"Environment" research area

Managing Septic System Contaminants

Primary Investigator - Sara HegerPrimary Investigator: Sara Heger
Industry Partners: Stantec
Award Type: Seed Grant - Postdoctoral Research Scholar (with NRRI Travel Grant)

Problem: There are over 600,000 subsurface sewage treatment systems (SSTS) processing over 40 billion gallons of wastewater per year in Minnesota. Even with proper siting and design there is the potential for nutrients to reach surface or groundwater particularly with commercial and cluster scale SSTS where regulations and risk increase in relation to nutrient removal in sensitive environments. Biochar and iron-enhanced sand (IES) have been found to be effective in treating stormwater but their performance for the treatment of wastewater from septic systems is poorly understood. 

Solution: This project will test several types of biochar and IES’s effectiveness at removing contaminants from wastewater in the laboratory (1) with absorption testing, and (2) in enhanced soil columns to evaluate its potential to improve SSTS treatment. 

Impact: The intended outcomes of this study are the development of a new sustainable technology for removal of dissolved contaminants from septic system wastewater. This work could open a new client base for biochar and IES across Minnesota. These outcomes will lead to mitigation of water pollution and jobs creation, topics that are vital to the health and well-being of Minnesota residents.