Monticello nuclear oil leak reaches Mississippi River
Xcel Energy says roughly 200 gallons of mineral oil leaked at the Monticello nuclear plant, and the company now confirms a small amount has appeared as a sheen along the Mississippi River shoreline, walking back an earlier statement that no oil reached the river. Xcel says its first sign of abnormal oil levels came Monday afternoon (earlier than first reported), containment and absorbent booms were placed in the discharge canal and on the river Tuesday, but the company has not quantified how much oil entered the river or how far downstream it has been seen; the Minnesota Pollution Control Agency is monitoring and working with Xcel to assess the impact.
📌 Key Facts
- Xcel confirms a "small amount" of mineral oil from a roughly 200‑gallon leak has appeared as a sheen along the Mississippi River shoreline.
- The company has walked back an earlier public statement that no oil reached the river, acknowledging oil may have seeped past containment.
- Xcel says its first sign of abnormal oil levels came Monday afternoon, a day earlier than it initially reported.
- Containment and absorbent booms were placed in the plant's discharge canal and on the Mississippi River Tuesday morning.
- Xcel has not disclosed how much oil entered the river or how far downstream the sheen has been seen.
- The Minnesota Pollution Control Agency (MPCA) is monitoring the situation and "working with Xcel to understand the impact."
📊 Relevant Data
Any discharge of oil into navigable waters that causes a visible sheen must be immediately reported to the National Response Center under the Clean Water Act, regardless of the quantity spilled.
When are You Required to Report an Oil Spill and Hazardous Substance Release — EPA
Mineral oil is generally not hazardous to aquatic life, with low acute toxicity to fish, invertebrates, and algae, though exceptions exist for certain species.
Mineral Oil - Technical Report - 2021 — AMS.usda.gov
Oil spills in rivers can harm aquatic organisms by coating gills of fish and invertebrates, leading to suffocation, and by direct toxic effects disrupting physiological activities.
How Oil Harms Animals and Plants in Marine Environments — NOAA's Office of Response and Restoration
The longer spilled oil remains in freshwater environments like rivers, the more it undergoes chemical changes, producing persistent compounds that can have increasing impacts on aquatic organisms.
The longer spilled oil lingers in freshwater, the more persistent compounds it produces — American Chemical Society
📰 Source Timeline (2)
Follow how coverage of this story developed over time
- Xcel now confirms that a "small amount" of mineral oil from the roughly 200‑gallon leak has appeared as a sheen along the Mississippi River shoreline.
- The company has walked back its earlier public statement that no oil reached the river, acknowledging the possibility that oil seeped past containment.
- Xcel says its first sign of abnormal oil levels came Monday afternoon, a day earlier than it initially reported.
- Containment and absorbent booms were placed not only in the discharge canal but also on the river on Tuesday morning.
- Xcel still will not say how much oil is believed to have entered the river or how far downstream the sheen has been seen; MPCA says it is monitoring and "working with Xcel to understand the impact."