The United States Treasury will have approximately $2 billion dollars worth of dollar coins in storage. Storing these dollar coins costs money. Storing these coins securely costs the government a lot of money.
My plan is to give Federal employees a small optional pay raise. Employees recieving this raise would have to A. take some portion of their salary (<0.5%) in the form of dollar coins and B. agree to spend the dollar coins rather than deposit them in the bank.
The total cost of this raise would be calculated to be less than what the government saves by not having to store the dollar coins. There would be additional savings if the dollar coins gained popularity due to this program.