TEPCO continues to say they still don't know whether the two are related.
The water sample from the same observation hole, No.1-1, was found with 3,000 Bq/liter of all-beta (including strontium) on June 29, 2013. The successive measurements showed higher all-beta from the same hole.
Here's the latest number of all-beta and tritium for the hole No.1-1, and the hole No.1-2, which they dug after detecting high all-beta in No.1-1.
The sample from the hole No.1-1 has high tritium (600,000 Bq/liter), but take a look at the sample from the hole No.1-2. It has extremely high amount of all-beta, at 900,000 Bq/liter. The sample also have higher amounts of cesium and other gamma nuclides compared to the sample from the hole No.1-1.
From TEPCO's handout for the press, 7/7/2013:
Just yesterday (July 6. 2013), Jiji Tsushin reported that the seawater sample collected on July 3 at the water intake for the Reactors 1-4 at Fukushima I Nuclear Power Plant was found with the highest amount of tritium since the accident, at 2,300 Bq/liter.
However, according to TEPCO, it still can't be determined whether the contaminated groundwater with high tritium content is leaking into the harbor.