The Massachusetts Water Resources Authority says there is no evidence of any water quality issues at the Quabbin Reservoir after seven young people were caught allegedly trespassing early Tuesday morning. No one at the MWRA was willing to speak, but in a statement the agency indicated water at the Quabbin is tested daily and continuously through a state-of-the-art, real-time monitoring system that detects any abnormalities immediately. It says samples analyzed at their labs on Tuesday all came back normal. And a spokesperson would only add the public does not need to worry about water quality. The Quabbin, which stores some 378 billion gallons of water, is one of the largest man-made public water supplies in the US, serving more than 2.5 million residents in metro-Boston, South Hadley, Chicopee and Wilbraham. Since the September 11th attacks, security at the Quabbin has been heightened through more surveillance cameras and restricting vehicle access. The State Police, which is responsible for security at the Quabbin, says a trooper came across five men and two women walking towards two cars parked at a reservoir entrance shortly after midnight Tuesday, long after the reservoir closes. A police spokesman says the men were from Pakistan, Saudi Arabia and Singapore with addresses in Amherst, Northampton, Sunderland, Cambridge and New York City. He says the group told police they were recent college graduates, and law enforcement databases show there are no warrants, detainers or advisories on them. But he says the seven people have been summoned to appear in court on a trespassing complaint.