Santo Stramacchia, looking out over a thousand azure, portable toilets, does not fear the momentous task that awaits him.

The Northborough field office manager for United Site Services is a key figure in making sure these porta-potties make it to the 26.2-mile race course, from Hopkinton to downtown Boston, in time for the iconic Boston Marathon on Monday.

His team is waiting for race day.

“Everybody’s already talking about it,” he said. “Everybody’s excited.”

In total, there will be 1,400 porta-potties at this year’s marathon, the Boston Athletic Association told GBH News.

The math to get to that number starts with a standard ratio for live events: one porta-potty per 100 people. But what makes the Boston Marathon’s bathroom logistics so complex is that the event covers a vast geographic area, with each spot along the course posing unique needs.

More than half of the toilets are concentrated at the start line in Hopkinton, where there will be 730 come Monday.

“You have your people at the start getting ready and you want as many restrooms as possible, because you don't want people having to wait in line,” said Michelle Stratton, the New England sector account manager for United Site Services.

About twelve blue and gray portable toilet units are arranged in lines outdoors in a dirt lot.
These portable toilet units in Northborough will be among those hauled to the Boston Marathon race course before Monday.
Hannah Loss GBH News

She’s helped to coordinate the marathon’s toilets for 24 years.

“It’s a lot of toilets,” she said.

The commodes in Hopkinton will be strategically placed, she said, like near bus drop-offs. And for any last-minute nervous bathroom breaks, a big cluster of 200 porta-potties will sit next to the start line in the CVS parking lot on Main Street.

Stramacchia said their plans include about 50 accessible toilets throughout the course for people with disabilities. And 30 four-way urinals will also help offset the flow of traffic near the start line — although those come with a disclaimer.

“You’ve got to be tall to use them, okay. Five-nine or shorter, you got problems. You need, like, a box to stand on,” he said.

Stramacchia is also keeping tabs on the toilet paper, trucks and trailers needed to keep things flowing smoothly. They’ll make sure the toilets are stocked with three rolls each.

And while his industry gets a bad rap, it’s not disgusting work.

“None of my guys go home with any feces on them,” Stramacchia said. “They’re clean every day.”

The BAA has the benefit of 127 years of marathons to know just how many toilets it needs for the 30,000 marathon runners, plus another 10,000 athletes running the 5k, 10k and half marathon in the days before the main event.

But they still use each year as a learning opportunity to tweak the calculation, especially if certain areas experience long lines or lots of traffic, said BAA operations production manager Will Pollard. That might mean noticing a line in Athletes’ Village, or getting feedback from volunteers along the route.

And, as the race has grown, so has the number of toilets.

“The needs ... of the porta-potty order is a big one,” he said. “Because as more people show up, you have more of a need for [toilets].”

After runners set out from Hopkinton, they’ll have access to the four or five potties at each of the 24 hydration stations along the course, Pollard said. Plus, more at each medical tent and another 115 around the finish line.

In the days counting down to the big day, United Site Services begins delivering the toilets, starting with locations downtown.

A liftgate will lower the porta-potties to the ground out of the back of a truck, where Stramacchia’s team will put on the finishing touches: filling the toilets with fresh water and dropping in a dye pack, affectionately called “blue juice.”

“Your blue, scented, beautiful lavender water — whatever the flavor of the month is,” he said.

As for the newest porta-potties, the ones Stramacchia calls “the best of the best”? The cleaner ones, with crisp stickers and no scuffs on the outside?

Those will go in another cluster by the finish line — where there are the most cameras, he said.