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DMR Home > Health & Safety > Shellfish > Growing Area Program > Survey & Report Schedules

Maine Shellfish Growing Area Survey and Reporting Schedules

Area Classifications

Each commercially harvested growing area is assigned a "classification" according to the results of its evaluation. A growing area may be classified as Approved, Conditionally Approved, Restricted, Conditionally Restricted, or Prohibited.

More information on how the classifications are determined and what they mean

Sanitary Surveys

A growing area's classification is determined by conducting a "sanitary survey," which is a three-fold process consisting of:

  • A shoreline survey, which identifies pollution sources that may impact water quality. The program evaluates sewage treatment plants, onsite sewage systems, animal farms, drainage ways, and wildlife;
  • Marine water sampling to determine fecal coliform bacterial levels in the marine water; and
  • Analysis of how weather conditions, tides, currents, and other factors may affect the distribution of pollutants in the area.

The completion of a sanitary survey is of paramount importance in making the distinction between acceptable and unacceptable growing areas, and is the key to accurate growing area classification as approved, conditionally approved, restricted, conditionally restricted, or prohibited. Under the NSSP Model Ordinance, a sanitary survey is required for each growing area prior to its approval by the state as a source of shellfish for human consumption or as a source for shellfish to be used in a depuration or relay operation.

Survey Reports

Keeping the sanitary survey current consists primarily of routinely evaluating major pollution sources, collecting water quality data from sampling stations under the selected NSSP water quality monitoring strategy (systematic random sampling), and analyzing the data to assure that the classification continues to represent current sanitary conditions in the growing area. The sanitary survey must be repeated fully every 12 years*. When a written sanitary survey report is not completed, the area must be placed in the closed status.

The sanitary quality of each growing area must be reviewed as often as is necessary to ensure that the classification is appropriate. Certain sanitary survey components are required by the Model Ordinance to be updated annually and triennially (every third year).

The growing area classification and the supporting data from the sanitary survey shall be reviewed at least every three years as part of a triennial re-evaluation. The triennial report must include the following:

  • A review of all the components that are required for an annual review;
  • Documentation of any new pollution sources and an evaluation of their effect on the growing area;
  • Reevaluation of all pollution sources, including the sources previously identified in the sanitary survey, as necessary to fully evaluate any changes in the sanitary conditions of the growing area;
  • A comprehensive report which analyzes the sanitary survey data and makes a determination that the existing growing area classification is correct or needs to be revised; and
  • If the triennial reevaluation determines that conditions have changed based on the information and data collected during the triennial review and that the growing area classification in incorrect, immediate action shall be initiated to reclassify the area.

The triennial reevaluation often includes the inspection of wastewater treatment plants or the collection of additional effluent samples to determine their impact on the growing area. The results of hydrodynamic studies, the collection of additional pollution source tracing samples (streams, pipes, etc.) and the results of additional field work as part of an investigation to determine the actual impact of pollution sources.

When a written triennial reevaluation report is not completed, the DMR must place the growing area in the closed status.

On an annual basis, the sanitary survey must be updated (annual report) to reflect any changes in the conditions in the growing area. The annual report must include the following:

  • Field observations of the pollution sources identified in the sanitary survey or subsequent triennial report; this may be completed by doing a drive-through survey, observations made during sample collection runs or through information from other sources (codes enforcement, licensed plumbing inspectors, treatment plant operators, other state agencies, etc.);
  • A review, at a minimum, of the past year’s water quality sample results by adding the year’s sample results to the data base collected under the requirements of the NSSP and under the systematic random sampling regime;
  • A review of available inspection reports and effluent samples collected from pollution sources;
  • A review of available performance standards for various types of discharges (OBD’s, wastewater treatment plants, combined sewer overflows, etc.) that impact the growing area; and
  • A report which documents the findings in the annual reevaluation.

If the annual reevaluation determines that conditions have changed based on the information and data collected during the annual review and that the growing area classification is incorrect, immediate action shall be initiated to reclassify the area.