This avoids mixing digested sludge with incoming sewage. Soybeans grown in sewage sludge likely contain elevated concentrations of metals. Anaerobic digesters were originally designed for operation using sewage sludge and manures. Pathogens could easily remain undetected in untreated sewage sludge. They can become concentrated in sewage sludge. There is no process which completely eliminates the need to dispose of treated sewage sludge. Vermicomposting can also be applied for treatment of sewage sludge. The approximately 5000 acres of land were fertilized with "treated municipal sewage sludge, or biosolids". Sewage discharge, specifically that of nutrient concentrated "sludge", can be especially damaging to ecosystem diversity. News reporters may use the term also for sewage sludge or biosolids. Kalogeo made products related to treating biomass, sludge, and wastewater. Some cattle raised in the United States feed on pastures fertilized with sewage sludge. It is notoriously over-abundant in human sewage sludge. Solids recovery is the percentage of dry solids recovered from the feed sludge. The secondary clarifier removes the activated sludge from the water.