Start a conversation about the border that separates the United States and Mexico, and you risk sparking compassionate conversation all over the political spectrum. One fact about the border, however, cannot be disputed: most of the border lies in dry and arid regions where water is scarce.
Border checkpoints use their fair share of resources, due to the large number of professionals who deal with everything from logistics to customs and immigration while processing both commercial and passenger crossings. One checkpoint between San Diego and Tijuana, Otay Mesa, has taken steps to reduce the amount of water wasted on a daily basis. The U.S. General Services Administration (GSA), the nation’s facilities manager, decided to install a wastewater treatment facility to reduce the amount of water consumption at this checkpoint several miles inland from the coast.
The GSA selected Worrell Water Technologies to design Otay Mesa’s wastewater recycling plant. Worrell’s process, which it calls Living Machine, is the technology behind the new system. Such a design was necessary because San Diego’s water infrastructure has been stretched thin between a growing population and a reduced water supply. The Living Machine’s system improves water efficiency through collecting wastewater, which is then cleansed through its proprietary three-step wastewater treatment process. The installation at Otay Mesa can treat up to 1500 gallons of wastewater a day.
To folks who walk along the pedestrian walkway between Mexico and California, the only evidence of Living Machine’s wastewater system is the surrounding landscape, which resembles a wetlands environment. The choice of plants is just one cog in the system, which collects, filters, and purifies the water through mostly natural methods. Water gathers in a tank, which can then be used to irrigate the surrounding landscape, cool air conditioning systems, or to flush the checkpoint’s toilets. Alternating anaerobic and aerobic cycles clean the water with a minimal need for energy. In sum, the system works like a natural wetlands ecosystem—one of the best and most sustainable methods available to filter and replenish freshwater resources.
Wastewater treatment systems like that of Worrell’s Living Machine are another step in improving water efficiency at facilities that have tenuous—or reliable–connections to local water grids. Their minimal energy requirements, effectiveness at preventing wastewater spills, and role in addressing water scarcity will prove invaluable, especially if they can scale and truly become cost-effective.