Less than two days of water quality sampling at local beaches may be all that’s needed to reduce illnesses among millions of beachgoers every year due to contaminated water, according to new Stanford research. The study, published in Environmental Science & Technology, presents a modeling framework that dependably predicts water quality at beaches after only a day or two of frequent water sampling. The approach, tested in California, could be used to keep tabs on otherwise unmonitored coastal areas, which is key to protecting the well-being of beachgoers and thriving ocean economies worldwide. Stanford researcher Ryan Searcy collects water samples from a tide pool at the Fitzgerald Marine Reserve, in Moss Beach, California. (Image credit: Meghan Shea)