Race Against Time: Wastewater Wet Well Storage and Spill Analysis in Lake Tahoe

Presentation Description: For wastewater pump stations, accurately quantifying the available upstream storage and associated time-to-spill is critical for informing and preparing appropriate response measures. This presentation includes 1) a description of a high-resolution, computational approach to quantifying upstream storage that enables rapid analysis of storage augmentation/modification scenarios and 2) a case study involving North Tahoe Public Utility District (NTPUD). NTPUD provides water, wastewater, and recreation services to approximately 5,000 customers and manages 74.8 miles of gravity sewers and 6.6 miles of force mains. Due to the proximity of Lake Tahoe to NTPUD’s wastewater infrastructure and the high consequences of a spill, NTPUD has adopted a forward-thinking and progressive approach to managing its infrastructure. This analysis demonstrates the importance of analyzing storage capacity and shows how utilities can leverage computational tools to anticipate emergencies and take preventative action. Additionally, the results of this analysis may be used to support the capacity analysis and spill emergency response plan components of the Sewer System Management Plan required as part of the Statewide Waste Discharge Requirements General Order for Sanitary Sewer Systems (Order 2022-0103-DWQ).