OSTP program makes recommendations to improve septic system management at adult foster care homes

The wet wipes clogging the equipment that University of Minnesota’s Onsite Sewage Treatment Program researchers use to study septic system effectiveness were the first clue as to why systems serving adult foster homes experience system failure at a greater rate than other residential treatment systems. Results of a study conducted by staff from the University of Minnesota’s Onsite Sewage Treatment Program at six foster homes in Chisago county show that adult foster care homes produce wastewater that is different than typical residential wastewater, with higher levels of contaminates that may contribute to decreased septic system performance. Bleach and other strong cleaning products for example, interfere with organisms required to break down solids in the wastewater.

Wet wipes were present in three of the studied sites; all the homes have residents who wear adult diapers. The wipes clogged OSTP sampling equipment and were deemed to be a risk to septic system pipes. “Best practices would be to dispose of the wipes with other solid wastes rather than flushing them,” says the study’s lead PI, Sara Heger.

Heger also pointed out above average water flow at several of the studied homes as a problem for system longevity, stirring up solids in pretreatment tanks and creating ponding in the soil treatment area. The resulting surface discharge threatens the surrounding environment and can create a human health hazard. Frequency of laundering linens and clothing appeared to be the greatest culprit in the high wastewater output.

While the study concludes that septic output contamination levels are difficult to manage, adjustments by the caregivers in the home during their daily activities could reduce wastewater output and toxicity. Recommendations for these sites include installing water saving devices, limiting the use of personal care products, cleaners and sanitizers, using natural cleaners, and educating staff and residents about proper disposal of non-organic material. In addition, many of the systems need updating to meet current treatment and dispersal requirements. When upgrades are made on these facilities, the addition of advanced treatment should be considered to assist in the removal of pharmaceuticals, personal care products and organic material prior to the soil treatment area.

More detailed information on this study can be found on the OSTP website: www.septic.umn.edu/research/

OSTPPhoto credit: Sara Heger
Items not intended for processing in
septic systems or too much use
of one product can cause premature
system failure. Here, paper products
block the inlet baffle on a septic
tank, interfering with the system’s
ability to break down human waste.