Tokyo Electric Power Co. admitted Thursday that its latest problem with radioactive water has shattered the trust it was building in Fukushima, especially among fishermen, and that the decommissioning of the Fukushima No. 1 plant might be delayed.

“To make progress with the decommissioning effort and solve the tainted-water issue, the trust of the people in Fukushima is the most important thing. We’ve been working with that in mind, but unfortunately, we have damaged that trust this time,” said Naohiro Masuda, president of Fukushima Daiichi Decontamination & Decommissioning Engineering Co., the internal unit in charge of scrapping the meltdown-hit plant.

“Due to the damaged trust, all of the schedules for the decommissioning tasks could be delayed, but we’d like to rebuild trust as soon as possible,” so Tepco can improve the plant’s condition faster, said Masuda, who peppered the news conference with repeated apologies.

One task expected to be affected by the surge in radiation detected in the water draining into the sea, is the pumping up of slightly tainted groundwater from wells around the reactor buildings. Because about 300 tons of clean groundwater seep into the reactor buildings each day before mingling with the tainted cooling water, Tepco is hoping to use the pumping maneuver to reduce the amount of groundwater and treat it so it can be dumped into the sea. The utility, however, needs the fishermen’s approval to dump it — a task the latest problem seems to have endangered.

This is not to be confused with the so-called groundwater bypass, which involves intercepting clean groundwater before it arrives at the plant and pumping it into the ocean. This operation is already underway.

Tepco also plans to drop more sandbags of zeolite, an adsorbent, in the drainage system to reduce the level of contamination by the end of March.

The utility said the source of the contamination is the roof of the No. 2 reactor building, which was damaged by an explosion during the crisis and remains heavily contaminated. Since runoff from the roof flows into the drainage system, radiation levels soar when it rains, data shows.

The roof has pools of water containing 29,400 becquerels of cesium per liter and 52,000 becquerels of other beta ray-emitting substances, such as toxic strontium-90, which causes bone cancer.

Tepco also has detected some 1,050 becquerels of cesium and 1,500 becquerels of beta ray-emitting materials per liter of water in an outlet leading to the sea.

Masuda said Tepco had no intention of hiding the information and did not think it was as urgent as reporting on its other decommissioning tasks, such as managing the hundreds of water storage tanks and removing tainted water from the underground trenches connected to the reactor buildings.

He vowed that Tepco will make efforts to keenly discern what information Fukushima people are interested in and swiftly make it available.

On Tuesday, the beleaguered utility said it knew that the abnormally toxic rainwater was leaking from the drainage ditch into the seas since last spring. It said the lack of visible impact in seawater samples taken about 1 km from the drainage outlet gave it reason to believe it was not necessary to disclose the information.