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Beach Status -> Portland Area-> Higgins Beach-> Monitoring Data

Actual Enterococci Values Measured At Sites by Date:

Sample DateEnterococci CountTide StageWater TemperatureAir TemperatureSalinity
8/28/2017<10 ME  14.915.634
8/21/201710 MF  16.420.432
8/14/2017<10 ME  14.91733
8/7/2017<10 MF  14.815.733
7/31/2017<10 ME  15.61932
7/24/201720 MF  15.415.632
7/17/2017<10 ME  17.319.732
7/10/201710 MF  14.317.533
7/5/201710 H  15.220.233
6/26/201731 MF  14.919.832
6/19/2017<10 ME  14.61532
6/12/201720 MF  1624.730
6/5/2017<10 HE  11.912.132
8/29/201620 H  19.625.434
8/22/201620 LF  19.720.532
8/15/2016<10 H  18.719.732
8/8/2016<10 L  16.22134
8/1/201641 HF  17.421.433
7/25/2016<10 L  18.119.933
7/18/201610 HF  18.81933
7/11/2016<10 ME  16.317.633
7/6/201641 MF  18.620.433
6/27/201620 ME  17.517.833
6/20/201610 MF  161634
6/13/2016<10 ME  12.816.534
6/8/201620 MF  17.121.130
6/7/20161664 L  15.615.830
6/1/2016<10 ME  14.520.932
8/31/201541 MF  17.821.532
8/24/2015<10 ME  19.619.332
8/17/2015<10 LF  18.923.333
8/10/2015<10 HE  17.519.533
8/3/201552 LF  17.518.633
7/28/2015<10 LE  22.420.732
7/27/2015201 HE  17.120.232
7/21/2015<10 MF  18.116.833
7/20/2015670 LF  17.318.232
7/13/2015<10 H  18.52432
7/6/2015<10 L  15.72333
6/29/201531 H  14.314.633
6/22/201552 LE  14.317.332
6/15/201552 HF  13.612.933
6/8/201510 LE  12.511.733
6/5/2015<10 LF  10.71133
6/3/2015183 MF  9.39.833
9/3/201410 ME  1722.831
8/25/2014<10 MF  16.121.131
8/18/201420 ME  16.118.232
8/11/201410 MF  16.817 
8/4/2014<10 ME  18.218.232
7/28/201431 MF  15.217.232
7/21/2014<10 ME  15.418.232
7/14/201410 MF  14.916.2 
7/7/201431 ME  15.117.731
6/30/2014<10 L  17.31732
6/23/2014<10 H  15.117.331
6/16/201410 L  11.216.932
6/9/2014<10 H  15.11631
6/2/201410 L  11.91331
9/4/201330 MF  17.315.533
8/26/201320 L  1616.234
8/19/2013<10 HF  16.620.133
8/12/2013<10 L  16.117.133
8/5/2013<10 HF  16.117.532
7/29/2013<10 LE  16.317.232
7/22/201352 MF  16.219.533
7/15/201331 LE  20.128.130
7/8/201341 MF  18.121.931
7/5/2013<10 HF  19.223.628
7/3/2013142 HE  14.415.932
7/1/201330 LE  14.716.932
6/25/201320 H  19.521.530
6/24/20131956 MF  15.819.129
6/17/2013<10 ME  13.117.932
6/10/201330 LF  13.413.932
6/3/2013<10 HE  12.713.433
5/29/201330 L    31
8/29/201220 H  15.618.635
8/27/2012<10 ME  18.819.132
8/22/201210 L  17.91833
8/21/201231 H  20.822.530
8/20/201286 MF  181832
8/15/201241 HF  20.321.132
8/13/201210 HE  19.524.332
8/9/201210 MF  21.722.533
8/8/2012573 LE  18.719.734
8/6/201210 L  1922.433
8/1/201286 MF  15.619.632
7/30/201220 H  17.918.833
7/25/201220 LE  12.320.335
7/23/2012<10 LF  16.617.533
7/18/201241 MF  18.321.534
7/16/2012<10 HF  17.221.731
7/11/201210 ME  7.819.531
7/9/201210 LE  16.219.432
7/2/2012<10 HF  15.225.232
6/25/2012<10 L  17.918.830
6/18/2012<10 MF  16.113.730
6/11/201210 ME  15.714.430
6/6/2012119 MF  12.311.431
6/4/20121160 MF  12.29.430
5/30/201210 ME  1513.931
8/30/201197 MF  16.218.233
8/23/2011<10 ME  15.216.234
8/17/2011<10 H  18.821.730
8/16/2011794 LF  16.515.834
8/9/2011<10 ME  17.62231
8/2/201175 MF    30
7/26/2011<10 ME  17.91830
7/20/2011<10 MF  19.121.132
7/19/2011860 LF  172432
7/12/201110 HF  172330
7/5/201110 LF  1520.732
6/28/2011<10 HF  161825
6/21/2011<10 L  15.821.831
6/14/2011<10 H  13.411.831
6/7/2011<10 L  13.715.531
5/31/201130 HF  12.520.529
8/31/2010<10 L  18.925.633
8/24/201020 MF  17.419.633
8/17/201010 ME  16.21835
8/10/201052 MF  152531
8/3/2010<10 LE  18.619.232
7/27/2010<10 MF    32
7/20/2010<10 ME    32
7/13/201074 MF    30
7/6/2010<10 ME  202230
6/29/201041 MF  15.316.133
6/22/2010<10 HE  13.919.532
6/15/201020 MF  12.519.932
6/8/2010<10 HE  12.917.933
6/1/2010<10 LF  13.315.532
9/8/2009<10 MF  16.820.732
9/1/2009<10 HE  16.916.730
8/25/200910 L  222330
8/18/200941 HE  20.725.431
8/11/2009<10 L  17.52131
8/4/200931 MF  1717.832
7/28/2009<10 ME  172230
7/21/200920 HF  17.320.430
7/10/200910 HF  18.919.525
7/9/2009377 MF  14.817.923
7/7/200920 MF  161328
6/30/2009<10 ME  13.814.330
6/23/200998 MF  13.61630
6/16/2009<10 ME  141630
6/9/200963 MF  111334
6/2/2009<10 ME  10.52034
8/26/2008<10 ME  13.616.533
8/19/200820 MF  17.318.931
8/12/200810 HE  17.515.330
8/5/200810 LF  16.81732
7/29/2008<10 HE  15.322.435
7/22/2008<10 MF  15.622.432
7/15/2008<10 HF  13.620.234
7/8/2008<10 LF  18.521.432
7/1/200820 H  16.518.632
6/24/200820 L  17.219.631
6/17/200810 HF  15.117.432
6/10/2008<10 ME  16.817.233
6/3/200810 H  10.715.332
8/30/200763 MF  18.519.732
8/28/2007657 MF  18.92133
8/21/200710 LE    34
8/14/200741 MF  17.819.832
8/7/200752 -     
7/31/200730 MF  18.825.831
7/24/2007<10 ME  18.119.130
7/19/200720 HF  15.217.332
7/17/200731 MF  14.524.532
7/10/200710 ME  14.517.132
7/3/2007<10 -     
6/26/2007<10 HE  16.225.531
6/19/200795 L  14.117.831
6/12/200710 ME  13.821.831
6/7/2007<10 L    32
6/5/20071334 MF  12.3215.227
11/17/200610 LE  11.812.130
8/29/2006<10 LF  151531
8/22/2006<10 HF  1419.533
8/15/200641 LE  15.51732
8/8/200641 HF  142233
8/1/200652 L  17.52231
7/25/2006<10 MF  202230
7/18/200641 LE  192530
7/12/2006<10 ME  1620.532
7/11/2006119 MF  16.51732
7/3/200620 LE  14.522.532
6/27/200670 LF  16.51830
6/20/200610 ME  161930
6/15/200620 LF  14.51930
6/13/20061517 MF  1417.525
6/6/200620 ME  1318.532
8/31/2005253 HF  172033
8/24/200520 LE  16.52333
8/19/200563 HF  171931
8/17/2005197 H  17.52733
8/10/2005<10 L  172632
8/3/2005<10 HF  162231
7/27/200533 LE  172030
7/20/200579 MF  172030
7/13/2005<10 L  1819.532
7/6/200519 MF  152131
6/29/2005<10 ME  172131
6/23/2005<10 -     
6/22/2005146 HF  121732
6/8/2005<10 MF  122030
6/1/2005<10 ME  11.513.530
9/2/200420 LF  141733
8/31/2004120 HF  162333
8/24/200430 LE  13.51734
8/17/200420 -  171933
8/10/2004<10 ME  162235
8/3/2004  -  18.52530
7/20/2004  -  15.518.532
7/13/2004<10 H  17.52131
7/6/2004<10 L  161835
6/29/2004<10 LE  141634
Sample DateEnterococci CountTide StageWater TemperatureAir TemperatureSalinity
8/28/2017<10 ME  14.615.434
8/21/2017<10 MF  162032
8/14/2017<10 ME  14.916.833
8/7/2017<10 MF  14.415.832
7/31/2017<10 ME  15.920.633
7/24/201710 MF  15.516.332
7/17/2017<10 ME  16.920.132
7/10/2017<10 MF  14.316.333
7/5/2017<10 H  15.322.433
6/26/201710 MF  14.52032
6/19/2017<10 ME  13.715.332
6/12/2017<10 MF  152932
6/5/201710 HE  1211.630
8/29/201620 H  19.823.333
8/22/201620 LF  19.719.832
8/15/2016<10 H  18.620.533
8/8/2016<10 L  15.321.134
8/1/201620 HF  18.121.333
7/25/2016<10 L  17.720.434
7/18/201652 MF  18.818.734
7/11/2016<10 ME  16.318.234
7/6/201631 MF  16.922.732
6/27/201652 ME  17.517.933
6/20/2016<10 MF  16.515.134
6/13/2016<10 ME  12.416.734
6/8/201630 MF  16.919.731
6/7/201663 L  151633
6/1/201610 HE  142132
8/31/201520 MF  1822.333
8/24/2015<10 ME  19.819.632
8/17/201510 LF  1921.833
8/10/201510 HE  17.31933
8/3/201597 LF  17.918.433
7/28/2015<10 LE  22.621.633
7/27/2015<10 HE  16.819.632
7/21/2015<10 MF  17.817.333
7/20/2015576 LF  16.816.733
7/13/2015<10 H  182532
7/6/2015<10 L  15.823.331
6/29/201551 H  13.613.530
6/22/2015<10 LE  13.716.929
6/15/2015<10 HF  13.21332
6/8/201510 LE  12.812.133
6/3/201520 MF  9.310.434
9/3/2014<10 ME  16.521.932
8/25/2014<10 MF  16.520.633
8/18/2014<10 ME  16.118.333
8/11/201462 MF  17.117.4 
8/4/201410 ME  17.618.232
7/28/201441 MF  15.317.732
7/21/2014<10 ME  15.418.232
7/14/201410 MF  15.315.732
7/7/201410 ME  15.217.531
6/30/2014<10 L  17.116.632
6/23/2014<10 H  15.31732
6/16/2014<10 L  11.61732
6/9/2014<10 H  14.816.330
6/2/201410 L  11.512.532
9/4/201372 MF  17.116.433
8/26/201310 L  1616.334
8/19/201310 HF  16.620.733
8/12/201320 L  15.916.831
8/5/201310 MF  15.717.132
7/29/201320 ME  16.216.733
7/22/201310 MF  16.219.733
7/15/201310 LE  20.627.830
7/8/201385 MF  17.621.630
7/5/2013<10 HF  18.922.728
7/3/2013288 H  14.515.432
7/1/2013118 ME  13.516.829
6/25/2013<10 H  19.120.729
6/24/2013617 MF  14.919.630
6/17/201352 ME  13.121.331
6/10/201352 LF  13.714.532
6/3/2013<10 HE  12.713.232
5/29/201310 LF   11.630
8/29/2012<10 H  15.918.235
8/27/201220 ME  18.81932
8/22/2012<10 L  17.717.833
8/21/2012<10 HF  21.32331
8/20/201220 MF  18.418.333
8/15/201231 HF  20.521.331
8/13/201210 ME  19.223.532
8/9/201220 MF  21.222.532
8/8/2012<10 LE  18.719.634
8/6/2012<10 L  19.82331
8/1/2012<10 MF  15.119.531
7/30/201231 H  16.917.633
7/25/201240 LE  12.920.334
7/23/2012<10 LF  15.417.925
7/18/2012<10 MF  18.721.332
7/16/2012<10 HF  17.82330
7/11/2012<10 ME  16.81731
7/9/201210 LE  16.319.732
7/2/201210 HF  15.424.430
6/25/2012<10 L  1819.430
6/18/201220 MF  15.913.930
6/11/2012<10 ME  15.614.729
6/6/201263 MF  12.511.132
6/4/2012865 MF  12.79.731
5/30/2012<10 ME  1513.931
8/30/201196 MF  15.918.334
8/23/201110 ME  15.116.934
8/16/2011<10 LF  16.71535
8/9/2011<10 ME  17.523.234
8/3/201110 H    31
8/2/2011359 MF    31
7/26/201120 HE  17.91831
7/19/201120 MF  17.32630
7/12/2011<10 HF  182430
7/5/2011<10 MF  162231
6/28/201110 HF  161725
6/21/2011<10 L  15.623.231
6/14/2011<10 H  13.312.231
6/7/2011<10 L  13.815.332
5/31/2011<10 HF  12.72429
8/31/2010<10 L  18.925.433
8/24/2010<10 MF  17.419.433
8/17/2010<10 LE  16.718.432
8/10/201041 MF  14.524.631
8/3/2010<10 ME  17.919.533
7/27/2010<10 MF    32
7/20/2010<10 ME    31
7/13/201052 MF    30
7/6/2010<10 ME  19.421.331
6/29/201020 MF  15.516.333
6/22/2010<10 H  14.419.333
6/15/2010<10 MF  12.51932
6/8/2010<10 ME  12.716.733
6/1/2010<10 LF  13.31433
9/8/2009<10 MF  16.820.732
9/1/2009<10 HE  16.72030
8/25/200930 L  222330
8/18/2009<10 HE  20.123.631
8/11/2009<10 L  17.52131
8/4/200910 MF  171831
7/28/200910 ME  16.821.830
7/21/200910 H  17.319.830
7/14/2009<10 ME  13.914.132
7/10/2009<10 HF  18.920.225
7/9/2009687 MF  14.917.726
7/7/2009122 MF  171428
6/30/200941 ME  13.614.330
6/23/200975 MF  13.71630
6/16/2009<10 ME  14.215.230
6/9/200920 MF  121432
6/2/2009<10 ME  10.419.733
8/26/2008<10 ME  13.816.533
8/19/200810 MF  17.719.131
8/12/2008<10 ME  16.815.330
8/5/200820 LF  16.317.231
7/29/200810 HE  162335
7/22/2008<10 MF  16.423.432
7/15/200820 HF  13.620.235
7/8/200810 LF  202231
7/1/200875 H  16.618.831
6/24/2008<10 L  16.719.332
6/17/2008<10 HF  1517.132
6/10/2008<10 ME  1617.233
6/3/2008<10 H  10.915.332
8/30/2007<10 MF    33
8/28/200783 MF  19.82033
8/21/200710 LE    34
8/14/200752 MF  17.819.932
8/7/200731 -     
7/31/200752 MF  1925.832
7/24/2007<10 ME  18.119.731
7/19/200720 HF  15.217.532
7/17/200710 MF  14.724.432
7/10/2007<10 HE  14.516.533
7/3/200710 -     
6/26/200710 HE  17.126.832
6/19/200784 L  1418.631
6/12/200710 ME  13.72231
6/7/2007<10 L    32
6/5/2007<10 MF  12.315.6226
11/17/2006134 LE  11.812.130
8/29/2006<10 LF  151531
8/22/2006<10 HF  1419.532
8/15/200620 LE  151732
8/8/200610 HF  1422.531
8/1/200630 LE  1721.532
7/25/200610 MF  192231
7/18/200610 LE  1925.531
7/12/2006<10 ME  15.517.532
7/11/2006144 MF  16.516.532
7/3/2006<10 LE  1422.532
6/27/200662 MF  16.51832
6/20/2006<10 ME  162029
6/15/2006<10 LF  1519.530
6/13/2006448 MF  13.51828
6/6/2006<10 ME  13.517.532
8/31/2005110 HF  172032
8/24/200530 L  16.52830
8/19/200598 HF  171931
8/17/2005173 H  182834
8/10/2005<10 L  182734
8/3/2005<10 HF  1622.532
7/27/200541 LE  17.52030
7/22/200562 MF  1826.530
7/20/2005105 MF  16.52130
7/13/200531 L  1819.532
7/6/200512 MF  151830
6/29/2005<10 ME  1721.531
6/23/2005<10 -     
6/22/200595 HF  11.51733
6/8/200535 MF  132029
6/1/2005<10 ME  1213.530
9/2/200420 LF  141734
8/31/2004180 HF  162233
8/24/2004<10 ME  1316.533
8/17/2004<10 -  181833
8/10/200410 ME  162234
8/3/2004  -  18.52432
7/20/2004  -  1618.532
7/13/2004<10 HF  172030
7/6/2004<10 LE  161734
6/29/2004<10 LE  161734
Sample DateEnterococci CountTide StageWater TemperatureAir TemperatureSalinity
8/28/2017<10 LE  14.916.134
8/21/2017<10 HF  17.119.232
8/14/2017<10 ME  14.716.933
8/7/2017<10 MF  14.715.833
7/31/2017<10 ME  16.120.931
7/24/201720 MF  15.116.133
7/17/2017<10 ME  18.32029
7/10/201710 MF  14.317.433
7/5/201710 HF  15.521.333
6/26/2017<10 MF  12.816.733
6/19/2017<10 ME  16.115.933
6/12/2017<10 MF  15.720.929
6/5/201731 HE  12.111.732
8/29/2016<10 H  19.325.332
8/22/2016<10 LF  20.220.931
8/15/2016<10 H  19.620.331
8/8/2016<10 L  1622.334
8/1/2016<10 HF  17.921.933
7/25/201610 L  17.519.233
7/18/201610 HF  19.41933
7/11/2016<10 ME  16.417.234
7/6/201620 MF  17.520.232
6/27/201610 LE  17.817.135
6/20/201610 MF  16.315.935
6/13/201610 ME  13.418.134
6/8/201630 MF  17.320.430
6/7/20162489 LF  14.416.628
6/1/2016<10 ME  15.120.633
8/31/201510 MF  17.621.731
8/24/201510 ME  19.620.133
8/17/2015<10 LF  18.521.133
8/10/2015<10 HE  18.219.234
8/3/201541 LF  17.41934
7/27/201510 HE  17.219.731
7/21/2015<10 MF  17.617.534
7/20/2015794 L  17.518.130
7/13/201530 H  192332
7/6/2015<10 L  15.324.432
6/29/201531 H  14.314.633
6/22/201575 LE  14.816.830
6/15/201531 HF  13.413.232
6/8/201531 LE  12.112.132
6/5/201541 LF  10.811.633
6/3/2015495 MF  9.61030
9/3/2014<10 ME  17.122.531
8/25/201410 MF  1620.831
8/18/2014<10 ME  16.117.332
8/11/201441 MF  16.917.732
8/4/2014<10 ME  18.318.131
7/28/201420 MF  14.717.632
7/21/201410 ME  15.419.732
7/14/201441 MF  15.116.2 
7/7/2014<10 ME  1517.231
6/30/2014<10 LF  1716.532
6/23/2014<10 H  15.417.331
6/16/201410 L  11.616.432
6/9/201410 H  15.31631
6/2/2014<10 L  11.61432
9/4/201320 MF  17.416.933
8/26/201320 L  16.216.634
8/19/201310 H  16.520.633
8/12/201310 L  1616.633
8/5/2013<10 HF  15.917.932
7/29/201320 LE  16.716.932
7/22/201371 HF  16.118.933
7/15/2013<10 LE  20.827.628
7/8/201320 MF  17.521.633
7/5/2013<10 H  18.52325
7/3/2013122 HE  14.414.733
7/1/201310 LE  14.617.233
6/25/201331 H  18.621.230
6/24/2013295 MF  14.719.431
6/17/201341 ME  14.115.432
6/10/201352 LE  13.514.132
6/3/2013<10 HE  12.913.333
5/29/201341 L    31
8/29/2012<10 H  15.818.534
8/27/201252 ME  18.919.632
8/22/2012<10 L  17.717.634
8/21/201210 H  25.222.730
8/20/2012315 MF  1819.326
8/15/201220 HF  20.420.632
8/13/201210 HE  19.922.132
8/8/2012<10 LE  18.719.734
8/6/201275 L  20.622.131
8/1/201220 MF  15.819.633
7/30/2012<10 H  17.719.233
7/25/201210 LE  13.419.335
7/23/201230 LF  16.81831
7/18/201220 MF  18.421.732
7/16/2012<10 HF  16.82131
7/11/201210 ME  16.81731
7/9/201210 LE  16.421.332
7/2/2012<10 HF  14.320.432
6/25/2012<10 L  17.920.430
6/18/2012<10 MF  16.114.230
6/11/2012<10 ME  15.415.930
6/6/201285 MF  12.211.131
6/4/20128664 MF  13.210.826
5/30/2012<10 ME  14.513.831
8/30/201184 MF  1618.432
8/23/2011<10 ME  15.216.834
8/17/2011<10 H  19.120.530
8/16/2011845 LF  16.515.828
8/9/201110 HE  18.222.233
8/2/201141 MF    31
7/26/2011<10 ME  1818.333
7/19/2011<10 LF  1625.335
7/12/201110 H  192431
7/5/201120 LF  142231
6/28/2011<10 HF  171830
6/21/2011<10 LE  15.321.930
6/14/201131 HF  13.312.731
6/7/201110 L  15.116.731
5/31/2011<10 HF  12.523.430
8/31/2010<10 L  18.621.132
8/24/201010 MF  17.418.933
8/17/2010<10 ME  16.317.432
8/10/201030 MF  1625.531
8/3/201031 LE  19.519.232
7/27/2010<10 MF    32
7/20/201010 ME    31
7/6/2010<10 ME  18.822.331
6/29/201031 MF  15.516.530
6/22/2010<10 HE  15.119.733
6/15/201010 MF  12.919.932
6/8/2010<10 HE  1316.533
6/1/2010<10 LF  13.114.632

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 Higgins Beach:


 

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.