On 26 May 2014, Japan forwarded to the IAEA a message it had sent to all missions, consular posts, embassies and international organisations in Japan announcing that groundwater at Fukushima Daiichi Nuclear Power Station will be released for the second time on 27 May 2014.
TEPCO has made detailed analysis of results of the groundwater to be released, and all these results show that that the radioactive levels of sampled water are substantially below the operational targets.
TEPCO has also been providing measurement data related to the ground water bypass in documents such as the following: http://www.tepco.co.jp/en/nu/fukushima-np/f1/smp/2014/images/gw_drainage_140523-e.pdf, which are posted here.