Texas regulators are warning that wastewater from fracking in the biggest US oil basin is causing a “widespread” increase in underground pressure — a development that risks hindering crude output and harming the environment.

Shale oil wells in the Permian Basin generate millions of gallons of chemical-laced water, which drillers then pump back into the earth. Landowners and activists have said for years that this process causes toxic leaks. Now the state’s powerful oil and gas regulator, the Railroad Commission of Texas, is acknowledging the scale of the problem and imposing restrictions that could increase crude production costs.

Restrictions on both deep and shallow injection zones could mean producers will have to pump their wastewater farther afield, increase recycling or pay to clean it up. All of these options would add to costs in the Permian, which accounts for about half of America's total crude production.

Permian Basin oil production has soared over the past decade to about 6.7 million barrels of oil each day — more than the output from Iraq and Kuwait combined. But for each barrel of crude, it produces three to five barrels of water that contain so much salt and toxic materials that pumping it back underground is the only cost-effective disposal method.

bloomberg.com - Why the biggest US oil field is at risk of leaking poisonous water

While OXY is not cited in the article its cost of extraction could increase by new regulations on wastewater disposal.