The California-Nevada Section of the American Water Works Association (CA-NV AWWA) returns with its Spring Conference on April 11-14, 2022, at the Disneyland® Hotel in Anaheim, CA. The conference reaches skilled distribution operators, treatment operators, engineers, and field professionals from the world of drinking water.
We’re delighted to confirm that Todd S. Webster, Ph.D., P.E., Vice President, Envirogen, will be presenting with Matt Baumgardner, Director of Public Works, City of San Fernando, CA.
Wednesday April 13 at 10am PDT:
“Implementing Design Improvements of Regenerable Ion Exchange for the Treatment of Groundwater Contaminated with Nitrate – A Case Study (City of San Fernando)”
The City of San Fernando (City) and Envirogen are collaborating on the implementation of an updated design of Envirogen’s SimPACK™ regenerable ion exchange (IX) treatment system. This new system is capable of processing 1000 gpm (227 m3/hr) from the City’s Well 3 groundwater extraction well that is contaminated with nitrate. This new system is a supplement to an existing Well 7A IX treatment system, also treating 1000 gpm (227 m3/hr) of nitrate-laden groundwater, originally purchased by the City in 2013 from Envirogen.
The new Well 3 treatment system is designed to handle higher levels of nitrate compared to the previously installed Well 7A system. Once installed and operational, the City intends to blend the combined water sources from Well 3 and Well 7A, treating the combined nitrate-laden groundwater using the two IX systems (existing and new).
The SimPACK system is a multi-bed design operated in a staggered mode process. The staggered bed is Envirogen’s N+3 method, allowing all but three of the vessels to be online while two vessels are being regenerated and one vessel is in standby. This design provides system redundancy, as required by the California Water Resources Board (CWRB)-Division of Drinking Water, while producing a consistent effluent water quality that meets the target water quality requirements. Nitrate levels are monitored using an online nitrate analyzer that can measure alternately between the influent and effluent sample points. The process of transitioning vessels from online to regeneration to standby is completely controlled by the provided Programmable Logic Controller (PLC).
The new system consists of the following improvements in design:
- Larger vessel design and less vessels to allow for reduction in required valves and controls.
- Single in-line design to allow for easier maintenance and operation.
- Treatment unit installed in a larger, longer engineered container to shelter the system from weather and tampering, while also providing easier vessel and controls access.
- Utilization of nitrate selective resin and an updated PLC featuring enhanced Envirogen SimPACK control logic to minimize waste rates and salt consumption.
This presentation will detail the unique site characteristics and water chemistry of the City of San Fernando wells, the differences between the two treatment plants, the improvements made with the updated regenerable IX system, the regulatory aspects in the implementation of the treatment plant in 2022, and the associated treatment costs.
In addition, as waste brine reduction continues to be a critical concern, potential brine processing unit options for 2022 and beyond will be addressed. Finally, adaptability of the regenerable IX technology to other emerging contaminants of concern on the regulatory horizon will also be covered.
