CARY - About 5,000 gallons of untreated wastewater spilled from Cary's sewer system in separate incidents last week, according to the town.

The first spill happened about 2:30 p.m. Monday near the 2000-block of Alston Avenue.

Town officials said the spill was caused when a faulty air valve failed.

Nearly 2,200 gallons of waste was discharged into a nearby storm drain.

A second spill occurred about 8 a.m. Tuesday.

That incident was the result of bricks and asphalt that blocked a sewer line near the 700-block of Braniff Drive.

About 2,800 gallons of untreated waste were discharged into an unnamed tributary of Crabtree Creek.

In both cases, town crews flushed the affected areas and pumped the flushing water back into the town's wastewater collection system.

Neither incident resulted in fish kills.

"We take every spill very seriously and devote significant resources toward keeping them from occurring," Sam Tingler, the town's chief of utility systems maintenance, said in a statement.