July 08,2015
LOS ANGELES— The current drought in California means less water runoff from cities and cleaner ocean water for beachgoers. Some beaches, however, are still polluted, including some tourist hotspots. Now, researchers are developing a faster way to check beach water quality.
The famous sun and surf of southern California may look glamorous, but what beachgoers cannot see in some of the ocean water is anything but attractive, says Angelo Bellomo of the Los Angeles County Department of Public Health.
“When we have runoff from the urban environment, it could be carrying with it contamination due to animal waste, sewage overflows; and if those enter the beaches through the normal pipes that terminate in the ocean, you want to avoid contact with water during those periods,” he says.
Bellomo says a number of infectious diseases could be transmitted in ocean water.
Plenty of people, however, play in the water at the beach at Santa Monica Pier, one of the most polluted beaches in California.
‘A little ridiculous’
Public health officials are concerned and are looking at a better way of determining water quality. Water at the beaches is monitored with a lab test. If the quality is poor, a sign is posted; but, it does not necessarily reflect what is in the water that day, says Leslie Griffin with the environmental group, Heal the Bay.
“Right now it takes 18 to 24 hours to get those water quality results, but we think that that is a little ridiculous because we want people to know the day of when they are going in the water whether or not they can be getting sick,” Griffith says.
Researchers in California are developing what they call a predictive modeling system that could speed up the process, says Heal the Bay’s James Alamillo.
“It can take 15 minutes to produce a similar result in terms of a public health decision,” Alamillo says.
‘Nowcasting’
With the help of computers, researchers pull data from the environment and a prediction is made about the water quality of that day. It is called "Nowcasting."
Some of the environmental data may include wind speed and direction, wave information and historic bacterial counts, but the beaches are unique in their own way, so the models have to be tailor-made for each one.
So far, Angelo Bellomo says the predictive modeling looks promising.
“We think that the modeling that we have seen so far is generally more accurate than the testing that we are doing, and the reason for that is that even though it is a model and it's predicting water quality, it is more timely,” Bellomo says.
Hong Kong and the U.S. state of Ohio have similar methods of predicting water quality. The experts on the U.S. West Coast say predictive modeling may be the best tool they have until technology advances and offers a faster way of testing the water in the lab.