The annual percentage rate for the loan is 3.3%, the total loaned is $26,000,000, the time for the loan is 30 years. To determine the total cost of the loan, we can use the following expression:

Where A is the final ammount, P is the ammount loaned, r is the annual rate, t is the elapsed time and n is the number of times it gets compounded. For our case, we have:

The total cost of the loan is $68,862,533. To determine the ammount each family has to pay per year, we first need to divide the total cost by 30, which is the number of years it'll take to pay the loan:

Then we have to divide the value above by 15,000, which is the number of families.

Each family has to pay $153.03 per year.