San Diego County Water System Groundwater Treatment

San Diego County, CA

PACE led the design-build team and served as Engineer of Record for a groundwater treatment facility. The facility, built in two phases, treats 99% of water and removes iron, manganese, and arsenic to meet U.S. Environmental Protection Agency (EPA) Primary and Secondary drinking water standards. PACE also provided programming, installation, and startup of a site-wide Supervisory Control and Data Acquisition (SCADA) system for all production and distribution facilities. The system consists of 12 potable water wells, six irrigation wells, five potable water storage tanks, and the groundwater treatment facility.

A 500-gallon-per-minute (gpm) iron and manganese filtration system was designed and installed using a brand-new proprietary filtration media (Penox), completely removing iron and manganese from the potable water supply without the use of complicated chemical injection systems. Iron and manganese cause discoloration of the water and sediment buildup within facility boilers. The client was spending an estimated $20,000 per month on cartridge and bag filter systems to remove sediment.

With the new system, simple backwashing completely restores and regenerates the media’s removal capacity. The system does not require costly media replacement typical with conventional systems (i.e., green sand filters). The backwash from the filters is sent to the wastewater reclamation facility at no cost. As intended, iron and manganese are no longer discoloring the water or leaving sediment in the pipes. Laboratory testing revealed that the media also removes arsenic in the presence of “free” iron. The filtered water had up to 50% less arsenic than the influent.

With a small-footprint system in mind, PACE was able to reduce capital and operational costs significantly and still provide a total treatment capacity of 500 gpm. PACE continues to provide testing and operating supervisory oversight services while the client manages day-to-day testing.

Key Features:

• 500 gpm wellhead treatment system
• Treats 99% of water and removes iron, manganese, and arsenic to EPA drinking water standards
• Completely removes iron and manganese from the potable water supply without chemical injections
• Multi-barrier treatment system including GAC filtration, Penox filtration, and chlorine disinfection
• Saved client $20,000 per month by using Penox filtration media
• Simple backwashing completely restores / regenerates the media’s removal capacity
• Reduced arsenic by up to 50% in the water supply expansion from 200 GPM of iron and manganese removal to 700 GPM
• Startup and commissioning services
• Instrumentation & Controls integration