The former manager of the pleaded not guilty to eight charges in Worcester Superior Court Thursday and was released on personal recognizance.
Henry Papuga was indicted in September on relating to tampering with water samples, following a 2009 boil water order. Both Papuga and William Kettlewell, his Boston-based criminal defense attorney, declined to comment following the arraignment hearing.
Judge James Lemire accepted the pleas and set the date for a pretrial conference of Nov. 14. Papuga, who lives in Milford, was allowed to return home on personal recognizance.
Papuga, 61, retired from the private utility company in 2009.
He was indicted Sept. 22 by a Worcester County grand jury on six counts of tampering with environmental monitoring device or method, and two counts of making false statements.
Prosecutors declined to comment following the arraignment.
In a press release that announced the indictment, state Attorney General Martha Coakley said the defendant had "tampered with water samples, which potentially put the health of thousands at risk.”