Meaning of "Federal Reserve’s various liquidity facilities" and something more I've found this link of San Francisco Fed. In it, it's stated that the Federal bank began «paying interest on reserves held against certain types of deposit liabilities.(...) This was important for monetary policy because the Federal Reserve’s various liquidity facilities initiated during the financial crisis caused upward pressure on excess reserves and placed downward pressure on the Federal funds rate. To counteract these pressures, on October 6, 2008, the Federal Reserve Board announced that it would begin paying interest on depository institutions’ reserve balances.»

I need help on clarifying the sentence in bold. Which facilities were those? What's the problem on an upward pressure on excess reserves, and downward pressure on the Federal funds rate? 

Any help would be appreciated.
Downward pressure on the Federal funds rate means bringing interest rates down even further (to ~0%). 

Upward pressure on excess reserves likely means increased incentive for banks to build up excess reserves. The part about reserves is bit ambiguous. After reading the article a couple of times, this is what I make out of the paragraph (my comments are in bold):


  This was important for monetary policy because the Federal Reserve’s
  various liquidity facilities initiated during the financial crisis
  caused upward pressure on excess reserves (provided banks with cash to increase reserves) and placed downward pressure
  on the Federal funds rate (lowered the interest rate to the target level ~0). To give  Fed a tool to counteract these pressures in the future when they decide to exit QE and tighten the monetary policy, on October
  6, 2008, the Federal Reserve Board announced that it would begin
  paying interest on depository institutions’ reserve balances. Paying interest on reserves gave the banks incentive to increase the reserves at the time. In the future, lowering interest rate paid on reserves would create downward pressure on excess reserves.


I found a footnote next to "Federal Reserve’s various liquidity facilities" part of the sentence leading to a page describing these facilities: 
Credit and Liquidity Programs and the Balance Sheet. It looks like a detailed technical description of QE programs Fed implemented after the 2008 crisis.