Sewage Transport Volumes and Physical Degradation Rates of Personal Care Wipes

As personal care wipes become increasingly popular, inappropriate disposal to the sewage system is raising significant environmental and economic concerns. Many common brands, while marketed as "flushable," do not degrade appreciably in the plumbing and piping fixtures that the sewage transits. As such, these wipes can cause a myriad of problems including sewer blockage and destruction of pumps and grinders. This work sought to better understand key factors influencing the onset of such problems, including the volume of wipes present in the sewer and the degradation rates associated with a variety of personal wipe products, both "flushable" and nonflushable. The results suggest no correlation between the quantity of wipes in sewage and either the preceding precipitation or the sewage flow rate. To examine their degradability within a sewer system, we evaluated the degradation over time for six commercially available wipes under four conditions: static, kinetic, tap water, and sewage water. Five of the six wipe types were greater than 93% intact after 48 h of exposure to sewer-like conditions and only one wipe type degraded to less than 14% of its initial volume after 48 h, which is similar to the degradation performance of tested toilet paper. Degradation rates were highest in tap water under kinetic conditions and lowest in raw sewage water under static conditions.