Founded in 2015, the Center for Clean Water Technology (CCWT) at Stony Brook University in New York has been developing a new technology for septic systems with an eye on reducing the amount of pollution in groundwater.
Researchers at the CCWT have developed septic systems that remove nitrogen from septic wastewater using biofilters. Biofilters are porous media for wastewater treatment composed of granular material (e.g., sand, gravel, crushed stone), and support both biological activities and transport processes like filtration or adsorption to remove contaminants. They provide a favorable environment for naturally occurring microorganisms, which break down septic wastewater pollutants.
Two septic systems were recently field tested by CCWT researchers. Each septic system uses two 50-foot diameter biofilter beds with gravel support media to remove nitrogen from septic wastewater. Each septic system also includes an equalization tank to store septic wastewater for about six hours, allowing septic effluent nitrogen levels to equalize. Equalized septic effluent (the wastewater seeping out of the septic system) is then distributed evenly through the two biofilter beds for nitrogen removal before seeping into the soil.
Results show that both septic systems removed up to 87 percent of total septic system nitrogen during this septic system field testing.
The septic systems developed by the CCWT are designed to replace traditional septic tanks with biofilters. The septic system components are commercially available for easy integration into existing septic systems.
Why is a better septic system needed?
Septic systems are used to treat septic wastewater at the source, which includes household gray water and flushed water from toilets. They are typically located underground near septic tanks, where septic wastewater is broken down by naturally occurring microorganisms.
Unfortunately, when septic systems fail, septic effluent can flow to nearby surface waters, contaminating them with septic pollutants like nitrogen. Nitrogen in septic effluent is the result of septic microorganisms breaking down organic nitrogen compounds in septic wastewater to make more energy available for growth.
One solution to prevent septic systems from failing is to have septic tank repair performed by a professional every three to five years. However, that doesn’t necessarily mean all septic systems will be repaired. Therefore, replacement of septic wastewater treatment systems with septic systems designed to reduce septic effluent nitrogen pollution is needed.
Potential benefits of the septic systems developed by the CCWT include:
- Higher septic system nitrification rates than traditional septic tanks for reduced septic effluent nitrogen levels
- Lower capital costs than conventional septic systems with septic effluent nitrification
- Septic system installation using existing septic tank space, which can be a significant advantage for septic system replacement
- Use of biofilter media that can be recycled after septic wastewater has been treated (biofilter media is much less expensive than other septic system components)
Researchers are seeking private-sector partners for septic system commercialization, which would include septic system installation and conversion to a septic system using biofilters. They believe their systems could be ready for installation in the Stony Brook area as soon as this summer.
At Gullett Sanitation Services, Inc., we’re committed to staying on top of the latest developments in our industry. For more information about how we can help keep your septic system operating smoothly for years to come, get in touch with us today.