We've all seen a homeless person pushing a shopping cart full of bottles and cans down the street, presumably destined for a bottle redemption center somewhere.

In a sense, this is one sign of success of the bottle deposit laws: The system was designed in part to encourage people to pick up litter because it would be worth something.

I saw an academic study recently indicating that bottle redemption actually accounts for significant income to many unemployed homeless people.

So I was sorry to hear that the Stop & Shop supermarket in Waterford has instituted a policy that would discourage someone from filling up a cart and wheeling on down to their redemption center.

I heard about the policy from a reader who is a regular customer of that Stop & Shop. He told me he likes to fill a cart with bottles and cans from his car when he is returning recyclables. He then wheels them over to the store's redemption center.

Just recently, though, he was stopped by a store employee and told that carriages are not allowed in the redemption area anymore.

Presumably, you now have to bring in the cans and bottles by bag or box, or individually.

This reader suggested his theory that the store was trying to discourage the many homeless who live in the immediate vicinity of the Waterford Stop & Shop from using the redemption center.

Sure enough, when I paid a visit, the store's redemption center is hardly a welcoming place. There are all kinds of hand-written signs posted on the doors, walls and windows, warning about the fine print of redemption laws and insisting on cleanliness and only brands of bottles and cans sold by the store.

The sign banning carts says they are not allowed in the center for "safety and sanitary" reasons.

Really?

The carts are all over the store and parking lot. Aren't they unsafe and unsanitary everywhere else?

I checked some other Stop & Shops in the area and discovered no similar rules against carts in the redemption centers, adding a little more credence to the theory that the Waterford rule is aimed at the many homeless who spend time near that store.

At the Stonington Stop & Shop, in fact, a polite handwritten sign asks customers to remove the carts from the bottle center when they are done.

A spokeswoman from the grocery chain's New England headquarters in Quincy, Mass., did not directly respond to my question, when I reached her by phone, about whether the homeless were being targeted by the redemption rules in Waterford.

She did suggest, though, that one difference between allowing the carts in the store itself and not in the redemption center is that the center is a small space with less room to maneuver.

Later, by email, the spokeswoman said each store is free to set its own rules about carriages in the bottle areas.

"In the case of the Waterford store, the store team had received many complaints about carts in the bottle room," the spokeswoman wrote. "It is highly used as there are not many recycling centers in the area."

She finished up the email citing sanitation and safety as reasons to keep the carts out.

For whatever reason, the Waterford Stop & Shop seems to run one of the region's most unwelcoming bottle redemption centers. And I doubt it is now the safest or cleanest either.

I visited a bunch on my quick tour of centers in the area, and I didn't see nearly so many harsh warning signs at any of the others.

Stop & Shop says the new policy was put in place in response to complaints from customers.

And yet it was a customer inconvenienced by the strict new rule in Waterford who complained to me.

I don't care so much if Stop & Shop is chasing away customers with restrictive redemption policies.

But I am sorry to think they might undermine the effectiveness of the bottle law.

Maybe the homeless will still visit and just double park carts on the sidewalk.

This is the opinion of David Collins