The complexities of water quality


It can give us life and it can kill us.

It can give us pleasure and it can cause fear.

It can be found everywhere and we can find ourselves without enough of it.

We can hold it yet it can be lighter than a feather.

It covers 71 percent of the Earth’s surface.

It makes up 60 percent of our bodies.

What is it? Water!

As Leonardo da Vinci said, “Water is the driving force of all nature.” And yet less than 1 percent of all water on Earth is clean, fresh water available to humans.

Water quality and quantity are local, state, regional, national and global issues. Today we know more about water than ever but it still seems to confound us. California has been in a severe drought for several years, while much of Ohio has suffered repeated drenching rains, and algal blooms continue to plague our recreational waters and drinking water supplies worldwide.

We have learned so much. No-till and cover crops help reduce soil erosion. Reducing and proper disposal of unwanted keeps them from washing into our streams, rivers, lakes and wetlands. Crop rotations disrupt disease and insect cycles, so fewer inputs are needed to produce food, fiber and fuel for the world. Turning the water off while we brush our teeth saves gallons of water each day.

We still need to learn more. We thought that curbing soil erosion and removing phosphates from household products were enough. While those practices have been hugely effective at dramatically reducing the amount of total phosphorus in our waters, much of it attached to soil particles, we are now wrestling with dissolved phosphorus.

We are perched on the horns of a dilemma. In no-till fields, application of nutrients through the years can result in those nutrients concentrating at the soil surface where they are less useful to plants and more prone to be dissolved in solution during big rain events. Once dissolved, those nutrients can then run off the surface or down to tile lines through pathways in the soil. Tillage can reduce dissolved phosphorus but tillage results in increased soil erosion and higher levels of total phosphorus. What is the answer?

The answer is that we just aren’t quite sure yet. Research is being conducted, some in Ohio, to help us figure this out. The Nature Conservancy, Ohio State University Extension and USDA Agricultural Research Service are testing an implement that maintains the benefits of no-till and allows for nutrient application just below the surface. Maumee River Basin farmers are installing sampling disks at the end of field tile or within drainage water management structures to better quantify nutrient losses so we can understand how practices influence water quality.

We are participating, too. Delaware, Knox, Licking, and Morrow Soil & Water Conservation Districts are the recipients of a Regional Conservation Partnership Program grant for the Upper Big Walnut Creek watershed. Some of the funding, which comes from the USDA Natural Resources Conservation Service, will cover the installation of a wood chip bioreactor and phosphorus removal structure along with five years of monitoring by the USDA Agricultural Research Service. We are currently in the design phase with late August or early September for construction of the system. The bioreactor is a large underground trench filled with wood chips which should reduce the amount of nitrate in drainage water. In this system, the water leaving the bioreactor then flows into the phosphorus removal structure, a confined bed filled with steel slag. The dissolved phosphorus should get trapped by the slag before the drainage water reaches a nearby stream.

Scientific research, innovation, cutting-edge technology and conservation are essential to addressing the complexities of water quality. The scientific research information gathered from our local monitoring project, as well as other projects across the country, will provide important new insights into ways to keep our water clean and healthy.
Brad RossContributing columnist

Brad Ross is communications specialist at the Delaware Soil and Water Conservation District. He can be reached at [email protected].

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