Motors blamed for river pollution

Estimated 10,000 gallons of petroleum entered water in summer 2003

Posted: Friday, November 21, 2003

Preliminary results of a study done by the Alaska Department of Environmental Conservation suggest that motorboat traffic is responsible for the majority of hydrocarbon pollution found in the Kenai River.

The Kenai River Petroleum Source Assessment 2003, conducted last summer by DEC researchers Tim Stevens and Kent Patrick-Riley, found that when boat traffic is highest on the river, pollution levels can rise to near or above the 10 parts per billion standard set by the state. Patrick-Riley and Stevens presented their findings in a report to the Kenai River Special Management Area Advisory Board on Thursday evening.

The findings are nothing new, but they are the most concrete evidence to date suggesting a correlation between increased boat traffic and pollution from oil and gas. Stevens told the board Thursday that their findings make it clear that the vast majority of the contamination comes from motorboats in the lower river.

"What we did find was contaminated sites and other sources do not appear to be contributing measurable levels of petroleum in the river, with the one exception of motorboats," Stevens told the board.

Overall, it's estimated by DEC that at least 10,000 gallons of petroleum products entered the river this summer. And Stevens cautioned that's probably a conservative estimate.

He said the DEC used data collected in 2003, as well as from studies done by other groups, to arrive at its results. Sampling was carried out at a number of sites in the lower river, at different times of the summer and at different water depths. In all, 284 samples were collected between May and August.

The highest levels of hydrocarbon contamination were found during the highest levels of boat use. Patrick-Riley said that when the July king salmon fishery began to pick up, a direct rise in hydrocarbon levels was observed.

"As soon as the boat traffic starts on July 1, bam," he said.

The levels observed were generally found to be below the level the state sets as acceptable for fish and other aquatic life. However, at several times of peak contamination, levels did approach the threshold of 10 parts per billion set by the state.

"We had two exceedances that were above 10 parts per billion," Stevens said.

DEC did not make any recommendations as to how contaminant levels can be brought down. However, both Stevens and Patrick-Riley said one factor appears to be a major contributor that will have to be looked at.

"This would be a lot worse if we didn't have four-stroke (outboards) on the river," said Patrick-Riley, who pointed out that two-stroke engines appear to be a major contributing factor. However, both he and Stevens cautioned that more modeling must be done to determine the exact causes of the contamination.

The state's study comes as no surprise to Kenai Watershed Forum Director Robert Ruffner. The forum has found similar results during the past three years in its own monitoring project.

Ruffner said Thursday that he welcomes the study and hopes it will spur the state to support the ongoing monitoring effort already in place on the Kenai.

"We've put a lot of time and effort into getting everyone on the same page with a five-year agreement that everyone signed on and agreed needs to happen," Ruffner said.

Ruffner said he's worried that now that the state has conducted its own study, future local monitoring efforts may be in jeopardy.

"We would really hope DEC would not work in a vacuum," he said.

However, he said he fully supports any work done to increase the amount of knowledge about pollution in the Kenai River, which supports local commercial fishing and tourism industries, as well as a large subsistence sockeye fishery.

"I'm very happy they did a follow-up study," Ruffner said.

Board member Jonne Slemons, who also works for DEC, said that as a result of the KWF and state studies, the state is now expected to increase its funding for Kenai River monitoring next year.

"A portion of the monitoring funds ... are being made available," Slemons said.

She noted that the cost of the recent study came to roughly $131,000 for the entire project.

Although the levels of contamination are not believed to pose an imminent risk to fish populations or humans, DEC believes the levels are something to be concerned about.

That's because increasingly high levels of exposure to hydrocarbons could eventually lead to negative consequences for area fish populations.

However, Stevens said, at this time, DEC doesn't see any imminent threat to the Kenai's fish at this time.

"We're told the low levels we're seeing would not be detected in fish tissues," he said.

Still, now that the state has compiled data showing that there are elevated levels of hydrocarbons in the Kenai, it is expected that groups like KRSMA will look into ways to lower the risks associated with such pollution.

That could prove to be a hot topic over the winter, as any solution brought forward is likely to impose upon one user group or another.

Ruffner said the Kenai Watershed Forum does not want to get into what steps need to be taken to cut down on the pollution. Instead, he simply wants to see a sustained effort to monitor exactly what's happening on the river.

"Our focus is on good science," he said. "We want to be separate from the decisions the community as a whole needs to make."

For now, DEC plans to further compile its data before releasing a final report in January. Until then, neither the state nor the KRSMA board will take any action to correct the problem. However, hydrocarbon levels on the Kenai during peak boat traffic times do seem to be becoming more of an issue as more data is collected.

"(The levels are) enough for us to be concerned about," Patrick-Riley said.


Due to a reporters error, misleading information appeared in an article in Fridays Peninsula Clarion about Kenai River petroleum contamination. According to Jonne Slemons, program manager for the DECs nonpoint-source water pollution control program, although new state funds are likely to become available for water quality monitoring statewide, there is no guarantee any of those funds will go toward monitoring efforts on the Kenai.

We are just making funding opportunities available state-wide, Slemons said Friday. We cant guarantee funding because it depends on the proposals we get.

Subscribe to Peninsula Clarion

Trending this week:


© 2018. All Rights Reserved. | Contact Us