State of the Waters: Cape Cod 2025
A project by the Association to Preserve Cape Cod.
How Healthy are the Waters of Cape Cod?
• Cape Cod’s saltwater embayments and freshwater ponds are suffering from the negative effects of too many nutrients.
• Declining water quality is due to pollution from septic systems, stormwater runoff, and fertilizer use.
• The quality of our drinking water supplies remained excellent or good.
Map Legend:
RED means Unacceptable: requires immediate restoration BLUE means Acceptable: requires ongoing protection
RED means Unacceptable: requires immediate restoration BLUE means Acceptable: requires ongoing protection
About the Grading
Learn more about how we grade, term definitions and our methodology.