WorldWide Drilling Rescource

Be Aware of Soil Contamination When Installing Soil Borings Adapted from Information by Talon/LPE Whether installing soil borings for an environmental investigation or geotechnical purposes, it’s important to keep an eye out for possible instances where contamination can reach subsurface soil and / or groundwater. Contaminating soil or ground- water can cause serious safety or legal challenges, which is why it is imperative to consider potential contamination which may occur with soil borings. Soil contamination could be present before a project begins, it could potentially occur during the course of drilling, or after the bore is installed. In any case, creating new areas of contamination, spreading existing contam- ination, or creating a pathway for contamination should always be avoided. It is crucial to find out as much information as possible about cur- rent site conditions, which will help in choosing the best soil drilling methods, so conduct a predrilling job walk with the drilling contractor. Examples of contamination sources or conditions: • Historic use - Pesticides from farming may linger in soil long after farming ends. Petroleum hydrocarbons and solvents may have leaked into soil and groundwater from gas stations or home auto / equipment repair. • Underground lines and tanks - Utility location services can identify underground lines for sewage to natural gas. Fuel, heating oil, or waste oil in underground storage tanks may be present but not visible. • Previous spills - Unusually discolored soil or distressed vegetation may be visible. • Trash - Toxic or hazardous chemicals may be present in discarded containers, which may be open or leaking. Steps to help avoid creating new conditions of contamination on the jobsite: • Entering and exiting sites clean - Drilling equipment should arrive at the jobsite clean. An on-site cleaning station can clean trucks or other equipment leaving the jobsite. • Geologic conditions - It is crucial to understand geologic and groundwater conditions at the jobsite. • Good housekeeping - Properly store toxic or hazardous materials. • Refueling or maintenance - Use drip pads or pans to avoid spills to the ground. Invest in a spill kit to quickly clean-up any leak or spill. • Stormwater drainage - Stormwater runoff can contain vehicle-related chemicals; divert stormwater from soil boring areas, or seal the top of the borehole. • After installing the borehole, plug it according to local and state regulations to prevent a pathway for contamination. 25 WorldWide Drilling Resource ® OCTOBER 2019 ENV