WASHINGTON — First, the National Park Service said it would cut back on selling its visitors bottled water to reduce the litter left behind.

Now, Congress – under pressure from the powerful bottled water industry – is threatening to cut off the federal money the Park Service is using to replace the disposable plastic water bottles with refilling stations.

But even if that happens, the Park Service said this week it’ll keep encouraging the parks to halt their bottled water sales, even with an edict from Congress. Park officials say they have such strong support for these bans that they would go it alone with help from friends and allies: The nonprofit groups that donate to park projects and the companies that have been selling the bottled water in the first place.

The cost of buying, installing and maintaining the refilling stations now in about 20 parks would almost certainly come from the Park Service’s network of friends groups and concession companies that contract with the agency to sell food, drinks and gifts and supplies.

“I feel very confident that those dollars will start flowing,” Norton said.

The Park Service’s David vs. Goliath stand comes during a standoff between the agency and the $13 billion bottled water industry over a policy Director Jonathan Jarvis enacted four years ago. Facing overflowing garbage cans and ever-growing recycling and landfill costs, he told the 408 parks, national monuments and historical sites across the country that they could eliminate sales of disposable plastic water bottles, as long as refilling stations, along with sales of reusable bottles, replaced them.

About 20 parks have taken Jarvis up on the offer, including the Grand Canyon, Canyonlands, Arches, Zion and Bryce Canyon, with more in the pipeline, officials said. Refilling stations cost anywhere from $2,000 to $15,000, Norton said, depending on how much pipe must be laid to a water source, which often is a spring.

Things got ugly this spring, when the International Bottled Water Association, which represents about 200 companies, mounted a full-court lobbying campaign on Capitol Hill to stop the Park Service’s latest effort at sustainability.

The hard work may pay off: Rep. Keith Rothfus, R-Pa., whose state employs 6,800 people at bottled water companies, tucked a last-minute amendment this month onto a government appropriations bill pending in the House. It prohibits the Park Service from spending taxpayer money to implement any ban on sales of bottled water.

Joe Doss, president and chief executive officer of the bottled water association, said that even if the Park Service can legally use private money to pay for bottled water alternatives, it should be careful about even thinking about subverting the (possible) will of Congress.