CARY - Grease and debris contributed to a sanitary sewer spills that caused 1,871 gallons of untreated waste to flow into a local tributary.

Cary officials said Friday that the spill, which was reported by officers with the town's police department on July 28, sent the untreated waste into an unnamed tributary of Swift Creek.

Town crews cleared the blockage, flushed the creek with dechlorinated water and raked the creek to remove any debris.

No fish were believed to be killed in the incident, town officials said.

To decrease such incidents, the town launched a full-time, safe disposal option last summer for residential waste cooking oils.

Cary residents can collect their cooking oils, fats and greases in a sealable container and contact the town to schedule a pickup when at least half gallon has been saved.

The program is aimed to reduce sewer blockage and overflows, accidental spills and disposals in landfills.

Since 2006, fats, oils and greases contributed to more than 20,000 gallons of untreated wastewater discharged into Cary area streams, creeks and lakes.