Jan 06, 2022

Cape Cod Water Quality Report Released

Microplastics from wastewater, storm water runoff and atmospheric fallout were deemed a concern in the report.

cape cod water quality

A new report found that surface water quality and groundwater throughout Cape Cod has degraded for the third year in a row.

The Association to Preserve Cape Cod's annual State of the Waters report was released Jan. 3, which tracks the water quality of the Cape's freshwater ponds, marine estuaries, and public drinking water.

APCC graded water resources including:

  • Coastal waters in embayments and estuaries;
  • Freshwater ponds and lakes; and
  • Public water supplies for drinking water. 

According to the report, most of the Cape’s coastal embayments and many freshwater ponds and lakes are suffering from water pollution. The report indicates that the Cape’s waters suffer from pollution due to: nutrient pollution, harmful bacteria, harmful algal and cyanobacteria blooms, mercury pollution, emerging contaminants and more.


On Cape Cod, excess nutrients originate largely from human sources and activities. Additionally, failed septic systems including flooded septic systems are a source of bacteria.

Many of the Cape’s estuaries and embayments are suffering from eutrophication caused by excess nitrogen. 

Excess nitrogen is a result of poorly treated wastewater and fertilizers used on lawns and other area, according to the report. The excess phosphorus on Cape Cod comes from septic systems that discharge phosphorus into groundwater that enters ponds and lakes, which is carried into ponds and lakes in storm water runoff. 

The 2021 embayment grades showed an increase in the number and percentage of unacceptable embayments compared to previous years. There were 41 unacceptable embayments, representing 87% of graded embayments. Additionally, microplastics from wastewater, storm water runoff and atmospheric fallout were deemed a concern.

Another observation is that climate change impacts for the Northeast are predicted to include warmer air and water temperatures year-round, which entails more intense storms and flooding.

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