PIERRE, S.D. (AP) -- A South Dakota House committee has rejected a measure that would have made it clear hydraulic fracturing is an acceptable production technique for oil and gas.

The Agriculture and Natural Resources Committee voted 9-4 to kill the bill after an aide to Gov. Dennis Daugaard said it is unnecessary because state law already allows hydraulic fracturing.

Hydraulic fracturing, also known as "fracking," involves pumping water, chemicals and grit underground at high pressure to create and prop open cracks in oil-bearing rock. That promotes the flow of oil.

Opponents argue fracking could harm underground water supplies, but supporters say it is safe.

South Dakota is seeking to expand the amount of oil and gas production in the state. The fracking process likely would be widely used in oil and gas wells.