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

Sheet2

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

****