Stormwater Runoff provides plant food

Today, more people are thinking about stormwater runoff as a resource.  In my opinion, we are missing an important opportunity with a readily available resource.  Everyone knows that stormwater runoff contains nutrients.  Some jurisdictions are so concerned with these nutrients that they base their water quality plan approvals solely on the removal of the metallic element phosphorus.

It is time we started to plant stormwater vegetable gardens in our BMPs to solve the nutrient problem while providing food for people and farm animals.

The justification for many “bio-based” best management practices (BMPs) is the fact that they can take up nutrients like phosphorus and nitrogen, thus “removing” them from the runoff.  This is, in fact, true, if the plants that take up the nutrients are physically removed from the BMP before they pass on to that great garden in the sky.  If they are allowed to expire, they will decompose and then pass on their carefully gathered nutrients to some other lucky plant or animal.  Even though our atmosphere is mostly nitrogen, this gaseous form of the element needs to be “fixed” to be available to plants.  This is mostly accomplished by bacteria in the soil.  This process, while important, is not the major source of nitrogen for plants.  Most of the available nitrogen comes from decomposers (fungi and bacteria) that break down existing organic material.  Regardless of the process, it is important to note that stormwater carries a ready source of useable nitrogen and phosphorus that we are literally wasting.  Using a biotic BMP is a handy way to get nutrients out of the water and back into plants where they belong. As an added bonus, other nasty metals and chemicals have been shown to be taken up by plants as well as phosphorus and nitrogen.

Now it might seem like putting metals and other pollution into the food chain via vegetable gardens is a bad idea, but if we confine these dangerous materials to a known location (people and farm animals), we can keep track of them and keep them from escaping to our lakes and rivers.  As it stands today, with practically no one actually removing plants (or anything else for that matter) from BMPs, all of the material taken up by the biological processes will eventually be released back into the water as the organic material dies and decomposes.  This material then proceeds downstream to parts unknown, where it is sure to be taken up by another plant or animal.  It now becomes impossible to know where the metals and chemicals might reside.  Some innocent child might catch a perch in the lake, and consume it, not knowing that the chemicals contained within might have come from an approved BMP.

If growing and eating vegetables laced with chemicals taken up from a bio-based BMP makes no sense, does it make any more sense to place these same chemicals into the food chain with no thought of where they might end up?  It does not, and I say we plant the veggie gardens and be sure the pollution does not go any further.  The gunk stops here. Bon appetit!

On October 12th, 2012, posted in: Blog by
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