Hi- The treasurer is held accountable for all school funds - and school funds will include any money deposited in an account using the school's EIN.
One possibility for these small accounts is that this money be put into a non-interest bearing account. Speak to your bank - but generally a non interest bearing account does not require an EIN because there is nothing for the bank to report to the IRS.
I hope this is helpful!
Deb Markowitz