NUTRIENT REMOVAL IN AN UNCERTAIN REGULATORY ENVIRONMENT

The Las Virgenes Municipal Water District (District) initiated a phased nutrient removal planning and implementation approach to meet existing nitrogen limits while maintaining flexibility for the future. A master plan was developed to assess facility needs and costs to meet a range of potential future nutrient removal requirements of total inorganic nitrogen (TIN) ranging from 10 mg N/L down to 2.5 mg N/L and with phosphorus at 0.4 mg P/L. The plan was updated to include potential limits of 1 mg N/L total nitrogen (TN) with 0.1 mg P/L phosphorus as a potential outcome of the TMDL determination process for the watershed. The project included a detailed evaluation of existing process performance to identify and implement facility improvements to meet current discharge requirements for the interim.