A plan to reduce landscape-altering nitrogen buildup in Rocky Mountain National Park won the unanimous endorsement of a state air-quality panel Thursday – but its weight is lighter than air.
The move by the Air Quality Control Commission marks the first effort in the country to rein in nitrogen by setting a “critical load,” or a maximum threshold, for the pollutant.
The commission conceded that nitrogen generated by vehicles, factories and farms along the Front Range is having a negative effect on the vegetation within the park.
But commissioners backed off any suggestion that proposed benchmarks would become mandatory – concerned that exceeding the critical load could result in restrictions on vehicles and industry.
“All we do by endorsing this is acknowledge that there is a problem,” Commissioner Jon Slutsky said.
“It stresses voluntary measures, and it sets a timetable, although it doesn’t really set anything in enforcement,” he said.
Studies conducted over the past 20 years have found high levels of nitrogen linked to changes in algae and other aquatic plants, elevated levels of nitrates in water and spruce trees and a shift in alpine-tundra plants from wildflowers to grasses and sedges.
The plan – a collaboration between the National Park Service, the U.S. Environmental Protection Agency and the state – has garnered the tentative support of industry, as long as restrictions on nitrogen generation are based on science and best-management practices and are not imposed abruptly.
Scientists suspect that about half of the nitrogen that has accumulated in the national park comes from ammonia produced in agriculture, and the other half from combustion from power plants, autos and other sources.
Nitrogen levels on the park’s eastern side are about 20 times as concentrated as would occur naturally, threatening populations of trout and wildflowers.
The plan calls for reducing nitrogen to a “sustainable level” by 2032, said Mike Silverstein, director of the state air-pollution control division.
Commissioner Douglas Lawson, however, said the reductions could “shut down Rocky Mountain National Park and Estes Park” if they become hard-and-fast rules that restrict motor-vehicle traffic.
Silverstein responded that participation in the nitrogen-reduction plan is entirely voluntary and many gains can be obtained through ongoing efforts to reduce other pollutants such as ozone and particulates.
Staff writer Steve Lipsher can be reached at 970-513-9495 or slipsher@denverpost.com.
