CROSSROADS, N.M. — Carl Johnson and son Justin, who have complained for years about spills of oilfield wastewater where they raise cattle in the high plains of New Mexico, stroll across a 1 1/2-acre patch of sandy soil — lifeless, save for a scattering of stunted weeds.

Five years ago, a broken pipe soaked the land with as much as 420,000 gallons of wastewater, a salty drilling byproduct that killed the shrubs and grass. It was among dozens of spills that have damaged the Johnsons’ grazing lands and made them worry about groundwater.

“If we lose our water,” Justin Johnson said, “that ruins our ranch.”

Their plight illustrates a side effect of oil and gas production that has worsened with the past decade’s drilling boom: spills of wastewater that foul the land, kill wildlife and threaten freshwater supplies.

An Associated Press analysis of data from leading oil- and gas-producing states found more than 180 million gallons of wastewater spilled from 2009 to 2014 in incidents involving ruptured pipes, overflowing storage tanks and even deliberate dumping. There were some 21,651 individual spills. The numbers are incomplete because many releases go unreported.