Boston Harbor:An Environmental Success Story
Cleaning Up MWRA Discharges
MWRA Primary and Secondary FlowsMillion Gallons Per Day
Chart1
406.190
381.391
371.492
376.193
380.994
338.495
426.496
285.767.7
135.4251
41.9301.8
53.3309.1
Primary-treated Flows
Secondary-treated Flows
Sheet1
YearPrimary-treated FlowsSecondary-treated Flows[flows entering the treatment plants]
90406.1
91381.3
92371.4
93376.1
94380.9
95338.4
96426.4
97285.767.7
98135.4251
9941.9301.8
0053.3309.1
&L&D
Sheet2
Sheet3
Decreased Bacteria Levels in Deer Island EffluentNumber of Days with High Bacteria Counts
Chart1
4990
387
100
212
223
212
100
170
70
72
61
51
40
201-10,000 Fecal coliform/100 ml
>10,000 Fecal coliform/100 ml
Sheet1
Bacteria levels in DI effluent 1988-2000
Year>10,000 Fecal coliform/100 ml201-10,000 Fecal coliform/100 mlNote: In Nov01 our limit goes up to 14,000
889049
89738
90010
91221
92322
93221
94010
95017
9607
9727
9816
9915
0004
&LMarch 2000
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Sheet3
MWRA Solids Discharges to Boston Harbor
Chart1
111.629.124
93.230.537
88.930.938
82.628.240
74.135.492
7334.493
77.539.794
55.332.295
61.837.696
55.830.397
32.99.198
33.49999
32.500
Deer Island
Nut Island
Sludge
Tons per day
Sheet1
MWRA Solids discharges to Boston Harbor 1988-2000
YearDeer IslandNut IslandSludge
88111.629.124
8993.230.537
9088.930.938
9182.628.240
9274.135.4
937334.4
9477.539.7
9555.332.2
9661.837.6
9755.830.3
9832.99.1
9933.4
0032.5
&L&D
Sheet2
Sheet3
MWRA Treatment Plant Metals Discharges 1989-2000
Chart1
390266214948526
358254114625718
29423262263318
2261783113268
245.2175.333.313.920.56.8
237.9191.834.824.927.26.8
211.2180.422.728.225.57.9
198.5184.826.316.718.99
161.4135.117.11116.96.3
120.880.811.5712.93.7
103.352.19.44.19.32.7
124.860.110.45.110.71.9
Zinc
Copper
Lead
Chromium
Nickel
Silver
Pounds per day discharged to Harbor
Sheet1
Metals discharges to Boston Harbor 1989-2000
ZincCopperLeadChromiumNickelSilver
89390266214948526
90358254114625718
9129423262263318
922261783113268
93245.2175.333.313.920.56.8
94237.9191.834.824.927.26.8
95211.2180.422.728.225.57.9
96198.5184.826.316.718.99
97161.4135.117.11116.96.3
98120.880.811.5712.93.7
99103.352.19.44.19.32.7
00124.860.110.45.110.71.9
&L&D
Sheet2
Sheet2
390266214948526
358254114625718
29423262263318
2261783113268
245.2175.333.313.920.56.8
237.9191.834.824.927.26.8
211.2180.422.728.225.57.9
198.5184.826.316.718.99
161.4135.117.11116.96.3
120.880.811.5712.93.7
103.352.19.44.19.32.7
124.860.110.45.110.71.9
Zinc
Copper
Lead
Chromium
Nickel
Silver
Average pounds per day discharged to Harbor
Metals in MWRA Treatment Plant Discharges 1989-2000
Questions (and grades) from 1990 State of Boston Harbor reportAre marine resources protected? Is it safe to eat fish and shellfish?Is it safe to swim? How does the Harbor rate aesthetically?
Overall 1990 Grade was D+
Are Marine Resources Protected? Animals in the Sediments
Assessing the health of the sediments and the animal communities that live in the sediments is an important piece of the monitoring program.
Most pollutants are associated with particles, and ultimately end up in the sediments. These animals cannot move to escape pollution effects, and so are very sensitive indicators of ecosystem health. We measure sediment quality, and the abundance and composition of the species present, and look for significant changes.Animals that live on rocky bottoms are sampled by photographing, using a remotely operated camera.
Ampelisca abdita:Tiny tube-dwelling crustaceanModerately pollution intolerantBuilds tubes in the sediment
Harbor sediment cross-section, sludge site, 1990
Harbor sediment cross-section, sludge site, 1996
Increased Species Diversity in Harbor Sediment Communities91929394959697981015202530354045Species per grab
Is it safe to eat fish and shellfish?
Mussels absorb and concentrate toxic contaminants from the water into their tissue
Deployment of Mussels
Decrease in PAH levelsin Mussels Deployed at Deer Island Predeployment LMW Concentration Predeployment HMW Concentration
Is it safe to swim?
Map by Suh Yuen Liang0-14 Open shellfishing14-88 Restr. Shellfishing88-200 Swimming200-1000 Boating>1000 PoorNo Data
Map by Suh Yuen Liang0-14 Open shellfishing14-88 Restr. Shellfishing88-200 Swimming200-1000 Boating>1000 PoorNo Data
Homaris americanusR. Michelson
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