Doesn't anyone actually do their own taxes?
We honestly don't know how much he will pay in taxes based on this award. Assuming he doesn't have a summer job, his marginal federal tax rate would be close to zero and possibly with such a large winnings, might bump him into the work credit, so he might actually pay negative income tax (i.e. receive money).
And even if he does have a summer job that paid him $10,000 - $20,000, after the standard deduction and personal exemption, he would probably be in the federal marginal tax bracket of 15% for a total tax somewhere around 12%.
Don't know his state income tax situation and doubt he would have to pay FICA taxes. So I would expect the winnings to marginally cost him between (-$300, $2400) in taxes.
This doesn't even take into account that he could claim running is a self-employed business (rather than a hobby). Therefore any expenses related to the business of running could be deducted, such as all his car mileage when he drives to his Sunday runs. At 56 cents a mile, it could add up pretty quickly.
So most likely his taxes would be *at most* in the hundreds, not five or six thousand dollars.