ODESSA, Texas -- Elaine Beadle initially thought the odor creeping into her home on this city's west side was a sewer leak.
It started about the time she moved in four years ago -- a smell like rotten eggs. Sometimes it got so bad her eyes burned.
She soon learned the real source: a tank battery that collects oil and gas from wells scattered throughout the vacant land and small homes near the intersection of University Drive and Loop 338.
The gas in the tank battery contains more than 300 times the lethal level of hydrogen sulfide, a common byproduct of oil production in West Texas.
A catastrophic leak at the battery, which served the J.E. Bagley lease, would allow potentially deadly doses of the gas to drift 95 feet, and the levels would be high enough to sicken people at 200 feet. The nearest homes are perhaps 100 to 150 feet from the battery.
The tank battery's operator, Cambrian Management, said there's no danger to Beadle or her neighbors because production on the J.E. Bagley Lease is small -- 40 to 50 barrels of crude a day and small amounts of gas. The worst-case emissions event could happen only if 24 hours' worth of gas production were released at once.
The battery has leaked four times since 2011, according to records from the Texas Railroad Commission, which regulates oil and gas drilling in the state.
The Railroad Commission has threatened three times to shut down production from the tank battery but has relented when the owner made repairs.
"We just get a letter stating they were working on it. They said that every time, and you still smell it," Beadle said.
Living with "sour gas" is an old story in West Texas, but it's beginning to happen in more oil-producing regions as the boom in onshore drilling pushes oil production into new places. Neither the states nor the federal government tracks the amount of hydrogen sulfide production, but complaints and permitting related to hydrogen sulfide are growing in four states, according to documents and interviews.
The gas is deadly in small amounts. It can stop a person's breathing at a concentration of 500 parts per million and render people unconscious within seconds at 700 parts per million.
There's a catch, too: As the concentration increases, the gas deadens people's sense of smell, making it hard for them to detect the danger. And if that's not enough, it can corrode steel and iron.
It has killed at least five oil field workers since the beginning of 2013 and in 1975 was responsible for one of the worst oil field accidents ever.
That has led to complaints from environmentalists, who say that state regulators aren't keeping up with the increase in sour gas production.
"More than anything else in oil and gas, hydrogen sulfide kills," said Neil Carman, clean air director of the Sierra Club's Lone Star Chapter in Texas.
Exact comparisons are difficult because each state keeps its records differently. In Kansas, state regulators received 15 requests to flare gas containing hydrogen sulfide in 2013, up from three in 2012 and none from 2009 to 2011, state records show. Most of those cases involve the Mississippi Lime field.
Oklahoma regulators calculated that oil and gas operators emitted 594 tons of hydrogen sulfide in 2011 and are planning to do more monitoring of air emissions overall. In New Mexico, which shares patches of the sour gas-producing Permian Basin with Texas, state officials received reports of five hydrogen sulfide releases in 2013, after receiving none in 2012 and four in 2011.
Texas tracks the amount of gas produced in fields that also have hydrogen sulfide, although it doesn't track the actual amounts of hydrogen sulfide, and not all of the gas produced in those fields is sour. The amount of gas from hydrogen sulfide-containing fields rose 48 percent over five years, from 1.2 trillion cubic feet in 2009 to 1.7 trillion cubic feet.
The state requires special permits for oil wells, pipelines and processing plants that handle gas containing more than 100 parts per million of hydrogen sulfide. The state issued 6,906 of the permits in 2013, up 63 percent from the 4,233 it issued in 2009.
A lethal leak
Texas and most other states adopted their hydrogen sulfide regulations nearly 40 years ago after an oil field accident showed the full potential danger from the gas.
Early in the morning on Feb. 2, 1975, an Arco oil well outside Denver City, Texas, sprang a leak. The well was being injected with gas in order to increase its pressure and force out more oil. The gas contained 40,000 parts per million of hydrogen sulfide, though, and the cold air and the windless conditions allowed the gas to concentrate along the ground, according to media reports from the time.
Nine people died, including eight who had gathered at the home of J.C. Patton, a farmer who lived 150 to 200 yards from the oil well.
"That stuff can get you so fast, you don't realize you're in it till it's too late," said Jack Watkins, who was a volunteer firefighter in Denver City in 1975.
Watkins and another firefighter strapped on air packs and helped find the victims after another rescue crew's vehicle got stuck in a field, he said in an interview. He passed a dead dog on the Patton home's back porch and came upon two people, both dead, in the cab of a pickup truck. A few steps later, J.C. Patton was sprawled on the ground. Nearby, two women and two teenage girls were in a passenger car, its engine still running. A man's body had fallen partially out of the car.
"You could tell they'd been fighting this gas -- they had washcloths over their mouths," Watkins said.
The ninth victim, an Arco worker, was on his way to help with the leak when he died in his pickup by the side of a nearby highway.
In the wake of the Denver City deaths, Texas adopted Statewide Rule 36. In addition to requiring permits for wells that produce hydrogen sulfide, the rule requires operators to file contingency plans in situations where a hydrogen sulfide leak could affect a populated area or a public road.
The Railroad Commission says the rules have worked well since then.
"Staff tells me anecdotally they have not had an off-lease fatality since the adoption of Statewide Rule 36," Gaye McElwain, a Railroad Commission spokeswoman, wrote in an email.
New wave of drilling creeps closer to homes
A few things have changed since the Texas rules were adopted. In 1975, oil production was declining in the state. Output peaked at more than 3.4 million barrels a day in 1972 and settled at just over 1 million barrels a day in the mid-2000s.
The downturn meant the Odessa area's boomtown growth slowed to a trickle. Ector County, which includes Odessa, saw its population more than double to about 91,000 people from 1950 to 1960. Between 1980 and 1992, it added 3,500 people, according to the "Handbook of Texas Online."
Starting about 2010, oil production began to rebound, as exploration companies used horizontal drilling and hydraulic fracturing to open up new fields. It turned out that the Permian Basin, already one of the most prolific oil regions in history, was sitting on several shale fields, stacked like layers in a wedding cake.
At the same time as the Wolfcamp, Spraberry and Cline shales were helping revive the Permian Basin's oil production, a few wildcatters were drilling the Eagle Ford Shale between San Antonio and Laredo.
By July, oil production in Texas had nearly tripled in five years to 3.1 million barrels a day, according to the U.S. Energy Department.
Some of the new shale fields, though, have high levels of hydrogen sulfide. Parts of the Eagle Ford field have a maximum concentration of 68,000 parts per million, 130 times the lethal level, according to Railroad Commission data.
Parts of the Wolfcamp and Spraberry fields, discovered in Ector County, have levels even higher -- 80,000 to 123,000 parts per million, according to Railroad Commission records.
And the Odessa region is growing again. Between 2010 and 2013, Ector County's population grew 8.9 percent to 149,000. Odessa and neighboring Midland were No. 2 and No. 3 on the Census Bureau's list of fastest-growing U.S. metro regions.
Similar situations are happening in Kansas and Oklahoma, where parts of the Mississippi Lime field have high levels of hydrogen sulfide.
In Oklahoma, two university students reported getting sick from hydrogen sulfide fumes while doing research on the Nature Conservancy's Tallgrass Prairie Preserve in 2012, preserve Director Bob Hamilton said.
In Kansas, the Oil Conservation Division received complaints in December from two people in Finney County who said they were being sickened by an Occidental Petroleum well that was venting gas with 800 parts per million of hydrogen sulfide.
In June, regulators discovered that gas with 130 parts per million of hydrogen sulfide was being piped directly to four homes and two business in Clark County, according to emails obtained under the state's freedom-of-information law.
Neither Oxy nor Kansas Gas was penalized for the problems, Ryan Hoffman, director of the Kansas Corporation Commission's oil and gas division, said in an interview.
Kansas bought hydrogen sulfide monitors for its 40 field inspectors last summer after two roustabouts were killed at a well site.
In November, one of the inspectors suggested to his supervisor that the commission buy more sophisticated monitors.
"With the work we do, sometimes there are wells venting in residential areas," the inspector wrote.
Danger or nuisance?
Complaints are on the rise in Texas, too -- more than 30 people called the Railroad Commission to report hydrogen sulfide odors in 2013, up from 11 in 2012 and 15 in 2011.
The Railroad Commission's Midland office sent a letter to oil producers in 2012 reminding them about the state regulations that prohibit venting gas in populated areas. The advisory came after an oil company working on a Spraberry-Wolfcamp well vented gas with hydrogen sulfide onto a neighborhood, prompting residents to leave their homes and call the local fire department.
Less than a half-mile from Beadle's neighborhood, a motorist reported that she was enveloped by a cloud of hydrogen sulfide when she stopped at a traffic light. The Railroad Commission found a valve stuck open on a tank battery operating by Occidental Petroleum, one of the biggest oil producers in the Permian Basin.
The Railroad Commission didn't impose a fine in either incident.
Occidental declined requests for an interview about the Kansas and Texas incidents but issued a statement saying it is committed to safety.
Beadle and her neighbors say the Bagley tank battery's problem illustrates how ineffective the Railroad Commission has been in policing hydrogen sulfide emissions, even after years of complaints.
"Every time I get close to getting something done, they sell it," said Bob Scott, who grew up in the neighborhood.
One of the first wells on the Bagley lease was drilled in 1937 and "shot" with 400 quarts of nitroglycerin to boost its production, according to records on file with Cambrian Management, the lease's manager. At the time, the wells were located in a rural area, but the city of Odessa has encroached on it over decades.
Several wells in the area were combined into one lease and then flooded with water in the 1960s to boost production.
The tank battery for the lease is connected by pipe to the four or five wells that are still producing. The tanks separate the oil and gas from wastewater, and the gas is either shipped out through a pipeline or burned in a flare.
Cambrian, based nearby in Midland, took over the lease in 2001.
In December 2011, a resident who lived three blocks from the tank battery complained to the Railroad Commission that fumes were giving his family headaches and causing his son's asthma to flare up. Scott complained in August 2013. In September 2013, Charles Wilson, who lives two blocks from the Beadles, called the commission, saying the smell was drifting into his home. In December 2013, Elaine Beadle's son, Rikki, called the commission.
The commission's inspectors found similar problems each time they were called out -- gas containing hydrogen sulfide was leaking from open hatches or cracks in the tanks, or because of malfunctioning equipment like the vapor recovery unit or the flare. In the December inspection, the inspectors wrote that their "personal h2s monitors alarmed on high alarm when trying to enter gate to battery."
After three of the complaints, the commission sent letters saying it would revoke Cambrian's permission to sell oil and gas from the well, a process known as a severance. The cases were dropped after Cambrian made repairs, even though the work sometimes took months.
After Wilson's complaint, the commission tried to take more extensive legal action, saying Cambrian hadn't updated its paperwork to show that the tank battery was in a sensitive area. The commission realized, though, that it had misfiled Cambrian's paperwork and dropped the action.
As of June, inspectors visiting the site found "a deffinant [sic] smell of h2s" although their monitors were no longer going off.
"With our technology that we have, they should be able to do something about the populated areas," Wilson said in an interview.
Cambrian President Alan Means, an affable Missouri native who keeps a baseball signed by the 1957 St. Louis Cardinals in his office, said he understands the neighbors' concerns but said there's no danger -- only a nuisance.
"I'd complain, too, because it stinks," he said.
There's equipment that could neutralize the hydrogen sulfide at the wellhead, but it's too expensive, Means said. The company could also move the battery away from the homes, which would require digging up and reinstalling the pipelines connecting it to the nearby wells. But at about $100,000, Means said he can't justify the cost.
"The tank battery was there long before the people were," he said. "They bought their houses, or rented them, knowing about it."
Calls for tougher oversight
The Railroad Commission declined interview requests. McElwain, the spokeswoman, defended its investigations in a series of emailed responses. But the real responsibility for air pollution complaints at people's homes lies with another agency, the Texas Commission on Environmental Quality, McElwain said in an email.
U.S. EPA has tried twice to tighten regulations on hydrogen sulfide, with limited success.
Hydrogen sulfide was on the original list of hazardous substances to be included in the Clean Air Act of 1990, which would have required it to be treated and monitored as an air pollutant. But it was removed before the act became law, after heavy lobbying from industry.
But in 2010, EPA moved to reinstate reporting requirements under the Toxics Release Inventory (TRI) program. TRI is a public database that is designed to provide individuals information about chemical pollutants and waste near where they live.
API, along with trade groups for paper companies and refiners, argued in 2010 that the exclusion of hydrogen sulfide from EPCRA hadn't caused any problems and said exposure to small amounts, such as 5 parts per million, haven't been shown to cause problems.
Nevertheless, EPA in 2011 reinstated the reporting requirements. But most oil and gas production facilities are exempt because they are small sources that fall below the reporting thresholds.
That leaves enforcement of hydrogen sulfide safety in the hands of state oil and gas regulators, many of whom are also tasked with promoting the industry they regulate. In Texas and Oklahoma, the regulators are elected statewide and frequently receive campaign contributions from energy companies.
Texas pursued enforcement cases against 2 percent of the 55,000 violations its oil and gas inspectors found in 2012. New Mexico's oil and gas regulation division hasn't been able to issue fines since 2009, when a court sided with an oil company that claimed only the state attorney general could pursue enforcement of oil regulations (EnergyWire, July 15, 2013; EnergyWire , Nov. 14, 2013).
Environmental groups say a combination of technology and tougher oversight could reduce the danger.
The Sierra Club and other environmental groups pointed to California's system of permits and monitors as a model when they pushed for EPA to tighten federal regulations. The state requires companies that emit hydrogen sulfide and other gases to run models showing whether their businesses pose a danger. If there's a risk, the local air control district steps in and can require the company to take steps to lower the emissions. The approach has worked, since the state's network of air monitors showed a decrease in sour gas levels, according to a letter the Sierra Club and other groups sent to EPA in 2009.
In February, Colorado started requiring oil and gas companies to check for leaks at wellheads, tank batteries and other equipment using infrared cameras and fix any problems within a set period of time. The rules are intended to cut down on emissions of methane, the main ingredient in natural gas, but they would also cut down on hydrogen sulfide and other toxic chemicals associated with energy production, said Andrew Williams, a senior state regulatory affairs manager at the nonprofit Environmental Defense Fund.
In Kansas and Oklahoma, parts of the Mississippi Lime field lie on American Indian land or on land where the tribes own the mineral rights. That has led to a tangle of state and federal agencies trying to oversee oil production, said Tom Williams, a consultant for the Houston-based Environmentally Friendly Drilling Program. Solving the jurisdictional problems and making sure the agencies have the staff and training they need would help them deal with the uptick in drilling, he said.
"Regulations aren't worth a hoot when you don't have competent regulators," he said.
Click here to see the oil fields in Texas containing hydrogen sulfide and the maximum concentrations.
Reporter Mike Soraghan contributed.