A rash of leaks in Santa Paula caused thousands of gallons in sewage to leak onto the city’s streets in February.

At least three major sewage spills in the city were caused by grease built up in the city’s underground pipelines, Interim Director of Public Works Jon Turner said.

“Grease is one of those things that is sort of a silent killer,” he said. “It will slowly collect.”

Left to collect long enough, though, grease can clog pipes and force sewage out of manholes and drains to the surface, as it did dramatically in February.

Hazardous materials discharge reports submitted to Ventura County’s environmental health division showed more than 5,500 gallons of sewage spilled in Santa Paula in the first two weeks of Santa Paula, about 1,000 gallons more than was reported spilled in the city in all of 2007, county records show. One of the recent spills, a Feb. 11 incident on North Mill Street that released an estimated 1,000 gallons, was caused by a plywood panel lodged in a pipeline, Turner said. A 750 gallon spill on Feb. 3 occurred when septic tank contents were pumped to the rear of a property on Lindsay Lane, and a smaller 150 gallon spill was reported on Feb. 2.

The remaining spills, two reported at 104 N. Palm Ave on Feb. 9 and 10 and one on Feb. 7 at 739 E. Pleasant St. released a combined 4,500 gallons of sewage, all because of cooking grease built up in pipes. Turner said that the amounts were more than the city is used to dealing with at one time, but the situation underscored an information campaign his department has tried to bring to Santa Paula residents.

Although restaurants are heavily regulated for how they dispose of the greasy byproducts of cooking oil and fried foods, few households have the information they need to properly dispose of cooking grease. Anytime somebody fries up dinner or whips together a batch of fajitas, for example, the first instinct is often to rinse the dishes into the sink.

“That is a no-no” Turner said. Grease hardens after it cools, so when it gets into the sewer system it can harden right in the pipes. Since it doesn’t mix with water it will only float as far as the water. Once it arrives at a low point it will gather and harden.

“It’s almost like an artery in the body,” he said. “It eventually closes and closes and closes. Unfortunately sewage isn’t as clean as your blood.”

Sometimes, water pressure is enough to dislodge the grease obstructions. Other times, though, the sewage can’t break through and is forced to the surface.

Turner said the recent release is more than the city is used to dealing with at once. Although small leaks happen occasionally, none happened in January and when they don’t occur they can become bigger problems. The city also has an active cleaning and maintenance program of its sewers and one fourth of the entire system is cleaned every year.

“It doesn’t make us happy,” he said. “Public works staff is actually determining where and why we’re experiencing the problems. You’re seeing this happening in a lot of older parts of town where the pipelines are smaller than other parts of town.”

Despite claims from dish detergent manufacturers that their soaps cut through dirt, Turner said the proper technique for disposing of cooking grease is to let pots and pans dry, then wipe them down with a paper towel. The towel should then be thrown in the regular trash and the dish can be washed as normal.

“Eventually, when you have 6,700 homes it collects, and we’re a small town,” Turner said.