We had this come up a few years ago when we did our playground. There was a seperate account opened just for playground funds (this was also done because the committee was applying for grant money which had to be spent on the playground) The committee ultimately is in charge, but having the treasurer of the PTO responsible for checks, deposits, makes things more smooth. And makes it easier when we get our taxes done every year, they all get done together.
The treasurer gets all statements for the playground, 5th grade(also a seperate account) and regular PTO account.

Could it be that the funds that go through the PTO are normally fairly modest? Playgrounds can easily run tens of thousands of dollars. It may be that the current treasurer isn't prepared to manage those kinds of funds - and the increased fundraising activity it will take.

Getting a new playground is going to require very close coordination with the school/district and they will ultimately own it. Would it be possible to negotiate with the school/district that the PTO will spearhead the fundraising/grant applications, but funds would be deposited into the school's account? You'd want a firm agreement as to the fact these funds are earmarked for the playground and not to be used elsewhere.

Very strange that the treasurer doesn't want to get involved -- as though she thinks she has veto power over anything related to money.

Our PTO did do fundraising for the playground 3 years ago. However, it's also the case in our town that the playground officially belongs to the town, which is responsible for maintenance. You might want to check with the recreation department of your town.

I am not a member of our PTO but would like to get the school a new playground. I have approached the PTO and have almost all of their support. However the treasurer has said that she does not want to be involved in the handeling of the money it will take to fund this project. What are my options when we start to raise money for the new playground?