Sundman has been running the Breakaway Holiday Programme as well as a weekly youth group, Raise Up.
"I try to be as green as I can by using recyclable or reusable cups over single use plastics, encouraging and educating young people on how to recycle," he said.
Before Sundman brought in a recycling plan a couple of months ago, the YMCA at Grey St threw all waste into the skip, which then went straight to the landfill.
It was a stray flyer advertising the conference in Thailand that caught Sundman's eye.
"For some reason I just looked at it, read it. It wasn't necessarily directed to me.
"I did some more research, applied for funding and then boom, gone."
Sundman will be giving a five minute presentation at the conference showing others what he had done at the YMCA here.
"I'm not totally sure of what to expect," he said. "I'm just keen to learn."
"I think the population of Bangkok is 9 million so that must be a considerable chunk of people in the entire country and how they deal with waste I'm keen to see."
He was also passionate about gardening.
"By growing veges from seeds you got given for free it sort of fills this gap where people are poor and they've got no food but they've got plenty of time on their hands so why not?
"If I can teach your children that are coming to our programmes how to grow veges and also how to cook them, why can't they do it at home?"
Sundman leaves for Thailand tomorrow.
