OPINION

MIKE MASTERSON: Nutrients spilling over

Since our state’s Department of Environmental Quality (cough) has decided to shirk its fundamental responsibility by using proxy groups without regulatory authority to simply monitor the ongoing contamination in portions of our Buffalo National River and its major tributary, Big Creek (both classified as impaired), I’ve decided to volunteer my assistance.

As an amateur, I’ll nonetheless try to help identify the potential primary source of the documented low dissolved oxygen levels, excessive algae from too many nutrients, and the health threat from pathogens and bacteria living inside those blooms.

The way things stand, the department has proposed classifying Big Creek and the Buffalo under a draft impairment category 4(b) reported to the EPA. Had it classified these streams differently, it would be required to identify and rectify the sources of impairment and address them. By opting for draft category 4b, the department conveniently allows itself to avoid determining the source.

Deep within the records of one of those monitoring groups, (the Big Creek Research and Extension Team out of the University of Arkansas’ Division of Agriculture) I found numbers that might well point to the obvious primary cause.

First, though, I researched the effects of excessive levels of phosphorus and nitrogen, both present in swine and other animal waste, when too much of either winds up in streams and lakes. Phosphorus is essential for plant life. Yet when an abundance of this fertilizer winds up in natural waters, the stuff can speed up a process called eutrophication (a reduction in dissolved oxygen in affected waterbodies caused by an increase of mineral and organic nutrients).

Excessive nitrogen in natural waters can cause severe illness in infants and domestic animals. Common sources include septic systems, animal feed lots, agricultural fertilizers, manure, industrial waste waters, sanitary landfills, and garbage dumps.

In excess, phosphorus and nitrogen will stimulate algae growth, which then reaches critical mass and dies. That condition ties up available oxygen in waterbodies, leading to dissolved oxygen depletion called anoxia, which is harmful to aquatic life.

That sure sounds to me like what’s happened to Big Creek and our beloved Buffalo National River to land each on the latest list of impaired streams.

My left eyebrow raised even higher when I got to page 83 of the Big Creek Research and Extension Team’s spring 2018 report. It belatedly revealed monitoring results from waste-spray fields at C&H Hog Farms.

The recorded data for 2015 showed Field 5a near Big Creek, where raw swine waste is regularly spread, lost 77.3 percent of the applied phosphorus to runoff, while Field 12 lost 45.9 percent. The runoff amounts for nitrogen were measured at 52.9 percent for 5a and 24.8 percent for Field 12.

That’s a lot of fertilizer spilling into Big Creek and through the Buffalo watershed. And that’s only the documented runoff from two of at least 16 spray fields. It doesn’t account for the unknown amounts of these contaminants that have been seeping for years into groundwater that steadily flows through the watershed’s fractured karst (limestone containing many fractures, voids, caves and solution channels) subsurface.

As I understand it, the original plan, approved by the Department of Environmental Quality, was for vegetation to absorb the raw-waste nutrients applied to the spray fields. But what happens when the constant overload of fertilizer overwhelms the fields’ ability to absorb and utilize it is then followed by a storm event?

The stuff not absorbed by plant life inevitably either runs off into Big Creek or soaks into the subsurface to drain rapidly downhill (proven by dye testing) through the karst for miles toward the Buffalo six miles downstream. It also becomes bound to those subsurface soils and stored as “Legacy P” (phosphorus buildup) to then be steadily released over many years.

Andrew Sharpley, the UA professor who directs the Big Creek team, has written about how storm events cause runoff from fields loaded with excessive nutrients. For example, a 1999 report in which he was the lead author says in some agricultural watersheds, 90 percent of annual algal-available phosphorous drainage originates from only 10 percent of the land area during just a few relatively large storms.

The report cites the example of more than 75 percent of annual water discharge from watersheds in Ohio and Oklahoma occurring during one or two severe storms, contributing over 90 percent of their annual total phosphorus exports.

It gets even more ominous. In another article, Sharpley wrote that phosphorous buildup in soils can require up to a century to return to normal.

In other words, the excess phosphorus C&H applies today (and over five years) can be expected to continue leaching into Big Creek and the Buffalo. For me, this means even Best Management Practices (BMPs), which Sharpley and the Watershed Management Plan tout as solutions, may only exacerbate the problem.

A person close to the matter offered a clear overview: Sharpley’s earlier research tells us what’s going on at C&H. C&H fields are receiving more phosphorus than the pasture grasses can use (approximately 80,000 pounds in excess per year, according to C&H’s Nutrient Management Plan). These fields were already saturated with the stuff. When we have only a handful of severe storms each year, up to 90 percent of the annual load of phosphorus is transported to Big Creek and through the watershed.

Earlier research shows it’s happening, he further explained. In 2015, the Big Creek team managed to capture such an event and a large percentage of the phosphorus and nitrogen C&H applied to those fields was shown to have run off into Big Creek. However, most fields are not monitored, nor are the amounts of nutrients entering the subsurface drainage network. Nutrients are increasing downstream from C&H and, lo and behold, Big Creek and the Buffalo are now impaired.

Hopefully this helps identify a potential primary source of our national river’s serious problem. Now, Arkansas Department of Environmental Quality, what will you do to resolve these disgraceful impairments?

Mike Masterson is a longtime Arkansas journalist. Email him at [email protected].

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