San Juan Bautista, Calif.

On a hot, bone-dry afternoon — not unlike the one last summer when something went horribly wrong here — Will Daniels stands on the edge of a field, its neat rows of seeded soil stretching toward the horizon. Any day now, the first glossy leaves of a new crop will sprout, and within weeks, tons of fresh salad greens will be harvested, processed and sent to market.

Daniels wishes he could rewind the clock to Aug. 15, 2006. Stop workers from picking that lethal crop. Shut down his processing lines. Drive the trucks straight to a landfill and dump the entire load. Do something, anything, to avoid sending to market bags of baby spinach that killed three people, including a 2-year-old boy, and sickened at least 200 others, many with kidney failure.

Before that outbreak, whenever Daniels visited the fertile fields of the Salinas Valley or watched his production lines, he saw a wholesome, nutritious product he was proud to provide.

Earthbound, the nation’s largest producer of gourmet salad greens, founded and owns Natural Selection Foods, which processed the bagged spinach that caused one of the worst food-poisoning outbreaks in recent years.

Days after the tragedy unfolded in mid-September, the company hired food safety microbiologist Mansour Samadpour. Right off the bat, Samadpour told Daniels and Earthbound Farm President Charles Sweat that they were delusional if they thought it wouldn’t happen again.

“Another bullet is coming your way,” he warned. “The question you have to answer is, will the processing eliminate the hazard? The answer for this industry is no. You can reduce; you cannot eliminate.”

Under the scientist’s guidance, Earthbound rapidly put in place the most aggressive testing and safety program in the industry. All its greens are now checked for pathogens, from seed to sale. Each lot is tested twice — upon arrival from a farm, and again when packaged products roll off processing lines.

The testing has confirmed what Samadpour already suspected: Inevitably, some crops are still contaminated with disease-causing bacteria. The challenge for the company is to make sure none reaches consumers. Hunting down pathogens in produce has become a personal crusade at Earthbound Farm. In the year since the E. coli outbreak, the company has subjected about 120 million pounds of salad greens to new testing methods at a cost of several million dollars. Other companies have mounted costly safety efforts, but no one else tests all greens.

“We’re not going to rest until we explore every possible safety improvement,” said Daniels, vice president of food quality and safety.

For consumers, there’s more at stake than one company’s obsession to make amends for a tragedy. It’s a question of whether pre-cut, bagged salads, consumed in increasing volumes, can ever be rendered safe — as pathogen-free as, say, a glass of pasteurized milk.

The phone call that changed Daniels’ life came last Sept. 14.

Daniels was meeting with organic growers when the Food and Drug Administration and state health officials called to break the news: People around the country were getting sick from E. coli, and many had eaten Dole baby spinach processed by Natural Selection Foods.

As the investigation unfolded, 13 bags with E. coli O157:H7were discovered, all processed at the company’s south plant in San Juan Bautista on a single day, Aug. 15. The trace-back shocked many, since Earthbound is an industry pioneer — not only the nation’s largest organic produce supplier, but the first to launch pre-washed salads back in 1986.

“I was devastated,” Daniels remembered. “It was an immediate feeling of, ‘How could I have let the company down? Where did we go wrong? What did we miss?’ “

With more than two decades in the business, Earthbound had a sanitary system that followed industry conventions. Greens were kept in cold storage and double-washed in chlorinated rinses before packaging.

Daniels immediately reviewed his records for Aug. 15. The system seemed to be functioning. The temperature and chlorination were on target.

Daniels was relieved. But then he realized that if nothing was broken, then their whole system had failed.

That’s when Earthbound Farm hired Samadpour, a former assistant professor of environmental health at the University of Washington who had helped the beef industry develop an E. coli detection program after a lethal 1993 outbreak at Jack in the Box restaurants.

Samadpour told Earthbound that the spinach outbreak wasn’t a fluke. Pathogens are everywhere, he said. After all, food isn’t born in a laboratory; it’s grown outdoors, where cows, wildlife and water all carry bacteria from feces. About 20 outbreaks already had been linked to leafy greens since 1995.

Federal and state investigators found that last year’s tainted spinach bags contained bacteria that genetically matched cow manure at a pasture near a field in San Benito County.

Samadpour advised Sweat and Daniels to immediately begin checking all greens for pathogens, which no one in the industry was doing.

Almost overnight, the company erected a laboratory with state-of-the-art equipment.

On Oct. 2, just 18 days after the spinach outbreak was discovered, the company launched its “test and hold” system in San Juan Bautista. Upon their arrival from farms, each truckload of greens was tested for pathogens.

Two days later, Daniels got a phone call from the lab. A contaminated batch of frisee had turned up from a field in the Salinas area.The whole load of gourmet greens, almost a ton, was packed onto a truck and hauled to a garbage dump.

It wouldn’t be the last.

Straight from a farm, a refrigerated truck pulls into Earthbound’s dock in San Juan Bautista early on a summer morning. The pallets of organic arugula are unloaded in a cavernous warehouse kept at a near-freezing 34 degrees.

A worker named Sonia, wearing sanitized gloves, a hard hat and a face mask, rolls a cart to the towering stacks of pallets. With forceps, she randomly pulls out three to five arugula leaves at a time. For each 1,600-pound lot of greens, Sonia plucks 60 of these “grab” samples, about 3 ounces total, then drops the leaves into a plastic bag labeled with a bar code identifying the farm and the date harvested.

Since the outbreak, Sonia and other Earthbound employees have extracted several million samples from the 40 truckloads that arrive daily, carrying enough salad greens to fill more than half a million bags every day. Each sealed bag is delivered to a trailer, where microbiologists are waiting to look for two strains of E. coli — including O157:H7, the virulent one that caused last year’s illnesses — and salmonella.

A lab worker adds nutrients and heats the leaves to 109 degrees for eight hours. Then he inserts a pink stick — a lateral flow device that resembles a drugstore pregnancy test — while another technician extracts DNA.

If those dual tests are positive, the lot is held four hours for two more sophisticated genetic tests that confirm the results.

Once cleared, greens are moved onto conveyor belts, where they are trimmed and triple-washed in chlorinated rinses. (After the outbreak, Earthbound added a third wash.) Then they are zapped with lasers to detect foreign objects. At the end of the line, packaged greens are held 12 hours and tested again.

Once a week, on average, a load of raw greens from a farm fails the tests.

Since the test-and-hold program began last October, 58 out of about 76,000 lots entering Earthbound’s plants in San Juan Bautista and Yuma, Ariz., have tested positive for pathogens, a rate of 0.0008%. That amounts to about 93,000 pounds of greens destroyed out of about 122 million pounds that growers sent to Earthbound in the last 10 1/2 months. They came from many farms — most in the Salinas area, but also in Arizona and the Coachella Valley. Investigators were dispatched to the fields the next day, but the sources remain a mystery.

Tests for finished products were added in February, and so far no packaged greens have failed. But odds are, pathogens will soon be found after processing. Chlorinated washes can reduce bacteria counts but not kill them all.

Samadpour predicts that four of Earthbound’s finished lots, nearly 4 tons, will test positive every year, most often in summer. If — or when, Samadpour says — that happens, Earthbound will dump it all in the trash, shut down the line and re-sanitize the plant.

Like most processors, Earthbound has also implemented pathogen-prevention measures in fields and plants, including inspections of harvest equipment, workers, compost and water.

Now the ultimate goal is to invent something that has eluded the industry: a full-proof method of sanitizing produce.

“Testing is not the cure,” Sweat said, “but it’s another hurdle for that product to clear before it goes to market. What we learned is we can’t always explain how something got contaminated. So we better put in more controls to detect it.”

In the lab he runs for Earthbound, Samadpour jots down the fatal formula for an E. coli outbreak. Every 15 minutes, one cell turns into two, then two into four — and before you know it, 24 hours later, millions of deadly microbes lurk on a spinach leaf.

“If 10 soldiers are well-armed against 20 attackers, you can hold them off. But if you have thousands attacking you, you’re in trouble,” he said. “Food safety is that way. One highly contaminated load will make history.”

For greens — and for ground beef, the leading cause of E. coli outbreaks — there is no “kill step,” or sanitizing system, that eliminates 99.99% of pathogens. Today’s best technology, triple washing, kills 99%. That means if a handful of leaves from a farm carries 10 million bacterial cells, 100,000 could remain — enough to make people sick.

Like an oddsmaker, Samadpour calculated the risk and came up with a mathematical formula designed to ensure that Earthbound sampled a big enough fraction of greens to prevent an outbreak, but not so big it would delay production and sacrifice freshness. The tests add 12 hours to the time it takes for the greens to reach consumers.

The company is now pushing for federal rules mandating testing. The rest of the industry’s “don’t test, don’t tell” approach is a potentially deadly and costly mistake, Samadpour said. A recall can cost the industry tens of millions of dollars.

“Companies that don’t test their products are putting themselves 100% at the mercy of their wash system, which everyone admits will not remove bacteria that is tightly attached or internalized,” he said.

But the industry is skeptical. Many question the accuracy of the testing because the technique has not been scientifically verified, and they worry about lab errors — false positives and negatives. They say it offers no quick fix and may give producers a false sense of security.

Fresh Express, the nation’s largest supplier of bagged greens, says “test and hold” is unnecessary at its plants because it has rigorous safety measures, including the largest buffers between cows and crops, and its food has never been involved in an outbreak.

“The ultimate goal is we don’t want anyone sick from our product,” said Kathy Means of the Produce Marketing Assn. “But there’s a variety of paths to get there. One size does not fit all.”

Trevor Suslow, a UC Davis microbial food safety specialist, has mixed feelings about whether extensive testing should occur at every plant. More important, he said, is to ensure that growers, processors, truckers and stores all have well-designed programs to minimize pathogens.

“I think we simply have to engage in pathogen testing at some level. But you can’t test yourself out of any or all contamination,” Suslow said. “Due to the low probability of catching something, it has limited real value. But it may be an essential step to prevent an egregious mistake.”

Earthbound’s tests aren’t foolproof. Because they are likely to miss some tainted leaves, people could occasionally still get sick. But they could stop big outbreaks, said Robert Mandrell, a U.S. Department of Agriculture research leader who specializes in genetic pathogen testing.

“Large outbreaks are the critical events to stop, so testing might help. Only time will tell,” Mandrell said. “As long as processors and buyers do not try to oversell a ‘not detected’ result, there is no downside, except the expended effort and resources.”

The new safety controls have cost Earthbound Farm “in the millions” over the last year, adding perhaps pennies per bag, Sweat said. The company, which produces $168 million in packaged salads annually — 6% of the market — has not raised prices to cover its costs, he said. Its greens are marketed mostly under the organic Earthbound Farm label, but also other names, including some Dole, Ready Pac and Trader Joe’s products.

Michael Doyle, the industry’s most vocal critic, said Earthbound “has made major strides in making products safer.”

“I believe that Earthbound is now the industry leader in providing food safety interventions to fresh-cut salads,” he said. “The rest of the industry would be well-advised to follow Earthbound’s lead.”

Nevertheless, Doyle, who is director of the University of Georgia’s Center for Food Safety, still won’t eat Earthbound’s food, or any pre-cut, bagged fruits and vegetables, because they are more prone to contamination than whole produce.

“The problem is they don’t have a bulletproof intervention,” Doyle said. “I still feel they have a ways to go. But I also think they are committed to have a product as safe as pasteurized milk.”

Sweat’s ultimate goal is to make bagged greens so safe that Doyle will accept his invitation to have a salad for lunch.

Earthbound employees are motivated — and still haunted — by victims of the food poisoning, particularly a 2-year-old Wisconsin boy who died after his mother made him a spinach smoothie.

“When I got word of that, it took me to my knees. Each one is devastating, but that was absolutely the most heart-wrenching thing I have ever gone through,” Sweat said. “For me to sit down at the table with a consumer who is going to eat one of our products, I need to be able to look them in the eye and tell them we are doing everything we can.”

One Carnegie Hill; 37 Wall Street; Chelsea Landmark; Ritz Plaza.

A GOLF simulator that lets residents imagine they’re playing the 18th hole at St. Andrews in Scotland.

A penthouse party room with sweeping city views where residents can entertain, say, 50 of their closest friends.

Swimming pools, yoga studios and massage rooms that would satisfy even the most driven New Yorkers.

And finally, the one thing that should make any apartment dweller’s heart skip a beat: a washer and dryer, even in a 450-square-foot studio.

These are the kinds of amenities that developers are using to redefine the term “luxury rental” in Manhattan, and, perhaps more to the point, to justify a whole new level of prices for people who want the feel of a high-end condominium but don’t want to buy.

With rental vacancies hovering at less than 1 percent, developers are confident that the rental market is strong enough to absorb thousands of new apartments, even if they come with rents that are two to three times current averages. That means studios that rent for as much as $3,500 a month, one-bedrooms for $6,000, and two-bedrooms for $11,000. These are, incidentally, the kind of prices that owners of high-end condos might get if they rented out their apartments, brokers say.

In recent years, developers have been focused more on condo development than on rental construction, but at least nine rental buildings have opened within the last year, and at least a dozen more are scheduled to open in the next two years. Most of these buildings are high-rises, which means that thousands of new apartments will become available in the next 18 months.

“Builders are realizing that they can build rentals with high amenities and real wow factor because people are willing to pay for it,” said Gary Malin, the chief operating officer of Citi Habitats. In many ways, the market for new rental buildings is merely following the lead set by the condominium market in the last five years, when developers raced to find the most talked-about new amenity.

The developers of these new rental buildings are also giving them a Club Med vibe. Some even have created the land-based equivalent of a cruise director — someone to organize Halloween parties, a softball team and the occasional ski trip or scuba diving lesson. All with particular renters in mind, of course.

“These are people who know how they want to feel when they walk into their lobby and their home,” said Cliff Finn, the managing director of new development marketing at Citi Habitats. “It’s about feeling successful.”

The Chelsea Landmark, a 38-story tower with 407 apartments at 25 West 25th Street, opened five months ago. The developer, Rose Associates, built 22,000 square feet of amenities that include a gym, the golf simulator, a Zen garden, a spa with an oversize whirlpool and sauna, two lounges with billiards tables, wireless Internet connections and free juice and coffee, and a demonstration kitchen where local chefs will be featured at monthly events.

“Not every builder is willing to spend the money to get the high rents,” said Adam R. Rose, the president of Rose Associates. “But we knew that with this building we would be able to skim off the top 5 percent of renters in every building around here,” including people from older Rose rental buildings, he said. About half of the 20,000 apartments that Rose owns and manages across the city are rentals.

Mr. Rose said his company would not have built a building as well appointed as the Chelsea Landmark a few years earlier. “What’s acceptable to the marketplace has changed drastically,” he said. “What we delivered 20 years ago in condos wouldn’t make it today in even the lowest-level rental building.”

New rental apartments now include name-brand stainless-steel kitchen appliances, granite countertops, marble baths and hardwood floors. “The days of parquet are gone,” Mr. Rose said.

He added, however, that while the materials used in apartments at the Chelsea Landmark were expensive, they were chosen to stand up to a potential revolving door of renters. The kitchen counters are made of manufactured quartz composite and the bathroom tiles are porcelain. “They don’t just look good; they’re indestructible,” he said.

The quality of apartment fixtures and the kinds of amenities in a building naturally vary, depending on a building’s location and the kind of tenant that the developer hopes to attract. Brokers and developers agree that the target audience for many of the new high-rises is young professionals in their 20s and early 30s who may earn as much as $300,000 a year but who just aren’t ready to own yet.

The people moving into 37 Wall Street, for example, are “downtown-oriented people who are still early in their careers, and they choose to rent, but they have a condo sensibility,” said Mr. Finn of Citi Habitats. They are people who can afford a $4,800 two-bedroom but who might not have the $300,000 they would need for a down payment on a comparable condo that might cost $1.5 million, he said.

Thirty-seven Wall is a former bank building that has been converted to 373 rental apartments. Amenities include a gym, a yoga studio, a screening room, a lounge and billiards room with a lush clubby feel, and 150 channels of DirecTV in each apartment.

Chris Mazzarella, who works at a market research company in SoHo and who moved into 37 Wall in May, said the building’s amenities were “a major decision maker on my part.” He lives in a studio and plans to spend plenty of time in the lounge either shooting pool or on his laptop, and in the gym working out. He also hopes to give a Super Bowl party in the screening room.

Mr. Mazzarella, who is 27, said most of his neighbors seem to be young professionals. “I definitely feel like I’m in my element,” he said.

A building like One Carnegie Hill, at 215 East 96th Street, has a slightly broader mix of renters: singles in their 20s and couples in their early 30s, some with young children. The building, which opened a year ago, has an enormous fitness center and a rooftop party room, but it also has a charming children’s playroom that comes with free child care on weekend mornings when parents might be working out in the gym.

It has a roof terrace for sunbathing and a third-floor terrace with a playground and three separate barbecue areas, where residents can give outdoor dinner parties.

Mindy Jaffe said she and her fiancé, Per Chilstrom, have made good use of the barbecue areas. “We’ve had people over, and you just can’t believe you’re in the city,” she said. “It’s like being in your own private outdoor space.”

Ms. Jaffe said she and Mr. Chilstrom, who are both 32 and who rent a one-bedroom, have each lived in all kinds of buildings, including walk-ups and buildings without doormen. “We’ve thought about buying but haven’t been ready to do it,” she said.

The top 19 floors at One Carnegie Hill are actually condop units, while the bottom 23 floors are rentals, with separate elevator banks for each portion. The fitness center and lounges are free to apartment owners and available to renters for an annual fee of $600 for one person and $1,000 for two.

David Wine, the president of Related Residential Development, the company that developed the building, said the fees were set well below market rates for health clubs. “We’re not viewing it as a profit center,” he said. “We want people to join and use the amenity because it improves their lifestyle, and it’s what living in the building is all about.”

With so many new buildings coming online, the owners and managers of some older rental buildings are renovating their common spaces and looking for other ways to compete.

Stonehenge Management, which owns and manages the Ritz Plaza, a 479-unit building at 235 West 48th Street that was built in 1990, recently renovated the building’s fitness center and pool and also created a lounge area that residents can use for private parties. As apartments become available, they are also being upgraded.

“We have no problem spending the money to keep up with the newer construction and to maintain the rents we maintain,” said Marc Kaplan, the director of leasing at Stonehenge.

Shigeki Morii, a media consultant, has lived at the Ritz Plaza with his wife, Yuko Hamada, for nearly 10 years and said he was pleased with the upgrades. He uses the gym regularly and takes his laptop to the lounge whenever his wife needs quiet in the apartment to concentrate on her work as a Broadway reviewer for a Japanese television company.

“I also like the social aspect of the building,” he said. “Especially at the gym, when you see the same people and take the same classes, it’s a good way to get to know each other.”

Mr. Wine said his company was always looking for ways to keep its buildings current. At 1 Union Square South, which is nine years old, Related recently doubled the size of the roof terrace, adding outdoor barbecues and private party space. And at the Westport at 500 West 56th Street, a building that is about four years old, Related is creating a second party room at the top of the building because the existing one is almost always booked.

“We’re continuously redoing lobbies and common spaces because we have to constantly compete with new construction,” Mr. Wine said.

Looking ahead, with many more rental buildings on the horizon, developers seem quite likely to continue their efforts to outdo one another and even themselves.

Mr. Finn of Citi Habitats said he was working with different developers on half a dozen new buildings that will open in the next two to three years, including two 60-story towers with 1,254 units planned by Silverstein Properties on West 42nd Street.

Although the new buildings are still in planning stages, developers seem to be pushing the design envelope in search of a resort aesthetic, he said. That could mean outdoor rooftop pools and apartments with higher ceilings and ever finer finishes.

“You’re going to see a whole new breed of rental product coming on,” he said. “Things that will give condos a real run for their money.”