Congress held a hearing on Capitol Hill Tuesday morning on the environmental impact of that controversial drilling technique.
Hyrdaulic fracturing, also called "fracking," involves injecting chemically treated water into the ground to crack shale deposits and release trapped natural gas. Industry advocates say the technique is well-regulated and safe, but opponents warn it could contaminate water supplies.
Hearing co-chair Sen. Ben Cardin listened to, among others, Robert Summers, Maryland's acting Environment secretary. Summers urged the federal government to take a more active role in regulating future hydraulic fracturing in western Maryland's Marcellus shale deposits.
Experts say that site, along with others in neighboring states, contain enough natural gas to last approximately 20 years.