According to Yomiuri Shinbun (3/26/2012), 120 tonnes of the concentrated, contaminated water after the reverse osmosis treatment had leaked from 5:30AM to 8:30PM when a worker noticed the leak and stopped the treatment. 80 liters of this water which contained 140,000 becquerels per cubic centimeter of all beta nuclides including radioactive strontium may have leaked into the ocean, as evidenced by the elevated radioactivity in the sea water at the southern exhaust water drain.
No word on tritium in the Yomiuri article.
TEPCO says the leaked water flowed into the side trench and may have flowed into the ocean.
Side trench? All I can discern is a natural drain of some sort where the gravels trail off and grass and dirt start.
From TEPCO's Photos for Press, 3/26/2012 (click for bigger pictures):
Pipe that leaked:
Plastic wrap and duct tape are what's holding the system. (Worked for Apollo 13.)
There are a few more pictures at the link.