Well Questions - Shock Chlorination and Hardness Treatment Suggestions

[Nona]

Hello,

We recently made some repairs to our well. The pump gave out and was replaced and the 6.25" steel casing was sleeved with a 4" PVC pipe to attempt to reduce the amount of sediment and iron in the water. We were told by the health department that we would need to shock chlorinate the well after the repairs to destroy any bacteria. Since there were no bacteria present prior to the repairs, we didn't think we needed to do this.

We just got our water test results back and, sure enough, there is coliform bacteria present in the water now (although fortunately no E. coli). We have been reading a lot about shock chlorination and the instructions vary from site to site, with the chlorine to sit in the system for anywhere from 12 to 48 hours. My first question is:

1) Is there any harm in leaving the chlorine in the system for 1 week while we are on vacation and then flushing it when we return? Is 12 hours really long enough for this type of treatment?

The other question I have relates to water treatment systems. Based on our recent water test, our water is as follows (values above recommended limits are starred):

Harness: 220* pH: 7.1 Iron: 0.26 mg/l (the PVC sleeving process cut this in half from a prior reading of 0.47 mg/l) Manganese: 0.26* mg/l Sodium: 14 mg/l Calcium: 74 mg/l Chloride: 11 mg/l Sulfate: 11 mg/l Small amounts of lead, copper, zinc and toluene (far below the hazardous limits)

The system I am thinking of using is the Puritec MC Series Complete because I like the idea that it can soften water without the use of salt and is pretty much maintenance free.

No contractors we have talked to have ever heard of these Puritec systems and there is almost no data on how effective they are. My other questions are:

2) Is the Puritec MC Series Complete a reputable brand?

3) Does anyone have any suggestions for treatment systems based on the above water test results?

Thank you!

[Clot]

You've just had a liner added that has been manufactured and installed by man. You must therefore expect coliforms.

Absolutely none. A week should be good provided chlorinated to above 40 mg/l., I'd rather 100ppm - sorry mg/l. I am personally sceptical of only 12 hours soak dependent upon conditions. Take your vacation, enjoy, - and flush on your return.

Those numbers seem fair to me.

Cannot advise you of equipment that side of The Pond. My main concern would be about bugs not the minerals.

HTH

Clot

[justalurker]

free.http://www.puritec.com/store/moreinfo.cfm?Product_ID=258>

The words "water softener" or "soften water" are conspicuously absent from the Puritec web site because they do not offer a water softener. The Puritec may "condition" the water in some aspects as a filter but it will not soften the water.

To "soften" water is to remove calcium (among other things like iron) from the water and that is commonly done by one of two methods.

One method is ion exchange as done by a water softener. A water softener exchanges either sodium ions (if using NaCl) or potassium ions (if using KCl as a SALT SUBSTITUTE) for calcium (and other) ions in the hard water. That's it, no ifs, no ands, no buts, and no sales double talk. Simple chemistry and physics. Softening water is not black magic. It is physics and chemistry with a side of mechanics. No matter how hard sales people try (and want) to they can not violate the laws of physics or change the nature of chemical actions and reactions.

The other is by a filter and/or membrane technology or distillation, but no simple filter will remove calcium. You would need a reverse osmosis unit large enough to service your entire house. You would not want to pay for that big an RO nor pay for the service and routine maintenance it would require and RO water would be very aggressive in your plumbing and it would waste a lot of water.

NO magnet(ic) gizmo or electronic gizmo or "conditioner" will soften water but people waste their money on them EVERYDAY.

Check out this URL for one story

and there are many more on the net if you Google.

Pick the right softener (not a box store brand), size it properly for your water conditions and usage and the SFR of your plumbing, and get a competent install and you should go 15-20 years.

[Chris Lewis]

I'd say _probably_ none. While it's pretty darn dilute, chlorine does attack copper and other metals. Very long dwell times may not be a good idea, or at least, if you've guessed at the bleach amount, and put in way too much.

The Ministry of Health of Ontario has the following detailed instructions on how to shock a well:

The above says 12 hours. Previous iterations said 24 hours IIRC - they must have had good reason to reduce it.

Ontario's MoH advisories of this type are pretty much on the ball, so I'd trust the 12 hours given.

[Rick Blaine]

Wrong - as you discovered. When you open the well, bacteria in the air and on the material (pump, pipe & wiring) will contaminate the well.

Total Coliform is a tracer. Although not dangerous in itself, it's an indicator that there could be other bacteria present that is dangerous. It's easier and cheaper to test for total coliform.

No harm at all. The times quoted are minimums. The lower amounts are based on ideal pH and temps. If you get outside the normal pH & temps, or if you have a problem with iron, it takes longer to completely sanitize the well.

[Charlesmurphy via HomeKB.com]

[Clot]

In my response, I included "and flush on your return". The amount of damage that chlorine will do to the structure of the pipework over a week is minimal and need not be considered.

[Nona]

Thank you all for these detailed and thoughtful responses! I will be reading the links and thinking through the other information you posted. For now, we will plan on a 1-week shock chlorination, being sure to measure the bleach very carefully. I also have a lot more to think about with regard to the "softening" systems after reading justalur's post.

These are the moments when I wonder what we ever did without the internet. I am still in awe that I received such great responses from an international consortium of experts in less than 24 hours!

[Gary Slusser]

Over the last 21 years I have shocked many wells. Shocking a well is at best a temporary fix. It can cause serious and expensive problems with the water quality, pump, electric cable, drop pipe and casing etc.. More chlorine is not better. Chlorine raises the pH of the water which decreases the disinfection properties of chlorine. Allowing a well and pump and your plumbing to sit in chlorine is not a good idea. Chlorine damages metals and power cable insulation etc.. And bleach is heavier than water, so the bleach settles to the bottom of the well and sits there doing nothing for the rest of the plumbing system unless you use water.

If you get around to buying equipment, seriously consider buying online and if have the desire and tools to install it yourself (it is simple plumbing), you'll save a lot of money and get as good or better equipment while preventing yourself from becoming dependent on a plumber or local dealer.

Gary Slusser Quality Water Associates