In Texas, there were more than 2,700 spills at oil and gas sites last year. But the state tracked only about half of those.
Unlike other states, Texas doesn't track spills of wastewater. The Texas Railroad Commission (RRC), which regulates oil and gas, tracks only spills of petroleum products -- primarily crude oil.
The difference in scrutiny makes no sense to Kerry Sublette, a chemical engineering professor at the University of Tulsa who says wastewater spills are more damaging.
"If you were trying to prevent spills," Sublette said, "wouldn't you want to look at what's causing them? Where they're happening? All that kind of information?"
Records compiled by EnergyWire show there were at least 2,732 spills reported to RRC district offices in 2015. The agency's record of spills of crude oil and condensate includes 1,485 spills, about 54 percent of the total number.
Those were among at least 10,348 spills and other mishaps across the country in 2015, compared with 11,283 in 2014, according to an EnergyWire analysis. In the 17 states where comparisons could be drawn, the number of spills dropped 8 percent (EnergyWire, July 21).
The RRC, whose name is a holdover from an era in which oil was transported by trains instead of pipelines, is one of the few agencies to post enforcement data. The agency reported finding 18 violations of spill reporting rules in 2015, and no violations of its oil spill regulations.
All spills are supposed to be reported to RRC district offices, though there is documented confusion about that requirement. In most offices, the mishaps get logged on spreadsheets.
If the spill is crude or condensate, and it's five barrels or more, the company must follow up with a specific form. Called an "H-8," the form requires information about the extent of the spill and how it's being cleaned up.
The H-8 forms are compiled, and data about them are posted on the RRC website.
But no such scrutiny is applied to spills composed entirely of wastewater, often called brine, salt water or produced water.
So, Cimarex Energy Co. didn't have to file a spill form after a crew lost control of the company's Sawtooth 55-6 well and spilled more than 700,000 gallons of wastewater in February 2015. The spill in Reeves County, west of Odessa, occurred after a gasket leaked, according to the district office spill log.
RRC officials say the spills must be cleaned up, but critics question how the agency can ensure proper cleanup if incidents aren't tracked.
In response to questions about spill reporting and tracking, RRC spokeswoman Ramona Nye stressed that agency rules prohibit polluting water with any oil field fluid, including wastewater. The agency reported 261 violations of its water protection rules in 2015.
"Protection of public safety and our natural resources is the Railroad Commission's highest priority," Nye said.
To get the spill totals for Texas, EnergyWire filed an open records request for the spill records from the agency's 11 district offices. The district office in Wichita Falls, covering the Panhandle, doesn't keep a spreadsheet of spills.
Large onshore oil spills can be dangerous to humans in the communities where they occur. But experts say brine spills are as damaging as oil spills to soil and plants -- sometimes much more so.
Oil can be scraped away, and what remains degrades over time. Salty, toxic wastewater can penetrate deeper into soil, reaching groundwater more easily and turning productive farmland into concrete-like hardpan.
"Unlike oil, time is not a cure," said Duke University geochemist Avner Vengosh, who has studied wastewater spills in several states (Greenwire, April 28). Researching spills in North Dakota, he and colleagues would visit sites of years-old spills and "find the brine there waiting for us to collect it."
Large spills can take companies years to clean up. And Sublette said if a spill isn't cleaned up, nothing will grow on the affected area for generations.
"It's the gift that keeps on giving," he said.
Sublette believes spill numbers documented in the district office logs are an undercount. He teaches workshops on spill cleanup, and in Texas he routinely meets oil company people who don't think that wastewater spills need to be reported to the state.
RRC representatives stress that operators are required to report any spill. But that's not always the understanding of those outside the agency's media affairs office. Last year, the agency's former director told EnergyWire that while cleanup is mandatory, reporting is voluntary (EnergyWire, Nov. 18, 2015).
And a manager for the University of Texas' University Lands system said his agency uses a spill cleanup guide that incorporates a 2005 RRC draft guide that says "all produced water notifications are voluntary."
"A lot of producers, they do not feel that they are compelled to report brine spills. That's their perception," Sublette said. Some companies, especially larger ones, report anyway because it's corporate policy. But, he said, "It appears some smaller companies are confused, or are taking advantage of the confusion."
Click here to see the EnergyWire national database of spills.
Click here for information about the data.
Reporter Pamela King contributed.