Water Quality

Nantucket proactively monitors the quality of its water systems in order to develop action plans to ensure public safety and strengthen the islands ecosystems. Water quality monitoring of Nantucket’s fresh and saltwater systems is primarily focused on summer-time conditions, as the warmer months typically have the lowest water quality conditions, which are the target of resource management.

The approach utilized for the collection and analysis of water samples from each of the estuaries of Nantucket is consistent year-to-year. This consistency is intended to maximize the value of the results by making the data perfectly cross comparable to water quality monitoring data collected across the Island of Nantucket from previous years and more broadly throughout the region (Cape Cod, Martha’s Vineyard). In this manner, inter-ecosystem comparisons can be made to better assess system health/impairment and function and formulate appropriate nutrient management strategies. This allows Nantucket to directly benefit from lessons learned throughout the wider region.

This page serves as a landing page to all things water quality. You will find on the left side how we divide the many aspects of water quality. 

How to Protect Water Quality at Home

There is no one solution to limiting nutrient pollution! Follow all of these guidelines for healthy Harbors and Ponds.

  • Get your septic system inspected every 5 years. Pump as recommended.
  • If you are located within 200m of a water body opt for a Nitrogen removing (I/A) system when your septic needs replacing.
  • Support sewer extensions which protect our Harbors, Ponds and drinking water wells from nutrients, bacteria and chemicals.
  • Choose licensed landscapers and ask them for written reports of sediment tests and fertilizer application schedules.
  • Select native landscaping that is accustomed to Nantucket’s harsh conditions; you will use less fertilizer, save money and protect our water resources.
  • Use EPA certified Safer Choice™ products that have less impact on our environment and your health.

To access to past documents related to Water Quality, visit the Town of Nantucket Digital Archives.