Carbon monoxide is killer on Lake Powell
By Maureen West and Judd Slivka
The Arizona Republic
Nov. 29, 2000

Carbon monoxide poisonings have caused nine deaths and 102 injuries at Lake Powell over the past decade, Arizona and federal investigators have discovered.

Two-thirds of these cases, including seven of the deaths, were associated with the exhaust from electric generators on privately owned houseboats.

Across the country, there have been similar incidents, but no one connected them with carbon monoxide poisoning until this past summer, when two Colorado boys apparently drowned in the northern Arizona lake. Click here to see bigger version of picture

When investigators conducted autopsies of the two boys, they discovered that the actual cause of death was asphyxiation due to excessive carbon monoxide exposure.

That led Dr. Robert Baron, a Phoenix emergency-room doctor who also works for the National Park Service, to renew inquiries he had been making into other deaths and injuries on the lake.

Teaming up with Jane McCammon, a carbon monoxide expert with the National Institute for Occupational Safety and Health, he found improbably high levels of the colorless, odorless and potentially deadly gas often gathering beneath the swimming deck of houseboats. It's a favorite place for swimmers to play, and it's also where many houseboat generators vent their exhaust.

Researchers call it the "death zone."

Six of the Lake Powell victims were swimming or working on their houseboats in the space under the swim deck.

"It is the scariest investigation I have ever done," said Jane McCammon, a carbon monoxide expert with the National Institute for Occupational Safety and Health. "The carbon monoxide concentrations are so high where you have your children playing, where you are watching them play."

Carbon monoxide concentrations were measured at 30,000 parts per million (ppm) in the death zone, 25 times the level of exposure (1,200 ppm) that's considered "immediately dangerous," she said. Even people sitting on the swim deck or slide were taking in carbon monoxide levels of 7,000 ppm, McCammon said.

Gas levels on one of the boats tested in September were so high that experts had to evacuate as fumes red-lined their equipment.

The two boys' deaths provided a key to a persistent national puzzle: Why were so many boaters dying outside their houseboats, beneath blue skies, on days that were supposed to be filled with fun, frolic and swimming?

Why, for example, did a Tennessee man fixing a problem on his houseboat's stern dive beneath the surface and not reappear? Why did the same thing happen when his son jumped in to save him?

Lake Powell, part of the Glen Canyon National Recreation Area on the Arizona-Utah border, is the first area to be extensively studied. But investigators are finding similar situations across the nation. Lake Cumberland, Ky., considered by many to be the houseboat capital of the country and the home of at least two major houseboat manufacturers, is next on investigators' lists. In August, 15 people on two houseboats were hospitalized after they were overcome by carbon monoxide fumes.

The U.S. Coast Guard, which is studying the issue, sees the danger but doesn't know what to do about it.

"The builders of these boats are technically not in violation of any rules," said Randolph Jay Doubt, a Coast Guard engineer. "We do not regulate design. We do not regulate materials," Doubt said. "It's difficult to think in terms of demanding a recall when you can't figure out what the problem is. If we know one problem, we can fix it. In this case, it's not so easy. We're not certain what the fix is. "We're at the point we've decided it's a design problem."

The Coast Guard is requesting proposals to come up with ways of fixing houseboats with "death zones." But the proposals aren't due until late December, and it is doubtful that any measures will be enacted until spring.

"I want the companies to come in and tell me what's appropriate," Doubt said.

Warning signs

Houseboating is big business on Lake Powell. In summers, various coves look like floating cities. Nearly 2,000 houseboats are moored at four of the lake's five marinas. Nearly 400 of those houseboats belong to Lake Powell Resorts and Marinas, the National Park Service's concessionaire for the lake.

None of the company's houseboats use a rear-venting system, said Steve Ward, the company's director of public relations. All of the company's boats use side vents; the last of the rear-venting boats were sold off some years ago. They made the change for safety reasons.

Perhaps it is telling: Every death on the lake has come on a houseboat with rear vents - and with private owners or multiple owners, like a time-share condominium. Though some companies in the houseboat industry are moving away from rear exhaust vents, the older boats are still around, being passed from person to person because of the price tag.

The manufacturers are aware of the investigation. The National Park Service sent a report describing the deaths and injuries to the nearly 60 houseboat manufacturers nationwide.

Five years ago, Sumerset Houseboats started using side vents to air out generator exhaust. But previous to that, the company's boats used an exhaust vent for the generator beneath the afterdeck.

"It was the industry standard to vent out the back," said R. Michael Johnson, a Sumerset spokesman. "Then people started putting slides over the back. They started putting huge swim decks over the back." Many of the industry leaders, recognizing the safety problems, adjusted.

Still, they see enough of a potential problem that many companies run aggressive boater education campaigns.

"Warning," screams a sign on the hatch of Sumerset boats, "Do not swim with generator running. Carbon monoxide poisoning could occur." With warnings - and carbon monoxide detectors a standard item in newer houseboats, including all the rental boats on Lake Powell - the industry does deflect some of the blame on boaters who build outsized swim decks or ignore the warning on the generator hatch. "It's like locking yourself in a garage with the car running," Johnson said. "Yes, the car will kill you, but is it General Motors' fault?"

But others, such as McCammon, wonder why the manufacturers would build the swim area, including slides, over the exhaust area.

Key to the puzzle

Logan and Dillon Dixey, 8 and 11 years old, were swimming around and under their family's houseboat on Lake Powell this summer. They swam into the "death zone."

Suddenly, Logan lost consciousness and sank to his death. Dillon went into convulsions. His older brother Connor, on the boat, thought Dillon was just goofing around.

Then Dillon sank, too.

With those deaths, something clicked in Baron, the co-director of the emergency center at Good Samaritan Regional Medical Center and the medical director for Glen Canyon National Recreation Area. In 1995, Baron first raised concerns about several mysterious deaths and injuries at the lake, but he couldn't identify a unifying pattern. A young woman died at the back end of an open boat. Healthy young people were having seizures or falling unconscious while swimming.

"I couldn't come up with one reason," Baron said.

So many people were traumatized after the death of the Dixey boys in August that Baron called a panel of federal officials to look at all boating-related carbon monoxide injuries.

"Something bigger is going on here," he told them.

Officials were surprised to find more than 100 carbon monoxide cases.

"Until this fall, until Jane McCammon's readings, we had no data on carbon monoxide levels, no proof. All we had were people going unconscious. Before it was all guesses. Now it is real," Baron said. The Lake Powell statistics, if typical of recreation houseboat communities, may mean that houseboats might be responsible for thousands of injuries or deaths across the United States, McCammon said. The design of the houseboats involved in the fatalities all have a generator exhaust system that directs the exhaust fumes underneath the back deck and swim platform. In most designs, there is a cavity underneath the back deck created by the back step where exhaust is trapped.

While the houseboat's main engine isn't normally running while people swim, the generator is often running continuously to operate appliances, often including televisions, VCRs, air-conditioners and lights.

Of the 67 non-fatal carbon monoxide poisonings on houseboats, 30 people were outdoors, and 25 of them lost consciousness, including 12 who were pulled from the water and revived.

A mother trying to keep her daughter from sunburn kept calling the little girl to the side of the boat to get suntan lotion. A few minutes later, the young girl was unconscious and sinking. Her mother saved her, and she recovered.

Another girl was trying to get sand out of her bathing suit when she lost consciousness. Again, she was saved.

Children can be affected faster because their heart and breathing rates are quicker, Baron said.

A solution?

Both McCammon and Baron insist that the boats must be recalled and corrected.

"I don't want to read another report about another child or adult who died," McCammon said.

"I have seen enough and don't want it to happen again," Baron agreed. "The manufacturers have to realize there is a problem and to do something about it. People are dying."

Unlike automobiles, neither the main engines nor electrical generators of houseboats typically have catalytic converters, which would remove up to 90 percent of carbon monoxide and reduce air pollution in recreation areas.

But the Coast Guard remains unwilling to issue a recall.

"It's not just houseboats that use this design," the Coast Guard's Doubt said. "So if we issue a recall on the houseboat design, we recall a lot more than just houseboats."

Retrofits can be expensive, since they often need the boat to be taken out of the water, which requires a truck, then rerouting the exhaust system through the side of the hull.

Until the Coast Guard decides what to do, authorities will have to rely on education programs and voluntary action.

The Arizona Department of Health Service and the Arizona Game & Fish Department plan today to launch a public awareness campaign to educate boaters about carbon monoxide poisoning.

"For boaters, being poisoned by a deadly gas is probably the furthest thing from their minds," DHS Director Catherine Eden said. "We want people to take steps to ensure they don't become part of these alarming statistics. The hazards of carbon monoxide will become the top priority of the state's boat safety program. A statewide effort is especially important because similar conditions to Lake Powell exist on lakes across Arizona."

And while Kenneth Dixey, whose two sons drowned in the cold water of Lake Powell this summer, says he is heartened that someone is taking notice, a bitterness remains.

"Why did it take my two sons' lives to get this going?"


Reach the reporters at or (602) 444-8167; and at or (602) 444-8097.
Copyright 2000, The Arizona Republic. All rights reserved. This article graciously provided courtesy of The Arizona Republic.