Municipal Guide To Clean Water: Conducting Sanitary Surveys to Improve Coastal Water Quality
• Risk Assessment Matrix
Before heading to the field, read through the RAM and become familiarized with the process and the resources neces- sary to successfully complete the exercise. Obtain copies of data and reports specific to the beach management area(s) as
described in Part I of this guide.
Completing the RAM
A RAM should be completed for each BMA.2 The matrix should be updated frequently, typically every one to three years, depending on conditions and new information available. The frequency of updates depends on new development, in- crease in activities posing a risk to water quality, designated use of the waterbody, etc. The coastal surf zone is a dynamic environment where conditions can change very rapidly. Each beach management area has its own set of factors or char- acteristics impacting water quality, and the RAM helps to determine what those factors are.
If bacteria levels are consistently above the US EPA safety limit,3 simply examining the areas/properties directly on or adja- cent to the beach may not be sufficient to thoroughly investigate all of the actual and potential sources of fecal contamination affecting the beach. Further sanitary survey work includes additional monitoring of freshwater inputs, property and septic sys- tem inspections within the watershed, and documenting offshore activities (unsanitary boating practices, dumping) contribut- ing to poor water quality. Removing sources of bacterial pollution can lead to measurable improvements in water quality.
While completing the RAM be sure to:
Complete all sections of the RAM as thoroughly as possible.
Integrate the expertise and knowledge of local officials (code enforcement officers, local plumbing inspectors,
planners, conservation commission members).
Refer to the Definitions for terms used in the RAM.
Complete the Following Sections of the RAM:
Access previous years’ monitoring, notification (beach posting), and environmental data to determine each criterion’s point value. This information can be found from MHB Program data, sanitary surveys, special studies, and local weather monitoring stations (e.g., sewage treatment plant).
Total the number of points and enter the sum in the Section I. Total Points Box.
Potential and Actual Sources of Contamination
Access the appropriate data/reports and conduct on-site evaluation to obtain the information for this section.
Fill out each segment and record individual totals. Transfer the sums to the associated boxes at the end of this section.
Total the number of points from each segment and enter the sum in the Section II. Total Points Box.
Initially, a RAM may be completed for the entire beach which is then separated into BMAs.
The US EPA has deemed Enterococci bacteria as the most appropriate indicator organism for marine recreational waters. The single sample safety limit for marine waters is 104 MPN or cfus per 100 ml, 35 geometric mean value (five records within a 30-day period). For fresh water (zero salinity), the single sample limit is 61 MPN or cfus per 100 mls, and a geometric mean of 33.