Lawn fertilizer taints estuary

Conservation groups launch effort to protect local water resources

PORTSMOUTH The answer to reducing environmental damage in local water bodies lies right in our own back and front yards.

The Conservation Law Foundation has joined forces with local conservation groups to launch a new initiative called Smart Fertilizer Use to reduce nitrogen levels in the Great Bay Estuary. While much of the nitrogen reaching the estuary comes from sewage treatment plants, there is also a portion that comes from fertilizer used in residential lawns, Great Bay-Piscataqua Waterkeeper Jeff Barnum said.

"My interest lies in clean water, and too much nitrogen in our water is a big deal," Barnum said. "We should be paying attention not only to sewage treatment plants, but also onto problems we can do something about."

Barnum said 40 percent of all Seacoast homeowners fertilize their lawns, with about half of those residents employing a professional to do the work. These treated lawns contribute about 115 tons of nitrogen to the estuary each year, he said.

Want a visual?

Imagine 230 pickup trucks dumping loads of nitrogen into the water. That amount of lawn-linked nitrogen, combined with the 1,250 tons of nitrogen coming from sewage plants and other sources, has a huge impact on the underwater ecosystem, Barnum said.

According to the federal Environmental Protection Association, nitrogen is essential to a healthy ecosystem, but too much of the nutrient can increase the amount of algae in the water. Algae blooms can cause great harm to water quality, food resources and habitats. Algae decreases oxygen in the water that fish and other aquatic life need to survive.

The EPA also warns of the danger that high nitrogen levels pose to humans: "Some algal blooms are harmful to humans because they produce elevated toxins and bacterial growth that can make people sick if they come into contact with polluted water, consume tainted fish or shellfish, or drink contaminated water."

One way to do your part in nitrogen reduction is to determine whether your lawn actually needs fertilizing, according to Barnum. The University of New Hampshire and University of Maine offer testing services, and do-it-yourself kits are available online. You may find your lawn doesn't need fertilizer at all. If it does, Barnum recommends an organic, slow-release fertilizer that is phosphorus-free.

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Lawn fertilizer taints estuary