State of Boston Harbor: Questions and Answers About the Outfall

the State of Boston Harbor

questions and answers about the new outfall 1996

Massachusetts Water Resources Authority the state of boston harbor questions and answers about the new outfall

November 1997

prepared under the direction of: Douglas B. MacDonald, Executive Director John F. Fitzgerald, Director, Sewerage Division

board of directors Trudy Coxe, Chair John J. Carroll, Vice Chair Lorraine M. Downey, Secretary Norman P. Jacques Joseph A. MacRitchie Vincent G. Mannering Donald A. Mitchell Samuel G. Mygatt Andrew Pappastergion Robert Spinney Marie T. Turner

Technical Report No. 1997-05 Second Printing Massachusetts Water Resources Authority acknowledgements

prepared by: Andrea C. Rex Michael S. Connor

edited by: Sally Rege Carroll

graphics by: Steve Hussey Susan Curran Ford Rita Berkeley Jenny Siegel Ilse Stryjewski

design and layout by: Rita Berkeley Jenny Siegel

GIS data provided by: Massachusetts Department of Environmental Protection, Massachusetts Division of Fisheries & Wildlife, MassGIS, National Oceanic & Atmospheric Administration

acknowledgements Many people contributed information and advice for this report. The authors wish to thank: Don Anderson, Michael Bothner, Steve Cibik, Cathy Coniaris, Maury Hall, Doug Hersh, Kenneth Keay, Josh Lieberman, Michael Mickelson, Michael Moore, Peggy Murray, Carl Pawlowski, Michael P. Quinlin, Susan Redlich,Virginia Renick, Jack Schwartz, and Meg Tabacsko. Special thanks to Wendy Smith Leo for her contribution. table of contents

1 Executive Summary Endnotes 26

Part I: References 26 Boston Harbor Quality Update 2 List of web sites 28

2 Introduction

Boston Harbor Quality Update

6 Part II: 8 The New Outfall: Frequently Asked Questions 10

12 How was the Massachusetts Bay site chosen?

14 How will the new outfall benefit water quality?

16 Will the discharge be very contaminated? 18 The seasonal cycle of the Bays 20 How healthy is the marine ecosystem of the Bays?

How will the discharge affect the health of the Bays? Bay outfall 24 with secondary What about the right whale? treatment Will we know if the outfall is causing a problem?

What will be done if a problem occurs? < 6

(mg/L) Bay > 9 16.4 mi. S tell 9.5 mi. wa Boston 36.6 mi.

New Outfall

Cap B list of list of figures

tables

10 Table 1: Comparison of primary and secondary treatment 10 Table 2: Toxic contaminants reduced by treatment

3 figures 3 3 Figure 1: Bacteria counts in Deer Island effluent 14 Figure 15: Resources and stressors in the Bays 3 15 Figure 2: Solids discharged to Boston Harbor Figure 16: Multiple sources of toxic contaminants 3 15 4 Figure 3: PAHs in mussels near Deer Island decreased 15 Figure 17: Distribution of silver in surface sediments 4 Figure 4: Metals discharges to Boston Harbor declined 16 Figure 18: Winter flounder liver disease rates 5 17 Figure 5: Industrial metals entering treatment plants Figure 19: Modeled surface chlorophyll a 6 17 7 Figure 6: Water at Harbor beaches is cleaner 19 Figure 20: Modeled dissolved oxygen in bottom water 8 21 Figure 7: Healthier animal communities on the Harbor floor Figure 21: Modeled particulate organic carbon deposition 22 9 Figure 8: Liver disease and contaminants in winter flounder 22 Figure 22: Feeding northern right whale 11 23 Figure 9: Location of outfalls in Harbor and Bay Figure 23: MWRA monitors the Harbor and Bay at all scales 12 23 Figure10: Schematic views of outfall and diffusers 25 Figure 24: Monitoring locations in the Bays Figure 11: Diluted effluent rises to surface in winter, and is trapped Figure 25: Beneficial and nuisance algal blooms

beneath surface in summer Figure 26: Dissolved oxygen at the Bay outfall site

Figure 12: Dilution contours, Harbor and Bay outfalls Figure 27: Sediment silver at the Bay outfall site

Figure 13: Secondary wastewater treatment schematic Figure 28: Contingency plan process flowchart

Figure 14: The seasonal cycle of the Bays executive summary

be issued soon. The development of primary treatment. Pathogens are sig- addition, MWRA is required to conduct he continuing improvements the permit has revealed continuing nificantly reduced by secondary treat- an outfall monitoring program that is in the waters of Boston questions about the new outfall and its ment. With less solids in the waste- linked to its Contingency Plan, an Harbor have been described potential impacts on Massachusetts water, disinfection is more effective. action plan that incorporates water in the State of Boston and Cape Cod Bays. This report quality conditions that trigger MWRA Harbor reports over the last addresses frequently asked questions (2) Better Dilution: A four- action. These trigger parameters are few years. Elimination of about this outfall, including the overar- year scientific and engineering study, based on permit limits, state water sludge discharges into the ching concern: Could the Bays regulatory review, and extensive public quality standards, and expert scientific Harbor, prevention of float- become degraded by sewage effluent participation determined that a dis- opinion. Table pollution, and system improve- as Boston Harbor once was? The charge site 9.5 miles northeast of Deer Five years of baseline monitoring ments including the start-up of the new answer is no, for these three reasons: Island would be the best location for have revealed much about the Bay primary treatment plant in 1995, have the health of both the Harbor and the system’s natural variability, information visibly improved the Harbor’s environ- (1) Cleaner Effluent: The Bay. The outfall, equipped with 440 that will help distinguish between ment. Already, reductions in the secondary effluent that will be dis- diffuser ports over the last 1.25 miles, natural and outfall-related phenomena amounts of pathogens, toxic metals charged to the Bay will be much will dilute the effluent in water 100 feet once the outfall is on-line. Through vig- and petroleum products in the primary cleaner than past discharges due to: deep in the Bay, compared to a depth ilant monitoring, problems can be effluent have been accompanied by Source reduction: Fewer pollutants of only 30 feet in the Harbor. detected and addressed. fewer swimmers’ advisories at Harbor are being allowed to enter the sewer Computer modeling results indicate The outfall’s impact has received beaches, evidence of healthier animal system, in part through stricter over- that the effluent will have very limited extra scrutiny because of the important communities on the Harbor floor, and a sight of industrial dischargers. Now, impacts near the outfall in Massachu- role that Cape Cod Bay plays in the lower incidence of liver disease in the only a small portion of toxic metals setts Bay, and virtually no effect on life of the endangered North Atlantic Harbor’s flounder. entering the treatment plants are from Cape Cod Bay. Surface chlorophyll a, right whale. Although no effects are In August 1997, the Massachusetts industrial sources. a measure of algal blooms, will expected, MWRA’s intensive moni- Water Resources Authority (MWRA) Improved treatment: Secondary increase only in the immediate outfall toring is designed to detect any outfall- began the next phase of the Boston treatment will remove even more cont- area, and will be reduced significantly related environmental changes that Harbor Project—the implementation of aminants before discharge and meet in the Harbor. might affect the whales’ feeding secondary treatment. Beginning in stringent state and federal water grounds. 1998, a long outfall will discharge sec- quality standards. While primary treat- (3) Constant Monitoring While there are many sources of ondary effluent into Massachusetts ment removes 50% to 60% of the total and Contingency Planning: pollutants to the Bays system, most of Bay instead of into the shallower suspended solids in wastewater, sec- MWRA’s National Pollutant Discharge the Bays region supports a healthy waters of the Harbor. This outfall relo- ondary treatment removes more than Elimination System (NPDES) permit marine ecosystem. MWRA's sec- cation will allow the Harbor to continue 85% of these solids. Oxygen-depleting for the new treatment plant and outfall, ondary treatment and the better dilu- recovering from the poorly treated substances will also be more than which will be one of the most compre- tion provided by the new outfall will sewage that it received for more than 85% removed, compared with 40% hensive and protective permits ever contribute to an overall improvement in a century. removed by primary treatment. issued, will require that state and the health of the Harbor and Bays. A draft of the new discharge permit Toxic contaminants will be up to federal water quality criteria not be vio- for the Deer Island Treatment Plant will 90% removed, compared to 50% by lated as a result of the discharge. In PART I boston harbor quality introduction update

he ongoing transformation of a once-degraded Boston Harbor to a Boston Harbor is an estuary that is non-industrial contributions to toxic valued regional resource is a story of environmental recovery. The part of the Massachusetts Bays metal loads in the wastewater received system. Conditions in the Harbor, by MWRA treatment plants. Harbor's progress over the past decade is due to ambitious anti- including treatment plant discharges at pollution projects, especially MWRA's new Deer Island sewage the existing, nearshore outfall loca- The benefits of better wastewater treatment plant which serves 43 Boston area communities. When tions, measurably affect the Bay as a treatment and management are most Tsecondary sewage treatment is entirely on-line in 1999, sewage result of strong tidal flushing. Improve- apparent along the Harbor beaches, treatment in the greater Boston area will finally be in compliance with the ments in the Harbor generally also downtown along the walkways of the improve Massachusetts Bay. Inner Harbor, and near the former federal standards prescribed in the 1972 Clean Water Act. sludge discharge site in President MWRA is now making progress toward two major milestones at the treat- Better wastewater management, Roads. Unsightly sewage-related ment plant: the three-part phase-in of secondary treatment from 1997 to including fewer untreated combined floating matter has been practically 1999, and completion of the 9.5-mile effluent outfall into Massachusetts sewer overflow discharges and reduc- eliminated. Figure 6 shows that, for the tions in contaminants entering the most part, the number of swimmers’ Bay. Secondary treatment will remove even more solids and toxic conta- 2 sewage system, has substantially advisories (beach postings) due to cont- minants from primary-treated wastewater. The new outfall will reach deep lowered contamination in the Harbor. aminated water have declined since the water where over 400 diffuser ports will rapidly disperse treated effluent into Figure 1 shows that MWRA's improve- mid-to-late 1980s. the marine environment. ments to the reliability of disinfection since 1989 have greatly reduced the Bottom-dwelling animal communities, Minimizing adverse effects of wastewater discharge on the marine envi- pathogens discharged to the Harbor. for example, the shrimp-like amphipod ronment includes three fundamental strategies: Figure 2 illustrates improvements in Ampelisca, have increased in abun- 1 aggressive source reduction: preventing pollutants from entering removal of solids (and associated toxic dance and diversity (Figure 7). The the waste stream and, in particular, enforcing strict limits on industry's pollutants) from the wastewater. health of winter flounder has improved discharge of toxic contaminants to the sewer system; Studies of contaminants in mussels as shown by the decline of flounder placed near Deer Island, for example liver disease since the mid-1980s improved treatment: removing contamination from wastewater before 2 PAHs (Figure 3), confirm that environ- (Figure 8a). Flounder caught in Boston discharge; and mental levels of toxic chemicals have Harbor are safe to eat, as illustrated in 3 effective dilution: mixing wastewater quickly with large volumes of also decreased. Figures 8b and 8c. PCB levels in seawater to achieve very low concentrations of any remaining contami- flounder fillet are measured at about Dramatic reductions since 1989 in 100 parts per billion—well below the nants in the marine environment. toxic metals contained in the effluent FDA limit of 2,000 parts per billion. Like- Despite the benefits of improved treatment, the relocation of the outfall discharged from MWRA’s treatment wise, mercury levels in flounder fillet are has raised questions about the effects of discharging effluent into the plants are shown in Figure 4. Figure 5 measured at levels 10-fold lower than waters of Massachusetts Bay. This year’s State of Boston Harbor report is shows that industry's discharge of toxic the FDA limit. principally devoted to the major questions asked about the new outfall. metals into the sewers now constitutes only a small portion of the total metals loadings. A challenge for the future will be to decrease household and other Bacteria counts in Deer Island effluent Metals discharges to Boston Harbor now rarely exceed permit limits from MWRA treatment plants declined

200 PAHs in mussels near Deer Island 1200 201-10,000 Fecal decreased Copper Nickel coliform/100 ml 1000 Zinc Chromium 150 >10,000 Fecal 1500 Lead Silver coliform/100 ml 800

1200 100 600

900 Pounds per Day 400 50 Days per Year of High Counts of High Year per Days 600 200 Parts per billion 0 0 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 300 1989 1990 1991 1992 1993 1994 1995 1996 1997 Fiscal Year Fiscal Year

Figure High1. bacteria counts in Deer Island effluent have 0 Figure Metals4. loadings to Boston Harbor from the Deer and Nut decreased dramatically since 1989. Graph shows number of days per 1987 1991 1992 1993 1994 1995 1996 Island treatment plants have decreased dramatically since the 1980s. year that bacteria in effluent exceeded the permit limit of 200 colonies Decreases in FY 1992 reflect the elimination of sludge discharges into per 100 ml. Extremely high (greater than 10,000) bacteria counts, once the Harbor (MWRA monitoring data). Figure Low3. molecular weight polynuclear aromatic hydrocarbons, common, have been eliminated. (MWRA monitoring data). which are potentially cancer causing chemicals created by combustion of fossil fuels, are measured in mussels deployed and grown near Deer 3 Island. Levels of PAHs in mussels have remained relatively low since Industrial metals are a small part of total 1993 (Mitchell et al. 1996, data for 1996 from Mitchell et al.,report in metals entering treatment plants Solids discharged to Boston Harbor prep.). (Pounds/day) 150 Sludge solids 5.5 0.5 1 2

120 Effluent 246 13 suspended solids 40 20

90 COPPER LEAD CHROMIUM SILVER

60 0.04 0.08 2 8.3

Tons Discharged per Day Discharged Tons 2.5 0.8 25 321

0 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 CADMIUM MERCURY NICKEL ZINC Fiscal Year

Figure The2. amount of solids discharged to the Harbor from Deer Figure Industrial5. metals loadings in influent to the Deer and Nut Island and Nut Island treatment plants has decreased to about half that dis- treatment plants before treatment are only a small portion of the total. The charged in the late 1980’s, after the elimination of sludge discharges and wedges show, for various metals, the pounds per day originating from indus- improved primary treatment. (MWRA monitoring data). trial sources as compared to the total loading in influent (MWRA monitoring data). boston harbor quality

update Healthier animal communities on the Harbor floor Water at Harbor beaches is cleaner 1989 -1990 Ampelisca Tubemats

50 Constitution Beach 40 30 Figure Swimmers’6. advi- 20 sories have decreased since 10 the late 1980s. Storm drain 0 contamination and leaking 85-86 87-88 89-90 91-92 93-94 local sewers remain a problem 50 Winthrop Beach at Wollaston Beach. (Data Figure. Ampelisca7 40 from Metropolitan District Com- tube mats have increas- 30 mission beach monitoring ingly colonized Boston 20 program.) Harbor since sludge dis- 10 charges stopped, espe- 0 cially in the area of the 85-86 87-88 89-90 91-92 93-94 Harbor that was most 1995 50 Short Beach severely affected: the Ampelisca Tubemats northern Harbor. These 4 40 30 crustaceans increase the 20 amount of oxygen in the sediments and are a 10 favored flounder prey. 0 85-86 87-88 89-90 91-92 93-94 (Data through 1995 from Hilbig et al., 1996. 1996 50 Carson Beach data in prep, Hilbig et al.) 40 30 20 10 0 85-86 87-88 89-90 91-92 93-94

50 Pleasure Bay Ampelisca abdita 40 This tiny crustacean is pollu- 30 tion-intolerant. Ampelisca 1996 20 lives in tubes that it builds Ampelisca Tubemats 10 into the sediment; these 0 85-86 87-88 89-90 91-92 93-94 tubes form thick mats that provide shelter for other small 50 Malibu Beach animals (illustration after 40 Bousfield,1973). 30 Percentage of Beach Days Posted with Swimmers' Advisories with Swimmers' Posted Beach Days of Percentage 20 10 0 85-86 87-88 89-90 91-92 93-94

50 Tenean Beach 40 Less liver disease, lower contaminant levels in winter flounder

80 PART II Liver Tumors 70 Early Liver Disease 60 The New Outfall: Frequently Asked Questions 50 Despite these documented improve- 40 ments in Boston Harbor, its history of 30 problems invites the question, “Could the Questions about the new outfall 20 Bays become degraded by treatment discussed in this report are: 10 plant effluent from the new outfall?” • How was the Massachusetts Bay 0 0 0 0 0 % of Deer Island Flounder with Disease % of Deer Island Flounder 0 Observers, experts, citizens, and marine site chosen? 84 87 88 89 90 91 92 93 94 95 96 scientists have generally concluded, • How will the new outfall benefit "No." Three important reasons are: (1) water quality? Figure 8a.The reduction in liver disease, including cancer, in winter flounder has followed the the effluent to be discharged into the Bay • Will the discharge be very banning of DDT and PCBs, and the decreasing discharge of PAHs from wastewater. (1984 flounder will meet the secondary treatment stan- contaminated? liver lesion data from Murchelano and Wolke 1985; 1987 data through 1995, from Mitchell et al. 1996, dard and thereby be much cleaner than 1996 from report in prep.) • How healthy is the marine the primary effluent and sludge that were ecosystem of the Bays? discharged into Boston Harbor until 5 500 • How will the discharge affect PCBs in winter flounder (fillet) caught near Deer Island 1991; (2) there is much greater dilution are well below the FDA limit of 2,000 parts per billion. at the discharge site in the Bay than in the health of the Bays? 400 Levels have greatly decreased since the mid-late 1980s. the shallower waters of the Harbor; and • What about the right whale? 300 (3) there will be constant monitoring of • Will we know if the outfall is MWRA's effluent and the water quality in causing a problem? 200 the Bays.

PCBs in parts per billion • What will be done if a problem 100 Throughout the report, we discuss occurs? results of scientific studies which have 0 increased our understanding of the Bays 1985 1986 1987 1988 1989 ...... 1992 1993 1994 1995 1996 ecosystem and how pollution impacts can best be prevented. In addition, we 150 Mercury levels in winter flounder caught near Deer point out areas of scientific uncertainty. Island have been well below the FDA limit of 1,000 Continual monitoring, linked to a flexible, 120 parts per billion. Levels have decreased since the evolving response plan, will help assure late 1980s. 90 that MWRA is accountable for examining and re-examining areas of uncertainty. 60 By obtaining and using new scientific information in its planning, MWRA and all

Mercury parts per billion 30 others interested in the health of the Bays can work together to provide the 0 ...... 1987 1988 1989 1990 1992 1993 1994 1995 1996 best protection for invaluable marine

Figure 8b,c.PCBs and mercury in flounder caught off Deer Island have been well within guide- lines for human consumption since the mid 1980s, and have decreased since the late 1980s. (toxic resources. chemistry data from National Status and Trends Program 1987; 1985 - 1991 data are from Schwartz et al. 1991 and 1993; 1992 - 1994 data from Hillman and Pevens 1995, 1996 data from Mitchell et al. report in prep.) how was the Massachusetts Bay site chosen?

fter a four-year long process including oceanographic and engineering studies, regulatory review, and extensive public participation, the 9.5-mile site for the outfall discharge was found to Abe the best location for the health of nearshore and offshore waters.

The outfall siting process began in shore, were evaluated in detail by areas of important habitat. 1986 with the appointment of the Facili- MWRA and EPA independently. Sites The computer model predicted that Deer Island ties Planning Citizens Advisory Com- more distant than 10 miles were elimi- Outfalls mittee (FPCAC), which included 27 par- nated from consideration because con- water depth and current patterns would ticipants representing agencies, envi- struction would not have been feasible produce the most effective dilution of Boston Harbor ronmental groups, community officials, at a reasonable cost. Siting studies effluent at three of the most distant can- didate sites. These predictions were Old and other interested individuals. The were done in 1987 and 1988, including Nut Island FPCAC developed criteria used in the engineering studies by four different confirmed by oceanographic field Outfalls siting process, and reviewed and com- leading engineering firms as well as the studies. (closed 7/98) mented extensively on the environ- Massachusetts Institute of Technology 6 mental impact reports. and the Georgia Institute of Technology. After an extensive period of regulatory Figure 9a.Present outfall locations in Boston Oceanographic work was done by Bat- and public review and comment, the Harbor At the outset of the siting process, telle Ocean Sciences, the New England Final Supplemental Environmental the United States Environmental Pro- Aquarium, MIT, and the US Geological Impact Statement confirmed that the Cape AnnMassachusetts tection Agency (EPA) ruled acceptable Survey. Biological, chemical, and phys- 9.5-mile site (Figure 9b) was the Bay only those sites that (1) could provide ical oceanographic information to optimum location for the outfall because 16.4 mi. S tell an initial dilution of 50 parts seawater to support the siting analysis was col- it is in an area of strong random off- 9.5 mi. wa ge n one part effluent; (2) were far enough lected in Broad Sound, Nantasket Bight, shore currents, has a sufficient water Boston B 36.6 mi. a

n from shore so that particles could not and western Massachusetts Bay. depth, and would be feasible to con- k be transported directly to shore on the struct. In 1988, the EPA published its New Outfall next incoming tide; and (3) avoided Along with oceanographic measure- Record of Decision on the outfall site, Provincetown sensitive and unique resources. ments, a computer model of pollutant which also required MWRA to conduct transport in Massachusetts and Cape monitoring of the effects of the ocean The existing Deer Island and Nut Cod Bays was used to predict likely discharge on the Massachusetts Bay Cape Cod Island discharge locations (Figure 9a) effects of prospective outfall discharges: environment. Bay at the mouth of Boston Harbor did not any discharge site had to show the meet any of the above criteria—for ability to attain compliance with state example, the dilution there is only 14 and federal water quality criteria. Other Figure 9b.Future outfall location in Massachusetts parts seawater to one part effluent. criteria to evaluate potential sites were Bay Therefore, because of insufficient based on discussions with citizens and depth and dilution, Boston Harbor was scientific advisory groups, and included not chosen as a site for the new outfall. protection of commercial on-the-water Seven potential sites, from a location activities, maintenance and enhance- in Broad Sound to a site 10 miles off- ment of aesthetics, and avoidance of Riser

Schematic views of outfall and diffusers

Sediment Diffuser head

Bedrock

Figure Figure 10c.The diffuser heads each 10a. disperse the effluent through eight ports. The outfall tunnel is bored through bedrock, and the diffuser section of the outfall is located along the Effluent final 1.25 miles of the structure.

Figure 10b.The 55 risers carry effluent Figures 10a-d show the structure of from the deep rock outfall tunnel up to the diffuser heads at the seafloor. the new outfall. The outfall will provide a larger measure of environmental protection than the existing outfalls. Cur- rently, wastewater is discharged within Sea level Boston Harbor from two short (less 0 100 than a mile long) outfalls at Deer Island and three short outfalls at Nut Island. -50 50 Because all wastewater treatment will Seafloor -100 0 be consolidated on Deer island, it was -150 necessary to build a larger outfall and 24' - 3" -50

Inside Diameter to locate the discharge in deeper water. -200 Since the continental shelf off the East -100 -250 Coast has a very gentle slope, the -150 + outfall had to be relatively long. Depth below sea level (feet) 43,026' Outfall Tunnel -300 -200 Depth below seafloor at diffuser end -350 Slope: 0.05% -250 6,600'+ -380 -280

Figure 10d.Cross-section diagram of outfall pipe NOTE: Diagrams not drawn to scale how will the new outfall benefit water quality?

apid mixing with a large volume of seawater will Sea Surface Effluent mixed with seawater rises to the surf Diluted effluent rises quickly dilute the constituents of the effluent to to surface in winter background levels. R What ultimately Figure 11a. The new outfall is designed to maxi- new location will be about 150 to 1, happens to the effluent plume depends upon seasonal effects on the density of mize mixing and dilution of effluent. At compared to the present dilution near ocean water in Massachusetts Bay. Sea- Seawater is cold, the present time, treated wastewater Deer Island of 14 to 1. dense,and well-mixed water density is controlled by tempera- effluents from the Deer Island and Nut Because effluent is mostly fresh from surface to ture and salinity. Warmer temperatures bottom. Island treatment plants are discharged water, it is lighter than seawater. Buoy- and lower salinity make seawater lighter,

30 meters while cooler temperatures and higher near shore within Boston Harbor. ancy causes the effluent to rise toward salinity make seawater heavier. In the Strong tidal currents eventually carry the ocean surface, rapidly mixing with winter, the waters of the Bay are about the effluent into Massachusetts Bay, but the surrounding water. This vertical Buoyant freshwater effluent the same density top to bottom and are rises and mixes rapidly each incoming tide brings some of the mixing causes the density of the well mixed. When the seawater has a 8 effluent back into the Harbor. Because effluent plume to increase, and the relatively uniform density top to bottom, the effluent plume will rise to the surface the Harbor is shallow (on average only mixed effluent becomes about as dense as it mixes. 30 feet deep), the effluent plumes as seawater. This mixing happens Sea Floor receive little dilution and reach the within a few minutes, and within a dis- Diffuser head surface, where they are visible. With tance of tens of meters from the dif- onshore winds, the effluent can reach fuser. the shoreline. By contrast, the new off- In the winter, the effluent plume, after Sea Surfac Diluted effluent shore location is in an area where circu- mixing, will reach the surface. In the Surface layer: seawater is well mixed and less dens trapped beneath lation is greater and more variable, pro- summer, effluent will be trapped below 5 meters surface in summer viding better mixing. the surface because it quickly takes on Pycnocline layer: seawater density increaseswith d The new outfall (illustrated on the the same (denser) characteristics as Figure 11b.In the summer, the previous page in Figure 10a-d) will the bottom water (Figures 11a and 11b). surface water is warmed and becomes increasingly lighter, setting up a layering Through mixing, effluent reaches same

carry effluent 9.5 miles (15 kilometers) After initial mixing, whether the plume 10 meters density as surrounding water and stops rising effect. The level where the density off shore to a location where Massa- surfaces or not, it will be mixed horizon- change is most abrupt is called the pycn- chusetts Bay is 100 feet (30 meters) tally by currents at the new outfall site. ocline. deep. The effluent will be discharged These currents vary in direction, helping Effluent becomes increasingly dense through 55 diffuser heads each with to further disperse the effluent. The as it mixes with seawater, and will rise up only to the depth where it is no longer eight outlets (ports), creating a diffuser outfall is distant enough from shore so lighter than the surrounding water—at that altogether will be 1.25 miles (2000 that even shoreward currents will not Bottom layer: the pycnocline. Thus the effluent plume meters) long. The long diffuser area carry the effluent close to beaches or 15 meters seawater well mixed will be trapped below the pycnocline. At and denser Buoyant freshwater effluent the outfall site, this is about 50 feet (15 and multiple ports will effectively dis- shellfish beds. rises and mixes rapidly perse the effluent to maximize dilution. meters) below the surface.

The initial dilution of the effluent at the Sea Floor

Diffuser head Dilution contours, Harbor outfall location Dilution contours, new Bay outfall location

Average Modeled Average Modeled Dilution of Sewage Dilution of Sewage Effluent Effluent

DILUTION AREA DILUTION AREA (Square miles) (Square miles) < 200 77 < 200 3 9

200 - 400 56 200 - 400 30

400 - 600 59 400 - 600 151

600 - 800 77 600 - 800 48

800 -1000 116 800 - 1000 54

Figure 12a. Figure 12b. Moving the outfall offshore greatly reduces the area most affected by effluent. These two figures show the results of computer model predictions of effluent dilution during winter conditions at the present and future outfall locations. At present (12a), 77 square miles all of Boston Harbor and the South Shore to Cohasset Harbor, now have a dilution factor of less than 200-fold. At the future outfall location (12b), only 3 square miles, immedi- ately above the diffusers will have a dilution of less than 200-fold. The dilution model assumes concentrations in effluent are the same for both Harbor and Bay outfalls: this is true for nutrients. The illustration does not take into account the effect of improved treatment in lowering the concentrations of contaminants in effluent. Model predictions based on winds and currents, winter 1990-1991. (Model created by R. Signell and H. L. Jenter of the U. S. Geological Survey and A. Blumberg of HydroQual, Inc.) will the discharge be very contaminated?

he secondary effluent discharge will meet stringent state and federal standards to ensure that it will not pose a threat to either human health or the health of the Tenvironment.

Treatment is a critical step in mini- 13), the concentration of toxic pollu- Tables 1 and 2. Secondary treatment at the Deer Island treatment plant, combined mizing adverse effects of sewage dis- tants in the effluent is very low–mea- with dilution at the new outfall, will ensure that levels of toxic contaminants in the receiving waters charges. The centerpiece of the Boston sured in parts per billion or parts per are well within water quality standards. The table shows selected toxic constituents of wastewater Harbor Project is the state-of-the-art trillion. Levels of many of these pollu- that are regulated by EPA. For most constituents, the final concentration in the receiving water will primary and secondary treatment plant tants in the secondary effluent are be far lower than EPA criteria (for details see end note, p.26). nearing completion on Deer Island. already low enough to meet regulatory Table 1. Comparison of primary and secondary removal of pollutants This massive, multibillion dollar project standards for receiving water. In fact, was built to comply with strict environ- after dilution at the new outfall, most Pollutant Primary removal Secondary removal mental regulations in order to protect contaminants are 10 to 1000 times human health, the health of the Harbor, lower than water quality standards Total suspended solids (TSS) 50-60% 85+% 10 and the ecology of the Bays system. allow. The secondary-treated wastewater to Nutrients are the only components of Biochemical oxygen demand (BOD) 25-40% 85+% be discharged into Massachusetts Bay sewage entering the treatment plant Toxic contaminants is very different from the inadequately that are not significantly reduced by 0-50% 50-90% treated primary effluent and sludge that secondary treatment. Therefore, Nutrients 5% 10-15% were discharged into Boston Harbor for MWRA carefully monitors the potential decades. As shown in Table 1, while effect of nutrient issues on the Bays Pathogens 0-50%* 80-99+%* primary treatment removes 50 to 60 system, and nutrients have received percent of the total suspended solids in particularly intensive scrutiny by regula- *These numbers indicate removal before disinfection. Disinfection further reduces pathogens to safe levels. wastewater, secondary treatment tory agencies. increases the removal of Table 2. Toxic contaminants reduced by treatment and dilution solids to 85 percent or Helpful Microbes Parts per trillion more. Parts per billion (micrograms/liter) (nanograms/liter) Table 2 shows the Tiny microbes including levels of toxic pollu- bacteria, ciliates, and TOTAL Copper PCBs7 tants in primary and rotifers, as seen here Mercury Lead DDTs PAH through a microscope at secondary treated Primary effluent1 103 0.3 29.2 31 54,932 57 effluent, and the pre- about 500-fold magnifica- dicted concentrations tion, are the key to sec- Secondary effluent1,2 21.6 0.1 3.3 3 3,250 12 in the area around the ondary treatment. These Concentration after 0.27 0.0013 0.04 0.008 8.93 0.033 new outfall after dilution helpful micro-organisms feed dilution3 compared to water quality vigorously on the wastewater standards. during treatment, breaking down Receiving water 2.9 0.025 8.5 2.02 42,000 0.045 quality standards4,5,6 After secondary treatment (Figure and removing contaminants. nutrients

Nutrients, especially nitrogen and phosphorous, are familiar as the active ingredi- ents in lawn and agricultural fertilizers. Nutrients Secondary wastewater treatment schematic are also essential for the growth of plants (sea- grasses, seaweed, and microscopic floating algae Return Activated Sludge called phytoplankton) in the ocean. In the marine environment, excessive amounts of nutrients, espe- Secondary Influent Secondary Reactors cially nitrogen, stimulate the growth of phytoplank- Sludge ton and seaweeds and can cause nuisance algal 11 Waste Sludge Primary Effluent to Secondary Clarifiers to Centrifuge, blooms like brown or red tides (eutrophication). The Secondary Treatment Digesters, & Pelletizing eventual decaying of these plants can deplete dis- Facility Contaminted airfromreactors solved oxygen levels in the water and sediment. Secondary Effluent

Nutrients from the present outfalls exit the Disinfection Chambers Cryogenic Oxygen Facility Atmosphere Harbor to the Bay in effluent plumes at the sur- Effluent to Outfall Pure Oxygen face of the water, where sunlight and nutrients induce abundant phytoplankton growth. One Odor Removing major benefit of the new outfall is that diluted Air Scrubbers effluent will be discharged at the bottom of Massachusetts Bay, 110 feet below the water's surface. During the summer when there is the Figure 13. Secondary wastewater treatment follows pri- break down contaminants. After about two hours, more sludge mary treatment at Deer Island. Primary treatment removes solids and scum are separated out in the secondary clarifiers. A por- most light, the discharge will be trapped by by simple physical processes: in settling tanks (clarifiers), heavy tion of the secondary sludge, rich in beneficial microbes (acti- stratification about 50 feet below the surface. solids (sludge) sink to the bottom and lighter solids (scum) float to vated), is returned to the reactors, where it is used to treat more the surface. These solids are removed; the remaining liquid is pri- primary effluent. Waste sludge and scum are sent to Deer Most phytoplankton growth is at the surface, mary effluent, which is then undergoes secondary treatment. Island’s egg-shaped digesters, to be further broken down by where there is a lot of light. Nutrients from the Within the secondary reactors, the primary effluent is mixed with microbes and eventually converted to fertilizer pellets. The clari- pure oxygen. The oxygen and mixing stimulate the rapid growth fied secondary effluent is disinfected and discharged to the discharge at the sea floor will generally not of beneficial microbes (bacteria, protozoans, and other tiny ocean through Deer Island’s outfalls (Figure after D. Duest, reach the surface during the summer, when organisms) in the wastewater, which consume more solids and MWRA) there is the most potential for excess growth. Therefore, the outfall is not likely to contribute to eutrophication in the Bay. the seasonal cycle of Figure 14.

the Bays Little daylight in winter undamental to all the processes in the Bays is the annual seasonal cycle. In order to be able to recognize the effect of effluent discharge on the environment, it is important to first under- Fstand the changes that happen naturally. Over the past five years, MWRA’s baseline monitoring program and extensive studies by the US Geological Survey and the Massachusetts Bays Program Longer days spur have provided a good understanding of the Bays' seasonal cycle. phytoplankton growth.

In November through April, winds and cooling mix the waters of the Bays. Nutrients are plentiful, but in December and January the pene- tration of light into the water is rarely enough to support the growth of phytoplankton (microscopic floating algae at the base of the food web). As the days lengthen in early spring, increases in light and in nutrient levels trigger the rapid growth of phytoplankton.

The spring bloom of phytoplankton starts in the shallower waters of Waters are cold and Cape Cod Bay, providing food for zooplankton (tiny animals, including well mixed and rich 12 juvenile forms of animals like fish and jellyfish, and abundant tiny in nutrients Right whales feed on crustaceans called copepods) carried into the Bays by strong currents abundant zooplankton from the Gulf of Maine. In turn, the fast-multiplying zooplankton pro- in Cape Cod Bay and vide food for many marine species including the northern right whale. Stellwagen Bank. A single right whale feeding in Cape Cod Bay can consume about one ton of these plankton daily.

Later in the spring, the surface waters of the Bays warm and strat- Legend ify. The phytoplankton grow abundantly at the surface, where they Color indicates approximate water receive ample light. Because vertical mixing is prevented by stratifica- temperature (F) tion, the nutrients at the surface do not get replenished from the bottom waters. The phytoplankton use up the nutrients in the surface 35 40 45 50 55 60 65 water and die, eventually sinking to the bottom and providing food to the bottom-dwelling animal communities which show a growth spurt in mid-summer. Dead plankton ce

In the water column, bacteria use up dissolved oxygen through their respiration as they consume the dead plankton; the lowest dis- January February March April solved oxygen levels in the Bays occur from August to October. In the 11 fall, cooling of surface waters and strong winds allow mixing throughout the water column, bringing fresh nutrients to the surface, stimulat- 9 ing a new growth of phytoplankton—the fall bloom. By mid-winter, light levels have declined, ending the fall bloom. The plankton die and 7 Spring Bloom decay, releasing nutrients. Nutrient levels increase throughout the water column, preparing the Bays for the next spring bloom. Fall and winter winds aid in mixing.

Warming decreases surface water density

Phytoplankton use up nutrients in surface Mixing causes nutrients to increase waters, plankton growth slows. Surface waters in surface waters: fall bloom. begin to cool 13 and mix downward. Stratification: minimal mixing between surface and bottom.

cells and fecal matter from zooplankton drift down through the water column. As this material decays, nutrients in the water are replenished.

May June July August September October November December

11 Dissolved Oxygen Concentration (mg/L) 9

Stratified Period Fall Bloom 7 how healthy is the marine ecosystem of the Bays?

he Bays system supports a rich and diverse ecosystem of normal plant and animal communities, but signs of stress are evident. Stress results from multiple causes, including overfishing and contamination. The highest levels of contamination are nearshore— T sources include rivers, the atmosphere, sewer overflows, treatment plants, and past use of disposal areas.

An overview of the Bays system Bacterial contamination of beaches North Essex At the southern end of the Gulf of and shellfish beds is a concern along Ocean Sanctuary Maine, the Massachusetts/Cape Cod most of the Bays’ coastline. The chief Figure 15. Bay system extends from the New sources of this contamination are sewer Resources and stres- Hampshire border to the tip of Cape pipe overflows, stormwater runoff, and sors in Massachusetts Cod, encompassing about 1650 square leaks from septic systems. Treatment and Cape Cod Bays Stellwagen Bank miles. plants are a relatively minor source of National Marine A strong southward coastal current and contamination. Sanctuary a large flow of water from the Merrimack Levels of toxic contaminants in the South Essex Ocean Sanctuary River produce an average flow south water are highest near the coast and, 14 through the Bays, exiting to the open except for a few pollutants like polychlori- IWS Ste Atlantic (Figure 15). Strong tide and wind nated biphenyls (PCBs), generally meet FA llw ag effects produce circulation patterns that water quality standards throughout the e n MBDS are highly variable from day to day. Bays. However, the sediments near B a Shipping Lane n urban shorelines like Boston Harbor, k

Rich resources and multiple Salem Sound, and Broad Sound have stressors significant levels of contamination. The beaches, wetlands, rocky shores, In sediments, as in the water column, Legend and deep offshore waters of the Bays contaminant levels decrease with dis- Federal Marine provide important habitat for many plant Sanctuary tance from shore except at former waste State Ocean and animal communities including com- disposal sites in Massachusetts Bay. Sanctuary mercially important species of fish and State Area of Critical Contamination in offshore sediments is Environmental Concern shellfish, and rare or endangered ani- not high enough to cause detrimental Cape Cod Bay mals and birds. Barrier beaches CapeMarine Cod Bay Sanctuary ecological effects, according to National Ocean Sanctuary There are a variety of environmental Cape Cod Bay Oceanic and Atmospheric Administration Industrial discharges Area of stressors in the Bays system: historical standards. In fact, monitoring has shown Sewage treatment plant Critical whale hunting and ongoing commercial that the bottom-dwelling animal commu- outfalls Environmental fishing; disappearance of habitat such as nities are typical of the Gulf of Maine New MWRA outfall site Concern (Right Whale salt marshes; dams that hinder fish ecosystem. Former Mass Bay Disposal Site, Sanctuary) migration and spawning; commercial Toxic organic compounds and metals or Foul Area (FA) shipping and boating activities; and pollu- have many sources. Three examples Former Industrial Waste Site (IWS) tion. illustrating this are chlorinated pesticides Present Mass. Bay Disposal Site (MBDS) (especially DDT and its breakdown prod- Many sources of pollution, past ucts), PCBs, and mercury. DDT was Average ocean current direction and present banned in 1972 and PCBs were phased Multiple sources of toxic contaminants Distribution of silver in surface Winter flounder liver disease rates to the Bays sediments

Present Annual Loading: MWRA Primary Treatment 0.18 Broad Sound

44% Future Outfall site Deer Island Flats 22% 0.15 43% 1.18 0.23 Chlorinated Pesticides PCBs Mercury 14% Total = 20.7 kg/year Total= 51 kg/year Total = 358 kg/year 8.9 1.82 Nantasket Beach Legend 0.42 0.27 Atmosphere Rivers MWRA 2.7 5.5 5.7 Other Treatment Plants Other sources

Future Annual Loading; MWRA Secondary Treatment 0.32 Eastern Cape Cod Bay 2% Chlorinated Pesticides PCBs Mercury 0.51 Total = 8.8 kg/year Total = 27 kg/year Total = 332 kg/year 0.69 Estimated existing inventories in Massachusetts Bay Chlorinated PCBs (kg) Mercury (kg) Pesticides (kg) 15 39 Water 47 300 Figure 17. Sediment silver concentrations (measured Figure 18. Flounder liver disease is high in Boston Harbor and Broad Sediment 430-1520 510-1800 40,000-80,000 as parts per million of the mud fraction of sediment) Sound, and low in Cape Cod Bay. The percentage of flounder showing early decrease with distance from the coast. Cape Cod Bay has liver disease decreases with distance from Boston Harbor—flounder at the somewhat higher silver concentrations than more northern new outfall site may be affected by toxic pollutants from the coastal sources Annual inputs (loadings) of chlorinated Figure 16. locations; this may reflect sediment resuspension and trans- or from old waste disposal sites. Improved treatment, continued source pesticides and PCBs to Massachusetts Bay are small com- port by currents to Cape Cod Bay (data from Bothner et al. reduction, and improved dilution and dispersion at the new location will min- pared to existing accumulations from past sources. The 1993). imize flounders’ exposure to the contaminants (PAHs,pesticides, and PCBs) source of mercury is primarily atmospheric. Secondary treat- thought to cause this disease (data from Mitchell et al. 1996). ment reduces MWRA’s contributions. The pie chart areas reflect the relative amounts of present vs. future loads. and chlorinated pesticides Harbor to Cape Cod Bay (Figure 17), show that contaminant-related liver dis- (Annual loading data from Mitchell et al. 1997, Massachu- setts Bay estimates of existing inventory from data by Shea, entering the Bays will continue with higher concentrations in parts of ease is at very low levels in Cape Cod 1993, 1996 in prep.; Bothner et al. 1993. Estimates based on to decrease in the future, and Cape Cod Bay than in other offshore Bay compared to the area close to model in Shea 1995). are slowly degrading in the waters. Because the Harbor apparently Boston Harbor. out of production beginning in 1971. environment. was the source, these silver concentra- These contaminants can bioaccumulate tions correspond quite well to the mod- Future decreases in contamina- in marine mammals and fish. Historical contamination signals eled dilution of the effluent dispersed tion Figure 16 shows that the present MWRA’s monitoring program has into Massachusetts Bay from the exist- As MWRA’s contribution of toxic pol- inputs to Massachusetts Bay from all revealed that past sewage discharges ing Harbor outfalls (Figure 12a). lutants continues to decrease due to sources combined of PCBs and chlori- into Boston Harbor have contributed Despite the pattern of silver (and source reduction and treatment nated pesticides are a small fraction of contaminants to broad areas of Cape other sewage tracers not shown), the improvements, the existing gradient of the amounts that have accumulated Cod Bay as a result of tidal flushing. contaminants are not causing signifi- pollutants in the Bay should gradually from past inputs, when the chemicals Past inputs of sewage and sludge in cant impacts on the health of marine life lessen. In addition, moving the effluent were being used in large amounts. Sec- Boston Harbor contained silver, which in Cape Cod Bay. Bottom-dwelling ani- discharge to the new outfall site (see ondary treatment will greatly reduce was historically discharged in large mal communities in the Bay are typical page 9) will reduce the concentration of MWRA’s contribution of PCBs to Mass- amounts by the photographic industry. for the Gulf of Maine as a whole. Data dissolved contaminants reaching Cape achusetts Bay. The amounts of PCBs A gradient of silver extends from the gathered on winter flounder (Figure 18) Cod Bay from Boston. how will the discharge affect the health of the Bays? sing computer modeling, MWRA has predicted that increased pollutant removals by secondary treatment, combined with improved dilution of effluent provided by the new out- Ufall, will improve the health of Boston Harbor and Massachusetts and Cape Cod Bays. Computer model annual cycle of phytoplankton growth; of chlorophyll a, a major algal pigment the surface, where there is enough Scientists assisting MWRA have the annual cycle of nutrients in the sur- that is a good measure of phytoplank- light to support vigorous growth. developed a detailed computer model face and bottom waters; and the effect ton abundance. to predict impacts on Boston Harbor of stratification on the minimum dis- Figures 19a and 19b show concen- Dissolved oxygen in bottom and the Massachusetts and Cape Cod solved oxygen concentrations trations of chlorophyll a at the surface water Bays from discharges of secondary- observed in October. for Boston Harbor and Massachusetts Animals and plants living in the treated effluent at the new 9.5-mile After the usefulness of the computer Bay predicted by the Bays Eutrophi- marine environment need adequate outfall location. This forecast is con- model was established by these tests, cation Model. The figures show a five- dissolved oxygen (DO) in the water for trasted with modeled impacts from the scientists used the model to predict the day average in August, when the Bays respiration. If DO levels fall too low, discharges of primary effluent at the likely impacts of discharging secondary are stratified. There is a large fish and other animals may die. Bot- outfall location near Deer Island within effluent through the new outfall into decrease in surface chlorophyll a lev- tom waters, because they are not in

16 Boston Harbor. The model is a time- Massachusetts Bay. Figures 19-21 els in Boston Harbor and no increase contact with the atmosphere, are most variable, three-dimensional, hydrody- show the model predictions for three in Massachusetts Bay after the 9.5- likely to experience low DO. Factors namic and water quality model called major components of concern: surface mile outfall and secondary treatment that decrease the levels of DO in the the Bays Eutrophication Model. It was chlorophyll a, bottom dissolved oxy- are on-line. This is largely because of water are: high water temperature— developed by the U. S. Geological gen, and particulate organic carbon improved dilution, and because at the oxygen is less soluble at warmer tem- Survey and Hydroqual, Inc., the com- flux. new deeper location, discharged nutri- peratures, and respiration rates of all pany that also developed water quality ents will mostly be below the summer life increase; too much oxygen- models for the Chesapeake Bay and pycnocline in the Bay. Nutrients will demanding organic matter in the sedi- Chlorophyll a Long Island Sound. not be available to phytoplankton at ment; and stratification of the water Because primary and secondary treatment do little to Figure 19. Modeled surface chlorophyll a, August Verifying the model remove nutrients from In the course of developing and test- sewage effluent, one of the a b ing the model, modeling results were major questions regarding Harbor outfall Bay outfall with secondary compared to actual environmental with primary relocation of the effluent dis- treatment treatment observations in the Massachusetts Bay charge to the 9.5-mile site system made in 1989-1992. The offshore is what effect nutri- model results agreed quite well with ents would have on phyto- observed data, and reproduced the plankton growth: would 10 major processes affecting the Bays adding nutrients offshore system: the annual cycle of surface promote blooms of phyto- water heating and stratification; the plankton? One important spring freshet associated with the Mer- measure of the status of (ug/L) 5 rimack River and other northern rivers eutrophication in the Bays (ug/L) discharging to the Gulf of Maine; the system is the concentration < 1 < 1 Figure 20. Modeled dissolved oxygen in bottom water, October a b Harbor outfall Bay outfall with primary with secondary treatment treatment

> 9 > 9

(mg/L) (mg/L)

< 6 < 6 column, which prevents more highly export of nutrients and BOD from decreased diversity, as has happened POC to the sediments near the new 17 oxygenated surface waters from Boston Harbor. Figure 20b shows that in Boston Harbor. POC can be con- outfall. reaching the bottom. Concerns about secondary treatment and the long out- tributed directly by an effluent dis- The model shows a high deposition the outfall related to dissolved oxygen fall result in improved bottom DO, both charge, or indirectly by increased phy- rate in Boston Harbor with the present are whether inputs of materials that in the Harbor and near the outfall. toplankton and zooplankton outfall and primary treatment (Figure use up oxygen (measured as bio- Most of this improvement is explained abundance, some of which ultimately 21a). With the new outfall and sec- chemical oxygen demand, or BOD) by increased removal of BOD through deposit in the sediments. A concern ondary treatment, POC flux is dramati- and nutrients might cause bottom DO secondary treatment. with the 9.5-mile outfall location has cally reduced in both the Harbor and to violate the water quality standard. been the potential effect of adding the Bay (Figure 21b). Monitoring has shown that bottom Particulate organic water DO has occasionally fallen carbon flux Figure 21. Modeled deposition of particulate organic carbon below the standard at the new outfall The animal community site. The state standard for DO is 6 living on the ocean floor a b mg/l in Massachusetts Bay, and 5 mg/l relies for food on organic Harbor outfall Bay outfall with primary in most of Boston Harbor. matter deposited to the with secondary treatment treatment Bottom DO levels are generally low- sediment through the over- est in October because the water col- lying water column—the umn has been stratified since April particulate organic carbon (see page 12). The model shows that (POC) flux. However, depo- 1000 1000 with the Harbor discharge and primary sition of too much organic treatment (Figure 20a), the lowest DO matter in the sediments can is in the Inner Harbor, and DO is also deplete sediment DO. (mg C/m2-d) (mg C/m2-d) depressed near the future outfall area. Excess food as POC will This offshore DO depression is partly destabilize the normal com- < 125 natural, and partly reflects the present munity structure, leading to < 125 what about the right whale?

ndangered northern right whales, when visiting Massachusetts and Cape Cod Bays, will be exposed to lower amounts of toxic pollutants and pathogens because of improved wastewater treatment. Hypothe- Esized effects of nutrients on plankton that are food for the right whale are being carefully monitored.

The northern right whale (Eubalaena potential pollution sources like the ciently protective of the whales as well. glacialis) is the world’s most endan- MWRA outfall must be reviewed under gered large whale. From an original the Endangered Species Act, although Calanus What about toxic and bioaccu- population size of at least 10,000 ani- the long outfall discharge is mulation effects of metals and mals, extensive hunting for more than distant–more than 16 miles–from identi- PCBs? 800 years drove the species to near- fied right whale habitat. Levels of these contaminants in the extinction. Only about 300 individuals 2.5 mm In 1993, EPA conducted a compre- discharge will be so low (page 10) that remain in the North Atlantic; fewer in hensive Biological Assessment on the short-term, acute toxic effects are not a the North Pacific. Despite an interna- potential impact of the MWRA outfall on concern. The focus is on average levels tional ban on hunting right whales since Acartia endangered species and NMFS issued of contamination Bay-wide and the 1949, the population is increasing at a a Biological Opinion. The conclusion 18 effects of long-term chronic exposure, very slow rate, in contrast to other pro- was that the outfall was not likely to such as bioaccumulation, and the 1 mm tected whales which have recovered jeopardize the species. Nevertheless, potential for sublethal effects like more quickly. the critical status of the right whale decreased fertility. The explanation of this slow recovery requires special and continued consider- Measurements of organochlorine com- is not known. Natural causes such ation. Issues that have received ongoing ern right whale (see illustration, Figure pounds, like PCBs, in right whales indi- as competition with other species, or scrutiny include the potential for impacts 22). Right whales are baleen whales; cate relatively low tissue levels com- genetic factors like inbreeding, or from pathogens, toxic chemicals, and they feed by swimming open-mouthed pared to other marine mammals. behavioral factors may be important. nutrients, as described below. through patches of zooplankton, strain- Although exposure to toxic chemicals Human-induced mortality includes colli- ing may possibly be a factor in right whale sions with ships and entanglement with Will the whales be threatened reproductive failure, moving the outfall millions (about one ton a day) of tiny fishing gear. Finally, habitat degradation by infectious bacteria, viruses location from within the Harbor to the crustaceans, called copepods, from the has been identified as a potentially or protozoans in the effluent? 9.5-mile location offshore will not water. In the spring, right whales feed in important cause of the whale popula- Secondary treatment is highly effec- increase the risk to whales because the Cape Cod Bay and Stellwagen Bank, tion’s low rate of increase. Reduction in tive at removing pathogens from the inputs of these contaminants to the where there are intense blooms of large food availability, physical interference wastewater. Secondary-treated effluent Bays system will not be increased. and nutritious copepods like Calanus with whales through shipping, mining is also disinfected more effectively than Rather, secondary treatment will sub- finmarchicus. The whales feed in dense and dredging activities, and pollution primary effluent. Improved removal com- stantially decrease any toxic chemicals Calanus patches, created by wind and impacts are factors that could degrade bined with higher dilution will signifi- MWRA contributes to the Bays system. current patterns as well as copepod whale habitat. cantly decrease the levels of pathogens swimming behavior. Cape Cod Bay and Stellwagen Bank in both the Harbor and the Bays. The Offshore Calanus zooplankton com- Will increased nutrients cause are important late winter/spring feeding microbiological water quality will meet munities differ from their nearshore decreased food availability? areas for these migratory animals, and human swimming standards and the counterparts. Nearshore zooplankton In order to better understand nutrient have been identified by the National much more stringent shellfishing stan- are typified by species like Acartia, issues, it helps to know something Marine Fisheries Service (NMFS) as dards. These standards should be suffi- which are smaller, less nutritious, and critical habitat to be protected. Therefore about the feeding biology of the north- apparently do not form the dense patches required to sustain a feeding could worsen them. whale. Different types of copepods eat To help address both of these food different kinds of phytoplankton. It has availability issues, MWRA has used the been suggested that the nutrients dis- Bays Eutrophication Model (page 16). charged by the new outfall could cause The model shows that we can expect to plankton the Bay environment to favor zooplank- see effects of nutrient discharges limited ton like Acartia—not good food for right to the immediate area of the outfall, so it phytoplankton zooplankton whales. is unlikely that there would be any outfall- Tiny floating plants (algae), especially Tiny floating animals, including juve- Another nutrient-related whale-feeding related changes as far away as right diatoms, that are carried about with nile forms of fish, jellyfish, and shell- concern is nuisance algal blooms: will the whale habitat. If any changes in phyto- ocean currents. These plants (illus- fish. Very small crustaceans, the cope- plankton or zooplankton do result from trated at right) grow most abundantly pods (see drawings on left), are often outfall cause blooms of Phaeocystis, near the surface of the water, where abundant in zooplankton. Zooplankton the discharge, they would first occur near which seems to interfere with whale feed- they receive maximum light. At the eat phytoplankton, and in turn are ing, or brown or red tides which might be the outfall. Therefore, MWRA is monitor- base of the marine food web, phyto- eaten by fish and other marine animals, toxic? Blooms of Phaeocystis and ing intensively for changes in plankton plankton grow using nutrients in the including northern right whales. Alexandrium have occurred in the Bays, composition there. MWRA also monitors water, and are eaten by zooplankton. so the question is whether the outfall Cape Cod Bay for any significant changes.

Figure 22. Feeding northern right whale. High springtime nutrient levels in the water, combined with wind and current patterns, stimulate the abundant growth of phytoplankton and Calanus cope- 19 pods in Cape Cod Bay and Stellwagen Bank. The nutritious copepods are found in dense patches, favored by filter-feeding northern right whales. The whales feed in Massachusetts and Cape Cod Bays in the spring before continuing their migration north to the Bay of Fundy. MWRA monitoring will detect changes in phytoplankton or zooplankton communities. (Illustration by S. Hussey, after S. Landry, cour- tesy of New England Aquarium). will we know if the outfall is causing a problem? aseline monitoring, which has been conducted since 1992, is telling us a lot about natural environmental variability. The more we understand the Bays system, the more quickly and confidently we can determine if an apparent impact is discharge-related. Scientists and regulators have estab- Blished threshold values of environmental parameters that will trigger MWRA action.

Permit, trigger parameters, and ease in flounder. Twenty-two trigger implemented the most comprehensive thresholds parameters are incorporated in the marine monitoring program in the Monitoring at all scales MWRA’s National Pollutant Dis- outfall monitoring program. nation for a secondary-treated sewage Perhaps the biggest challenge in pol- charge Elimination System (NPDES) Threshold values are measurements discharge, and will continue post-dis- lution effects monitoring is to charac- permit for the new treatment plant and of trigger parameters selected as indi- charge monitoring after the outfall terize the natural variability in the envi- outfall, to be issued jointly by EPA and cators of the need for action, and are begins operating in 1998. Actions to be ronment. Within the general patterns of the Massachusetts Department of based on expected permit limits, state taken by MWRA if any unexpected seasonal and habitat differences, the Environmental Protection (DEP), will water quality standards, and expert impacts occur are detailed in the Con- marine environment can be unpre- incorporate stringent limits and testing opinion. To alert MWRA to any tingency Plan described at the end of dictable. Changes occur in the physi- requirements for Deer Island effluent changes, each trigger parameter has this report. cal and biological environment that are discharges. The permit will be one of thresholds that are defined as caution Massachusetts Bay has become one 20 unrelated to human activities. Plants, the most comprehensive and protec- or warning levels. These thresholds of the most thoroughly studied marine animals and plankton in Massachu- tive permits ever issued, and will are based on monitoring data collected environments anywhere. As recom- setts and Cape Cod Bays have what is require that state and federal water since 1992 under the guidance of the mended by the National Academy of termed a patchy distribution in space quality criteria not be violated as a Outfall Monitoring Task Force, which Sciences’ National Research Council, and time; where and when they are result of the discharge. In addition, includes academic scientists, govern- the monitoring program focuses on the found are greatly affected by local MWRA has been conducting an exten- ment agency representatives, and citi- potential impacts of nutrients, organic winds, currents, sediment types, or sive outfall monitoring program, which zens groups. material, toxic contaminants, animal behavior. This means we must is linked to an action plan—the Contin- pathogens, solids, and floating debris. measure local changes, as well as gency Plan—that incorporates trigger Contaminants are measured and bio- Monitoring comprehensively understand broader, general parameters and threshold values for logical observations made in effluent, Years of study by MWRA, scientists processes. MWRA actions. water, sediment, plankton, fish, and at major universities, research institu- The most frequent measurements shellfish. Even satellite data is used to Trigger parameters are environmen- tions including the Woods Hole are by moored instruments that collect measure chlorophyll, temperature, and tally significant components of effluent Oceanographic Institution, and govern- data at one location at intervals only other ocean conditions (Figure 23). or the marine ecosystem that, if certain ment agencies including the EPA and minutes apart. In the critical area (threshold) levels are exceeded, indi- Geological Survey, have shown that Sampling is most intensive in the around the outfall, oceanographic ves- cate a potential for environmental risk. the combination of improved waste- immediate discharge area (within three sels frequently collect water and sedi- Examples of trigger parameters for water treatment at Deer Island and the miles of the diffuser). In addition, sam- ment samples for detailed chemical effluent are total suspended solids, dilution provided by discharge of efflu- pling stations more than 30 miles away and biological analyses. At sites dis- biochemical oxygen demand, and toxic ent into deeper Bay waters will gener- in Cape Cod Bay are included (Figure tant from the outfall location, less fre- contaminants. Examples of environ- ally benefit Massachusetts Bay and 24). Since the inception of the monitor- quent sampling will enable us to moni- mental trigger parameters are water Boston Harbor. Nevertheless, to ing program, 3.4 million data records tor the general health of the area. The column dissolved oxygen concentra- ensure that any potential unforeseen have been collected and stored in big, regional picture, on a scale of kilo- tion, chlorophyll a concentration, ben- environmental impacts of the outfall MWRA’s marine monitoring database, meters, is generated by satellite thic community structure, and liver dis- relocation are addressed, MWRA has and more than 200 reports written. images. Figure 23. MWRA monitors the Harbor and Bay at all scales; data are collected by satellite, ship, and mooring. Scientists on oceanographic ships collect water, plankton, fish, shellfish, and sediment samples for MWRA throughout the Bays for laboratory analysis.

These two moored instrument arrays, owned by the U.S. Geological Survey, This floating buoy owned continuously measure sediment by the National Oceanic deposition rates, ocean currents, and and Atmospheric Administration other parameters like temperature. The tripod (below) gathers data at collects oceanographic data such 21 as wave height, at the the ocean floor, the instrument at right Satellites like SEASTAR collect climate surface of the sea. makes measurements at mid-depths. data and measure parameters such as chlorophyll a over hundreds of square miles.

Example of data (water temperature) collected continuously by moored instruments compared to survey data collected by ship. 20

10 USGS Mooring (5m) 5

Temperatures (C) Temperatures Ship survey (10m) 0 Jan Feb Mar Apr May Jun Jul AugSep Oct Nov Dec Monitoring locations in the Bays. Indicators of the Bays’ Beneficial algal blooms health vary naturally Baseline monitoring has 10,000,000 Skeletonema costatum shown that, within the 1,000,000 Asterionellopsis glacialis Thalassionema nitzschioides overall seasonal cycle, Thallassiosira nordenskioldii 100,000 there is intense variation Ceratium tripos 10,000 from year to year. For Asterionellopsis glacialis instance, Figure 25 shows 1,000 differences in abundance 100 of dominant (beneficial) 10 phytoplankton and nui- Maximum abundance (cells/liter)

0 sance phytoplankton in the 1992 1993 1994 1995 1996 Bays since baseline moni- Outfall toring began in 1992. The Nuisance algal blooms maximum abundances of beneficial phytoplankton,

10,000,000 Phaeocystis pouchetti like Skeletonema andTha-

22 1,000,000 lassiosira, vary relatively Pseudo-nitzschia pungens little from year to year. 100,000 By contrast, nuisance phy- 10,000 toplankton like red tide

1,000 (Alexandrium tamarense,

100 the cause of paralytic shellfish poisoning) or 10

Maximum abundance (cells/liter) Alexandrium tamarense blooms that lower bay- 0 wide oxygen concentra- Legend 1992 1993 1994 1995 1996 tions, discolor the water, or produce foul odors, are much more Baseline water quality Beneficial and nuisance monitoring nearfield Figure 25. erratic from year to year. Large nui- algal blooms have different inter-annual pat- sance blooms are interspersed with no Baseline water quality terns. Nuisance algal blooms have occurred monitoring farfield during the baseline monitoring period. These blooms. In 1992 and in the spring of blooms are less predictable than the normal, 1997 (not shown), there were large nui- Flounder, lobster, or beneficial algal blooms which produce food mussel sampling sance Phaeocystis blooms in Cape Cod and oxygen. Continued monitoring will Bay and Buzzards Bay. The 1997 Soft sediment bottom surveys enable MWRA to detect whether changes in algal blooms are related to the outfall (MWRA bloom apparently interfered with right USGS mooring monitoring data). whale feeding, as right whales left Cape Cod Bay earlier than usual that year (Mayo, 1997). Nuisance blooms can be linked to the larger circulation in the Figure 24. Monitoring stations include water, sediment, and the biota close to and dis- Gulf of Maine: for example, winds, cur- tant from the new outfall site. rents and spring runoff during May determine whether red tide enters Dissolved oxygen levels in bottom water at the Bay outfall site Massachusetts Bay or is transported 13 Figure 26. Baseline monitoring out to sea (Anderson, 1997). shows low dissolved oxygen can occur in bottom waters at the future outfall Figure 26 shows another example of 12 site. Average natural variability: in 1994 and 1995, dissolved oxygen levels measured dur- average oxygen concentration in the 11 ing surveys of the bottom waters of the bottom waters of the Bay fell below the outfall nearfield area show dramatic seasonal fluctuations, as well as varying caution level. This measurement would 10 trigger more intensive evaluation once from year to year. In 1994, the average DO in October almost violated the state the new outfall comes on-line, an exam- 9 water quality standard, and did fall ple of a natural phenomenon that could below the caution (6.5 mg/l) level in have been interpreted as outfall-related. 1994 and in 1995. Another measure- 8 ment, the percent saturation of DO, not Another example of a measurement shown, violated the warning level in Average dissolved oxygen (mg/l) Average that, if the new outfall were in use, 7 1994 and 1995. These violations are could have been attributed to sewage Caution level related to the warmer temperatures during those years; in the post-dis- effluent, was a pattern of silver deposi- Warning level (Water quality standard) 6 tion in the sediments near the new out- charge period such low levels would trigger notification of the Outfall Moni- fall site. Figure 27 shows that silver toring Task Force (error bars represent 5 23 concentrations spiked up to more than Apr Jul Oct Apr Jul Oct Apr Jul Oct Apr Jul Oct Apr Jul Oct one standard deviation; MWRA moni- double their baseline value in February 1992 1993 1994 1995 1996 toring data). 1993 after an unusually severe storm in December of 1992. That storm caused Sediment silver concentrations at the Bay outfall site (1989-1996) redistribution of silver into the muddy 2 Figure 27. Silver concentrations in sediments sampled. By February 1994, sediment near the future outfall site increased after a major storm. A major silver concentrations declined to near- storm occurred in December 1992, background levels. If the new outfall causing resuspension of sediments from had been commissioned, it might have 1.5 shallower inshore areas, which rede- seemed reasonable to attribute the ele- posited into deeper offshore areas, including a small muddy area near the vated silver concentration to the outfall, Major storm December 1992 future outfall site (average is mean of but now we know that severe storms three measurements error bars show one standard deviation; data from can create a pattern like this one. 1 Observations of natural year-to-year Bothner 1997 in press, Bothner et al. 1997 in press). variation of phenomena like nuisance blooms and the spike of silver in the area near the outfall site provide an 0.5

important context for examining per million) Sediment silver concentration (parts changes after the long outfall is commissioned. Information like this will help MWRA, scientific experts, regulators, and interested citizens to know where 0 to look for likely causes of suspected 9-Jul-96 Apr-89 1-Jun-91 7-Jun-94 5-Oct-94 5-Oct-93 1-Feb-92 10-Jul-90 18-Oct-91 12-Feb-91 15-Feb-94 17-Jun-93 21-Oct-92 23-Oct-90 15-Feb-96 18-Feb-93 14-Feb-95 26-Sep-95 13-Jun-95 28-Mar-90 environmental problems. 19-May-92 what will be done if a problem occurs? he Contingency Plan describes how, if monitoring results indicate a possible environmental problem, MWRA and the regulatory agencies will act to determine the cause of the problem and what corrective Tactions should be taken.

The Outfall Contingency Plan more serious warning level (Figure 28). marine ecosystem from the operation of Court. The report will also be available The Outfall Contingency Plan was The response to any threshold the outfall. If the effects of effluent dis- to the public. The report will summarize developed to create a process to iden- exceedance, even before the cause charges must be reduced, examples of monitoring results and any tify and respond to water quality has been discovered, will be to decide corrective activities could include the exceedances, responses related to the changes that potentially could be whether treatment plant operations can addition of specific enhanced treatment Contingency Plan, and corrective activi- related to effluent discharges. Even be altered to reduce the discharge of technologies and increased pollutant ties that have occurred over the previ- though it is not expected that these dis- the relevant pollutant. prevention and regulation. ous year. The report will also propose charges will affect the environment If MWRA discharges have caused a changes to the Contingency Plan, as adversely, the Contingency Plan needed. Changes are expected to be caution level to be exceeded, MWRA How the Contingency Plan describes the criteria and process that will expand its monitoring to closely guided primarily by OMTF recommen- is accountable to the public MWRA, regulatory agencies, and the track any change in effluent quality and dations. To ensure that the Contingency Plan 24 Outfall Monitoring Task Force (OMTF) environmental conditions, and provide provides appropriate environmental pro- would use to assess potential changes, the information necessary to: How the Contingency Plan tection, every step of the implementa- make information on those changes will be enforced 1) evaluate the cause and effect of the tion process will be open to public input available to the public, and respond The Contingency Plan is one portion exceedance; and and review. In addition, MWRA will pro- appropriately to avoid harm to the of many obligations, both state and fed- 2) review applicable trigger parameters duce a quarterly Wastewater Perfor- marine environment. eral, that MWRA is required to meet: and thresholds. mance Report to provide the public with information about plant performance • The NPDES permit imposes extensive How the Contingency Plan If the threshold exceeded is a warn- and monitoring results. The report is requirements on MWRA discharges, works ing level, the proposed response will designed to: including effluent monitoring, report- The Contingency Plan identifies trig- include both early notification to EPA ing, plant maintenance and opera- ger parameters, conditions that can and DEP and the quick development of • provide information about key waste- tions, and the industrial pretreatment suggest that effluent quality or environ- a Response Plan. A Response Plan water operations; program. Requirements for the com- mental conditions may be changing or includes a schedule for implementing • demonstrate day-to-day progress in bined sewer overflow (CSO) program likely to change in the future. To alert actions such as additional monitoring, achieving goals and objectives; and and sludge-to-fertilizer plant are also MWRA to different degrees of observed included; making further adjustments in plant • compare actual performance against change, each trigger parameter has • A Federal Court Order guides the con- operations, or undertaking an Engineer- trigger parameters and other impor- thresholds that are defined as caution struction of the new treatment facili- ing Feasibility Study regarding specific tant water quality monitoring or plant or warning levels. These thresholds are ties, sludge-to fertilizer plant, CSO potential corrective activities. performance targets. based on monitoring data collected projects, and the industrial pretreat- since 1992. ment program, as well as treatment In the event that a threshold is Corrective activities Once a year, MWRA will also develop plant staffing; exceeded, the process for responding Corrective activities have been identi- an Outfall Monitoring Overview/Contin- • The Massachusetts Executive Office will vary somewhat depending on fied in the Contingency Plan (or may be gency Plan report that will be submitted of Environmental Affairs and EPA whether the threshold is a caution or a identified in the future) as potential solu- to the Outfall Monitoring Task Force as have overseen the development and tions to unexpected impacts in the well as to EPA, DEP, and the Federal implementation of MWRA’s Outfall Monitoring Plan, which has also been The Contingency Plan is designed Figure 28. Contingency plan process flowchart submitted to the Federal Court. to build on and be consistent with MWRA’s regulatory and judicial oblig- To ensure that even greater over- ations. The Plan also represents the sight and enforcement opportunities matching of MWRA’s obligations with Ongoing Monitoring are provided, the new draft NPDES a clear line of accountability to the permit being developed for public com- Court, regulatory agencies, and the ment by EPA and DEP is expected to public. Preliminary Data Schedule include requirements to ensure that the Reported to MWRA Contingency Plan will be implemented as described and intended.

NO Caution Level Annual Monitoring Report Exceeded?

outfall monitoring YES Notify Plant Staff & OMSAP Adjust Operations 25 5 days task force if Needed

In 1990, the Massachusetts Secretary of Environmental Affairs formed Warning NO YES Accelerate Data Level Confirmation the Outfall Monitoring Task Force (OMTF) to advise the MWRA. The Exceeded? OMTF, composed of scientists and representatives from government agencies and regional environmental groups, guides MWRA’s monitoring program. The Task Force directed MWRA to monitor in four general 30 days OMSAP Confirms Caution OMSAP Confirms Warning areas: effluent, water column, sediment, and living resources. The Level Exceedance Level Exceedance OMTF meets regularly to review MWRA’s findings and approves

changes in monitoring annually based on new scientific information. MWRA Develops The Task Force also sets priorities regarding the environmental issues Response Plan and questions MWRA should address with its monitoring program. 90 days Caution Level Exceedance OMTF meetings are open to the public. Reported in Quarterly Exceedance and Response Wastewater Performance Report Plan Reported in Quarterly Wastewater Performance Report

Evaluations Actions and Follow-up 180 days Reported in Quarterly Wastewater Performance Report endnotes references

endnotes for Table 2 endangering the health of ten Brink, and F.T. Man- • Coats, D. A. 1995. 1994 82 pp. people who eat the seafood. heim, 199X, Metal concen- Annual soft-bottom benthic 1 Maximum value measured trations in surface sedi- monitoring: Massachusetts • Hydroqual, Inc. and Norman- during Deer Island detailed 5 Water quality criteria for ments of Boston Bay outfall studies. MWRA deau Associates, Inc. 1995. effluent studies (Butler et al. copper, mercury and lead Harbor–changes with time. Enviro. Quality Dept. Tech A water quality model for 1997), except for total are EPA chronic criteria. Marine Environmental Rpt. Series No. 95-20. Massachusetts and Cape PCBs, which are average Water quality criteria for Research, in press. MWRA, Boston MA. 184 Cod Bays: calibration of the values. DDTs, PAH and PCBs are pp. Bays Eutrophication Model human health criteria. 2 Secondary effluent from • Bothner, M. H., M. Buchholtz (BEM). MWRA Enviro. Deer Island pilot secondary 6 The criterion for fluoran- ten Brink, C. M. Parmenter, • Galya, D. P. , J. Bleiler, and Quality Dept. Tech. Rpt. plant. thene is given because W. M. d’Angelo, and M. W. K. Hickey. 1997. Outfall Series No. 95-8. MWRA, there is no established crite- Doughten. 1993. The distri- monitoring overview report Boston MA. 402 pp. 3 After appropriate dilution rion for total PAH. bution of silver and other 1995. MWRA Enviro. Qual- factor (80:1 for copper, lead metals in sediments from ity Dept. Tech Rpt. Series • Hull, R. N. and G. W. Suter. and mercury available in 7 Comparing PCBs in effluent Massachusetts and Cape No. 97-2. MWRA, Boston 1995. Toxicological bench- area nearest diffuser, after to the water quality criterion Cod Bays-—an interim MA. 48 pp. marks for screening conta- initial mixing. Dilution factor is problematic because compilation. U.S. Geologi- minants of potential concern is 364:1 for DDTs, PAH, and ambient levels in all Massa- cal Survey. Open file report • Hilbig, B., J. A. Blake, E. for effects on sediment- PCBs, available in the out- chusetts waters already vio- 26 93-725. Butler, D. C. Rhoads, G. associated biota: 1994 revi- fall nearfield area.) late the human health stan- Wallace, and I. P. Williams. sion. Oak Ridge National dard. 4 EPA determines three cate- • Bousfield, E.L. 1973. Shal- 1996. Benthic biology and Laboratory Report gories of receiving water low-water Gammaridean sedimentology: 1995 base- ES/ER/TM-95/RI. 28 pp. quality criteria: acute, Amphipoda of New Eng- line conditions in Massa- references chronic, and human health. land. Cornell Univ. Press, chusetts and Cape Cod • Long, E. R. and L. G. Mor- Different criteria are applied • Anderson, D. M., B. A. Ithaca and London. 321 pp. Bays. MWRA Enviro. Qual- gan. 1990. The potential for to different types of dis- Keafer, and J. T. Turner. ity Dept. Tech. Rpt. Series biological effects of sedi- charges. Acute criteria are 1997. ‘Red tides’ in Massa- •Butler, E., M. Higgins, J. Chi- No. 96-5. MWRA, Boston ment absorbed contami- applied to small areas or chusetts Bay: Nearshore apella, and W. Sung. 1997. MA. 230 pp. nants tested in the National brief discharges, and specify processes and transfer of Deer Island effluent charac- Status and Trends Program. the maximum concentration toxins through the pelagic terization studies: January • Hilbig, B., J. A. Blake, D. C. NOAA. Technical Memoran- of a constituent an organism food web. Report to MWRA. 1995-December 1995. Rhoads, and I. P. Williams. dum NOS OMA 52. U. S. can be safely exposed to for MWRA Enviro. Quality 1996. Boston Harbor soft- National Oceanic and a short duration. Chronic cri- •Bitton, Gabriel. 1994. Waste- Dept. Tech Rpt. Series No. bottom benthic monitoring Atmospheric Administration, teria are applied to large water microbiology.Wiley- 97-3. MWRA, Boston MA. program: 1995 results. Seattle, Washington. 175 areas or long-term dis- Liss, Inc. New York. 478 91 pp. MWRA Enviro. Quality pp. charges and specify the pp. Dept. Tech. Rpt. Series No. maximum concentration of a • Cibik, S.J., B. L. Howes, C. 96-8. MWRA, Boston MA. • Long, E. R., D. D. MacDon- constituent that an organism • Bothner, M. H., 1997, Metal D. Taylor, D. M. Anderson, 94 pp. ald, S. L. Smith, F. D. can be safely exposed to for concentrations in sediments C. S. Davis, and T. C. Loder Calder. 1995. Incidence of a long period of time. of Boston Harbor document III. 1996. 1995 Annual water • Hillman, R.E. and C.S. adverse biological effects Human health criteria reflect environmental change. column monitoring report. Peven. 1995. 1994 annual within ranges of chemical the concentration of a con- USGS Fact Sheet, 97-xxx, MWRA Enviro. Quality fish and shellfish report. concentrations in marine stituent that fish and shell- 2p. in press. Dept. Tech Rpt. Series No. MWRA Enviro. Quality and estuarine sediments. fish can live in without • Bothner, M. H., M. Buchholtz 96-7. MWRA, Boston MA. Dept. Tech. Rpt. Series No. Environmental Manage- 241 pp. 95-5. MWRA, Boston, MA. ment. 19 (1):81-97. • Massachusetts Bays Pro- • Mitchell, D. F., T. Mounce, J. Science Center Reference from Boston Harbor, Salem • USEPA.1989. Assessing gram,1996. The Massachu- Morton, K. Sullivan, M. Document 92-05. 87 pp. Harbor, and coastal Massa- human health risks from setts Bays 1996 Compre- Moore, and P. Downey. chusetts. EOEA and MA chemically contaminated hensive Conservation and 1996. 1995 Annual fish and • National Marine Fisheries DFWELE. fish and shellfish. EPA Doc- Management Plan: an shellfish report. MWRA Service. 1995. Marine ument No. EPA-503/8-89- Evolving Plan for Action. Enviro. Quality Dept. Tech Mammal Investigation. An • Schwartz, J.P., N.M. Duston, 002. Office of Marine and Mass. Executive Office of Rpt. Series No. 96-3. independent scientific peer and C.A. Batdorf. 1991. Estuarine Protection (WH- Environmental Affairs, MWRA, Boston MA. 112 review of North Atlantic PCBs in winter flounder, 556F) and the Office of Boston, MA. pp. right whale research sup- American lobster, and Water Regulations and ported by the Northeast bivalve molluscs from Standards (WH-552). • Massachusetts Water • Mitchell, D. F., M. Wade, W. Fisheries Science Center: A Boston Harbor, Salem Har- Washington, DC. Resources Authority. 1991. Sung, and M. Moore. 1997. workshop held in Woods bor, and coastal Massachu- Effluent outfall monitoring 1996 Toxics issues review. Hole, Massachusetts, Octo- setts: 1984-1989. EOEA plan phase I: baseline stud- MWRA Enviro. Quality ber 3-7, 1994. Woods Hole and MA DFWELE Publica- ies. MWRA Enviro. Quality Dept. Tech Rpt. Series No. MA: NOAA/NMFS/NEFSC. tion 16, 966-63-250-W-91- Miscellaneous Rpt. Series 97-4. MWRA, Boston MA. Center Ref. Doc. 95-01. 30 C.R. No. ms-2. MWRA, Boston 134 pp. pp.

MA. 95 pp. • Shea, D. 1993. Annual 27 • Murchelano, R. A. and R. E. • National Research Council. review of toxic contami- • Massachusetts Water Wolke. 1985. Epizootic car- 1993. Managing waste- nants discharged by Resources Authority. 1995. cinoma in winter flounder water in coastal urban MWRA. MWRA Enviro. Effluent outfall monitoring Pseudopleuronectes ameri- areas. National Academy of Quality Dept. Tech Rpt. plan phase II: post dis- canus. Science 228:587- Sciences, National Acad- Series No. 93-18. MWRA, charge monitoring (draft). 589. emy Press, Washington Boston MA. 68 pp. MWRA Enviro. Quality Draft D.C. 11/95. MWRA, Boston MA. • National Marine Fisheries • Shea, D. 1995. Multimedia Service. 1991. Recovery • Pawlowski, C., K.E. Keay, E. fate model of organic conta- • Massachusetts Water plan for the northern right Graham, D.I. Taylor, A.C. minants in Massachusetts Resources Authority. 1997. whale (Eubalena glacialis). Rex and M.S. Connor. Bay. MWRA Enviro. Quality Contingency Plan. February Prepared by the Right 1996. The State of Boston Dept. Tech Rpt. Series No. 1997. 41 pp. Whale Recovery Team for Harbor 1995: The new 95-18. MWRA, Boston MA. the National Marine Fish- treatment plant makes its 15 pp. • Mayo, Charles. 1997. Food eries Service, Silver Spring, mark. MWRA Enviro. Qual- resources and foraging MD. 86 pp. ity Dept. Tech Rpt. Series • Signell, R. P., H. L. Jenter, imperatives of the northern No. 96-6. MWRA, Boston and A. F. Blumberg. 1996. right whale Eubalaena • National Marine Fisheries MA. 22 pp. Circulation and effluent dilu- glacialis in Massachusetts Service. 1992. Marine tion modeling in Massachu- and Cape Cod Bays. Mammal Investigation. The • Schwartz, J.P., N.M. Duston, setts Bay: model implemen- Abstract in Conference right whale in the western and C.A. Batdorf. 1993. tation, verification and Proceedings vol 1, Coastal North Atlantic: A science Metal concentrations in win- results. U. S. Geological Zone ‘97. and management work- ter flounder, American lob- Survey Open File Report shop. Northeast Fisheries ster, and bivalve molluscs 96-015. internet web sites

EPA Region 1 data1/SEDIMENTS/hathaway/readm Save the Harbor / Save the Bay mwra http://www.epa.gov/region01/ e. http://www.tiac.net/users/shsb/index.h National Marine Fisheries Service - North- Information about the MWRA 1st.htm tml east Regional Office, Gloucester MA http://www.mwra.state.ma.us http://www.wh.whoi.edu/ro/doc/nero USGS Contaminant Transport Studies .html in Massachusetts Bay state and federal http://crusty.er.usgs.gov/ education USGS Woods Hole Field Center mbay/mbay.html Mass. Division of Marine Fisheries http://woodshole.er.usgs.gov/ References, documents, and data pertain- USGS Stellwagen Bank Information ing to the Mass. Bay ecosystem. http://www.magnet.state.ma.us/ Boston Harbor - Mass. Bay Ecosystems System http://massbay.mit.edu/ dfwele/dmf/dmf_toc.htm - Sediment Bibliography http://vineyard.er.usgs.gov/ Mass. Executive Office of Environmental http://coast-enviro.er.usgs.gov/ MIT Mass Bay research bibliography Affairs (EOEA) MassBib/default.htm Northeast Fisheries Science Center - http://opal-www.unh.edu/edims.html Woods Hole http://www.magnet.state.ma.us/envir/ Boston Harbor Ecosystems - USGS, Digital Orthophotos of Boston Harbor and http://www.wh.whoi.edu/noaa.html eoea.htm New England Aquarium surrounding area - MASS GIS, MIT Departments within EOEA http://coast- http://ortho.mit.edu/ enviro.er.usgs.gov/boseco/ 28 (DEM, DEP, DFWELE, DFA, MDC) advocacy groups Gulf of Maine Council on the Marine Envi- http://www.magnet.state.ma.us/en Coastal Ocean Modeling at the USGS ronment - Environmental Data vir/ The Boston Harbor Association Woods Hole Field Center and Information Management System depts.htm http://www.tbha.org/ http://crusty.er.usgs.gov/ (EDIMS) Northern right whale information A Geologic Map of the Sea Floor in Center for Coastal Studies, Provincetown http://massbay.mit.edu/bibliography.h http://www.magnet.state.ma.us/en Western Massachusetts Bay, MA tml vir/ Constructed from Digital Sidescan- http://www.provincetown.com/coast New England Aquarium rtwhale.htm Sonar Images, Photography, alstudies/index.html http://www.neaq.org/ and Sediment Samples Program Offices of EOEA (MCZM, Charles River Watershed Association http://woodshole.er.usgs.gov/ MEPA, DCS, OTA, MassGIS, STEP) http://www.crwa.org/ Cetacean Research Unit - research, edu- http://www.magnet.state.ma.us/en data1/CDROMS/massbay.dds3/ cation, conservation vir/ massbay.html Merrimack River Watershed Association http://www.friendly.net:80/ units.htm Gulf of Maine Information System http://www.merrimack.org/ user-homepages/b/birdman/ http://oracle.er.usgs.gov/GoMaine/ MDC beach water quality National Resources Defense Council: http://www.magnet.state.ma.us/mdc/ Gulf of Maine Red Tides Testing the Waters 1997 - How other organizations harbor.htm http://crusty.er.usgs.gov/ does your vacation beach rate? wgulf/wgulf.html http://www.nrdc.org/nrdcpro/ttw/ New England Water Environment Associ- MDC guide to Boston area reservations, summas.html ation (NEWEA) including coastal and Harbor island sites. Ocean engineer Marinna Martini’s web http://www.newea.org/ http://www.magnet.state.ma.us/mdc/ page on oceanography tools. Neponset River Watershed Association reserv.htm http://marine.usgs.gov/ http://www.walpole.ma.us/nepon- Northeast Business Environmental Net- ~mmartini/instment/tools.htm set.htm work (NBEN) Boston Harbor Islands National Recre- http://nben.org/index.html ation Area USGS Branch of Atlantic Marine Geol- Safer Waters In Massachusetts, Inc. http://www.nps.gov/boha/ ogy, Sediment Database http://www.nahant.org/swim/html http://woodshole.er.usgs.gov/ massachusetts water resources authority

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