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Healthy Beach Days
Based on bacteria monitoring at Maine?s coastal swimming beaches, this indicator shows the relationship between total beach days and healthy swimming days.
The number of beach days is based on the length of the Maine Healthy Beaches (MHB) monitoring season and the number of beaches monitored. A beach action day results when monitoring shows bacteria levels above the limit considered safe for swimming, resulting in an advisory being posted. A healthy beach day is a day with no advisory. The 2016 beach season had the the lowest percentage (5%) of exceedances in the program's history. Maine experienced below average rainfall during the summer months, contributing to a decrease in the number of beach advisory days. If Maine experiences another dry summer in 2017, this trend is expected to repeat itself.
When Maine has a rainy summer, stormwater carries bacteria from throughout the watershed (the area of land that eventually drains to the beach) to the shoreline. Fortunately this flush of stormwater often dissipates with tidal flushing and on average, nearly 90% of resamples, taken the day after an exceedance, find that bacteria counts have returned to safe levels. Some beach managers choose to issue ?precautionary rainfall advisories? based on local precipitation levels. An advisory might be triggered by more than one inch of rainfall within 24 hours and then lifted 24 hours after the rainfall ceased (or two full tide cycles). When monitoring finds recurring bacteria problem, MHB works with local stakeholders to identify potential sources of bacteria and address those problems. This has resulted in numerous success stories, such as fixing residential sewer lines that are mistakenly connected to storm sewer, replacing old and leaky sewer lines, eliminating malfunctioning septic systems, and installing boat pump out stations. Correcting pollution sources, combined with other efforts in the watershed, should result in lower bacteria levels on the beach.
Contact: Tracy Krueger (207) 215-6851
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