| New York City's drinking water supply is threatened by the potential development of the Catskill/Delaware watershed. The effectiveness of alternative on-site wastewater treatment systems (OSWT) in this drinking water supply watershed was evaluated during the course of a one year field study and modeling analysis. Samples were collected from five replicates of four types of alternative OSWT and four replicates of convention OSWT at each stage in the treatment train monthly and analyzed for carbon and nutrients. Field data was used in the construction of models which calculated a conservative estimate of the total mass loading of nutrients and carbon to the Catskill/Delaware watershed from the 20,000 conventional OSWT systems currently installed within it. Concurrently the model estimates the total mass loading to the watershed from 20,000 alternative OSWT systems of a single type. This analysis, field observations, point estimates, and cost-benefit analysis support the use of peat and sand filters.; Keywords: Aerobic treatment unit, carbon, nitrogen, on-site wastewater treatment, peat filter, phosphorus, sand filter... |
