It might seem harmless at first: a thread of dental floss tossed in the toilet, a contact lens swirling down the drain of the bathroom sink. But even the tiniest of items can contaminate waterways.

The small fragments of plastic contact lenses are believed to be contributing to the growing problem of microplastic pollution. Pharmaceuticals, which are also frequently flushed down the drain, have been found in our drinking water, and the consequences are not fully known.

Larger products like wipes and tampons are also clogging sewer systems, resulting in billions of dollars in maintenance and repair costs.

Wondering what’s safe to flush or wash down the drain? We spoke with several wastewater management experts who explained why many frequently disposed items belong in a garbage can, not the toilet.

Disposable wipes
Many wipes claim on their packaging to be “flushable,” but almost all of them contain rayon or viscose, said Rob Villée, executive director of the Plainfield Area Regional Sewerage Authority in Middlesex, N.J.

“Unfortunately, the natural water bodies these get into do not have the heat or micro-organism levels to effectively degrade these,” he added. “That is why we see rayon accumulating in the oceans.”

While toilet paper will break down in anywhere from a minute to four minutes, wipes take at least six hours to disintegrate, Mr. Villée said.

Furthermore, the pumps at collection systems that move waste downstream to treatment plants cannot tear them apart.

“We see pumps that are designed to pump up to half a million gallons a day clogging,” Mr. Villée said. Now that wipes are used around the world, he added, “it’s a problem internationally.”

READ MORE

https://www.nytimes.com/2018/08/25/science/do-not-flush-down-toilet.html