Betty Ronston finally got tired of those plastic grocery bags that have a way of piling up in storage drawers or kitchen closets.

"I've thrown so many away, and I know they're in the landfill a long time, and that bothers me because I've got grandkids," Ronston said Thursday as she left the Dover Super Fresh store.

Ronston now totes her groceries in two colorful reusable bags, doing her bit to reduce her environmental footprint.

That's just what Bear Democrat Rep. Valerie Longhurst wanted to encourage when she sponsored legislation to require larger stores to set up recycling containers and sell reusable bags. The law took effect Tuesday.

"You see more and more people out there with canvas bags," Longhurst said.

And yet even Ronston still has a surplus of plastic bags, which have an ability to seemingly multiply on their own.

"I've got one of those storage things. [The bags] are handy -- but I've got too many," she said.

Dover resident June Butler said she reuses her bags by putting her trash in them.

"I've seen where you can deposit them [in store recycling bins] and I might start doing that," Butler said. "I don't really need that many of them for my trash."

The law affects stores with at least 7,000 square feet of retail sales space or chains of three or more stores with at least 3,000 square feet of retail space each. It applies not only to grocery stores but to other retailers as well.

Most bills that make it to the governor's desk are the result of compromise, and this one was no exception. If Longhurst had her way, plastic bags would be banned -- but she knew that wouldn't sail politically.

So Longhurst worked with the Delaware State Chamber of Commerce to craft legislation that could pass.

"They all were in agreement on it," she said.

It is uncertain, though, just how much of an impact the new law will have.

An informal check of a number of Delaware grocery stores this week showed that all were in compliance with the law the day it took effect -- and had been for some time.

Indeed, most grocery chains trumpet their environmental efforts. Acme Markets and its parent company, for example, report that the company has recycled 11.5 million pounds of plastic bags and wrap.

Whether shoppers will actually use the new state-mandated service also remains to be seen, particularly in communities with convenient recycling programs already in place.

"I didn't know they had a bin here," shopper Monica Edwards said as she loaded bags of groceries into the trunk of her car at the Super Fresh. The store's recycling barrel is in a prominent spot inside the entrance.

"I usually either use them for trash bags or I put them in the recycling bin thing," Edwards said, referring to Dover's curbside recycling system. She said she'd probably continue to recycle the bags at home rather than take them back to the store.

Frederica resident Jane Jones is another shopper who's unlikely to use the store bins. She takes her bags to the recycle bins near the Town Hall -- and she finds uses for the ones she doesn't immediately recycle.

"We use them to bring vegetables in from the garden," she said.

But some people obviously are returning their bags. On Tuesday the bag bin at the nearby Food Lion market was filled almost to overflowing.

Even if the law's impact is open to debate, Longhurst said she expects it to be as much about consciousness-raising as it is about recycling.

"I think it raises awareness about what plastic bags do to the environment," Longhurst said

There is no debate that plastic bags wind up as unsightly litter, scattered on roadsides or snagged in tree limbs.

But the extent of the problem -- and even the number of bags produced each year -- are in dispute.

Longhurst's legislation states that an estimated 500 billion to 1 trillion bags are used worldwide. But the International Trade Commission reported in 2003 that Americans used just 87.5 billion bags.

The bill also states that the bags cause "the deaths of thousands of marine and land animals through ingestion and entanglement." But the National Oceanic and Atmospheric Administration has debunked a commonly quoted statistic that 100,000 marine mammals or sea turtles die yearly due to plastic bags and plastic debris.

"We were able to find no information to support this statement," the agency stated.

Environment Australia, that nation's counterpart to the U.S. Environmental Protection Agency, said the erroneous statistic was published in a 2002 study. The report was corrected in 2006.

Supermarkets haven't really needed a state mandate to recycle plastic bags. Stores sell the bags to recyclers who, depending on the commodities market, pay up to $500 a ton for them.

"It certainly helps to offset the costs," said Jennifer Killinger, spokeswoman for the American Chemistry Council.

The industry-funded council lobbies against plastic-bag bans and taxes, and helped bankroll the successful effort to defeat a Seattle ballot initiative this summer that would have slapped a 20-cent tax on plastic and paper bags. It supports legislation such as Longhurst's.

Supermarkets are experts in distribution of goods, Killinger said, so sending the recyclable material to a buyer is not an undue burden.

Most of the bags are recycled into composite lumber products such as Trex, while others are made back into bags. Some even become plastic shopping carts.

"What's getting left out of a lot of the [news] coverage from the consumer aspect, there are all sorts of materials that can be recycled every day. Dry cleaning bags, it's the exact same material. Newspaper bags, the wraps that come around bathroom tissue ... it's all polyethylene film," Killinger said.

In 2007, the most recent year for which figures are available, U.S. recycling efforts resulted in the recovery of an estimated 830 million pounds of post-consumer polyethylene film, including plastic bags.

Although Longhurst would like to see the bags banned, mandating recycling bins and encouraging the use of reusable bags is a good first step, she said.

"You have to crawl before you walk," she said.