Of the 1,073 releases reported last year, about 60 percent involved oil and one-third spread brine. In about two-thirds of the cases, material was not contained to the accident site and leaked into the ground or waterways.
But the official data gives only a partial picture, Roberts said, missing an unknown number of unreported incidents.
"One, five, 10, 100? If it didn't get reported, how do you count them?" he said.
He said truckers often dump their wastewater rather than wait in line at injection wells. The Department of Mineral Resources asks companies how much brine their wells produce and how much they dispose of as waste, but its inspectors don't audit those numbers. Short of catching someone in the act, there's no way to stop illegal dumping.
The state also has no real estimate for how much fluid spills out accidentally from tanks, pipes, trucks and other equipment. Companies are supposed to report spill volumes, but officials acknowledge the numbers are often inexact or flat-out wrong. In 40 cases last year, the company responsible didn't know how much had spilled so it simply listed the volume of fluid as zero.
In one case last July, workers for Petro Harvester, a small, Texas-based oil company, noticed a swath of dead vegetation in a field near one of the company's saltwater disposal lines. The company reported the spill the next day, estimating that 12,600 gallons of brine had leaked.
When state and county officials came to assess the damage, however, they found evidence of a much larger accident. The leak, which had gone undetected for days or weeks, had sterilized about 24 acres of land. Officials later estimated the spill to be at least 2 million gallons of brine, Roberts said, which would make it the largest ever in the state.
Yet state records still put the volume at 12,600 gallons and Roberts sees no reason to change it.
"It's almost like rubbing salt in a raw wound," Roberts said, criticizing efforts to tabulate a number as "bean counting." Changing a report would not change reality, nor would it help anyone, he added. "If we try to go back and revisit the past over and over and over again, what's it going to do? Nothing good."
In a written statement, Petro Harvester said tests showed the spill had not contaminated groundwater and that it would continue monitoring the site for signs of damage. State records show the company hired a contractor to cover the land with 40 truckloads of a chemical that leaches salt from the soil.
Nearly a year later, however, even weeds won't grow in the area, said Darwin Peterson, who farms the land. While Petro Harvester has promised to compensate him for lost crops, Peterson said he hasn't heard from the company in months and he doesn't expect the land to be usable for years. "It's pretty devastating," he said.
The Department of Mineral Resources and the Health Department have the authority to sanction companies that spill or dump fluids, but they rarely do.
The Department of Mineral Resources has issued just 45 enforcement actions over the last three years. Spokeswoman Alison Ritter could not say how many of those were for spills or releases, as opposed to other drilling violations, or how many resulted in fines.
The Health Department has taken just one action against an oil company in the past three years, citing Continental Resources for oil and brine spills that turned two streams into temporary toxic dumps. The department initially fined Continental $328,500, plus about $14,000 for agency costs. Ultimately, however, the state settled and Continental paid just $35,000 in fines.