Viruses are in the news. Children around the country are sickened with enterovirus D68, one of a group of very contagious viruses that live in the intestinal track. Therefore, they are in the waste of infected people. People are really alarmed to learn about the spread of ebola virus, that moves through contact with bodily fluids, like human waste. When waste containing viruses are washed or flushed down the drain from an infected person, what happens to them?
If in rural or some suburban areas, it enters a septic system. Fortunately, if properly sited and designed, septic systems offer the best protection from viruses spread by human waste. Unsaturated soil quickly and easily traps viruses, keeping them from reaching ground or surface water. While a virus in the soil may be active for a few months, as long as they remain below the soil surface, people using the yard are protected.
Beware of sewage surfacing in the yard or discharged to ditches. In these situations, the removal ability of the soil has been bypassed and a virus can be easily contracted. If you have untreated sewage in the yard or nearby ditch, you may be able to keep children away, but be sure to keep pets away as well. Pets can track viruses into the home if they walk or play in infected areas.
Research at OSU is showing that two to four feet depth of unsaturated soil is needed to remove bacteria and virus from sewage. In some cases, the minimum state standards on unsaturated soil depth may not be enough to provide complete virus removal. Some homes, located in areas with seasonal high water tables, use drains to move water off the lot. In recent tests of this drainage water, researchers are finding bacteria and viruses.
In wet areas of Ohio, a rural homeowner can disinfect their wastewater to provide added protection for their family and neighbors. OSU research is looking at the effectiveness of chlorinators and ultraviolet light disinfection systems, commercially available for home septic systems. Research is also examining new, highly effective disinfectants, like chlorine dioxide, for use in home septic systems.
To find out more about soil and how septic systems can prevent the spread of disease look at Bulletin 896 Suitability of Ohio Soils for Treating Wastewater. Bulletin 943 Reuse of Reclaimed Wastewater – Disinfection to Protect Public Health provides information of chlorine and ultraviolet light disinfection systems. The bulletin also presents the OSU research on chlorine dioxide for disinfection. Get copies of these bulletins through your local Ohio State University Extension office or order online at estore.osu-extension.org. To find out more about septic systems and how they work to protect the public health go to the website for the OSU Soil Environment Technology Learning Lab at setll.osu.edu.