Ponding in its two open rock trickling filters and the manifold pressure relief tube spilling over during normal dose cycles plagued the Rushville (N.Y.) Wastewater Treatment Plant and produced dissolved oxygen and ammonia issues. The situation worsened each year with increased flows.The breaking point arrived when the small lagoon system treating wastewater from the local high school neared the end of its life expectancy. The school board, which owned and operated the system, preferred hooking to the Rushville sewer instead of upgrading its facility. But the additional 8,000 gpd from the school would cause the plant to exceed its permitted
