There would usually be at least a couple hundred people splashing in the water, picnicking on the beach and running through the grass; but on a particularly warm morning July 22, the sand along the shore at Eagle Island State Park was neatly groomed and untouched, the water completely still. The park was virtually empty, owing to the bright yellow signs scattered around the grounds declaring the beach closed until further notice.
Gary Shelley was there, though. Eagle Island park manager for the past 10 years, he looked over the empty, sun-baked beach in evident disappointment.
"I miss the people," he said, with shoulders slumping. "I want to get them back here as quick as we can."
Shelley was at home on Sunday, July 13, when his assistant park manager called with bad news: People were posting on Eagle Island's Facebook page that their families got sick after swimming at the park. But Shelley had just seen the results from water samples taken on July 9--which look for E. coli and other fecal coliform--and they all came back normal.
Regardless, the Idaho Department of Parks and Recreation made the call, and closed the park the next day, after it was established that the water was tainted with norovirus, a stomach bug that causes vomiting and diarrhea for a few days.
While the park reopened July 26 after nearly two weeks of cleanup efforts, the problem remains that IDPR's tests could never have caught the illness that sickened Eagle Island's visitors.
There isn't a standard test to detect norovirus in water; only patient samples reveal the illness. And unlike other waterborne illnesses, a virus doesn't simply start to grow--an ill person brought norovirus into the park, where it spread.
That left Shelley and his crew with the difficult task of what to do with the water at Eagle Island State Park, which meanders through wetlands and eventually meets up with the Boise River, meaning disinfecting or treating the water wasn't an option. It was too early in the season to close the beach completely, and temperatures wouldn't cool off enough to kill the virus anytime soon.
So IDPR promised to drain the pond--but "drain" isn't quite the right word. It opened the floodgates, but there was no flood. The water sat stagnant around the open weir, only seeping away, and slowly refilling from a large metal pipe with a trickle of groundwater spilling from it. Shelley estimated it would take two weeks to drop the water level three feet, and then refill it again.
"The word 'drain' kind of denotes emptying it out," said Keith Hobbs, operations administrator for the Idaho Department of Parks and Recreation. "We're not going to be able to do that. We're lowering it as much as we can, moving that water out of this system, and replacing it. This ditch was never really designed to drain the lake," Hobbs said.
"But this is the only solution we have," Shelley added.
Eagle Island State Park's swimming area is 12 feet at its deepest. The temperature of the water hovers around 80 degrees in the summer, and about 2,500 people visit the park on a typical Saturday.
The water at the pond is tested twice a month in two different locations. Sandy Point, Discovery and Spring Shores Marina are also tested on the first and the 15th of each month, although with the recent troubles at Eagle Island, Shelley has upped sampling to a weekly schedule.
Lauri Monnot, watershed coordinator for the Department of Environmental Quality at the Boise Regional Office, couldn't hide how tired she sounded after the outbreak of norovirus at Eagle Island substantially lengthened her workdays. She said public swim areas should be tested weekly during the recreation season.
"Warm, moist conditions are favorable for rapid bacteria growth," Monnot said. "This in combination with large numbers of people in a water body can cause E. coli bacteria concentrations to increase within days."
The DEQ works with city and state parks and recreation departments on water sampling protocol, abiding by the State Water Quality Standards and the Environmental Protection Agency's Recreational Water Quality Criteria. E. Coli in particular comes from untreated sewage or feces from wildlife, waterfowl, dogs and livestock. It's not uncommon in natural waters, but elevated levels can make swimmers sick.
Most popular swimming areas around Boise are tested weekly during the summer, including the Ann Morrison take-out on the Boise River, and Quinn's Pond, near the Boise River Park (which is 30 feet deeper than Eagle Island). Other places along the Boise River, like Veteran's Parkway and the Glenwood Bridge, are tested monthly, year-round. Each of Boise's outdoor municipal pools are also tested weekly--although if that sounds like a lot, some commercial swimming areas test their water up to every two hours.
Back at Eagle Island, park staff turned over the sand every three days to expose it to ultraviolet light, which kills norovirus. Increased UV exposure was also the point behind drawing down the water.
Even though it has been cleared for resumed swimming, the abrupt drop in visitation has had an impact on the park. Eagle Island is run almost entirely on revenue gathered from visitors, who pay $5 per vehicle. With almost 600 parking spots sitting empty for a few weeks, that's a huge hit--especially at the peak of the season. The closure has forced Shelley to make some tough decisions.
"We have a staff of 12 summer seasonal employees," Shelley said. "Now that visitation is down, do we let them go early? Or do we keep them on and hope that we can reopen and visitation comes back?"
Shelley has never had to deal with this before. The park had elevated levels of E. coli a few years ago, but it was close enough to the end of the season that officials simply closed the beach early and colder temperatures killed the bacteria.
Despite its reopening on July 26, Hobbs said visitation at the park didn't amount to a normal weekend.
"It was a bit on the slow side," he said. "There were people, but it was a bit slow."