Chatfield Hollow State Park in Killingworth has reopened today after Department of Energy and Environmental Protection employees received threatening e-mails that included a threat to poison the waters.
Tests of the water showed no harmful substance, officials said.
On Tuesday, officers from the state Department of Energy and Environmental Protection arrested Wayde A. Isakson, 55, of Madison, who is accused of sending emails that threatened to kill people at DEEP and to poison the waters at Chatfield Hollow State Park.
DEEP officials said several employees received "threatening" emails, starting around 3 p.m. and no one was specifically targeted.
In response to the threats, DEEP emergency officials closed the Chatfield Hollow Park and swimming area.
"We do our best to patrol actively and we hope the public will keep an eye out on things and assist us in our mission to have an open society yet be safe.," said Col. Kyle Overturf of the DEEP.
DEEP offiicals said they do not think any other parts of the park were in danger or threatened and they are looking in whether there is a link between Isakson and the state agency.
"It's kind of sad because we go there a lot," said Erin Fredericksen, of Killingworth, whose mother was rushed out of the park when officials shut it down. "It's a good place."
John O'Leary, another Killingworth resident, was surprised by the threat.
"That just sounds crazy to me. It seems outrageous," O'Leary said.
Isakson was charged with first-degree threatening, first-degree breach of peace and making terroristic threats. He was taken to the State Police Troop F barracks in Westbrook to be processed.
State police say Isakson has been turned over to a medical facility for evaluation.
He is due in court in Middletown on Sept. 10.