Impacts on the Moyaone Reserve's Trees
The complex array of toxic air emissions from the Charles Station Gas Compressor is detrimental to the entire ecosystem, including humans, all plants and animals, soil, and groundwater. The greater the total amount of toxin, the greater the effect; the more chemicals in the mix, the greater the effect of each toxin.
The picture is bad enough if we just look at an estimate of the effects of ozone emitted from the gas compressor into our woodlands. Ozone (O3) is probably the most important plant-toxic air pollutant in the United States. It is a very active form of oxygen that causes a variety of problems for plants.
Ozone, formed from breakdown of nitrous oxides and formaldehyde, will be emitted from the compressor 24 hours a day, in “blowdowns” when the system is being tested (100 times per year=twice per week), in “blowdowns” when it is necessary to equilibrate the pressure of gas within the pipeline, and in “blowdowns” when there is the rare accident—which we are all hoping won’t be explosions!
The amount of ozone that remains local, rather than being distributed over Accokeek, Bryan’s Road, Potomac River area and beyond, is determined by a number of factors. These include Dominion Energy’s construction choices and the location of the gas compressor.
Dominion Energy’s permit applications to various regulatory agencies seem to have different stack heights for each, from stacks of 50 ft to 83 ft apparently to ensure that the stacks won’t interfere with Mt. Vernon’s viewshed. “Best engineering practice” height is related to the height of buildings and surrounding topography and approximates 113.5 ft. The trees in the woodland range from 150 ft (tulip poplar, sycamore) to 80 ft.
The pipeline gas compressor will be located at the base of Strawberry Hill to the south, a steep hill to the east, a more gradual height increase to the Moyaone Reserve ridges to the north, and valley to the west. At this location, with building parameters as stated in the permit applications, there is a high probability that there will be significant downwash of the emissions plume to heights less than that of the trees in the woodland especially during relatively calm, warm days. Thus, especially June through September, emissions will concentrate within the leaf canopy of the trees during peak growing season.
Think of tiny, tiny ozone molecules bouncing around, ever upward, in amongst the leaves and twigs in the crowns of the trees. The greater the concentration, the more damage to leaf stomates, the less able the leaves are to absorb CO2. By the end of the growing season, the leaves will not have produced enough photosynthate over the summer to keep the trees healthy. They will not have the capability to make chemicals that would have protected them against insects, disease, and fungal attacks. Trees will have a shorter life; young trees are unlikely to mature.
Stomates in some species are more sensitive to ozone. These species grow less and are more susceptible to insect pests and diseases. With the advent of the Dominion gas compressor on Barry Hill Road, the Moyaone will be losing many of its trees: Sweetgum, Black Cherry, Box Elder, Red Maple, Ash, Tulip Tree, Scarlet & Pin Oaks, Sycamore, Walnut, American Linden. Many species have not yet been tested for sensitivity.