Mary Snyder and her husband had already spent a decade feeling like they were drowning in more medical debt than they could count, let alone pay off, when a sewage backup caused the plumbing in their Arlington home to go haywire.

Unsure how they'd ever pay a plumber to repair the system and damage to the house while living paycheck to paycheck, the couple didn't head to the local branch of a national bank, but rather, a small office in the basement of their parish, St. Ann Church in Arlington.

With "zero credit," no bank would have made a loan, but the longtime parishioners were members of St. Ann Federal Credit Union, a member-owned cooperative organization. The credit union has a unique mission: to provide an alternative for parishioners who might otherwise turn to high-interest credit cards or predatory lenders. Manager Mary Green sat down with the couple to provide financial counseling and approved a $1,200 loan at 8 percent interest, covering emergency expenses.

"She wasn't pitying us," said Snyder, whose name has been changed for privacy reasons. "She was helping us in a very real way, which is hard to describe when your entire world is out of whack."

The couple paid off the loan within a year.

'It gives us our dignity back'

St. Ann, founded in 1949, follows all the same federal regulations as large credit unions such as USAA or Navy Federal, though it is staffed by just two part-time employees and a team of volunteers. The credit union, which used to be run out of the church boiler room, has $300,000 in assets. It doesn't offer debit or credit cards, or even checking accounts. Its first responsibility is to the approximately 180 members, all registered St. Ann parishioners, who earn a competitive dividend (currently 1 percent) on federally insured savings accounts. But the heart of the mission is granting personal unsecured signature loans aimed at people who might otherwise turn to a payday lender - at anywhere from 100 to 500 percent interest.

"I've made dozens of loans over the past four years to people who I have no idea how they're going to pay me back," said Green. "And only one went bad."

Green, who worked as a lawyer specializing in banking regulations before spending 15 years at home with her children, knows there's no magic bullet to rebuild finances. "I tell people you don't get in that trouble overnight and I can't get you out overnight," she said.

But when someone appears at Green's door deep in debt from a used car loan or a maxed-out credit card, she provides one-on-one financial counseling, even if she can't provide a loan. And when she makes a leap of faith, it pays off.

"They respond to my telephone calls; they respond to my emails. They don't run away from me because I treat them with respect. They're hardworking people," Green said.

That includes Snyder and her husband, who both work three part-time jobs to provide for their 12-year-old son, who has Down Syndrome, significant disabilities stemming from hydrops fetalis in pregnancy, and neuroendocrine cancer. Since paying off the initial loan, the family has taken out another $6,500 in automobile loans - which they are on track to pay off ahead of schedule.

"It gives us our dignity back," said Snyder. "It makes us feel like we're contributing members of society again as opposed to pariahs looking up from the gutter. It makes us feel like people have heard our plea."

Inspired by Catholic social teaching

St. Ann might seem unique, but American parishes were instrumental in the credit union movement during the early-to-mid-20th century. St. Mary's Bank, the first credit union in the United States, was founded in 1908 by a Msgr. Pierre Hevey, a French-Canadian priest in Manchester, N.H., to help his parishioners, mostly immigrant millworkers, save and borrow money. La Caisse Populaire, Ste-Marie ("The People's Bank"), as it was called at the time, cost just $5 to join, and members' deposits were held in a metal box at the bank president's home.

Related: Catholic credit unions show solidarity

Catholic parishes were influenced by Pope Leo XIII's groundbreaking 1891 encyclical, "Rerum Novarum," and the principle of subsidiarity - that social change is best handled on the lowest possible level. The pontiff's concerns about unregulated capitalism and the concentration of wealth, land and industry, inspired many Catholics to create credit unions and other cooperatives, according to David Bovee, an associate professor of history at Fort Hays State University in Kansas.

During the 1920s and '30s, hundreds of parishes, assisted by the National Catholic Rural Life Conference (NCRLC), formed their own credit unions in an effort to alleviate poverty in their communities and lead the United States out of the Great Depression.

"In accordance with the principle of subsidiarity, at the parish level, people could invest," and the widespread "boom and bust cycle" could be avoided, Bovee said. One NCRLC leader said that "it takes away from ruthless competition, which is pagan, and substitutes brotherly love, which is Christian."

By 1960, the number of parish credit unions grew to 1,224, according to Bovee. That number has shrunk over ensuing decades due to increasing regulatory burdens, the 2008 financial crisis and other factors. Today, there are only about 100 Catholic credit unions in the United States, including two based in the Arlington Diocese at the Cathedral of St. Thomas More and Our Lady, Queen of Peace in Arlington. Not all are in a position to conduct the same outreach as St. Ann; but the credit unions that do, make an impact.

"At the moment we got that loan, no matter how little it is, it allowed us to go to sleep, wake up and say 'This is a new day,'" said Snyder. "Which is no small thing."