Millipore has periodically caused Pass Through and Interference at the Town's Publicly Owned Treatment Works ( POTW ) and violated EPA's prohibition on introducing wastewater with a pH lower than 5.0 standard units (S.U.) into a POTW. Also, on several occasions, Millipore has violated the EPA's general pretreatment regulations by failing to notify the Town of slug discharges capable of impairing the POTW treatment plant.