BLADES, Del. — State environmental officials say more chemical contamination has been found in private wells in a southern Delaware town where residents were advised last month not to drink the water.

Officials said Tuesday that elevated levels of perfluorinated compounds have been found in three more private wells in Blades.

Of 44 private wells sampled so far, six of 39 test results received have exceeded the Environmental Protection Agency’s health advisory level for PFCs of 70 parts per trillion. Another had a concentration below the advisory level but close enough that the homeowner was provided with a carbon filtration system.

A new carbon filtration system also has been has installed for the town’s three public wells, all of which were found last month to have PFC levels above the EPA advisory level.