You flush, and it goes away. Or does it?

There's more going down the sewer pipes than you might imagine, and some of it is damaging stuff.

Newspaper headlines report the presence of drugs in our drinking water, male fish producing eggs, and the alarming fact that tiny plastic beads may be killing our lakes. It's easy to ignore our role in all of this. We just assume that someone, somewhere, is dealing with our waste — if we think about it at all.

But we have to remember that there is no "flush, and away." The choices we make every day are critical to solving these problems.

Thousands of chemicals exist in consumer products and medications, many of them unnecessary. Tests of water quality routinely find antibiotics and prescription drugs for everything from epilepsy to depression in the discharge from wastewater treatment plants. Although critical for human health, medications are often flushed down the toilet and find their way into our surface water, where they can harm fish, native mussels and other aquatic life.

Unnecessary perfumes and antimicrobials, routinely used in soaps, shampoos and personal-care items, also end up in surface water, where they can damage rivers and lakes. Wastewater treatment plants were not designed to eliminate these man-made compounds. As a result, we cannot reliably and affordably remove them.

Nonchemical, inert materials in our wastewater also have economic and environmental impacts. Microbeads, the tiny plastic particles used in personal-care products such as toothpaste and facial scrubs, aren't biodegradable and persist in the environment. The beads are so small that they pass through treatment plants and are released into rivers, lakes and eventually the ocean. Along the way, they adsorb contaminants from the water and enter the food chain as food for small aquatic species. As those animals are eaten by larger animals, the concentrated contaminants move up the food chain, eventually becoming part of our diet.

"Flushable" wipes cause expensive and damaging clogs in sewer systems, resulting in plugged drains, sewer backups, clogged and broken pumps, and increased maintenance and repair costs for taxpayers.

Wastewater treatment comes at a price, one that we continue to make worse with our personal choices. In Switzerland, the upgrade of 123 wastewater treatment plants to remove trace chemicals such as medications and personal-care products is estimated to cost $3.38 billion; a similar effort in the United States would cost hundreds of billions of dollars.

There are, however, easy and inexpensive ways to stop the discharge of these chemicals, beads and wipes into our sewer system and environment. We can all help the environment through some very simple actions:

• Dispose of unused medicines responsibly, not down the drain. The Minnesota Pollution Control Agency, as well as many law enforcement agencies, can provide guidance on the best way to dispose of these products.

• Purchase personal-care products with the environment in mind, limiting perfumes, antimicrobials and other synthetic chemicals.

• Purchase products that either do not contain microbeads or that substitute natural materials (such as ground nut hulls) in their manufacture.

• Flushable wipes are neither degradable nor trouble-free. Dispose of these wipes in the trash, not down the toilet.

We all have choices — ones that we make almost daily through our purchases and behavior. Let's make those choices smart ones that help preserve our lakes, rivers and environment.

Learn more about how you play a critical role in keeping our surface water clean and safe for all living creatures at the EcoExperience at the Minnesota State Fair.

Paige J. Novak is a professor in the University of Minnesota's Department of Civil, Environmental and Geo-Engineering and its BioTechnology Institute. Larry Rogacki is assistant general manager, support services, for the Metropolitan Council's Environmental Services Division.