Residents of Jackson Township have been up in arms over the recent dumping of treated sewer waste on about 800 acres in their area.

But what exactly is the sludge product?

According to Carole Shanahan, the residuals program manager of the Allegheny County Sanitary Authority, even the name sludge is not correct in describing the product.

""Sludge is the material that comes to our plant," she said during a presentation prior to the Jackson Township supervisor meeting Wednesday evening. "Biosolids more accurately describes the material coming out of our treatment plant. Since the material is treated, it's safe and we call it biosolids."

Ms. Shanahan said the product includes about 2.5 to 3.5 percent nitrogen, 20 to 30 percent lime and 1 percent phosphorous.

"Our particular process uses a lot of lime, which is very good for strip-mined lands," she said, likening the sanitizing effect of lime to outhouses that had buckets of lime to throw down the shoot.

She explained that people's concerns about metals were understandable, but that ALCOSAN tested for 10 heavy-metal concentrations as opposed to the state and federal regulations of testing for nine heavy-metal concentrations.

"Plants need a certain amount of metals," she said, referring to metals such as magnesium, copper and sulfur. "When you get the metals in the right amount, it's safe. We test the material more than it's required."

The company also tests for radioactivity, dioxins and pathogens, which is also more than federal and state requirements.

"Because we use lime with our own material, we maintain a certain level of pH," Ms. Shanahan said. "We test for pathogens even though the pH levels say there shouldn't be anything left. We are almost at the level of Class A biosolids."

She compared her product to a listing of commercially-available fertilizers and said that ALCO Soil is safer than most of them. "We're going for the safety of the material here."

During her presentation, she also showed pictures of former strip-mined sites and pasture land where the product had been spread, and explained that the dark green areas were where the product had been placed.

"It can be spread on slopes that are 20 feet deep. The very nice defined lines shows just how well the material stays put," she said. "If it would've washed away, you would have seen dark green streaks of pasture grass."

She said that 60 percent of all biosolids produced from water sewage treatment plants are used to spread on soil nationwide.

"I'm here to tell you that we produce a safe product," Ms. Shanahan said. "The reason for our (ALCOSAN's) existence is to protect the public health."