- Proposed ocean outfall for a wastewater treatment plant.
- 3D modeling of near- and far-field mixing of the effluent.
- A 3D model was used to simulate the mixing and concentrations of a conservative effluent tracer and various indicator bacteria (assuming no chlorination).
Joint Water Pollution Control Plant Outfall Monitoring
Los Angeles County Sanitation District
Manhattan Beach, CA
The Sanitation Districts of Los Angeles County (LACSD) are in the Feasibility Study stage of evaluating the location for a new ocean outfall to carry treated wastewater from the Joint Water Pollution Control Plant (JWPCP) in Carson, California, to an ocean discharge location off the southern California coast near the Palos Verdes and San Pedro Shelves. As part of the Feasibility Study process, Flow Science used the three-dimensional computational fluid dynamics model ELCOM to evaluate the impact of this proposed ocean outfall. The near-field effluent discharge model, NRFIELD2, coupled with the far-field hydrodynamic model, ELCOM, was used to simulate the mixing and determine the concentrations of a conservative effluent tracer and various indicator bacteria (assuming no chlorination). The coupled model was validated by comparing against measured current and temperature data in the vicinity of the potential discharge sites. The water quality impacts of five proposed diffuser discharge sites were evaluated and the modeling results will be used by LACSD to estimate the rate of compliance with water quality criteria for bacteria at selected locations at the shore and inshore regions without chlorination.