Very little, other than the damage to the reputation of Fukushima fish (which is completely unwarranted) and to sales for Fukushima fishermen. This is based in fear rather than science.
Your question mentions contaminated water, as if the water was being pumped straight out of the reactor basements. This will not be the case. It is first treated to remove most radioactive contaminants.
After the explosions at Fukushima Dai-ichi scattered radiation in much of the prefecture, more than 40 countries refused to import food items from Japan, dealing a grievous blow to the famers and fishermen of the prefecture. In addition, many within Japan would also not buy food or fish products from Fukushima and neighbouring prefectures.
One unintended consequences of the Fukushima nuclear disaster almost a decade ago is that Japan now plans to build as many as 22 new coal-burning power plants — one of the dirtiest sources of electricity — at 17 different sites over the next five years. This is at a time when the world needs to slash carbon dioxide emissions to fight global warming. Together, the 22 power plants would emit almost as much carbon dioxide annually as all the passenger cars sold each year in the United States.
In just three years the Fukushima Dai-ichi site will have no more room to make the specialised tanks that are used store water that has been used to cool the melted reactors, or has seeped through the site from the surrounding hills. There’s currently over 1.15 million tons of this radioactive water being stored at the facility in 960 tanks and it’s continuing to accumulate at a rate of about 150 tons a day, meaning the tanks could reach full capacity by the summer of 2022.
It has been eight years now since the meltdowns, and the water just off the Dai-ichi plant still contains contamination that washed there from the plant. But, a little further away, Kitai-izumi Beach is now open again. It is a popular spot for surfers as it gets some of the best waves in Japan, as you can see in the photo.
As of January last year a report out of TEPCO and the various parties involved in decommissioning documents that 15 workers from Fukushima Daiichi have developed cancer.
A major problem at Fukushima Dai-ichi is the flow of groundwater through the plant from the surrounding hills. This water flows into the irradiated debris in the basements of the destroyed reactors and then from there into the sea.
Six years after the Fukushima meltdowns engineers at the Fukushima Dai-ichi plant have succeeded in guiding a small robot to the heart of the heavily damaged Reactor 3 reactor and located the fuel which melted onto the floor of the reactor building. Earlier robots had failed, getting caught on debris or suffering circuit malfunctions from excess radiation (see previous blog about this).
Areas of Fukushima previously abandoned in March 2011 have been declared safe to return to. At the end of March, Japan lifted evacuation orders for residential areas, including abandoned towns, just 2.5 miles from the Fukushima Daiichi nuclear plant. But there is concern over a risk posed by new ‘residents’, hundreds of wild boars, who can attack people or cause potentially fatal car crashes.
A new report out from TEPCO reports that 15 workers at the plant have developed cancer (as of Mar 2017). These cancers are considered sufficiently linked to their work at the plant during the initial disaster and during the subsequent effort to regain control of the site. So far TEPCO has only acknowledged one such worker as having gotten cancer as a result of working at the site.