry disinfection unit, which can use chlorine, ultraviolet light, or ozone.

Answer 4

It could also be contaminated from beavers building dams further up hill. Their droppings can have cysts that  can make you deathly ill. You need to be cautious as to how you attempt to purify the water.

There are commercial UV systems that put intense UV bulbs inside quartz tubes that go into the water. They need a lot of control to make sure that the UV is still coming out strongly (lamp output tends to degrade) and that water is running to cool the lamps. There needs to be a tank for the raw water which goes through the treatment before heading to a storage tank. Those features tend to make the systems pricey. Call your local health department and see if they have recommendations (including names of neighbors who have successfully run UV systems). You typically need a chlorine system as a backup or you will have no water if the UV part fails.