Engineers at the Naval Facilities Engineering Command's Engineering Service Center have designed, built and tested an innovative storm water treatment system to remove heavy metal pollutants released from the roofs of Navy industrial buildings.
"The Navy is committed to protecting the environment and our natural resources. We have recognized the fact that introducing heavy metals into storm water runoff is a huge problem and have taken steps to prevent this from occuring," said Naval Facilities Engineering Service Center Commanding Officer Capt. Gregory J. Zielinski. "This new water treatment system will eliminate the possibility of tainted storm water runoff entering our nation's ecosystems, and we believe it is a long-term solution to remedy these issues."
The system consists of treatment tanks packed with bone char and ferrous-coated activated alumina and will be installed at building downspouts. Initial testing was conducted at Norfolk Naval Base building V88 which was recently identified as a contributor of heavy metal pollutants found at a nearby storm water outfall. Results showed excellent pollutant removal efficiency, removing copper and zinc pollutants to levels that will help Norfolk comply with storm water outfall requirements.
To gauge the system's effectiveness, copper entered the tank at the rate of 156 parts per billion (ppb) and exited at less than 5 ppb. Zinc entered the tank at more than 1,000 ppb and exited at less than 5 ppb.
The system is a spin-off of the successful storm water treatment technology demonstrated at the Navy Recycling Center in San Diego and is projected to capture heavy metal pollutants for more than ten years before needing replacement.
