Interestingly the preferred method to inject funds recently has been the use of the overnight Repurchase Markets. An effective tool to keep member banks, and Hedge Funds liquid.
One final observation: a couple of hours before the Fed's announcement we will get to see the latest numbers on Inflation. And by all expectations the core inflation rate will come in at an annual rate of 2.3%. Remember core inflation is calculated without volatile items such as food and energy.
So the core inflation rate is 2.3%, while the Fed Funds rate will likely be 1.75%, over a ½ % below the inflation rate. And Interest Rate below the inflation rate indicates an extremely accommodating Fed.