They have apparently run out of space to store it but it will contaminate the sea even more than it already is.
From Fukushima Diary:
Tepco plans to discharge contaminated water into the environment, “Getting permission of related departments”In the first press conference of Tepco on 1/4/2013, Tepco implied they are to discharge contaminated water to the environment.
In this conference, Tepco commented they can finally start talking about the permission from the departments in charge once they manage to change the contaminated water into clean contaminated water by operating the multiple nuclide purifying system “ALPS”.
This facility called ALPS is supposed to be the ultimate water purifying facility but they have been failing in getting it in operation [Link 1], and it was not known why it was supposed to solve the contaminated water problem.
(ALPS ; A new water purifying facility of Toshiba, which is supposed to filter 62 sorts of nuclides including strontium. They expected to start the facility by this September, but because of the orders and reorganization of NISA and NRA, they can not start Alps yet. It’s not even known when they can start it.)
Tepco’s comment made it clear that the operation of ALPS justifies Tepco to discharge the contaminated water into the environment.
At this moment, the contaminated water tank is 96% full. Tepco decided to stock the contaminated water in 2 of the 4 holes dug in the ground covered with leakage isolation sheet, which were to stock the clean contaminated water purified by ALPS if it was in operation. (*1)
One of the independent administrative corporations in Yokohama, National Research Institute of Fisheries Science,Fisheries Research Agency started analyzing otolith 30 fish caught from offshore Miyagi and Fukushima after August, 2012 so that they can identify if the fish took radioactive material just after 311 or they are constantly taking it from the mud of sea ground etc. (*2)
However, if Tepco discharges contaminated water again, it is anticipated that the sea contamination would be even worse than now.