The MWRA outfall monitoring program.

What we measure and what we have observed so far.

Part 1. What we are monitoring.

Objectives:• test for compliance with

the Permit

• test for exceedance of contingency plan thresholds

• test whether environmental changes are greater than expected

Effluent• pathogen

indicators

• residual chlorine

• total suspended solids

• biochemical oxygen demand

• toxicity testing

• PCBs

• flow

• pH

• nitrogen loading

• numerous organic

and inorganic contaminants

Water column

• nutrients• chlorophyll• dissolved oxygen• temperature, salinity • light, water clarity• solids• phytoplankton• nuisance and noxious

algae • zooplankton • photosynthesis,

respiration• remote sensing, moored

instruments • marine mammal

observations• bacterial indicators,

viruses• diffuser mixing

21 nearfield sites (in a grid near outfall site)

28 farfield sites (distant from the outfall site)

17 nearfield, 6 farfield surveys each year

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M

U

R

U

M

M

M,UH

U

U

H

M

U

U

R

H

U

R

l# Humpback Whale# Minke Whale# Right Whale# Unidentified Whale

Nearfield

H

M

R

U42°0

0'

42°00'

42°1

5'

42°15'

42°3

0'

42°30'

71°00'

71°00'

70°45'

70°45'

70°30'

70°30'

70°15'

70°15'

N

LEGEND

Stellwagen Bank National Marine Sanctuary

Outfall Diffuser

0 5 10 15 Kilometers

Whale Sightings - 1998

1998

Whale sightingsduring MWRAsurveys

ll

l

l

l

ll

lll

l

l

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ll

l

l

ll

l

ll

ll

l

l

l

lF

U

U

U

R

U

M

UF

(F,M)

(H,U)

H

R

U

M

UU

FH

(H,F)

U

H

UU

U

# Humpback Whale# Minke Whale# Right Whale# Unidentified Whale

Nearfield

H

M

R

U42°0

0'

42°00'

42°1

5'

42°15'

42°3

0'

42°30'

71°00'

71°00'

70°45'

70°45'

70°30'

70°30'

70°15'

70°15'

N

LEGEND

Stellwagen Bank National Marine Sanctuary

Outfall Diffuser

0 5 10 15 Kilometers

Whale Sightings - 1999

F Finback Whale#

1999

l

lll

l

l

l

ll

ll

ll ll

ll lllll

l

l

U

M

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HU

MH

(H,F)

UHH

H

H

H

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UF

UU

U

U

U

U

M

# Humpback Whale# Minke Whale# Unidentified Whale

Nearfield

H

M

U42°0

0'

42°00'

42°1

5'

42°15'

42°3

0'

42°30'

71°00'

71°00'

70°45'

70°45'

70°30'

70°30'

70°15'

70°15'

N

LEGEND

Stellwagen Bank National Marine Sanctuary

Outfall Diffuser

0 5 10 15 Kilometers

Whale Sightings - 2000

F Finback Whale#

2000

Sediments• soft bottom community structure• rock cobble communities• sediment oxygen• toxic metal and organic chemicals• sediment bulk characteristics• chemistry, tracers• nutrient and oxygen flux

Sample locations for soft-bottom communities

FF10

FF12

FF13

NF02

NF04

NF05

NF07

NF08NF09

NF10NF12 NF13

NF14NF15

NF16NF17

NF18

NF19NF20

NF21

NF22

NF23

NF24

0 1 2 3 Kilometers

NF02 Sampling Location Name

Depth (meters):

LEGEND

N Farfield Nearfield

152025

303540

Outfall Diffuser

42°1

8'

42°18'

42°1

9'

42°19'

42°2

0'

42°20'

42°2

1'

42°21'

42°2

2'

42°22'

42°2

3'

42°23'

42°2

4'

42°24'

42°2

5'

42°25'

42°2

6'

42°26'

42°2

7'

42°27'

70°57'

70°57'

70°56'

70°56'

70°55'

70°55'

70°54'

70°54'

70°53'

70°53'

70°52'

70°52'

70°51'

70°51'

70°50'

70°50'

70°49'

70°49'

70°48'

70°48'

70°47'

70°47'

Fish and Shellfish• metals and organic

chemicals, including pesticides and PCBs in flounder and lobster

• bioaccumulation of toxic chemicals in transplanted mussels

• liver disease in flounder

Mussels:

collection and deployment locations

l

l

Cape Cod Bay

Mass Bay outfall

Dear Island Light

Sandwich

Gloucester

Boston Inner Harbor

42°0

0'

42°00'

42°1

5'

42°15'

42°3

0'

42°30'

71°00'

71°00'

70°45'

70°45'

70°30'

70°30'

70°15'

70°15'

l Collection Locations

0 5 10 15 Kilometers

Outfall Diffuser

Stellwagen Bank National Marine Sanctuary

LEGEND

N

Deployment Locations

Part 2.

What we have seen since the outfall was relocated.

MWRA response to exceedances.

In summer, the effluent discharged at the Massachusetts Bay outfall is trapped beneath the

thermocline

October 1999

Ammonium concentration (NH4+ uM)Boston nearfield Cape Ann

October 2000

0 10 20 30 40 50

Distance (km)

-100

-80

-60

-40

-20

0D

epth

(m

)F23 F24 N 20 N 21 N 16 F19 F27

1 3 5 7 9 11 13 15 30

Param eter: Am m oniumLast Survey D ay: 10/8/99Sam pling Event: W F99EBoston-N earfie ld T ransectC ontour In terva l =2 µM

0 10 20 30 40 50

Distance (km)

-100

-80

-60

-40

-20

0

Dep

th (

m)

F23 F24 N 20 N 21 N 16 F19 F27

1 3 5 7 9 11 13 15 30

Param eter: Am m oniumLast Survey D ay: 10/12/00Sam pling Event: W F00EBoston-N earfie ld T ransectC ontour In terva l =2 µM

Ongoing MonitoringData reported to MWRA

Threshold Exceeded?NO YES

Annual Monitoring

ReportNov 15

Notify: DITP

Regulatory agenciesOMSAP

Public (web and libraries)5 days

Threshold Level

Caution

Warning

•Adjust operations if needed•Review supporting data•Collect additional data if needed

< 90 days

•Evaluate MWRA contribution w OMSAP andregulators

•Plan/schedule to address MWRA impacts•Report every 30 days to regulators, public on evaluations, action andfollow-up

Adverse impact?YES

NO

Quarterly Wastewater Performance ReportsEvaluations, actions

and follow-up

Contingency Plan threshold exceedances for 2000

• Chlorine too high in treatment plant on 12/15/00.Control equipment installed.

• pH too low in treatment plant on 12/7/00. Artifact of sampling procedure.

• High chlorophyll in autumn 2000. A regional event.

• Low DO saturation in bottom waters in October 2000.Recognition of natural phenomena in revising the threshold.

Chlorophyll threshold exceedance autumn 2000

0

250

500

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

CapeCodBay

0

250

500

CapeAnn

0

250

500

nearfield

0

250

500

Boston Harbor

Areal Chlorophyll (mg per square meter)

September 6 2000

Satellite images of chlorophyll, averaged by month

J. Yoder1, J.O’Reilly2, S.Schollaert1, T. Ducas2

1URI,GSO, 2NOAA, NMFS

1997 1998 1999 2000 2001

Oct

ober

Sep

tem

ber

Harmful algal blooms in Massachusetts Bay

• Paralytic Shellfish Poisoning (PSP) Alexandrium• Noxious blooms (aesthetics) Phaeocystis• Amnesic Shellfish Poisoning (ASP) Pseudo-nitzschia

0

0.2

0.4

0.6

0.8

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10

15

20

0

50

100

150

200

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001

Alexandrium (cells/L)

Phaeocystis (million cells/L)

Pseudo-nitzschia (million cells/L)

60708090

100110120

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001

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6

8

10

12

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001

Dissolved oxygen in bottom waters of the nearfield

DO concentration (mg/L)

DO saturation (percent)

90-second animation of the rocky-bottom video surveyin July 2001 in the nearfield

The region surrounding the Massachusetts Bay Outfall site consists of a series of ridges and valleys.

B o sto n

M assach u se tts B ayO u tfa ll

Vertical Exaggeration 12X