(Photographs courtesy Lava Mae) 

If you woke up this morning and showered in the privacy of your own bathroom, consider yourself lucky: America's nearly 600,000 homeless people often don't have a clean place to clean up.

But in San Francisco, where the number of homeless has risen seven percent in the last decade, a non-profit organization is putting bathrooms on wheels and driving them to those in need. The group Lava Mae, whose name loosely translates to "wash me" in Spanish, is retrofitting decommissioned city buses with ensuite bathrooms and bringing them into neighborhoods like the Castro, the Mission and the Tenderloin, currently providing about 200 showers each week.

While food and shelter are certainly pressing needs, Lava Mae's founder Doniece Sandoval believes that a warm, private shower—something most people take for granted—provides an intangible essential: dignity. "You can't overcome adversity if you don't have dignity and a sense of self," Sandoval, a former marketing executive, told TODAY.

Sandoval first became interested in the issue in 2012, when she passed a young woman under an overpass near the San Francisco Design Center who was repeating over and over to herself that she'd never get clean. "It made me wonder what her chances were," said Sandoval, who was then inspired to research exactly how many public shower stalls existed in the city. Her findings were disheartening: Just 16 stalls for the estimated 3,500 people who sleep on the streets any given night.

"I started to ask myself, if you can put gourmet food on wheels and take it anywhere, why not have mobile showers and toilets?" Sandoval said.

Her initial research revealed a handful of small mobile-shower projects around the country, typically housed in trailers or converted RVs. Lava Mae came together when she heard that the city would be retiring old diesel buses. "I told myself, I want those buses!" she said. Three years later, Lava Mae has three buses that were donated by the city; two are currently operating at five different locations, and a third vehicle is scheduled to launch in early 2016.

A man who identified himself as Bobby said trying to get clean in the past has been a dirty, sometimes violent problem. He described his experience after his first shower in this video. "It was clean, it was quiet, I was not bothered … it was personal, I had enough time, people were courteous, they were kind, and I feel brand new," he said.

Another guest named Ron, who worked as a painter before a fall off a ladder left him disabled and eventually homeless, seemed hopeful for the future after his visit. "Even in the shelters, some of the showers are really, really dirty. You don't even want to take a shower in them … I can only hope that when I get a place my shower will be as nice," he said in another video.

Each bus has two private bathrooms, one of which is wheelchair accessible (Sandoval notes that about 40 percent of the group's clientele have some kind of disability). Along with the basic shower, sink and toilet, the sleek spaces, known as "hygiene pods," have soft lighting, digital controls for water, fixtures donated by Kohler, hair dryers and skylights. "Even though you're only going to be on the bus for 20 minutes or so, it's 20 minutes of complete privacy and respite to hopefully recharge yourself in a lot of ways," Sandoval said in a video that describes the bus remodel process.

The buses are parked near agencies that already serve the homeless, like the Mission Neighborhood Resource Center, which offers healthcare and other wellness programs. "If we can minimize the amount of time people have to run place to place to get essential services, we'll be able to help the problem better," Sandoval says.

It costs $75,000 to retrofit each bus with bathrooms and installnecessary fixtures such as a hot water heater and the hookup for a city fire hydrant, which is how Lava Mae draws its water (putting a large tank on a bus would likely destabilize it). Sandoval and her husband have funded Lava Mae through their own donations and a traditional fundraising campaign, during which the founder challenged herself to go one week without a shower.

"From an empathy perspective, I think this one experience gave me a sole sense of how hard and demoralizing it is to be dirty," she told KQED News. The group has also received grants through programs like Google's Impact Challenge (they were funded two years in a row) and Bank of the West's Innovation Award, which Sandoval received earlier this month.

What's next for Lava Mae? The group is launching an affiliate program so that others can mimic their process, as Sandoval said she's received close to 1,000 requests to bring the service to other areas in need. "What we are hoping to do is create an open-source toolkit for people to follow what we do A to Z, so they can recreate it," she said.