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Massachusetts · SuAsCo watershed

Sudbury River
water quality.

Explore public water-quality data, monitoring context, and recent river highlights for the Sudbury River in Massachusetts.

RouteSouthborough → ConcordPublic sourceOARS

What you can explore

Open the interactive Rivistry dashboard to view available measurements, station context, historical charts, reference lines, and recent weekly highlights for Sudbury River.

Open Sudbury River dashboard

Read the context

River measurements can vary with season, rainfall, temperature, flow, sampling location, and method. Rivistry presents them as evidence to understand and investigate—not as a standalone safety determination.

For the original monitoring information, visit OARS.

River-specific context

A river with a mercury legacy

The Sudbury has a documented history of mercury contamination that is especially important when interpreting fish, sediment, and long-term monitoring information.

Historical contaminant

Mercury contamination has been documented in the Sudbury River system, including bioaccumulation studies in freshwater mussels.

How to read current data

A current water-quality reading does not by itself measure mercury in fish or sediment. Rivistry keeps this historical context separate from present-day measurements.

Research source: National Park Service and NOAA

Keep following changes

Weekly River Updates compare new observations with previous readings, recent baselines, trends, and applicable reference values.

See Weekly River Updates →