Swimming with bacteria

Bacteria warning scares swimmers away from the Yuba.

Bacteria warning scares swimmers away from the Yuba.

Photo by Bob Lickter

Mid-span within the historic, shingle-covered bridge, shining through an open-air window, the olive green waters of the Yuba River glint in the mid-August sun. Verdant pools usually teeming with frolicking children and dogs are silent.

Nothing obvious is amiss, other than the recent controlled burn that scorched the ground from the historic pioneer cemetery right up to the Visitor’s Center, charring nearby trees.

Lichen-covered stone walls delineate paths leading past the massive barn, which houses ancient wagons in various states of disrepair.

Here, at Bridgeport, settlers forded the South Fork of the Yuba River on horseback, in wagons and on foot, prodding on their herds of cattle and sheep. The bridge, built in 1862, is the longest single-span wooden covered bridge in existence.

A metal sign reads, “Danger. Swift currents. Submerged objects. No lifeguard. No diving.” Other signs: “No alcoholic beverages.” “No glass containers.”

Stapled to wooden posts at trailheads leading down to the water, yellow paper notices ripple in the breeze. “DANGER. RIVER CONTAMINATED. Swimming Not Advised.” The Web site and telephone number of the Nevada County Department of Environmental Health are listed at the bottom.

In the parking lot, three women and a young girl are loading up a white minivan. There are no other cars.

“We heard that the contamination was at marginal levels. We thought there might be a dead deer [upstream],” said Jennifer Eggert, from Beale Air Force Base, as she loaded knapsacks in the van.

“There was hardly anyone here. Probably four cars at 2 p.m.” Jennifer Morris said, gazing pensively toward the water as she blew cigarette smoke out of the corner of her mouth. “It scared everybody off—as hot as it was today.”

“There was a pool with a little bit of slimy stuff,” said Eggert. “It smelled like dead fish.” She wrinkled her nose.

Buckled in the back seat, eager to go home, 5-year-old Kayla Nicole Eggert chirped, “It’s pretty and I like the water because it’s green.”

“I let [her] swim in it,” Kayla’s mother, Jennifer, said. “I wasn’t worried about it. If only people would pick up their trash.”

On that August day at Bridgeport, the Enterococcus bacteria level was just edging in on state thresholds advising beach goers to stay out of the water. The danger wasn’t clear and compelling at this site, but the bacteria’s presence was still cause for concern.

Surviving up to 30 days in fresh water, the bacteria’s presence is proof positive of fecal contamination from either human or animal sources and may indicate the existence of other disease-causing viruses and parasites, including polio, hepatitis A, giardia, amoebic dysentery and shigella.

Finding a convenient orifice or open wound, Enterococcus can take up residence in the human body, producing urinary tract and intestinal infections, endocarditis, and a variety of other disorders. What may start as a minor rash, ear infection or “stomach flu” within 48 hours after contact with bacteria-laden water may be the harbinger of more serious, long-lasting symptoms. Since Enterococcus is resistant to several types of antibiotics, treatment of the wrong kind can make matters worse.

On an afternoon in July, cars lined the roadsides a half-mile in both directions from the Highway 49 bridge where it crosses the Yuba. Four cars circled the small parking lot like sharks, their drivers hungrily eyeing parking spaces where river-goers congregated in the blazing July heat.

“Are you leaving?” a driver of a green Camaro called out, Eminem blaring from his speakers.

“Nope,” said the dreadlocked young man, flicking a blond lock out of his face as he hoisted his pack onto his shoulders. “Just got here.”

The passenger door of the battered Volvo opened and a young woman emerged. Dressed in a crop top and batik print skirt slung low below her pierced navel, she glared at the Camaro driver. “Valley,” she muttered.

Standing on the bridge built in 1921, now only used by pedestrians, three boys with baggy trunks to their knees assessed the spot where foolhardy teenagers plunge 60 feet into a shallow pool, evading the watchful gaze of rangers.

The river resounded with squeals of children and barking dogs. A throng of swimmers traversed the maze of boulder-strewn emerald pools. The beach and flat rocks were littered with oiled sun worshippers prone on towels.

A month later, at the Highway 49 bridge crossing, bacteria counts registered beyond the maximum number detectable by the test, 40 times the acceptable state guidelines.

“We’ve never seen so many parking spots,” Andy Smith of Auburn said.

Underneath the arch of the majestic concrete bridge, a dozen people swam. A man in trunks sat on a rock in the middle of the river fishing, a child with inflatable water wings at his side.

The current, dappled with a white spittle, floated lazily by a woman sunbathing on a raft idled in an eddy. A teenage boy dove from a rock and surfaced among a group of girls, some of whom were attempting to keep their heads above water.

Mothers waded in the shallows, conversing, as children splashed each other. A fully clothed Hispanic family with four children sat upon rocks midstream. The trail from which they entered the river did not have a warning sign translated into Spanish.

“We put out all the signs we were given, said Tim Worley, a park maintenance aide. “The Spanish one, we had to make up ourselves.” Worley noted that there were fewer swimmers than usual.

“I personally wouldn’t swim in it,” he said.

“I’ve been swimming in it for years,” said Will Simmons of Los Angeles. “It didn’t bother me. I didn’t see the signs—I heard about [the contamination] from my parents.”

Not until last year were the Yuba’s waters tested. The State Department of Parks and Recreation began sampling to assess impacts to the river from recreational use and the non-profit South Yuba River Citizens League (SYRCL) launched a river-monitoring program.

In June, a state sample disclosed elevated bacteria levels. Officials, considering the possibility of a false positive, re-tested. Bacteria had skyrocketed and officials alerted the Nevada County Environmental Health Department in mid-July.

A health advisory was issued on August 1, a month after initial contamination was detected, and signs were posted at the China Dam area, where contamination appears to originate.

“I have sometimes noticed a rather distinctive foul odor [there], especially in late summer,” said Bob Lickter, publisher of online journal Nevada City Free Press.

Speculation as to causes has centered on campers and recreational bathers, dogs, native species, dirty diapers, dead animals and septic systems. But SYRCL’s River Science Director Lynell Garfield and 55 trained river monitors have repeatedly scoured the watershed, searching in vain for a visible source of contamination.

Garfield said that low water flow is concentrating the problem. Limited rainfall precluded “flushing” of the river this winter. Water temperatures hovering around 70 degrees combined with “an exorbitant amount of green algae” provide conditions “ripe for bacteria.”

Hoping to pinpoint the problem, Garfield took additional samples. Bacterial levels had surged and the no-swim advisory was expanded to include 3 miles of river on August 8. The following day, 15 miles, from Edwards Crossing to Bridgeport, were declared unsafe.

Adding to the mystery, test results at one site fluctuated wildly, from slightly elevated to off the chart. A weary Garfield plans to take samples at half-hour intervals to see if readings vary throughout the day.

Though this is the first health advisory ever issued for the Yuba, recent contamination could be indicative of a long-standing problem, since water monitoring only began last year.

Whether the contamination is from a single or multiple sources, it is unlikely that conditions will improve until the rains come. Nearly a decade ago, the Yuba hosted 700,000 visitors a year. Recent estimates are much higher.

The site’s popularity raises questions about how many people might have suffered ill health effects from the river, but chalked symptoms up to the flu, fatigue or something they ate.

Park Ranger Mike Smittle posed the troubling question: “Who knows if this hasn’t been here for years?”