What is the best most thorough method of testing one's water?

January 25, 2010 12:45 PM

I am thinking about cultivating a small vegetable patch area near a river. What would be the best method to thoroughly test the water for nasty contaminants like arsenic, lead or other spooky chemicals I can't even pronounce?

Dear Hive Mind,

The area is pretty much off grid, no utility lines what so ever. I am thinking using small amounts of river water for irrigation purposes for organic raised beds of vegetables.

A lot of the kits out there are very simple, testing only a minor amount of chemicals. If I am going to consume what I grow I need to be absolute positive that the water is decent.

Water P.H levels would as well would be great.

Thank you so much for your time,

posted by Sentus to home & garden (18 answers total)

You might also want to test the soil! What has this place been used for previously? If you're in the US you can call your local Agricultural Extension office or your local health department to find out about water testing.
posted by mareli at 12:49 PM on January 25, 2010 [1 favorite]

Testing river water for contamination is one of those things that might be of limited utility, depending on what river and where. If you're downstream from mining operation you could get constant leaching, but if you're downstream from Hank's Unethical Battery Recycling and Donuts, everything might look great today. But next week, after Hank had to run down to the shop, late at night, to "get something he forgot" the results might be different.

I have seen information on line for wells where the water collected was used for public consumption. I would imagine that something similar existed for rivers and lakes, but I don't have a URL for you.
posted by Kid Charlemagne at 1:00 PM on January 25, 2010 [2 favorites]

Additionally, if you are in the US, you can get detailed watershed information here - all you need is your ZIP code.
posted by jquinby at 1:02 PM on January 25, 2010

How detailed do you want to go? There's this one from Discover Testing that looks for 77 items including arsenic, lead and many hard-to-pronounce chemicals. It's a little costly, but thorough.
posted by Tooty McTootsalot at 1:05 PM on January 25, 2010

You may also be interested in EPA's My Environment site.
posted by Tooty McTootsalot at 1:07 PM on January 25, 2010

Kid Charlmegne makes a good point. Perhaps there are local water engineers (is that the right term) who can give you better advice than the people here.
posted by dfriedman at 1:09 PM on January 25, 2010

If I am going to consume what I grow I need to be absolute positive that the water is decent.

This just isn't going to happen. There are many nasty things out there that could, at least theoretically, be found in water. You can't test for them all and even if you could, it would be prohibitively expensive. Also, just because the water tests clean one day, doesn't mean it won't be contaminated another day. You can reduce your risk by testing, but you can't eliminate it.

It would be very useful to think about what is upstream of you and what contamination that may cause. It is very difficult for people to provide you with useful answers here without knowing anything about the river and the watershed.

Finally, there is a lot of testing already going on and there may be data available for your river. Check with municipalities and higher levels of government, environmental groups, and any possible industrial emitters.
posted by ssg at 1:28 PM on January 25, 2010

I know that you plan to divert only "small amounts" of water from the river, but the legality of doing this varies widely by state. Especially in the western states (Utah, Colorado) water rights are so tightly regulated and complicated that rain barrels can even be illegal. (Colorado, I'm looking at you here.)

As for testing, if you're within city limits, it's likely that a lot of people are testing your water. For example, if you were in (to use a random example I found on the internet) Sedgwick County, Kansas, your water would be tested by: The City of Wichita, Sedgwick County, the Kansas Department of Health and Environment, the Kansas Department of Wildlife and Parks, and the United States Geological Survey. Perhaps you can check with the analogues in your area?
posted by purpleclover at 3:39 PM on January 25, 2010

As a civil engineer that mostly specialized in hydrology you can't ever be sure. Also any contimants in the water may be quite natural depending on the mineralogy of the watershed.

If the site you are using isn't contimated by something that the plants can metabolize (not all toxic/dangerous substances can be taken up by a plant, and not all of those will make it into the part you are eating) any small amounts in the water are not likely to be dangerous.

The easiest way to estimate the danger is to look into the history of the site and the watershed. Was there any heavy industry upstream? (this could include sawmills, smelters, mining, quarrying as well as manufacturing). If so how long ago and on what scale? On a long enough time line all pollution reduces to background levels. Of course this could include many thousands of years. Your county extension agent is the best place to start (call the main line to the county public works to get this number). iF the area is off grid without utilities it is very unlikely you will get dangerous contimanation in the stream. You could always get the test done that is required to certify wells for drinking water quality-this will pick up most dangerous contimates (especially pathogens). Good luck and enjoy your new self reliant lifestyle.

Don't be too paranoid about this stuff, the hype is often overblown and sooner or later somthing will get you-have fun in the meantime.
posted by bartonlong at 3:50 PM on January 25, 2010

Most of those metals don't exist in your average streamwater in any great concentration (unless of course you're directly downstream of a mine as mentioned above) but they do accumulate in the streambed and floodplain sediments, which presumably includes your vegetable plot (and they bioaccumulate and biomagnify in creatures that live along the river). If you have any reason to suspect nastiness, you want to test the sediments and soil, not just the water, and, as others have said, a single grab sample of water provides minimal information about what's in your water. At the very least, you should Surf Your Watershed as mentioned above, which will help you find out who is already testing water in your watershed and what pollutants your stream is listed for. And if you're going to test the water, get a grab sample of the stream in stormflow as well as at baseflow.
posted by hydropsyche at 5:12 PM on January 25, 2010

The Cooperative Extension Service has tons of soil quality and water quality data. And gardening info.
posted by theora55 at 5:36 PM on January 25, 2010

2nding baronlong. Unless you have reason to believe your water/soil are contaminated, I don't see why you'd let the risk of spooky chemicals keep you from gardening. Public information is your friend. Are there upstream NPDES dischargers? Are there any CERCLA/Superfund sites nearby? How about Formerly Used Defense Sites? Landfills? Etc. If you can answer no to these questions, then I'd say good enough.

I tend to disagree that bioaccumulation of metals would be a concern. Bioaccumulation is a problem with fish because big fish eat the little fish that eat the littler fish that eat the plankton that absorb the metals. By the time the flounder gets to your dinner plate, it's loaded. To my knowledge, vegetables don't really work this way.
posted by gueneverey at 5:37 PM on January 25, 2010

I know that you plan to divert only "small amounts" of water from the river, but the legality of doing this varies widely by state.

This

My midwestern father asked the realtor for a small property in eastern washington something along the lines of, "So I can just take water from the river, right?" and the agent laughed in his face. In a lot of places, water rights are complex and dearly fought. No idea what the situation is where you're located, of course. Don't even know what country.

However, there is not, to my mind, any moral problem to what you propose and, were I in your shoes, my second thought after, "Is this water going to kill me?" would be "how do I not get raise a stink?" If you're in the US, the answer is contacting your county extension agent. Extension agents are a lot like EMTs and such in that their job specifically precludes any enforcement role. And, if you're lucky, your agent will know about Hank's Unethical Battery Disposal Service and be able to give you nudge-nudge-wink-wink advice about it. The other sources mentioned are great sources of information but they have the unfortunate risk of potentially drawing unwanted attention. The extension agent minimizes this possibility and, I don't know about yours, but mine is happy to answer anonymous "hypothetical" questions about what's legal.

The civil engineers and hydrologists upthread are absolutely authorities on this sort of issue and I would trust their advice w/o hesitation but I'd prefer my interaction be mediated by the extension. I say this as someone whose absolutely legal, inspected, and permitted-within-an-inch-of-their-lives activities* still drew drew complaints and a hassle, draw as little attention as possible.

* which were also conducted to a far higher standard of humane-ness, safety, and environmental stewardship than the EPWSUSDAHSA come close to requiring, because that's how we roll.
posted by stet at 6:09 PM on January 25, 2010

I think one of the things that you would not be able to test for any random day but could be quite harmful is a pathogen like e.coli from sewage or farm runoff. You might never even hear about it, but your vegetables could still be contaminated.
posted by oneirodynia at 6:34 PM on January 25, 2010

I tend to disagree that bioaccumulation of metals would be a concern. Bioaccumulation is a problem with fish because big fish eat the little fish that eat the littler fish that eat the plankton that absorb the metals. By the time the flounder gets to your dinner plate, it's loaded. To my knowledge, vegetables don't really work this way.

I mentioned bioaccumulation incidentally because I thought the poster might be interested in such an issue since they seem to know very little about aquatic ecology, not because it has anything to do with vegetables (hence the word "creatures"). And because I tend to overexplain things.

oneirodynia is correct that coliform bacteria are another consideration (possibly a greater one than metals), and they are something that might be more likely detected in a stormflow grab sample, rather than baseflow.
posted by hydropsyche at 7:29 PM on January 25, 2010

If the area is a flood plain you probably don't need to do raised beds because the soil should be pretty ideal as is. That is going to reduce your need for water quite a bit right there.
posted by fshgrl at 9:28 PM on January 25, 2010

The thing about E. coli is that it's everywhere and many tests out there won't tell the difference between the 100 trillion E. coli cells currently sharing my desk chair with me and the ones that will kill you (which in most cases is kind of the point).
posted by Kid Charlemagne at 10:15 PM on January 25, 2010

A significant amount of E.coli of any sort is an indicator of fecal contamination; it doesn't particularly matter if you can figure out if it's the bad kind or not if you prefer to avoid eating vegetables watered with raw sewage as a general principle (or more of an issue, feeding it to kids or immuno-compromised people) . Anyway, my main point is that with sewage spills you may never know that contamination has occurred because they can happen sporadically. So any pre-testing for heavy metals before planting the garden is not going to turn up the sewage spill that happens six weeks down the road.
posted by oneirodynia at 4:50 PM on January 28, 2010