Got my drinking water tests. Now, to interpret

I just got my well water tests back from the lab at U.S. Oil (! I know, but a reputable water testing lab according to our local Conservation Dept.).

No explanation sheet was included, and their web site is of no use. I sure would like to know what the results mean; I’m too impatient to wait until Monday, and an hour of googling didn’t turn up exactly what I had hoped for. Surely there are a handful of biological/chemical types among Dopers that could help?

My well is a 330-ft driven well, cased to 170’ and using a submersible electric pump. The water samples were taken from the cold faucet in the kitchen, early in the AM, without running the water much first (so lead was probably at its peak level). Bottles were supplied by the lab. Four tests were run on 3 samples.

The results:

Nitrogen (nitrate) = 0.0056 mg/l
Coliform Total = safe
E. Coli = safe
Lead = 1.4 µg/l

The US standard for Nitrates (max) is 10 mg/l, so it looks like I have no worry in this department. This very low-level contamination could come from nearby septics and/or miles-away farms.

I assume “safe” means “zero” but I wish they had quantified the Coliform & E. Coli numbers.

The lead puzzles me the most. The Fed max is 15 parts per billion, which I believe translates to 15 µg/l. My level is about 10% of that. But how close to dangerous is 10%? Is this a linear scale, and this is one-tenth as dangerous as 15 ppb?

And is lead exposure cumulative, so in 10 years of direct drinking from the faucet, I would get 100% of the max?

I have no children using this water at present, and rely on a Brita Filter for drinking & cooking purposes; Brita claims to remove 98% of lead. That sounds pretty darn good.

Still, I wonder. Any advice? Much appreciated.

Although Cecil himself is pretty reliable, anyone who drinks water because some clown on this site says it ought to be safe needs more examined besides their water. Wait till Monday and try your local water or health dept.

Correct…Coliform & E. Coli are bacteria. The lab tries to grow them using your water as a “seed”. They either grow or they don’t, no numbers involved.


The danger associated with lead is, indeed, from an accumulation over time. However the drinking water limit is set taking this accumulation into consideration. It is also set well below any level which is presently considered to constitute a risk. So even if your water contained 14.9ppb, it should still be safe to drink. Your water is just 10 times safer.

Remember that the concern about lead began with babies (who are at a considerably higher risk than adults) eating paint chips. But paint chips used to contain as much as 50% lead by weight. (Thats 500 million ppb.)

This site:

contains a lot of information. Be warned though, it lists all the things that can be wrong with lead and so could be a little on the alarming side.

Some Clown on this Site

Gee, what did I do to deserve that?

Since I have been drinking the water from this well and/or ground-water source for a few decades with no obvious evil effects, I doubt if I am acting foolishly by doing it for two more days. And yes, I will contact the proper authorities, but opinions expressed in SDMB are welcome, too.

After all, we have some smart, educated and experienced people on this Board. I respect and admire them and I appreciate their advice.

And thank you, zigaretten, for your good link and comments, in spite of your clown makeup. From what you say, it seems an E. coli level of “safe” means “zero bacterial colonies grown” and that’s the ideal.

Does anyone happen to know a site that shows the same specs for municipal water from various cities? It might be interesting to compare.

If you want to compare your water with City of Chicago water you can at this site:

-Just call me Emmet

Here are the Canadian Drinking Water Guidelines. Click on any of the parameters to go to a PDF file with several pages of info on each of them.

Just a note. There was a scam done in our neighborhood a few years back. An official-looking truck with a logo similar to county vehicles went down the street hanging a water-testing kit from each mailbox. The kit was complete with a little sample bottle and ominous-sounding literature about all the little nasties that could be in the water. Homeowners were asked to fill the bottle, fill out a bunch of forms (which asked a lot of personal info), then leave the kit hanging from the mailbox again for pickup. The literature went to great lenghts to masquerade as official correspondence from our county heath department. But it wasn’t. It was a scam by a local water purifier salesman.

No matter what was put into the bottles (investigators filled some with purified spring water), a letter arrived saying the water was contaminated with nasties and recommending that the company come by to discuss “purification options” to “protect the health of you and your family”.

Just FYI.

Yes, gingersnap, that’s good advice. A few years ago we had a similar operation in my neighborhood, but the names on the literature did not include any claims that I couldn’t verify. No claims of government agency support was made, but the company was obviously trying to sell water treatment systems.

Nevertheless, since the test was free, I submitted a sample on the appointed day. It came back as pure and safe enough to use, although with a ton of literature touting their treatment products. Why anyone would want to use their products after that kind of test result, I don’t know.

Since the sample I submitted did not come from my tap, but was commercial bottled water, at least the test wasn’t phony. Others in the neighborhood got acceptable results from their well test, although a high, but safe, iron content is to be expected from our wells. Most people have water softeners on their house systems to minimize this annoying characteristic – it is perfectly safe to use, but leaves rust stains in tubs & toilets over time. The very, very slight color & smell, plus my desire to avoid clogging the coffee maker, is why I use a Brita filter for critical purposes.

As far as my current test, it was sponsored by our local Door County Soil & Water Conservation Department. They arranged for a reputable lab to accept all our samples on a single day and provide test results at nearly half of a typical lab charge. I think they also chose which tests to offer based on knowledge of nearby conditions and past problems. About 200 local residents took them up on their offer; I haven’t yet heard results from others. I am going to encourage them to read this thread.

So I’m pretty sure this test was legitimate, but it’s wise to be careful!

And mmmiiikkkeee and Yeah, thanks for the links. The Canadian site is a good reference for severe detail. And compared to Chicago water (even the raw lake input!), mine is pretty darn good, although I never before thought of Chicago city water as a standard!