EVALUATION OF PEAT BIOFILTERS FOR ONSITE SEWAGE MANAGEMENT

The Alabama Department of Public Health and Baldwin County Health Depa rtment conducted a research project to measure the removal of fecal co liform bacteria from septic tank effluent. The study involved peat bio filters (Puraflo(TM)) as onsite sewage systems installed near Weeks Ba y Estuary in Baldwin County, Alabama. Puraflo(TM) was developed in Ire land by Bord na Mona to treat domestic wastewater. Funding was provide d the Gulf of Mexico Program to address the contamination of shellfish growing waters from failing onsite sewage disposal systems. Reduction s in fecal coliform densities by the Puraflo(TM) system averaged 93% o ver a 12-month period and 98% in the last three months of monitoring. Reductions of BOD, organic-nitrogen, and ammonia-nitrogen were 85%, 73 %, and 96%, respectively. Improvements observed over 12 months in effl uent quality suggest that the Puraflo(TM) system undergoes a process o f acclimation to its environment to reach maximum efficiency. Further study of the Puraflo(TM) system should be conducted to determine efflu ent quality after the system is fully acclimated. It was apparent from this study that use of the Puraflo(TM) system in the coastal region o f the Gulf of Mexico could greatly reduce the levels of fecal coliform bacteria entering shellfish-growing waters.