Some of the concerns addressed in the article seem to be about things that they did in the initial stages of the problem where no other solutions were available, for example, using seawater, or spraying water over the reactors.
I just checked on the
JIAF page where they provide updates and they are using freshwater for all the cooling now, and they have installed some storage tanks with some more storage tanks still to be installed. They are starting to process this contaminated water with filters.
To see a full status update including measures that they are working on or considering, see
this pdf