Well Water Problems and Chlorine Shocking (Long!)

Long saga below, thought some of you plumbers, homeowners, and DIYers might find interesting and/or have some thoughts to offer.

We built our house in 1984 and have a well and standard septic system.

The well isn't that deep--around 120' and they hit water around 30'. Well driller said we're on a north-south stream and had a flow rate of something like 22 gal. per minute, and should never run out of water. Water has always been good when we've had it tested, except hardness, which was around 10-12 grains when the well was new. My father-in-law, who did our plumbing, recommended not getting a softener. He said if we cleaned the sediment out of the electric water heater every other year we'd be fine. And that's been pretty much the case. Our first water heater lasted about 20 years, and we have to clear some mineral deposits off the faucet aerators now and then.

Last December we replaced our well pump for the second time. We had the usual discoloration after that was done, nothing serious.

A couple months ago we noticed a sulfur odor in our hot water. Our plumber replace the anode rod in the water heater, which fixed the problem...for a few weeks, then it came back. The plumber changed the anode rod again just to be sure--he said when he picked up the first one, it wasn't in a container indicate the type of metal, so he had to trust the plumbing supply guy's word that it was an aluminum rod. While here, we discussed putting in a treatment system, and he took a water sample and had it tested for hardness, but didn't check for bacteria. He suggested we do a peroxide cleanout of the hot water first, then have a full test done.

We did the peroxide cleanout earlier this week. For a 55' gal water heater it takes a large bottle of peroxide. Pretty easy, all you need to do is drain the tank, add the peroxide, refill, and let sit for three hours. Then drain the tank again, refill, and flush the hot water lines. This got rid of the odor. I was still concerned about the bacteria, though, and decided to stop by the well-driller's place the next day and get the full test kit. I took it back later the same day. They called Thursday and said the prelimary results were no e. coli (good) but high levels of other bacteria (bad, but since we've been drinking the water, not harmful--yet!) They recommended doing a chlorine shock right away. They won't have the full test results till next week, after which they'll recommend what type of treatment we need for the bacteria--infrared (I hope) or chlorination. We'll get a water softener as well.

So, we started the chlorine shock last night. Downloaded the instructions from Penn State Ag Extension website. One thing we noticed, the instructions mention that household bleach is usually around 5.5% available chlorine, but the generic bleach my wife had on hand was 7.9% available chlorine. Glad we checked. We reduced the amount of bleach accordingly. However, once we had it down the well, and started running the hose down the well to mix the chlorine and pull it into the house water, it took a long time to even detect a chlorine odor. We ended up adding another pint of bleach, which brought us back up to the amount recommended in the instructions anyway.

Before we did anything else, we also shut off power to the hot water heater, since we'd be flushing it out anyway.

We then ran all the faucets in the house till we could smell chlorine, which took a little longer than I expected, then let everything sit overnight. We finished at about 7:30 pm. The instructions said to wait at least 12 hours before continuing.

So around 9:30 this morning (14 hours) I began running the hoses outside to flush the chlorine from the well and pressure tank. It took two hoses running nearly 45 minutes (took a couple breaks to give the well and pump a rest) to run without odor. Drained onto the driveway and street out front, and a large bare piece of ground out back (although instructions said you could sprinkle on grass).

Then started flushing the cold faucets inside. Didn't want to put any more chlorine down the septic system than we had to, so we bucketed the water out of the laundry and kitchen sinks and dumped it in the driveway. Once we had the first floor clear, the upstairs faucets cleared out fairly quickly, about 5-7 minutes. For the hot side, I drained the water heater into our basement floor drains (which empty above ground way down the backyard). Filled the water heater again and let it drain again. I made sure we left a hot faucet open upstairs to allow air to enter (drains faster that way) and exit when refilling. Then we flushed the hot faucets out, which didn't take quite as long as the cold faucets.

Finally, we turned the power back on to the hot water heater.

Tonight and tomorrow, I'll activate some dry yeast and flush down a commode, to help offset the chlorine we put into the tank today. That's not in the shocking instructions, just my own precautionary step.

So that's it. Now we wait on the rest of the bacteria tests. I plan to retest the well for bacteria in two weeks, and again two weeks after that, to see if the bacteria level is coming back. Then we'll make a final decision on treatment.

We'll never know for sure, but I'm curious what caused the odor and bacteria problem now...dry summer, causing lower water table? Contamination when we changed the well pump? I've read some places where anytime the well pump is pulled you should shock the well, but we've had the pump pulled a couple times (first replacement, and one or two other times for wiring checks when the pump wouldn't run), and never had any problems. I realize we'll never know for sure.

So that's it...any thoughts--especially on treatment options--will be appreciated.

There's a good possibility that you had an iron eating bacteria in the well.

https://en.wikipedia.org/wiki/Iron_bacteria