BELCHERTOWN (CBS) – The state agency that oversees water testing in Massachusetts says the Quabbin Reservoir is safe following a trespassing incident.

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A state trooper caught seven people at the reservoir at 12:30 a.m. Tuesday.

The five men and two women were from Pakistan, Saudi Arabia and Singapore with addresses in Amherst, Cambridge, Sunderland and Northampton, and New York City.  Their names were not released.

The men told police they were chemical engineers who recently graduated from college and they were curious about the reservoir, which is the primary water source for millions, including the city of Boston.

State police said they were cross-checked with international databases and no warrants or advisories were found for any of those questioned and there was no evidence of terrorism.

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mapThe Massachusetts Water Resources Authority released a statement Wednesday saying the water in the Quabbin is safe.

“MWRA operates a state-of-the-art, real-time monitoring system around the clock to ensure the safety of our water supply. Any abnormalities are detected immediately. As an extra precaution, water quality samples were analyzed at MWRA’s lab yesterday and all came back normal. There is no evidence of any water quality issues at the Quabbin Reservoir following the trespassing incident.”

The trespassers will be summonsed to court.

“I want to reiterate that there was NO evidence of terrorism or any crime committed beyond the trespassing,” State Police spokesman David Procopio said in a statement.

“Further investigation is being undertaken because of the late hour when they were observed, their curious explanation for why they wanted to see the reservoir, and the fact that they were in an area marked no trespassing.”

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Troopers are increasing the number of routine checks at water supply facilities around the state as a precaution.