Beach Program Water Quality Standards The exceedance criteria, or level at which a sample fails, is 104 Enterococci bacteria per 100 milliliters of sample water, or Enterococci levels exceed the geometric mean of 35 counts of Enterococci per 100 mL of water in at least five samples collected over a 30-day period. This is one consideration for placing advisories at the beach. For the other considerations for advising against recreational water activities or for closing a beach click on How Beach Advisories are Determined. The Maine Healthy Coastal Beaches Program is providing the State of Maine with a system to monitor public beaches and notify the public when there is a potentially hazardous condition. The Maine Healthy Coastal Beaches Program ensures healthy, informed opportunities for swimming and other recreational water activities along the coast of Maine. Monitoring coastal water quality for swimming and other water contact usage is the responsibility of the local jurisdiction. It is not a mandated requirement from the State, nor does the State of Maine monitor public beaches other than those of their ownership. Maine has 46 public beaches and recreational waters on its coast, of which 36 of these are participating in the Maine Healthy Coastal Beaches Program. The Maine Healthy Coastal Beaches Program is currently monitoring these waters, educating the public about potential health risks at these waters, and notifying the public when a disease-causing microorganism is present and may pose a health risk. Maine’s Healthy Coastal Beaches Program will provide a current list of coastal beach advisories from participating towns/State Parks throughout the state. To view current beach advisories, go to Today’s Beach Status. The towns and State Parks currently post beach advisories when sample analyses result in bacteria levels above the state standard, and the conditions warrant it, indicating the possible presence of disease-causing organisms. These advisories are recommendations to the public to avoid water contact activities at the beach until further analyses reveal safe conditions. A decision to close or post beaches is based upon a Risk-Based Assessment Matrix tool to beaches for ongoing management decisions. Beaches are not “closed” simply on the exceedance of the bacterial count, but on the Risk Assessment Matrix factors which includes bather numbers, time of last rainfall, and history of known problems. This is a coordinated decision between the Beach Manager, Program Coordinator, and State Epidemiologist. The town/State Park beach managers may use their own discretion to actively close a beach to the public. The municipality/State Park must notify the Maine Healthy Coastal Beaches Program of their intentions to close or put up an advisory at a particular beach by indicating this on the on-line database. The Healthy Coastal Beaches Program has produced a sign with attachments for advisory or closure to indicate a beach advisory. Click here to view samples of the signs. What Is The Geometric Mean? Many wastewater dischargers, as well as regulators who monitor swimming beaches and shellfish areas, must test for and report fecal coliform bacteria concentrations. Often, the data must be summarized as a "geometric mean" (a type of average) of all the test results obtained during a reporting period. Typically, public health regulations identify a precise geometric mean concentration at which shellfish beds or swimming beaches must be closed. A geometric mean, unlike an arithmetic mean, tends to dampen the effect of very high or low values, which might bias the mean if a straight average (arithmetic mean) were calculated. This is helpful when analyzing bacteria concentrations, because levels may vary anywhere from 10 to 10,000 fold over a given period. How do you calculate a geometric mean? The easiest way to think of the geometric mean is that it is the average of the logarithmic values, converted back to a base 10 number. However, the actual formula and definition of the geometric mean is that it is the n-th root of the product of n numbers, or: Geometric Mean = n-th root of (X1)(X2)...(Xn) Where X1, X2, etc. represent the individual data points, and n is the total number of data points used in the calculation. Geometric Mean of Enterococci Counts For East End Beach : All Data Summer 2010 Summer 2009 Summer 2008 Summer 2007 Summer 2006 Summer 2005 Summer 2004 Summer 2003   Click For more information on the Geometric Mean. How will I know if it’s safe to swim at my local beach? There are several ways to determine whether it’s safe to swim at a beach. Check the Today’s Beach Status to see if the beach is listed. For further information, contact the Maine Healthy Coastal Beaches Program. Contact the local beach manager for that town or State Park. Staff will be able to give you information on whether the beach is part of the Healthy Coastal Beaches Program and if water quality is monitored at that beach. Look for any advisory/closure signs or other signs posted at the beach entrance or on the lifeguard stands. If there are no advisories (orange) or closures (red) posted, but there is an open (green) sign, this will indicate that this beach is open for recreation. Contact your local health official. A health official may be able to inform you whether a beach advisory has been posted at the beach you plan to visit.