Challenge: To maximize use of water available from the Leo J Vander Lans Advanced Water Treatment Facility (LVL AWTF) for replenishment of local drinking water aquifers. 

Solution: INTERA is part of a multi-firm team that is leading the permitting, design, and field oversight for drilling and testing of two new monitoring wells and an injection well that will inject advanced treated recycled water from the LVL AWTF. This treatment facility receives tertiary-treated water from the Long Beach Water Reclamation Plant and provides advanced treated recycled water for injection at the Alamitos Seawater Intrusion Barrier (Alamitos Barrier). The facility was built in 2003 and subsequently expanded in late 2014 to a capacity of 8 million gallons per day (MGD). The facility currently operates at roughly half-capacity to supply 4 to 6 MGD of advanced treated water to the Alamitos Barrier Project (ABP). To use the remaining LVL AWTF capacity, the new inland injection well will inject 2 MGD of advanced treated water into the subsurface to replenish the local drinking water aquifers.  

INTERA performed modeling analyses using the Alamitos Barrier Model to evaluate alternative locations/layouts and assess the feasibility of injecting up to 8 MGD from the LVL AWTF at potential new injection wells inland from the Alamitos Gap seawater barrier wells, and increased extraction from existing production wells. Particle tracking simulations were performed to evaluate residence times and travel paths of the recycled water to ensure that the injection and extraction wells would meet Title-22 requirements. INTERA geologists developed the design of the new inland injection well and prepared plans and bid specifications. We are also providing field oversight throughout the drilling, construction, and testing of the injection well and associated monitoring wells. 

INTERA is leading the development of the Title-22 Engineering Report and the associated Operations Optimization Plan (OOP). We assisted WRD in developing a permitting strategy in coordination with the Regional Water Quality Control Board (RWQCB) and California Department of Drinking Water (DDW). We are currently developing work plans and designs for an intrinsic tracer study for the inland injection well and an added tracer study for the ABP, both required by Title-22 Indirect Potable Reuse regulations for subsurface groundwater replenishment. We will also support WRD in implementing both tracer studies and perform analysis and reporting to validate groundwater modeling results. 

Results: Preliminary testing on the injection well indicates that it will operate at high efficiency with greater than anticipated capacity.