WASHINGTON — The Environmental Protection Agency has stopped monitoring mercury contamination in the Everglades and testing water after the recent floods in Colorado.

An $8 billion space telescope, the largest in the world, waits to be tested at minus-400 degrees Fahrenheit in a closed government facility in suburban Maryland, facing the possibility of costly delays.

Many of the half a million federal workers whose paychecks on Friday showed half of what they normally earn fretted about how to juggle bills and put off major purchases.

As the partial government shutdown reached its 11th day on Friday, it was affecting far more than the nation’s monuments and parks, with much of the little-noticed machinery of government shifted to idle. Jobs deemed essential continued to be performed, but other tasks that have paused may take a lasting toll, even if President Barack Obama and congressional Republicans reach an agreement to end the shutdown soon.

The temporary disruption of furloughed workers’ spending patterns, a skittishness likely to continue even after they go back to work, is capable of measurable damage to the nation’s growth rate, economists said. Federal workers are “spooked” and are likely to save more and spend less, said Mark Zandi, chief economist at Moody’s Analytics. “They’re going to be cautious at least into the next year,” he said.

Victor Anderson, a furloughed worker for the Internal Revenue Service in West Virginia, said, “I live from paycheck to paycheck just like every other American does.” Anderson, who earns $62,000 a year overseeing building maintenance, is worried that his credit rating will fall because he cannot pay bills this month.

“I’ve got to tell you, this is messing me up,” he said. “It’s going to take me a year once we go back to work to get squared away because of not getting my salary.”

The National Institutes of Health, the largest financial supporter of medical research in the world, has ground to a halt during the peak of its grant-making season, suspending millions of dollars in new research.

The country’s Antarctic program has been suspended, ejecting some of the world’s leading scientists from their lodgings at the South Pole, where they collect data crucial for understanding climate change.

Some agencies, like the EPA, have been virtually shuttered. Almost 95 percent of the agency’s 16,000 workers have been told to stay home. And while some longtime opponents of environmental regulation cheer that temporary outcome, others are deploring what could be lasting impacts on the environment.

“It is a polluter’s heyday,” said Sara Chieffo, the legislative director of the League of Conservation Voters. Normally, she said, “they are doing the inspections that need to be done, making sure that polluters are held to account.”

“We know that the longer this goes on, the cascading effects occur,” she added.

Dan Ronnenberg, who is on a furlough along with thousands of other safety inspectors for the Federal Aviation Administration, said tasks not being performed included inspections of the de-icing of aircraft on the tarmac and checks that pilots do not fly longer than allowed. He said the risks to flight safety increased the longer outside inspectors were off duty.

The shutdown initially sent about 800,000 workers home on Oct 1. The Defense Department recalled most of its 350,000 civilian workforce, and others who are deemed essential have returned piecemeal, including thousands of CIA employees and experts at the Centers for Disease Control and Prevention needed to confront a salmonella outbreak.

Agreements were reached between the federal government and states to reopen a number of national parks and monuments, including the Statue of Liberty, Grand Canyon National Park, Mount Rushmore and parks in Utah and Colorado.

But the shutdown has left close to 500,000 employees still on furlough, according to the American Federation of Government Employees.

The House passed a bill to ensure that they receive back pay, which the White House supports. Even if workers are financially made whole, their uncertainty about whether another shutdown could occur was giving many pause about making big purchases.

Andrew Sailes, a mechanic at Bolling Air Force Base in Washington, and his wife have put off buying a house for a year. “We’ve got to sit in our apartment until we get some more money,” he said. “We had to push everything back.”

The furlough comes on top of the all-agency spending cuts this year known as sequestration, which forced some workers to take unpaid leave and departments to cut budgets. Republicans applauded reducing the size of the government, but some economists calculated that the cuts have slowed the nation’s growth.

Scientists said that one of the most serious casualties might be the country’s reputation. Markus Kissler-Patig, the director of the Gemini Observatory, an international coalition with telescopes in Hawaii and Chile, said he was worried about the United States’ foreign partners if the coalition’s cash flow, which is administered by the National Science Foundation, were to run out. The foundation, which is almost entirely furloughed, cannot provide cash infusions during the shutdown.

“I am starting to hear informal feedback questioning whether the NSF is the right agency to run this international observatory,” he said.

Nor could the timing have been worse for the James Webb Space Telescope, an $8 billion contraption that unfolds like an origami figure in space and will be capable of detecting the universe’s earliest galaxies.

Scientists have toiled for years and were poised to put its inner workings to the test by simulating the vacuum of outer space in a structure the size of a grain silo when the shutdown halted work at the NASA-run facility in suburban Maryland.

“It’s just sitting there twiddling its thumbs,” said Matt Mountain, the director of NASA’s Space Telescope Science Institute.

At the EPA, officials have allowed about 900 employees to stay on the job, responding to imminent threats to the environment or to public health. Workers are reporting for duty at toxic waste sites that pose a direct threat to surrounding communities.

But officials said the bulk of the agency’s work had been suspended. Industrial chemicals are not being screened for potential health effects. Routine inspections of drinking water systems across the country have been halted.

No solution yet — Political divisions over the nation’s finances appeared to narrow on Friday as President Barack Obama and congressional Republicans showed greater flexibility in their negotiations. But officials headed into the weekend without a deal to end the shutdown and avert what could be a devastating default after the government reaches the current borrowing limit on Thursday.

While the outlines of an agreement that would involve a temporary fix followed by longer-term budget talks came into view, the president and lawmakers faced the challenge of framing such a deal in a way that all sides could accept politically.

“We’re obviously in a better place than we were a few days ago in terms of the constructive approach that we’ve seen of late,” Jay Carney, the White House press secretary, said late in the day after the president met with the entire Senate Republican conference and consulted by telephone with Rep. John Boehner of Ohio, the Republican speaker of the House. “But there’s not an agreement.”

Both houses of Congress were scheduled to meet over the weekend. But White House officials and senior lawmakers cautioned against expecting a quick deal, although much of the incendiary speech that has characterized the fiscal fight had given way to words like “constructive” and “progress.”

— New York Times News Service