Skip to main content

News release

December 14, 2023


Stephen Mikkelson, 218-316-3887,

Xcel Energy Inc. fined $14,000 related to tritiated water storage at Monticello nuclear facility

According to a Minnesota Pollution Control Agency (MPCA) enforcement investigation, Xcel Energy Inc. began storing groundwater contaminated with tritium in aboveground storage tanks before obtaining a required permit at its Monticello nuclear power plant. Tritium is a radioactive material that leaked from the company’s facility last fall and required cleanup and on-site storage. 

As part of Xcel Energy’s response and cleanup of the November 2022 release, the company needed to install temporary tanks. MPCA staff informed the company in March 2023 that the installation of storage tanks exceeding 1 million gallons of total capacity would require an aboveground storage tank major facility permit. 

After installing and filling more than 20 temporary tanks, the company began filling its newest tank with tritiated groundwater in early April before obtaining the required permit. That tank increased the total capacity of its temporary tanks to just over 1.4 million gallons. 

In addition to paying the $14,000 civil penalty, Xcel Energy was required to immediately obtain the permit before continuing its response and cleanup. The MPCA issued the appropriate permit in May 2023, requiring the use of temporary tanks to end by Nov. 1. The company has since transferred the tritiated water to a more permanent in-ground lined pond and has emptied and dismantled the temporary tanks.

MPCA rules and regulations are designed to protect human health and the environment by limiting pollution emissions and discharges from facilities. When companies do not fully comply with regulatory requirements, the resulting pollution can be harmful to people and the environment. 

When calculating penalties, the MPCA takes into account how seriously the violations affected or could have affected the environment and whether they were first-time or repeat violations. The agency also attempts to recover the economic benefit the company gained by failing to comply with environmental laws in a timely manner. 

Share this