Go in peace.

Organizers are assuring the hundreds of thousands, even millions, of people who will throng Philadelphia for Pope Francis' visit in September that they need not worry about bathroom access. Porta-potties will abound, about one for every 250 people.

And they'll be cleaned three times a day.

More than 3,000 porta-potties and about 350 urinal stalls will be set up for the papal crowds. Organizers say the fleet, plus area restaurant and public restrooms, will provide for the 1.5 million people expected.

Some portable toilet experts, however, question whether that's enough.

A Royal Flush Inc., the company providing the toilets, has many units already stocked in a shipyard near the Walt Whitman Bridge. Hundreds more will be bought and assembled on site to relieve crowds on the Parkway on Sept. 26 and 27.

"It's a weird topic, but it's one that needs to be talked about," said Bianca Bethel, ESM Productions' site manager for the Parkway papal events. "We don't want to be that city where people leave saying, 'I had no place to go to the restroom.' "

ESM is coordinating planning for the papal Parkway appearances, including the Saturday evening Festival of Families, expected to draw between 800,000 and one million people, and the papal Mass on Sunday afternoon on Sept. 27, which could see 1.5 million attendees. The Creative Group is producing non-Parkway events, including the pope's Saturday appearance at Independence Hall.

The 3,300 toilets include 300 handicap-accessible ones. A Royal Flush will also bring in some VIP, 28-foot bathroom trailers. A second company will provide the urinals, capable of accommodating up to 200,000 men, Bethel said.

Neither company would reveal the purchasing price for the loos, their transportation, and service, but Alexandra Townsend, the toilet company's co-owner, called it "a very big job."

Townsend's business knows the Parkway well. It has set up temporary bathrooms for the Made in America concert, as well as the Mummers Parade and the annual Broad Street Run - where 600 toilets cost the city about $35,000, Townsend said.

In 2014, A Royal Flush provided portable washrooms for Super Bowl XLVIII at MetLife Stadium in East Rutherford, N.J. It also hauled 2,300 toilets to the New York City Marathon at a cost of about $200,000.

This gig is bigger.

So how does a company determine the number of toilets needed for 1.5 million people over 48 hours? Bethel said her team looked at papal visits to Brazil and the Philippines, as well as the last two presidential inaugurations. Their formula of one toilet for every 250 people was industry standard for toilets cleaned frequently.

The temporary toilets can accommodate about 1.1 million people, Bethel said. Public restrooms and willing facilities in restaurants and commercial establishments are expected to make up the difference.

Bruce Willis, manager of Philadelphia Portable Potty Professionals, said he doesn't think that's enough.

Willis typically recommends 50 people per porta-potty at all-day events and two toilets per 50 if alcohol is served (unlikely at the papal events). If the toilets are pumped out regularly, the ratio of one per 250 people could be fine. But waiting times could be a problem.

"You have to make sure you're placing them strategically," he said.

Jeremy Everett, sales and business development manager for Johnny on the Spot L.L.C., said he would have projected closer to 5,000.

"The number seems extremely low," he said. "If you were going to have a million and a half people who weren't able to use anything else, you'd need a lot more than 3,300."

Donna Crilley Farrell, executive director of the World Meeting of Families Philadelphia, is confident there will be ample facilities for those who need them.

"They're the experts. We do feel comfortable with the estimate. It's something that was looked at very carefully," she said.

Bethel stressed the figures aren't finalized and could grow.

In fact, Everett said other agencies may add supplemental porta-potties of their own. His company is looking to bid on a SEPTA contract for 600 units at various stations.

For President Obama's 2009 inauguration, the District of Columbia brought in 5,000 porta-potties for an expected two million people. His 2013 inauguration was more modest - 1,500 portables for about 800,000 people. The decrease caused a mini-panic beforehand but turned out fine, with some of the portables going unused.

In Philadelphia, setup must be completed days in advance. Bethel assured that the plastic potties would be brought in gradually, with little impact on residents.

"It won't be Toilet City in Philadelphia," she said.

Townsend, the co-owner of A Royal Flush, said the company is negotiating to add hand sanitizers to its order.

Each porta-potty bank will have a truck driver, a manager, and an attendant to help keep lines moving. The teams will service the units three times a day and as needed, she said. Huge pumping trucks will be screened ahead of time for access by the Secret Service.

For those squirming at the thought of thousands of porta-potties in the hot September sun, Townsend offered some advice.

"The big secret is, always go for the center toilets," she said. "Everyone always goes to the ends and no one ever goes toward the center - we'll go to check them and they're brand-new."

BY THE NUMBERS

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3,000 - Regular porta-potties, mostly on the Parkway and also in parts of Center City, including near Independence Hall, for Pope Francis' visit

300 - Handicap-accessible porta-potties

350-400 - Urinals

60,000 - Rolls of toilet paper per day

675,000 - gallons of wastewater per day

5-7 minutes - Average time it takes to clean a portable toilet

$35,000 - Rough cost of the 600 porta-potties at the Broad Street Run

$200,000 - Rough cost of the 2,300 at the NYC marathon

SOURCE: ESM Productions and Alexandra Townsend, co-owner, A Royal Flush Inc.

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