Below is a message from Xcel Energy, dated May 12, 2025:

"Update from Xcel Energy on activity at the Monticello Nuclear Generating Plant

Xcel Energy continues its work to recover tritium from water that leaked into the ground beneath the Monticello Nuclear Generating Plant following an equipment failure in late 2022. Our teams have driven down tritium concentrations in the groundwater by more than 90% from their initial recordings.

Recent measurements from one of our monitoring wells near the Mississippi River detected tritium at 19,800 picocuries per liter, a concentration that has increased to just below the Environmental Protection Agency drinking water standard of 20,000 picocuries per liter. This measurement was from a well about 40 feet underground, far deeper than the riverbed. Shallower wells are not detecting tritium at that location. The reading is higher than previous readings at this same monitoring well, but far below the current highest concentrations of other wells, which are far from the river and beneath the plant. We will continue recovering impacted groundwater until our monitoring wells indicate all of the groundwater meets the EPA’s Safe Drinking Water Act standards. While the recent readings do not require any mandatory actions according to state or federal law or our operating permit, we are providing this update for awareness and transparency.

Tritium still has not been detected in the river above naturally occurring levels, despite the increased sampling we and state regulators have conducted today and in the past. Small amounts of tritium reaching the river would likely be at such low levels and diluted so quickly that it cannot be detected, even by highly sensitive instruments. The leaked tritium has also not affected any drinking water sources near Monticello or downstream along the river. Residents in the area do not need to take any action and can continue drinking the water they currently use.

We are adjusting the amount of water we pump to pull the leaked tritium away from the vicinity of the river and recover it more effectively. We expect measurements to fluctuate over time as we continue to retrieve the leaked water. We remain committed to being good neighbors and stewards of the environment, as well as following all regulations, as we continue the clean-up.

Tritium is a compound that is naturally present in the environment and is commonly created in the operation of nuclear power plants. It emits low levels of radiation, as do everyday materials people use and the food we all eat.

The plant’s regularly scheduled refueling outage, which began on Friday, April 18, remains on track. Residents in the area can expect to continue to see increased activity at the plant around the clock, as well as at local restaurants and hotels as several hundred specialized contractors in the area to help complete the work safely and effectively.

The company updates this page as new information is available. Media inquiries can be sent to:  mediainquiries@xcelenergy.com."