Fukushima nuclear disaster headquarter checked tritium at 51 locations (35 rivers, 13 lakes/dams, 3 cleanwater).
The samples were taken from 11/15/2011 ~ 12/15/2011.
As a result, tritium was measured at 44 places where they measured it at 29 locations in 2002.
Also, highest readings were much higher than 2002 like the graph below.
However, Fukushima nuclear disaster headquarter states still these 3 highest readins are lower than the maximum of 2000 ~ 2011 in all over Japan, so it is not a problem (River : ~1.7 Bq/L, Lake/Dam : ~3 Bq/L, Clean water : 2.1 Bq/L) though no detailed data is given.
Especially they measured tritium from the rivers in Iwaki city, where they didn’t measure it in 2002.
The detectable amount was 0.35 Bq/L. Cesium 134/137 were not measured supposedly.
No explanation is given why they took 6 months to publish this data.