Since the West Nile virus arrived in town, Berkeley residents haven’t stepped lightly over freestanding puddles, favored breeding grounds for the mosquitoes that carry the disease. So it’s odd that some of the most persistent puddles in town are being pr oduced by the Alta Bates Medical Center.
An antiquated de-watering system which pumps out uncontaminated ground water from below the hospital’s emergency room onto Colby and Prince streets and beyond, instead of into storm drains, became more than a mino r nuisance Aug. 5 when a dead crow in Berkeley tested positive for West Nile.
The mosquito-borne illness, imported from the Middle East and Asia and first detected in New York City five years ago, has since moved across the continent, reaching Southern C alifornia last year and the Bay Area this summer. In 2003, 264 Americans died from the virus, according to a report from the Center for Disease Control. None of the fatal cases originated in California.
Now Alta Bates officials are scurrying to solve the ir three-decade-old water woes after persistent complaints from the city and neighbors.
“It’s like a little harvest for [mosquito] larvae,” said Marcy McGaugh, who lives near the biggest puddle at a cul-de-sac on the 3200 block of Colby Street, where every three hours the hospital pumps out naturally occurring ground water through cylindrical drains drilled into the gutter. If the ground water remained it could percolate into the emergency room.
At about 2:30 p.m. Wednesday, the shoe-deep pool of water at the bend of the cul-de-sac measured about 12 feet long and three feet wide, enough to “make a couple of hundred mosquitoes fairly easily,” said John Rusmeisel, the district manager of the Alameda County Mosquito Abatement District.
Drains on Prince S treet release water downhill and onto Dana Street, where the city recently repaired potholes to stop water from pooling, although two neighbors said puddles still form.
“We have to figure out how to fix it,” said Frank Clements, Director of Facilities fo r Alta Bates and Summit Hospitals. As a stopgap measure he ordered hospital gardeners to sweep the water throughout the street to foster evaporation.
Perhaps the simplest remedy—diverting the water into the sanitary sewer system—is prohibited by East Bay MUD, which among other reasons doesn’t want to pay to treat additional gallons of sewer water.
Clements doesn’t think simply regrading the street would do the trick either. “It’s a natural low spot," he said. “It’s a dead end, turn around and cul-de-sac all in one.” he said. Plus, he added, there’s not a storm sewer drain for three blocks.
One possible solution involves an Alta Bates-financed plan already in the works that includes digging up Colby Street for underground repairs. If engineers determine that a storm drain is in close enough proximity, Clements said the hospital could possibly pipe the water through a revamped Colby.
Otherwise, the hospital will have to design a de-watering system that captures the ground water and use it to irrigate th e campus. Such systems are standard today, but were not in 1968, when the system was designed. Neither plan, however, would offer a quick solution, Clements warned.
Old infrastructure, along with hilly terrain and a moist climate, explains why Berkeley a nd Oakland lead the county in requests for service, said ACMAD’s Rusmeisel. Since July 1, the department has received 25 calls from Berkeley about water seepage. He said about one-quarter of the puddles have tested positive for mosquito larvae.
Rusmeisel has no record of a formal complaint at the Colby Street puddle and therefore hadn’t ordered testing to determine if the puddle has spawned mosquitoes. McGaugh insists she has contacted ACMAD, but says that the department has not adequately responded to her requests.
Rusmeisel said his reports showed that tests performed on the Dana Street puddles by the City of Berkeley Health Department tested positive for mosquito larvae. Puddles on Dwight Way between Milvia and Martin Luther King Jr. Way, caused by Alta Bates’ Herrick Campus, which uses the same antiquated de-watering system as the emergency room, have tested negative, he said.
Preventing standing water where mosquitos breed is among the most important preventative methods for controlling mosquito populations and consequently lowering the risk of West Nile. Rusmeisel said his department treats larvae-infested puddles with methoprene, an active ingredient in most flea collars, which kills the pests in their pupal stage.
Transmitting the West Nile virus starts when a mosquito first acquires the infection by feeding on a bird with virus in its blood. The virus lives in the mosquito and is transmitted to a new host in the mosquito’s saliva when the insect bites a person or an animal.
Only about one in every 150 people infected with West Nile virus develop severe illness, according to the CDC. Severe symptoms can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. People with weak immune systems, including elderly people, are most at risk.
So far this year in California, 189 people have been infected, nearly all in southern California and none in Alameda County.
For residents who keep open pools of water for fish ponds or water gardens, ACMAD offers larvae eating fish to control mosquito breeding.