Septic system aeration increases system performance, reduces presence of pharmaceuticals and endocrine disrupting compounds (EDCs)

In a recent study from Baylor University researchers demonstrated the positive impact septic system aeration has on improving system performance and reducing concentrations of endocrine disrupting compounds (EDCs) in septic system wastewater.

 

US EPA reports that approximately 25% of North American households (an estimated 60 million people rely on septic systems to treat wastewater. Approximately 10% of these (~ 6 million) suffer from failure in any given year. Potential ecological impacts of failing or poorly installed on-site wastewater treatment systems are varied, but often include eutrophication of waterways with blue green algae and bacterial contamination of aquatic systems.

 

More recently, several studies have identified compounds with endocrine activity in on-site wastewater or groundwater influenced by on-site systems. These endocrine disrupting compounds (EDCs) may be particularly prone to accumulating in areas with high concentrations of standard septic systems resulting in the potential impact on the reproduction of aquatic vertebrates.

 

In this study, a standard septic system was compared to an aerated system and a conventional municipal treatment system.

 

Some results of particular interest included:

–          Increased concentrations of carbon and nitrogen based contaminants from standard septic treatment system

–          Increased concentrations of hormones including testosterone and estrone in waste water from a standard septic system when compared to the municipal or aerated septic systems.

–          Toxicity studies carried out using the freshwater water flea, Daphnia magna demonstrated standard septic system effluent resulted in significant increase in mortality and reduced reproduction.

 

The results of this study are of particular relevance to areas with appreciable groundwater-surface water exchange with aeration treatment technology appearing to represent a robust option for onsite wastewater treatment.

*Comparative analysis of effluent water quality from a municipal treatment plant and two on-site wastewater treatment systems Santos N. Garcia, Rebekah L.Clubbs, Jacob K.Stanley, Brian Scheffe, Joe C.Yelderman Jr., Bryan W. Brooks. Chemosphere 92 (2013) 38–44.