Audubon Nature Center - 4700 North Griffin Avenue, Los Angeles

The Audubon Nature Center is a LEED-Platinum certified "green" development consisting of a nature center building complex with adjoining garden and courtyard areas. EPD helped the Audubon Society meet its sustainable development goals by designing a system that treats the building's wastewater for onsite reuse. Because the city does not yet permit the reuse of even highly treated wastewater within a building, the water is presently being used for subsurface irrigation. However, the system is designed to be easily modified to use this water for toilet flushing and other building processes such as cooling once the State Department of Health Services verifies continuous acceptable water quality.

The Audubon's wastewater treatment and reuse system consists of:

  • Orenco Advantex hybridized anaerobic/aerobic treatment and filtration.
  • Peracetic acid / ultraviolet light advanced oxidation disinfection.
  •  Discharge to a Geoflow subsurface irrigation system.

Once the city/state approves reuse of the treated water inside the building, there will be an estimated 70 percent water savings over a comparable conventionally-plumbed building.


City of Santa Monica Pico Branch Public Library

A system that automatically filters, disinfects, stores and delivers safe, reliable recycled rainwater to flush all toilets and urinals throughout the facility was conceived and designed by Kevin Poffenbarger, Principal PE at EPD Consultants. Water Recycling Systems, LLC worked along with Kevin’s designs to make this project happen.


The Big River Elementary School

Needles, CA

The newly constructed school needed a wastewater system solution that would be appropriate for the harsh desert weather conditions and its remote location. Integrated Water Services, Inc. was chosen to construct the treatment system, which included a state of the art denitrification technology to meet the regulatory requirements of the environmentally sensitive area. 

The 7,000 gpd onsite wastewater treatment system was designed by Kevin Poffenbarger, PE of EPD Consultants and includes the SeptiTech Recirculating Media Filtration Unit in combination with the ENR,LLC denitrification upflow filter. 

During the design phase, EPD was looking for denitrification solution that could comfortably meet the 10 mg/l limit, was cost effective, required minimal maintenance, and was able to handle fluctuating nitrate loading. EPD selected the ENR Upflow filter, which was configured in two, 12,000 gallon Xerxes tanks and installed below grade.

The IWS scope of work for the overall project included installing: 15,000 gallon equalization tank, two SeptiTech M3000 processor tanks configured in Containment Solution tanks, an Alkalinity and Carbon Feed System, UV Disinfection, and 18,000 ft2 of Geoflow drip dispersal. 

All the treatment system components were installed below grade to avoid the extreme temperature swings that impact the desert region. 

The overall construction schedule was 8 weeks and included work during the early summer months where temperatures reached over 110 degrees during the day. 

Natural Resources Defense Council Santa Monica Office - 1314 2nd Street, Santa Monica, California

The Natural Resources Defense Council Santa Monica office is a LEED-Platinum certified "green" building that has focused heavily on water conservation. EPD designed a system for this project that reuses storm water and gray water for toilet flushing and landscape irrigation. This water reuse system, in conjunction with waterless urinals, dual flush toilets, and high efficiency lavatories, reduces the building's total water use by more than 50 percent.  EPD's water reuse system collects gray water from sinks and showers and storm water from the roof; treats, filters, and disinfects the water; then reuses it for toilet flushing and highly efficient subsurface irrigation. The treatment process involves

  • Settling, aerobic pre-treatment and ozone disinfection.

  •  Multi-stage filtration including reverse osmosis in an Equaris Infinity System, final ozone and ultraviolet light disinfection.

The resulting product meets California Title 22 unrestricted non-potable reuse standards. The entire system is free of PVC, a material whose manufacture and disposal has been linked to health risks and environmental degradation. The system maximizes the efficiency of its reverse osmosis filter -- which can typically reject 3 gallons of water for every gallon produced -- by recycling the concentrate back into the system and rejecting it only when the water exceeds a high threshold. 

One gallon of purified water per minute is produced at a cost of about 1/2 cent per gallon.