omsap 080610 bacteria by 33z50F

VIEWS: 0 PAGES: 18

									Spatial and temporal patterns
 of sewage indicator bacteria
      in Boston Harbor
    and its tributary rivers

            Kelly Coughlin
     Environmental Quality, MWRA
90 sampling stations near CSOs, harbor beaches,
       treatment plant outfalls, offshore
Mass Bay Bacteria Monitoring
     Overview of bacterial monitoring in
       Boston Harbor and Mass Bay
• CSO Receiving Water Monitoring
   - ongoing since 1989
   - 50 locations in harbor and tributary rivers
   - 90 surveys per year, 25 station visits per year

• Joint MWRA/DCR Harbor Beach Monitoring
    - ongoing since 1996 (DCR since 1974)
    - five harbor beaches
    - ~70 sampling days during swimming season

• Mass Bay Bacteria Monitoring
   - since 1999
   - eleven locations in vicinity of outfall
   - one monthly survey plus adverse surveys
Bacterial Indicators Measured by MWRA
• Enterococcus measured continuously since
  1989 in fresh and marine waters

• Fecal coliform in Mass Bay (discontinued for
   harbor and beach monitoring in 2001, but has
   resumed for 2008 harbor sampling)

• E. coli beginning in 2001, now freshwater only

 • Enterococcus is required indicator for marine beaches and marine
   receiving waters (EPA, MADPH, MADEP).

 • E. coli is required indicator for CSO receiving waters, freshwater

 • Fecal coliform is required indicator for shellfish growing waters
   (FDA/MADMF)
                                 Harbor Tributary Rivers                                                    Dotted line is
                                                                                                            swimming
                                                                                                            standard,
                                                                                                            33 counts/100 mL
                                        Wet Weather                       Dry weather
                                                                                                            Enterococcus
                           600
                           500 River
                           Mystic                                                       Lower Charles River
600                                                            600
500                        400                                 500
400                        300                                 400
300                        200                                 300
200                        100                                 200
100                          0                                 100
   0                                                          0
                                  1989 - 1991       1992 - 1999           2000 - 2007
         1989 - 1991        1992 - 1999      2000 - 2007                  1989 - 1991         1992 - 1999    2000 - 2007


                                                        Lower Neponset River
                                 1200
                                 1000
( Note different scale )          800

                                  600
                                  400
                                  200
                                    0
                                          1989 - 1991       1992 - 1999         2000 - 2007
                                                                                                                 Dotted line is

                    Inner Harbor & Embayments                                                                    swimming standard,
                                                                                                                 35 counts/100 mL
                                                                                                                 Enterococcus

                                         Wet Weather                 Dry weather
                          80

                   Inner Harbor
                          60                                                          North Dorchester Bay
80                                                              80
70                        40
                                                                70
60                        20
                                                                60
50                         0
                                                                50
                                   1989 - 1991         1992 - 1999          2000 - 2007
40                                                            40
30                                                            30
20                                                            20
10                                                            10
 0                                                             0
     1989 - 1991    1992 - 1999        2000 - 2007                    1989 - 1991            1992 - 1999    2000 - 2007


                     Quincy Bay                                                           South Dorchester Bay
80                                                              80
70                                                              70
60                                                              60
50                                                              50
40                                                              40
30                                                              30
20                                                              20
10                                                              10
 0                                                               0
     1989 - 1991     1992 - 1999         2000 - 2007                   1989 - 1991            1992 - 1999    2000 - 2007
              Former Harbor Outfalls
                               Before and after closure

       Nut Island Outfall                             Deer Island Outfall
40                                            40

30                                            30

20                                            20

10                                            10

0                  Pr e-1998
                                               0                 Pre-2000




     Pre-closure               Post-closure        Pre-closure              Post-closure
      1995-1998                 1998-2001           1995-2000                2000-2001

     Dotted line is swimming standard, 35 counts/100 mL Enterococcus
Wet weather Enterococcus, 1987-1991
                      1987-1991
1992 - 1998
              1992 -1998
1999 - 2007
              1999 - 2007
Harbor Beach Monitoring
MWRA assists Mass. Dept. of Conservation and Recreation
(DCR) with daily beach monitoring at four beaches:

• Constitution Beach in East
  Boston
• Carson Beach and Pleasure
  Bay Beach in South Boston
• Tenean Beach in Dorchester
• Wollaston Beach in Quincy
                                Harbor beach water quality
% exceedences of Enterococcus                                                                                                                  Carson Beach
                                                                                                                                               Constitution Beach
single sample limit at harbor
                                                                                                                                               Tenean Beach
beaches, 1987 - 2007                                                                                                                           Wollaston Beach
25
25
20
20
15
15
10
10
5
5
0
0
       1987
                1988
                         1989
                                  1990
                                           1991
                                                    1992
                                                             1993
                                                                      1994
                                                                               1995
                                                                                        1996
                                                                                                 1997
                                                                                                          1998
                                                                                                                   1999
                                                                                                                            2000
                                                                                                                                     2001
                                                                                                                                              2002
                                                                                                                                                       2003
                                                                                                                                                                2004
                                                                                                                                                                         2005
                                                                                                                                                                                  2006
                                                                                                                                                                                           2007
     1987
              1988
                       1989
                                1990
                                         1991
                                                  1992
                                                           1993
                                                                    1994
                                                                             1995
                                                                                      1996
                                                                                               1997
                                                                                                        1998
                                                                                                                 1999
                                                                                                                          2000
                                                                                                                                   2001
                                                                                                                                            2002
                                                                                                                                                     2003
                                                                                                                                                              2004
                                                                                                                                                                       2005
                                                                                                                                                                                2006
                                                                                                                                                                                         2007
                        Wet weather impacts
                    on harbor beaches are variable
                 % Enterococcus exceedences at Wollaston, all locations combined
30
20
10
         0
              '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07

                                           Summer rainfall totals
         12
inches




          8
          4
          0
              '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07
Mass Bay Bacteria Monitoring
Mass Bay Bacteria Monitoring
     Samples Exceeding Unrestricted
Shellfishing Standard of 14 counts/100 mL    • 31 of 1179 samples
                                               collected since 2000
            Before Outfall   After Outfall     have exceeded the
Station
               Opened          Opened
                                               unrestricted shellfishing
  F13           0.0%            1.0%           standard of 14
                                               counts/100 mL
  F14           0.0%            1.0%
  F18           0.0%            5.0%         • 2 Enterococcus samples
                                               have exceeded the
  F24           0.0%            1.0%
                                               single sample swimming
  F25           0.0%            5.0%           standard of 104
 N02            0.0%            0.0%           counts/100 mL
 N09            0.0%            2.9%
 N16            0.0%            1.8%
 N20            4.3%            8.2%
Summary of Long Term Trends
         • CSO Receiving Water: dramatic
           improvements in tributary rivers, less
           change for locations further from shore;
           wet weather continues to affect water
           quality

         • Harbor Beaches: little improvement in
           water quality over time, postings primarily
           triggered by wet weather events

         • Mass Bay: vast majority of samples meet
           shellfishing and swimming standards, though
           exceedences do occasionally occur
        Acknowledgements
• Keary Berger, John Wladkowski, Christopher
Dorman, the harbor field team at DITP Central Lab
• Laura Ducott, Microbiology, DITP Central Lab

								
To top