Wastewater Treatment Upgrades
BBARWA’s Project includes multiple treatment process upgrades using the best available technology to produce over 700 million gallons, or 2,200 acre-feet (AFY) per year of purified water – this is referred to as Program water.
These upgrades, including but not limited to, ultrafiltration, reverse osmosis, an advanced oxidation process, and ultraviolet (UV) disinfection, will produce purified water that must meet or exceed all state and federal water quality standards.
A new pipeline will deliver the Program water to Stanfield Marsh/Big Bear Lake, providing a new and consistent inflow to be managed by the Big Bear Municipal Water District (BBMWD). Additional upgrades include the installation of 2 megawatts of solar panels on BBARWA property to reduce energy costs and improve valley wide redundancy for emergency power. To optimize costs, the treatment system will be designed to treat average flows. Peak flows that exceed plant capacity will continue to be sent to Lucerne Valley.
Process Descriptions
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Ultrafiltration: Ultrafiltration membranes are made of bundles of hollow membrane fibers with pore sizes so small that bacteria and virus cannot pass through
Reverse Osmosis: Reverse osmosis membranes allow water through a semi-permeable membrane using high pressure pumping. Dissolved constituents such as salts, nutrients, and metals are rejected as brine and the filtered water is essentially free of bacteria, viruses, and dissolved contaminants.
Ultraviolet Disinfection-Advanced Oxidation Process (UV-AOP): Ultraviolet Disinfection-Advanced Oxidation Process (UV-AOP) uses UV light and an oxidant to form oxidizing radicals which are capable of breaking bonds of harmful contaminants.
Brine Minimization: The brine from the Reverse Osmosis process is softened using a chemical process so it can be more easily treated through a secondary reverse osmosis process, leading to higher recovery of product water while minimizing the volume of the brine waste stream.
Enhanced Evaporation: The brine from the secondary reverse osmosis process is pumped and sprayed over a structure with a layered high surface area design that increases the rate of evaporation. The increased evaporation rate of the enhanced evaporation system significantly reduces the area required compared to a conventional evaporation pond.
Product Water Stabilization: Product water from the treatment process requires stabilization to bring it to a neutral pH and to match the water chemistry characteristics of Big Bear Lake to protect its beneficial uses.
Ammonia Removal: Residual ammonia nitrogen in the product water is removed with a process known as “breakpoint chlorination” to meet the stringent nitrogen limits for Big Bear Lake. Breakpoint chlorination is a simple and proven method for removing residual ammonia nitrogen and used as a common disinfection strategy used in both wastewater and drinking water treatment plants.
WWTP Upgrades Project Documents
Frequently Asked Questions