I wonder if you can answer a question that has stirred debate in our building. The composters persuaded the building to pay a company to pick up appropriate food waste for composting. On the other hand, all units have garbage disposals. I understand that the District has one of the most advanced sewage treatment systems, and that the waste ends up being used by farmers in Virginia and Maryland as a soil amendment.

So what’s better? Down the drain or trucked away?

Michael Rosenthal, Washington

There’s nothing that plumbers love more than customers who stand and watch them work while peppering them with questions. That’s what Answer Man does, which is how he knows that his plumber, at least, doesn’t even use a garbage disposal. The only thing he wants to see going down the drain of his kitchen sink is water.

Now, that may be because of some weird plumber Stockholm syndrome — don’t tarnish my pristine pipes! — or it may be that he feels that grinding up food waste and sending it along is just asking for trouble.

Answer Man asked D.C. Water what it prefers. The answer: Put food scraps in the compost bin or trash can.

“Yes, it is true that we have a state-of-the-art digester complex at Blue Plains that can take organic waste (poop) and turn it into a nifty little product for planting and gardening,” spokesman Vince Morris wrote in an email. “However, any food scraps are not as structurally straightforward as poop is — they come with the added risk of causing clogs and fatbergs, they are not chemically ready to be added to our sludge and we would much rather they do not go down the drain.”

So: Composting is the best thing to do with these scraps. Second best is the trash, where — depending on where you live — they will be incinerated or added to a landfill. Which brings us to our next question:

When I read your column about plastic bags gumming up the works, it reminded me of something we dealt with in Colorado. Every year the water department asked — begged — us not to flush dental floss down the toilet. They explained that their filters cannot stop something so small and it gets into the gears and can bring the whole system to a halt.

I’ll bet most people don’t realize this and the local water departments would appreciate it if you did a PSA in your column to let people know not to do this.

George Miller, Warrenton

Well, Vince?

“Yes, floss is a disaster for wastewater systems,” he said. “It never ever breaks down or loses its strength and can contribute to big clogs of fats, oil and grease or other rags and non-flushable items. It will bind and catch and cause headaches for both homeowners and their plumbing and also for the water authority. We strongly encourage all users to put their floss in the trash — never, ever in a toilet.”

What it boils down to: Don’t use your toilet or your sink as a trash can. And while we’re on the subject:

I’m impressed by your legwork researching recycling. Wouldn’t it be easier if product labels showed with clear graphics what can and can’t be recycled? For example, shouldn’t packages of pens, toothbrushes, coffee, tea bags, razors and other common products tell us what we can recycle? Can we recycle that nice plastic and paper container that pens come in? Can we recycle the pens?

It seems to me we’d have better compliance if consumers had clear information about what to recycle.

Sue Arnold, Arlington

That is a good idea. But Susan Collins of the Container Recycling Institute said there are too many variables to make it workable. Every community, she said, has different markets for its recyclables and thus has different rules for what to do with packaging and products.

Said Susan: “If I’m buying strawberries or blueberries, the maker doesn’t know what to put on the container because they could be selling to me — and in my community we’re not supposed to put it in the bin — or to a community five miles away that is supposed to put it in their bin.”

Helping Hand

It’s the time of year when I hope you will recycle some of your money by donating it to The Washington Post Helping Hand. That’s our annual fundraising drive for three local nonprofit groups that work to improve the lives of vulnerable people: So Others Might Eat, N Street Village and Bright Beginnings.

Our goal is to raise $250,000 by Jan. 3. You can read about the vital work these charities do — and make an online contribution — by visiting posthelpinghand.com.

Twitter: @johnkelly

For previous columns, visit washingtonpost.com/john-kelly.