Coliform bacteria! This sounds scarier than it really is. But we still were concerned when a water test showed that our well water contained these potential nasties.
Potential, because coliform bacteria are ubiquitous. Only certain types, like E. coli, can make you sick.
However, coliforms are used as "indicator organisms" for the possible presence of more dangerous bugs, as this helpful Oregon Department of Human Services bulletin discusses.
After we had our well pump pulled and replaced, we had our water tested. We do this every year. This was the first time coliform showed up. The lab only reported "present," not the estimated number, as that takes culturing (more time and expense, so not done unless you ask for it).
I did quite a bit of Googling "coliform bacteria well treatment" before concluding that we really should treat the well.
On the one hand, I read that 35% of wells in Pennsylvania were found to have coliforms, so this shows that they're usually harmless, since a third of people in that state aren't sick, so far as I know.
On the other hand, I kept seeing references to coliforms being a potential sign of much more serious (and less easily detectable) bacteria.
Not wanting to feel like I was taking my life into my hands every time I rinsed an apple (we use a reverse osmosis system for drinking water), yesterday a couple of guys from Sippel Well Drilling shocked our well. Not with electricity – with four cups of Clorox.
If you're thinking of treating your coliform infected well yourself, my advice is: Don't. Let a professional do it, the first time, at least. Once you learn the tricks of the trade, you can probably repeat the process on your own.
First, we needed to have an outflow installed on the pump housing. That's the valve on the left side of the photo. We didn't have a way to drain water directly from the well, and that's necessary (or highly desirable) for treating it.
The guys told me a story about going to a home where quite a few Clorox bottles were stacked by the well. The owners thought that more was better, which it isn't. Too much bleach can screw up your well. You need to know how much chlorine is needed, based on how much water is sitting in the well.
That's pretty easy to figure out, if you know some basic facts about your well. So step 1 is to pour bleach into the well. The guys didn't dilute it, though this often is recommended to avoid harming metal parts.
We shut off our house water, and bypassed our water treatment equipment. We didn't want to have bleach running into our septic system. Hopefully treating the coliform in the well, piping to the pressure tank, and the tank itself will take care of the problem.
Next a hose was connected in a loop from the newly installed valve back to an adapter that squeezed water back into the well, down the vent opening (on the right of the photo) where the bleach went in. The adapter was needed because the opening is so small.
This is a crucial step, because the bleach needs to be circulated in the well. Otherwise it'll just sit on top of the water. The Sippel crew ran the water until a high level of chlorine showed up on a test strip. That meant the bleach had reached the pump down at the bottom of the well.
Then we shut everything down and let the chlorine do its thing – eight hours minimum we were told; we decided to wait until the next morning, about 18 hours, partly because it was going to be easier to do the final steps in daylight.
Which were: (1) attaching a hose to the well housing valve and running water until it looked fairly clear, with no chlorine evident on the test strip, and (2) running raw water from a hose down at our house, to flush out the pressure tank and the pipe leading from the well to the tank.
There was quite a bit of magnesium (black flecks) showing up in the water at our house. So I decided to run our sprinkler system for a couple of hours, figuring that the system filter would catch most of the crud and that we might as well get some use out of the water we were flushing out of the well/pipes.
I suspect the flecks were dislodged from the piping somewhere along the line, given the strong air bursts after we started using the well again.
Things seem back to normal now. But with our complicated water treatment system and crappy well water, "normal" is always a precarious condition.
We were told to retest the water, both a raw sample and treated, in five days. This time we'll get a culture test done, so if we still have coliform bacteria we'll know how many.
It was a judgment call to not treat the house water lines. We might end up having to do this. But since it's a more complicated procedure and the chlorine could harm our septic system, we decided to start with a conservative bleach treatment – which also was the advice of the Sippel guys.
If you've got a similar problem, hope this description helps. We country homeowners have to stick together.
City folks don't realize what it takes to keep your own water and waste treatment system functioning, not to mention dealing with all the other complexities of rural life.
But a few hours ago a deer with two super-cute fawns wandered across our yard. Moments like those make memories of chorine and coliforms fade away. Fast.