Electronic Field Guide » Pre-Development Issues » Invasive Species Control

Prepared by Patrick Drohan (Ecosystem Science and Management)

Many kinds of material brought onto a Marcellus drill pad site may contain seeds of invasive plants that could take hold on the site and flourish.  These plants may then spread off-pad across your property.
Road cover material varies widely, but in Pennsylvania crushed limestone is often used. Stone not native to a site can pose potential problems when dust transmission occurs. For example, limestone used on sandstone-derived areas of the Allegheny Plateau can result in a temporary (1–2 year) increase in surface pH, which may help invasive plant species outcompete native species evolved to prefer the low pH conditions. The importation and placement of nonnative rock can also change infiltration and compaction patterns on a site, giving an advantage to nonnative and/or invasive plant species.
Trucks and other equipment coming on-site can carry the seeds of invasive species in mud on their tires or in water that is discharged to the site. Silt socks are currently a very popular erosion control device in Pennsylvania. They are large mesh tubes filled with wood chips or mulch.  If the wood material is not local to a site, it may serve as a vector for invasives transmission. 
The most important measure to take to minimize the introduction of invasive plants is to disturb as little soil as possible, because invasives thrive in disturbed soils. Areas that are disturbed should be monitored for the presence of invasives for at least two years after project completion.
Another important measure is to stabilize disturbed soils as soon as possible by planting with invasive-free seed and/or covering with invasive-free mulch, hay, rip-rap, or gravel. Avoid the use of fill and other materials from places where invasive plants occur.
In areas already colonized by invasives, it is best to work from areas free of invasives toward areas with invasives to minimize the spread of seed and other viable plant parts. For the same reason, locate the equipment staging area in an area free of invasives, if possible. Clean all tools and equipment after working in an area containing invasives. Cleaning may be done using water (while taking appropriate care with the wastewater), high-pressure air, or broom or brush.
Insects and Forest Pathogens
Local wood products are best to use on a site, because they can help minimize the transmission of woodborne pathogens and insects from other forests. For example, the Pennsylvania Department of Conservation and Natural Resources hopes to stem the spread of emerald ash borer and Asian longhorn beetle, two insects that can be harmful to timber resources. 

More about invasive species