Shellfish Water Quality Monitoring

A crucial part of Shellfish Water Quality Monitoring is completed by RIDEM's Office of Water Resources.

Staff who work in this program complete the required sanitary surveys and conduct routine water quality monitoring. Each shellfish growing area is assigned a "classification" based on the results of this evaluation. A growing area can be Approved for shellfishing, Conditionally Approved, Seasonally Approved or Prohibited.

All sanitary surveys are kept current by routinely evaluating major pollution sources, routinely collecting water quality data from established sampling stations according to NSSP sampling guidance and analyzing the data to assure that the classification continues to represent current sanitary conditions within the growing area. The sanitary survey is repeated in full every twelve (12) years and is updated on an annual and triennial schedule otherwise. The documents located on this site are the prevailing documents arranged by growing area. They are updated annually during our statewide review and re-classification process in May.

Always Refer to the applicable document "Notice of Polluted Shellfish Grounds" for the current legal descriptions of shellfish water classifications.

A sanitary shoreline survey is a three-fold process, consisting of:

  • The survey, which locates and identifies pollution sources that may impact water quality. RIDEM also evaluates sewage treatment plants, onsite wastewater treatment systems (OWTS), farming activities, stormwater runoff, and wildlife;
  • Analysis of how weather conditions, tides, currents, and other factors may affect the distribution of pollutants; and
  • Routine water sampling to determine fecal coliform bacterial levels in the marine water.

Sanitary surveys are the principal means in making the distinction between acceptable and unacceptable water quality, and are the vehicle used to accurately classify growing areas. The NSSP Model Ordinance, the federal guidance document for all shellfish harvesting states, mandates that a sanitary survey be completed for each growing area that is approved by the state as a source of shellfish for human consumption.

Historical copies of shoreline surveys and maps may be obtained by written request by Emailing the shellfish program at to initiate request and obtain details on process to obtain these records.

In addition to routine bacterial water quality monitoring, Shellfish Program personnel monitor shellfish growing waters for the presence of potentially harmful algae. This is consistent with NSSP guidance for phytoplankton biotoxin monitoring and is an important step in safeguarding public health. View Details on Rhode Island’s harmful algae bloom monitoring plan.