More Bad Fukushima News Radioactive substances found in groundwater By Ruth Brown, Newser Staff Posted Jun 19, 2013 12:54 PM CDT 13 comments Comments Workers in protective suits and masks wait to enter the emergency operation center at the crippled Fukushima Dai-ichi nuclear power station in Okuma, Japan. (AP Photo/David Guttenfelder, Pool, File) (Newser) – The fallout from Japan's Fukushima nuclear plant disaster continues. The latest: Tests found that groundwater there contained 30 times the legal level of the radioactive substance Strontium-90, and eight times the legal amount of the radioactive isotope tritium, reports the BBC. A TEPCO official says the working theory is that the contamination resulted from an April 2011 water leak from a damaged pit. But don't worry, he says, because the groundwater is contained by the plant's concrete foundations, and those aren't leaking. "When we look at the impact that [it] is having on the ocean, the levels seem to be within past trends and so we don't believe it's having an effect," says the official. The water was found at a monitoring well just 89 feet from the sea, reports the Japan Times. The plant is now building a shoreline barrier using waterproof liquid glass to further contain the groundwater.