At Home in Nature

  (Agate, Colorado)
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Catch that wheelbarrow!

We had such strong winds out at the farm that our wheelbarrow blew away, 2x4's were flying around, and other such mayhem occued.  In like a lion... out like a lion.  Luckily, we built our hoop houses and greenhouses strong enough to withstand the wind, and all the critters had excellent shelter behind their walls.  We struggled against the wind for a little while, but also decided it was a good day to catch up on paperwork.


Acid Rain

Acid rain is a reality for farmers, and every human being.

In Colorado, acid rain has been responsible for damage to our lands since before the 1980’s, and Rocky Mountain National Park (among other areas, including the Black Forest and Elbert County) are affected. 

The EPA ( describes the horrors of Acid Rain, and its ability to damage forests: “ ‘Acid rain’ is a broad term referring to a mixture of wet and dry deposition (deposited material) from the atmosphere containing higher than normal amounts of nitric and sulfuric acids. The precursors, or chemical forerunners, of acid rain formation result from both natural sources, such as volcanoes and decaying vegetation, and man-made sources, primarily emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) resulting from fossil fuel combustion. In the United States, roughly 2/3 of all SO2 and 1/4 of all NOx come from electric power generation that relies on burning fossil fuels, like coal.  Acid rain occurs when these gases react in the atmosphere with water, oxygen, and other chemicals to form various acidic compounds. The result is a mild solution of sulfuric acid and nitric acid. When sulfur dioxide and nitrogen oxides are released from power plants and other sources, prevailing winds blow these compounds across state and national borders, sometimes over hundreds of miles.”

The EPA describes two kinds of deposition, wet and dry.  “Wet deposition refers to acidic rain, fog, and snow. If the acid chemicals in the air are blown into areas where the weather is wet, the acids can fall to the ground in the form of rain, snow, fog, or mist. As this acidic water flows over and through the ground, it affects a variety of plants and animals. The strength of the effects depends on several factors, including how acidic the water is; the chemistry and buffering capacity of the soils involved; and the types of fish, trees, and other living things that rely on the water.  In areas where the weather is dry, the acid chemicals may become incorporated into dust or smoke and fall to the ground through dry deposition, sticking to the ground, buildings, homes, cars, and trees. Dry deposited gases and particles can be washed from these surfaces by rainstorms, leading to increased runoff. This runoff water makes the resulting mixture more acidic. About half of the acidity in the atmosphere falls back to earth through dry deposition.”

John T. Turk and Donald H. Campbell of the USGS in 1997 published Fact Sheet 043–97 on the subject and how it affects Colorado lands. 


The alpine and subalpine zones of the Rocky Mountains are among the largest undisturbed ecosystems in the United States. The Wilderness and Clean Air Acts give congressionally designated wilderness areas special protection from man-made change. However, many wilderness areas, including the Mt. Zirkel Wilderness Area, of the Rocky Mountains are located near economic deposits of fossil fuels (including some already developed), such as coal, petroleum, natural gas, and oil shale. To use these fossil fuels without damaging nearby wilderness areas and other Federal lands, the present environmental status of the wilderness areas and the possible risk of air pollution from future energy-resource development need to be understood…

…The Western Lake Survey, conducted by the U.S. Environmental Protection Agency in 1985, and numerous smaller surveys indicated that acid neutralizing capacity (ANC) differs greatly among regions in the Rocky Mountains. ANC is a measure of a lake—s ability to neutralize acidity, and lakes having small ANC occur throughout the Rocky Mountains. Because of differences in bedrock geology, soil development, and hydrology, those lakes having smallest ANC tend to be in specific mountain ranges such as the Bitterroot Range in Montana, the Wind River Range in Wyoming, the Uinta Mountains in Utah, the Colorado Front Range (including Rocky Mountain National Park), and the northern Park Range in Colorado (including the Mt. Zirkel Wilderness Area).

In northern Colorado, downwind of the Yampa River valley, an area of high concentrations of sulfate, nitrate, and acidity in wetfall and snowpack overlaps an area containing lakes having very small ANC. Thus, at present (1997) levels of emissions from all sources, including energy development, the Mt. Zirkel Wilderness Area contains hydrologic systems that may be the most affected by acid deposition in the Rocky Mountains.

The USGS has examined the release of pollutants from the snowpack in an acid pulse at the USGS Water, Energy, and Biogeochemical Budgets (WEBB) site in the Loch Vale watershed in Rocky Mountain National Park. The relative amplification of snowpack acidity in the early stages of snowmelt has been determined at the WEBB site. An amplification factor was applied to the measured acidity in the snowpack at Buffalo Pass, adjacent to the Mt. Zirkel Wilderness Area. Projections indicate that the early snowmelt that fills temporary ponds used by amphibians for breeding likely is more acidic than the level at which biological damage occurs (fig. 3). In the area around Dumont Lake, just south of the Mt. Zirkel Wilderness Area, 60 to 100 percent of tiger salamander eggs were dead or unviable in ponds at about pH 5.0 or less, about 40 percent between pH 5.0 and 6.0, and about 20 percent were dead or unviable at about pH 6.0 or greater (Kiesecker, 1991). Laboratory experiments using these eggs indicated that pH lower than about 6.0 also resulted in slower hatching of eggs, slower growth to maturity, and decreased ability to catch and eat tadpoles, which are a common food. At less than about pH 6.0, growth to maturity was so slow that ponds would be likely to dry up, and salamanders would die before they could mature. Smaller size also made them more susceptible to predation. Harte and Hoffman (1989) reported that less than half as many tiger salamander embryos survived at about pH 5.6 or less compared to those surviving at about pH 6.1 or greater. Salamanders that survive toxic conditions, drying up of ponds, and predation as eggs or larvae may have to survive a second acid pulse the following year. Some individual salamanders may be genetically able to mature in two years rather than maturing in their first year. However, they would have to winter over in deeper ponds and would still be in the acid-sensitive larval stage during snowmelt of the following spring.

Although the tiger salamander seems to be the only aquatic species studied in natural habitats adjacent to the Mt. Zirkel Wilderness Area, other species in the wilderness are also sensitive to acid toxicity. Embryos of other amphibians, such as boreal toads, chorus frogs, northern leopard frogs, and wood frogs have as much as 50 percent mortality at pH 4.3 to 4.8 (Corn and Vertucci, 1992). Embryo and fry of rainbow trout have increased mortality at about pH 5.5 (Baker and Christensen, 1991). Three zooplankton species that are common food for the tiger salamander and for fish had 100 percent mortality within 1-5 days of exposure to a pH of 5.0 (Harte and Hoffman, 1989). Thus, in sensitive ponds, streams, and lakes in and near the Mt. Zirkel Wilderness Area, a wide range of biological damage may occur.

Between December 1992 and May 1993, the Hayden Power Plant was partially shutdown because of mechanical problems, which resulted in a 58-percent decrease in its sulfur dioxide emissions (Dan Ely, Colorado Department of Public Health and Environment, written commun., 1997). The USGS sampled snow deposited in and near the Mt. Zirkel Wilderness Area during normal operation and during the period of partial shutdown. Although the Hayden Power Plant is the largest local source of sulfur dioxide (Watson and others, 1996) and although sulfur dioxide emissions were reduced during shutdown, acidity of the snowpack increased during the partial shutdown and remained at levels determined to be injurious to amphibians. The most likely explanations of the still-toxic snowpack acidities are a combination of: (1) Seasonal differences in snow chemistry, and (2) a likely overload of the ability of the local atmosphere to fully convert all the sulfur dioxide to sulfuric acid. At present (1997) emissions rates of sulfur dioxide from all local sources, the natural production rate of oxidants in the atmosphere may control the amount of sulfuric acid produced and deposited to the snowpack.

It is not known how much emissions reduction may be required from all local sources before sulfuric acid production and deposition become controlled by emissions rates and would be reduced. Pollution controls that are planned for the Hayden Power Plant are expected to reduce sulfur dioxide emissions from the plant by about 85 percent (Dan Ely, Colorado Department of Public Health and Environment, oral commun., 1997). However, no studies have been done to indicate the effectiveness of this level of emissions reduction. Data collected during the partial shutdown of the Hayden Power Plant indicated that a reduction of 58 percent had no measurable effect. Therefore, it is possible that the pollution controls will not fully remedy problems related to the acidity of the snowpack.

Because the Mt. Zirkel Wilderness Area may be the area most affected by acid deposition in the Rocky Mountains and because reductions in local emissions of acid precursors are planned, an opportunity exists to investigate the causes and effects of acid deposition that could help protect all Rocky Mountain wilderness areas. Little scientific information exists to indicate which aspects of the hydrologic and biologic systems of Rocky Mountain watersheds are most sensitive to acidification. Further, although some damage to aquatic resources likely occurs at present levels of emissions, natural hydrologic and other processes might protect these ecosystems in ways not documented elsewhere. Documentation of the effects of acidification on lakes and aquatic organisms could provide a benchmark for evaluating effects of energy development and associated emissions everywhere in the Rocky Mountains.


It is not just power plants, it is every one of us driving our vehicles, burning fossil fuels.  Urban planners design our cities so we cannot live next to where we work, so we must drive.  It is our government policy that is destroying our forests.  It is we, the people, who allow this to happen.


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