SHOULD the National Park Service stop selling bottled water at Independence Park? At first glance, the question may strike some as the height of annoying nanny-state interference - like the citywide ban on foie gras or, even worse, New York Mayor Bloomberg's attempt to ban oversize drinks with sugar in them. (Not to mention Mayor Nutter's failed attempt to impose a tax on sugary drinks that went down the drain a few years ago.)

Given the concerns over the health impacts of sugary drinks, banning bottled water might be seen as the action of an evil nanny, one who wants to keep you fat.

But a campaign to ban bottled water comes at the behest of environmental and other groups to bring attention to a variety of global water problems and corporate big-footing, and although it's a complex issue, it's worth noting.

The group Corporate Accountability International is spearheading the campaign - it has succeeded in a bottled-water ban at other national parks, including the Grand Canyon - and its reasoning goes like this: Corporations are raking in huge profits by marketing bottled water, and part of that marketing suggests that bottled water is purer than public-water sources . . . even though some of that bottled water actually is tap water. The group's concern: By luring consumers to prefer bottled over public water, companies suggest that public water is less valuable, and makes us less invested in making sure that our public-water sources are fully funded and that we demand the right investments.

The lack of such investments is legion, and we just have to look to the Schuylkill, in some ways the source of all public water in the country. Philadelphia was the first place in the country to create a public-water system, when disease wiped out thousands and dirty, polluted water was seen as the culprit. The public demanded clean water - mainly because they didn't have refrigerators full of Evian in the 18th century.

These days, a recent Water Department move to raise rates to cover infrastructure improvements was met with outrage and political pushback.

The CAI group is also nervous about having too much water in private hands, especially in countries where access to clean and safe water is scarcer.

The campaign is prompting an unsurprising pushback from bottlers and marketers of water, saying that it makes no sense to require people to buy reusable bottles and fill them with tap water when soda, juice and other drinks are being sold. But supporters of the ban say that water should be seen not as a commodity but as a right. (An instructive report called Public Water Works! is at http://ph.ly/waterworks.) The ubiquity of bottled water certainly has an impact on how much of it we drink; according to a report in the Inquirer, bottled-water sales reached $11.7 billion in 2012. Banning bottled water is likely to drive up the sales of less-healthy drinks.

That's a conundrum, one of many for an issue that has no easy answers. But the accountability group should get credit for not being afraid of sparking the conversation.