Bathtub Faucet Leak

My bathtub faucet has been a little leaky since I moved into the place in late February.  And by 'a little leaky' I mean that as long as I paid attention and turned it completely off it would stop dripping but if I was lax and just casually shut it off it dripped every few seconds.

That changed about 3 weeks ago.  After my shower I turned off the faucet and it continued to let out a steady stream of water.  This could not be called 'dripping'.  No matter how hard I tried I could not get the thing completely off and the water practically poured out of it.  Frustrating.

I went about my business and got ready for the day, thinking that maybe the flow would slow a bit once the pipes were drained.  About 15 minutes later I went back to check and it was just like I had left it.  So I put that bucket under the faucet to measure how much was coming out.

That bucket, which holds 2.5 gallons, was full in 30 minutes.  I was aghast.  Holy precious water wasting, Batman!  It just so happens that I had to use the toilet then so instead of flushing with the flush handle I dumped my bucket of water into the toilet to flush.  Look at me with my savvy water saving knowledge! I then plugged the tub with the plan of using that water to flush until the maintenance guy could come up and fix my faucet.  After 10 hours the tub was full.  Insane.  Sadly, the maintenance guy had to drain a lot of my water to get at the faucet and fix it.  But it does not leak any more!