Another water quality issue?

Brad RossContributing Columnist

While on vacation last month, I received an email from a good friend asking about the recent nitrate alert in Columbus’ drinking water. He asked if I would address this issue in my column. It’s nice to have a “set-up man” to generate ideas for me — so thanks, Bill!

While nitrate is a serious threat to newborn babies, it does not pose a problem for older children or adults. However, newborn babies should never be given water in formula when the nitrate levels are above 10 milligrams per liter. By law, public water supplies are tested daily and alerts go out whenever that level of 10 milligrams is exceeded.

On those rare occasions when nitrate levels exceed 10 milligrams and an alert is issued, there really is nothing a consumer can do other than use bottled water. Boiling the water makes the situation worse by raising the nitrate concentration. Water with high nitrate levels is safe for bathing, laundry and all general household use. The only real danger is for newborn infants, so purchasing distilled water to prepare formula is a safe, easy solution.

Nitrate is a nutrient essential for plant growth. It is taken up by plants through the soil. We consume as much as 50-70 mg of nitrates per day in our fruits and vegetables. This nutrient is provided to the plants by several sources: commercial fertilizer, livestock manure, and/or nitrogen-fixing bacteria. Without getting too technical, some plants (legumes, for example) store nitrogen that is fixated by microorganisms in the soil. The microorganisms collect the nitrate from the atmosphere in a gaseous state and convert, or fixate the gas into a solid state that the plants can feed on. To give you an idea of the presence of nitrate in our lives, nearly 70 percent of our atmosphere is made up of nitrate (in its gaseous state).

Conservationists have promoted the use of cover crops and crop rotations that include legumes because of the benefit of creating nitrogen which is less susceptible to runoff than commercial fertilizer. However, in most cases, not all of the plant growth needs can be met without providing additional nitrogen. In a normal rainfall season (whatever that is in Ohio!), nitrogen applications can be timed so that plant uptake is optimal and little runoff occurs. As you all know, this spring and early summer has been a huge challenge for farmers, golf course managers, gardeners and landscapers in terms of fertilizer applications. No one wants to broadcast fertilizer only to have it wash off and not be taken up by the plants. The heavy downpours of rain that central Ohio has experienced the past month or more have left them scratching their heads.

While homeowners and landscapers want to see green grass, they merely need to wait for the weather to cooperate and then add more nitrogen. Farmers, however, may not have that option. Once the crop grows to a certain height, replacing the lost fertilizer is not possible and crop yields may be seriously reduced. This cuts into the available food supply, increases the cost of food to the consumer, and/or reduces the farmers’ income.

Because of the increased storm intensities, the heightened awareness of water quality issues, and the high cost of fertilizer, ag producers are trying diligently to find ways to grow food and fiber and protect our water supply at the same time. More long-term research is needed to provide answers on nutrient management. The Delaware Soil and Water Conservation District has been working with USDA-Agriculture Research Service on water quality monitoring sites and will be installing a bioreactor in partnership with ARS to conduct research on the ability to filter out pollutants such as phosphorous and nitrogen. Watch for more information later this summer as the bioreactor is installed.

If you are a homeowner, lawn care professional, gardener, golf course manager or anyone applying fertilizer, we encourage you to soil test and provide only the nutrients needed for successful plant growth.

For more information on nitrates in drinking water, bulletins can be purchased through OSU Extension’s e-store at

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

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