Drinking the Sangamon


“Might I interest you in some refreshing Sangamon River water?” my new friend Keith Alexander asked as he pushed his mug my way. What was in his mug looked more like coffee with cream. Which in truth, it was.

Keith is the Director of Water Management for the City of Decatur. Keith’s job is to extract and purify about 20 million gallons of water daily from the Sangamon River to quench the thirst of the residents of Decatur.

Yes, not far downstream from us an entire town drinks of the waters of the Sangamon River. Not only that, but Decatur’s industries add Sangamon River water to their corn starch, high fructose corn syrup and ethanol that goes out to the “marketplace to the world”. I’ll bet you never realized that Sangamon River water may be consumed by humans around the world and there’s a good chance you have some in the gas tank of the car right out in your driveway!

Anyway, I met up with Keith for pie and coffee late one recent afternoon at the Brown Bag Deli in Monticello. He had the Blueberry-Peach, which, due to a slight labeling error, turned out to be Apple-Cranberry-Walnut. I had the Blueberry, which it turned out to be, along with coffee, black.

But Keith’s coffee with cream better demonstrated the typical color and consistency of the water of the Sangamon River, or as it’s known in his parts, “Lake Decatur.” At least, that’s how the water of the Sangamon comes into Keith’s water treatment facility. Keith was illustrating that the number one issue in his treatment facility is “suspended solids” in the water of the Lake. This was because the residents of Decatur don’t want to turn on their water tap and get what looks like coffee with cream.

Apparently, the way to get these solids out is to use “flocking agents” (here I had visions of seagulls in fedoras and dark shades). Flocking agents induce “flocculation” which basically means clumping these solids, making it possible to remove them and make clean water. Which is one of many steps involved in drinking the Sangamon.

Keith’s suspended solids problem originates upstream. And upstream of Keith on the Sangamon River is, well, us. All those suspended solids are also known as Central Illinois topsoil, some of the best and most productive in the world. The topsoil is draining off of the farmland and eroding from the banks of the river and its tributaries in the 925 square mile Upper Sangamon River watershed that flows south and west and ultimately converges on Lake Decatur.

Keith verified that at peak flow the Sangamon River can be carrying 25,000 tons of topsoil down the river per hour! And much of that topsoil drops to the bottom as the river slows down at Lake Decatur, settling to the bottom of the lake.

So the problem of suspended solids, which is referred to in water-speak as “turbidity,” is not just about getting them out of the drinking water. It is also about getting them off the bottom of the lake, where suspended solids have reduced the holding capacity of the lake to only 154 days, were the Sangamon to quit flowing, which during droughts, it does. The original plan called for a water supply of two years.

This turbidity issue is not new for those in Decatur who drink of the Sangamon. The dam on the Sangamon River that created Lake Decatur was constructed in 1922. And by the 1930’s, they were already realizing that the lake was filling in with dirt coming from farmers’ fields throughout the watershed.

We’ve come a long way since 1922: gone to the moon and back, cured several widepspread diseases, developed amazing life-improving wonders like the internet, Twitter and Sprite “Zero”, but in the meantime, Lake Decatur is still filling in with dirt.

So much so that the City of Decatur, on Ke.ith’s recommendation, will spend $90 million of taxpayer money over the next 5 years, digging out our watershed’s valuable topsoil from the bottom of Lake Decatur to increase the holding capacity and normal flow of the Lake.

So when they dredge it, I figured area farmers would be thrilled to be able to get their valued topsoil back again. Not so fast, explained Keith.

Because this is not your average high-dollar-value Central Illinois topsoil; it’s your average, pretty close to worthless bottom-of-the-lake, silty, topsoil. Having spent so much time on the bottom of the lake, it’s now a very fine, almost powdery topsoil and subject to drying up and hardening very quickly. Some studies have shown it can be used to make marginal land less marginal, but overall, it needs some healthy amendments to ever be used as topsoil again. So they’ll just be piling it up away from the lake and leaving it there, hoping that somewhere along the way, they can think of something to do with it. But getting it out of the lake will dramatically increase the lake’s storage capacity.

There are other challenges Keith faces in trying to turn Sangamon River water to drinking water. One of which is nitrates, which is a way of saying “annhydrous ammonia” with fewer syllables, which is a polite way of saying “manure” or “urea.” All of which is quite effective as fertilizer and harmless and essential to life in small quantitities. In larger quantities, it can rob the bloodstream of oxygen and turn babies blue, killing them if left untreated.

And apparently the Sangamon River can have nitrates in larger quantities, which makes it important to remove.

Another issue is phosphates, which is another fertilizer. Phosphates encourage algae growth in the lake and create a problem called “eutrophication” which starts a cycle that robs the water of the lake of oxygen. It is primarily phosphates that are causing the “dead zone” at the end of the Mississippi River in the Gulf of Mexico.

But despite the suspended solids, nitrates, phosphates and all the regular evils in nearly all water supplies such as choloform bacteria, the Sangamon is still a very healthy river and has dependably kept the City of Decatur and its local businesses in the drink for nearly a century now. And you can’t fault a river for that.

In talking with Keith, one quickly realizes that most of the problems with drinking the Sangamon originate not naturally, but from the deliberate behaviors of those upstream. So much so that they have invested heavily in programs – providing both education and financial support – geared to help preserve topsoil and keep it, fertilizer, herbicides and pesticides on the land where they belong. In addition, Decatur’s $90 million investment in the Sangamon shows it’s tremendous value as a drinking water source, and their intention for it to be so for years into the future.

Being conscious of those living downstream from us is always important. And thinking about those living downstream can possibly (hopefully) help to change our perceptions of “our” river and how we who live upstream think about, perceive and relate to it. As environmental writer Wendell Berry has paraphrased the Golden Rule: “Do unto those downstream what you would have those upstream do unto you.”

And remember that those downstream are drinking the Sangamon.

Appeared as Notes from the River, Mahomet Citizen, May 1, 2014, by Scott Hays


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