Heal the Bay – Partners with Stanford and UCLA For App That Predicts Beach Pollution
Thinking of hanging out at the beach near Santa Monica Pier this weekend? Now you can find out that same day if it’s safe to swim or not before making the long drive (or Metro trip) out west.
Heal the Bay, in partnership with Stanford University and UCLA, has officially rolled out its NowCast tool in California, a new water-quality forecasting system that promises a whole new way of keeping swimmers safe at their favorite beaches.
NowCasting is a technique that uses predictive statistical models to forecast water quality at a beach based on observed environmental conditions; such as rainfall, waves, tides and past bacteria concentrations. Just as the weatherman on the 11 p.m. news predicts if it will be sunny tomorrow, Heal the Bay’s staff scientists are able to predict if it is safe to swim at a given beach on any given morning.
Ryan Searcy, who creates the models and runs the daily forecasts, said that over the next three years, 15 to 25 beaches from San Francisco to San Diego will be added to the program, which is intended to keep swimmers, surfers and beachgoers safe.
Under the current monitoring protocol, health officials determine if a beach is safe or not by sampling for indicator bacteria (organisms whose presence suggests that other, more harmful bacteria and viruses are also present). Unfortunately, monitoring results do not come back from the lab for 24-48 hours.
In that time, beach conditions may very well have changed from when the sample was taken, potentially exposing ocean users to bacterial pollution. Additionally, most beaches in California are only sampled for bacteria once a week, leaving it to the public to decide whether to recreate or not based on days-old information.
Heal the Bay regularly assigns letter grades, A to F, based on levels of harmful bacteria found in the water to more than 400 beaches throughout California. The better the grade a beach receives, the lower the risk of illness from intestinal bugs, skin rashes and ear and upper respiratory infections. The report is not designed to measure trash or toxin amounts at beaches.
“Most beaches only sample their beach water once every seven days so we really only have a sample data for one day out of the week and the rest of the days are kind of left hanging to wonder, ‘OK, where is the water quality now?’” Searcy said. “Based on statistics and years of data, we are now making a more educated guess than just relying on a sample that was taken, say, on Monday.”
If the bacteria level is predicted by the NowCast system to be above the acceptable standards set by the state, then water quality is assumed to be poor, and a beach posting is recommended. A new prediction will then be made the following day.
These models are also more accurate than the current method of waiting 24 hours for results to come back from the lab. Over the last few decades, water quality in the Santa Monica Bay (and across the state) has improved dramatically. However, there is still much work to be done to clean up the local beaches and reduce the number of swimmers, surfers, divers and other ocean users that get sick.
Predictions are made every morning during the summer based on current environmental conditions. Local health agencies can then use these predictions to notify the public of water conditions before most people arrive to the beach.
NowCast predictions are available for the following five beaches in Southern California:
– Arroyo Burro (Hendry’s) in Santa Barbara
– East Beach (near Mission Creek) in Santa Barbara
– Santa Monica Pier
– Belmont Pier in Long Beach
– Doheny State Beach in Orange County
Over the next three years, they plan to add an additional 15-20 beaches and expand the program across California — from the breezy beaches of San Francisco to the classic surf spots of San Diego.
About Heal the Bay
Heal the Bay is an environmental nonprofit dedicated to making the coastal waters and watersheds of Greater Los Angeles safe, healthy and clean. Our philosophy at Heal the Bay is that no one should get sick from a day at the beach. To make a decision about which beach is best for them and their family, people should be armed with the most accurate and timely water quality information available. Think of the water quality NowCast just as you do sunscreen – protect yourself from poor water conditions before you get in the water. You should be catching waves, not bugs!
Download the beach report card app on your mobile device to find daily predictions for all of the NowCast beaches mentioned above. You can also access the lastest grades for our full complement of beaches that we monitor each week statewide — more than 400 beaches up and down the coast!
SOURCE: Heal the Bay, OC Register