How can I tell if my local river is degrading?

Anonymous asked this question on 5/15/2000:

What is the best way to go about testing local waters (such as creeks)for pollution? And what chemicals should I be testing for (pH, ammonia, alkalinity, etc.)?

JesseGordon gave this response on 5/15/2000:

The basic items to measure are:

A) "DO" = dissolved oxygen, a measure of how healthy the water is, and how much cellular activity there is.

B) "FC" = fecal coliform, which comes from mammalian feces. That measures sewage or animal runoff, and is the primary reason waterways get closed for "health reasons" (swimming in excrement gets you sick).

C) "pH" = Acidity. Too acid, or too alkaline, and fish die. Chemical pollution often affects pH, so it's a good measure of general chemical pollution.

D) "Turbidity" = how much silt and mud are in the waterway. This measures if there's been too much logging or road construction upstream, which deposits lots of silt. Too much silt and the fish die, because they spawn in the crevices between rocks which get filled in by silt.

You can read my study on one river (Buffalo River, in Arkansas) which uses those four pollution criteria, at . Look at chapter 4,, for a summary, or the appendices on pollution for nitty-gritty details.

Are you just starting a long-term pollution study? Or do you have some data already?

If you have data already (data collected by the Park Service is what I used in the study above), of course you should use whatever they have, since the best data spans a long time period (I used 4 years in that study).

If you're just starting, the basic procedure is to pick a dozen collection points (we used 20-odd points on a 200-mile river, all selected at the confluence of the larger tributaries). Then send someone out every couple of days to do the chemistry. It's a big project; we had local high schools do the chemistry at each point along the river.

The reason you need long periods of time is because often pollution levels are seasonal; because you want to account for the effects of rain (which thins out chemicals, but roils up sediment); and because you want to find the trend over time (for which you'll need multiple years).

Feel free to follow up with more specifics....

Anonymous asked this follow-up question on 5/15/2000:

Thank you so much; that information helps a lot. Our assignment is to come up with an experimental play using the scientific method and then carry it out. I was going to have the 1st step (the problem) be: How much more water pollution is there now than there was in the year 1990? However, I found no information about the pollution of local waters in 1990. Do you have any suggestions as to where I could go to find this information? And since this is only a short-term project, how can I add to my research to make it more accurate, instead of just presenting my results from one test?

Anonymous rated this answer:

JesseGordon gave this response on 5/15/2000:

Rephrase your question as "Is water pollution getting more or less or staying the same over the years?" In other words, get rid of the specific starting point (1990) and use whatever data you have available.

The National Park Service keeps tabs on pollution levels in most waterways in the National Parks and National Rivers, so if you have one near you, use that. Park rangers are always happy to help on things like this. If you're not near any National Parks, you can try some state parks with rivers in them, and maybe you'll find one that collects data.

The scientific method would require that you do some statistical analysis on the data you collected, to see if there's a significant increase in pollution levels. To keep it simple, you can use just one type of data (turbidity is nice, because it measures "muddiness" which everyone can see; it actually measures the degree of deforestation and bank erosion upstream). You can use the statistical methods in the paper I cited above --it's all pretty standard.

If you don't know about all that statistical stuff, do a "qualitative study" instead. Your question could be, "How has local development affected biodiversity?" Loss of species is actually a major results of water pollution as well as development in general.

Find a dozen old-timers who've lived around a local river for decades (ask at the library or town hall), and have them describe the number of plants and animals that used to be there, which are no longer there. In most residential areas, the "species count" has dropped dramatically in recent decades. You'll likely be surprised to hear that there used to be eagles, or wolves, or whatever, right where you live.

You can do a "species survey" of the same area today, and compare the old-timer's list to your list. A little easier, and more fun if you like field work instead of spreadsheet work.

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