More than a third of England's designated bathing waters are in Devon and Cornwall. This includes popular beaches such as Sennen Cove and Porthcurno on Cornwall's dramatic west coast, to Fistral on the county's north coast, Bigbury-on-Sea in south Devon and surfing hotspot Croyde Bay in north Devon. The Environment Agency, the regulator which monitors water quality at bathing waters, rates bathing waters from "excellent" to "poor" based on bacteria found in water samples collected over a rolling four-year period. Samples taken from the water are tested in a lab for elevated levels of E. Coli and intestinal enterococci. The bacteria can be found in sewage and other waste and can lead to sickness, stomach cramps, vomiting, and diarrhea.