Maryland’s Republican Gov. Larry Hogan signed a bill into law that bans hydraulic fracturing, or fracking, making Maryland the second state to ban the practice.

The law was finalized one week after the state legislature passed the bill. On March 27, state senators voted 35 to 10 to approve the bill.

Hogan tweeted on April 4, “proud to sign seven bills into law today, including a ban on #fracking here in Maryland. #MDGA17.”

Maryland follows New York state, which banned hydraulic fracturing in 2015, as the only two states with laws banning the drilling practice. Both states sit atop parts of the prolific Marcellus Shale Formation.

Maryland doesn’t currently host any hydraulic fracturing site. But the oil and gas industry has eyed western Maryland because of its potential for production.

The oil and gas sector had dismissed last week’s legislative vote as “politically motivated” and said it would prevent an economic revival in the western reaches of Maryland.