(Editor’s note: The following compilation is the final installment in a three-part series detailing the Interstate 99 highway project. In part one, staff writer G. Kerry Webster provided an insight on the project. Yesterday’s installment explores the financial benefits and positives this 33 mile stretch of highway will bring. Today, Daily Herald correspondent Mark Nale will examine the environmental impacts involved with the project.)
Trees are cut, earth moved, and thousands of tons of limestone fill hauled from the New Enterprise Stone and Lime quarry below Tyrone for the construction of the final phase of I-99. This section, Bald Eagle to Port Matilda, will connect the already finished and still-under-construction sections of I-99 to complete a four-lane interstate link between the Pennsylvania Turnpike and I-80.
According to PennDOT engineer Bert Kisner, the entire highway should be open for traffic sometime during 2007. Commuters, vacationers and commercial traffic will have a faster and safer route through our area — but there is a cost — an environmental cost. No matter where the highway is built, the environment always comes out the loser.
Habitat destruction, sediment entering streams, and possible groundwater disruption are the immediate impacts of construction, but the long-term impacts are even more important.
The environmental impacts can be broken down into primary and secondary effects. Primary effects are those caused directly by the construction and completion of the roadway. Secondary impacts are caused by the development that sometimes follows the opening of a interstate highway.
Primary Effects
The actual footprint of the highway corridor removes or greatly disturbs hundreds of acres of forest, wetlands, fields, and reverting fields – all home for deer, wild turkeys, assorted songbirds, and a multitude of other plant and animal species. It also disturbs several streams and serves as somewhat of a barrier to the movement of animals along the Bald Eagle Ridge.
Lost wildlife habitat that becomes an interchange, bridge, or road bed, is lost; there is no way to get around that. According to Kisner, the losses are mitigated. Whenever possible, an attempt is made to replace lost habitat, such as wetlands, or enhance existing habitat. All of this is covered in PENNDOT’s Natural Resource Compensation Plan, the details of which are hammered out among PENNDOT and federal and state environmental agencies before construction permits are issued.
The public knows little about the details found in the 130-page Mitigation Report or the 70-page Compensation Plan. As part of the plan, for example, PENNDOT donated $200,000 to the Conservation Fund, which in turn partially funded the purchase of the new 2,410-acre State Game Lands 323 in Centre County. As well as being useful for hunting, this property was identified as an Important Bird Area by the National Audubon Society and it is now preserved for public use.
Also included in the plan are 160 acres of wetland habitat mitigation, 597 acres of terrestrial habitat mitigation, and 18,170 linear feet for stream habitat mitigation. Kisner added, “Out of respect for the environmental sensitivity of the area, we went over and above what was required by the law and, in some cases, even going above the figures in the Compensation Plan.”
Most environmental organizations and resource agencies consider loss of habitat the biggest negative factor facing wildlife today. The habitat lost to construction, even if partially mitigated, is one of the long-term effects of I-99.
The second largest primary impact of the highway is increased storm water run-off and decreased percolation of water into the ground. Our wells, springs and all local reservoirs depend on rainwater soaking or percolating into the ground to recharge the underground aquifers. Increased run-off makes floods more of a possibility and can raise the flood crest of local streams and rivers.
Each mile of four-lane I-99 covers over 11.6 acres of ground with a surface (concrete or blacktop) that nearly eliminates percolation and causes rainwater to flow off the highway corridor. One inch of rain on an acre of land equals over 27,000 gallons of water.
In the 1970s, when the Tyrone bypass was completed, stormwater management meant getting the water off of the highway corridor as quickly as possible. There was no stormwater retention built into the plans. To further delineate the problem, a one-inch rain event on the bypass, which could be delivered in a heavy thundershower, sends an extra 2.2 million gallons of water into Bald Eagle Creek and the Little Juniata River. In comparison, a one-inch thundershower on a dry forested hillside has mostly percolation with very little run-off.
Current I-99 construction has much higher standards of stormwater management. All water originating on the right-of-way will be channeled into stormwater retention ponds. Ponds are designed to hold the first inch of a rain event. You may have also noticed that the stormwater management ponds along the Grazierville to Altoona section of I-99 were enlarged several years ago when their original size proved to be inadequate.
Recently retired Centre County Planning Director Bob Donaldson has been studying the possible impacts of I-99 (then called the Route 220 Relocation Project) since the early 1990s. I spoke with him recently about the secondary impacts, all caused by the development that this new four-lane highway could cause.
According to Donaldson, “The highway itself isn’t going to necessarily generate a whole lot of additional development.” Look at the Kylertown or Snowshoe exits of I-80, for example.
“However, put a highway through a community that is already growing and you’ll see more development,” he added.
Development brings more people and causes yet more wildlife habitat to be lost. Having more people changes the nature of a once-rural life desired by most people living here. More traffic and its resulting air pollution, more water use, and more waste generated are additional long-term environment problems.
What Donaldson sees as the biggest environmental problem is the amount of imperviousness (rooftops, parking lots, secondary roads) that is created by development. He said, “It ruins the aesthetics and creates more and more stormwater that becomes more and more difficult to control.”
More run-off also means less percolation and that, coupled with increased water use and future droughts, further stresses our water supply. It also means less cool water for the Little Juniata River, Bald Eagle Creek, and other area trout streams.
Because of topography and wetlands, Donaldson sees little development occurring at the Port Matilda interchange, with the exception of maybe a gas station or a fast food restaurant . What further development will happen at Bald Eagle, Tyrone, Grazierville and Bellwood is anyone’s guess, but Donaldson expects some.
In addition to the increased volume of stormwater, Donaldson added, “We need to pay more attention to the pollution that comes from parking lots.” Grease, oil, gasoline, anti-freeze and other things drip from vehicles and end up in the stormwater.
Donaldson also sees a scattering of residential dwellings farther away from the growth center of State College. In effect, a better highway allows people to relocate farther away from their jobs and still have a reasonable and safe commute. Greater pressure for home sites will take more farmland and increase the likelihood of new sewer lines, which subsequently promotes additional development. A broadening of the circle of development will change Warriors Mark and the other townships surrounding Tyrone, Port Matilda, and probably even Bellwood.
While the completion of I-99 is touted as a much-needed economic boost for our area, it comes with a loss of wildlife habitat, increased stormwater surge, and less water underground for people and streams. Hopefully we won’t destroy our forests and trout streams, both economic and environmental treasures, while building a safer and more efficient highway system.
