On September 6, 2000 a 9.5-mile outfall began discharging
Greater Boston's treated wastewater (effluent) into Massachusetts
Bay instead of Boston Harbor. When Deer Island Treatment Plant
(DITP) discharges to the harbor ended, dramatic changes occurred
near the former harbor outfalls--reductions in bacteria
and ammonium concentrations,
and improvements in water clarity.
Data gathered on the quality of sediments, water,
and sea life in Boston Harbor and Massachusetts Bay show that
the Massachusetts Bay outfall has been functioning as anticipated-providing
rapid dilution to the effluent-with no significant adverse
impacts. Harbor data show even further improvements as nutrients
decrease to levels more typical of a natural estuary.
on Boston Harbor
SAMPLING SITES THROUGHOUT MASSACHUSETTS
has set up nearfield and farfield
monitoring stations. The nearfield stations are within about
3 miles of the outfall diffuser, to monitor any changes
occurring near the discharge. The farfield stations are
in Boston Harbor, Massachusetts Bay, Cape Cod Bay, and the
Stellwagen Bank National Marine Sanctuary to assess any
changes that may be occurring farther away from the discharge.
MWRA's discharge permit for the bay outfall has
strict monitoring requirements designed to identify unexpected
impacts from operation of the outfall. There is little doubt
that the Boston
Harbor Project benefits the marine environment and the
people of the region, but moving the effluent outfall from the
harbor to Massachusetts Bay caused some concern. To address
these concerns, MWRA implemented an extensive monitoring program
to measure the health of the bay.
Monitoring is managed by MWRA staff and carried
out by consultant, universities, and government agencies. The
bay's water, plankton, sediment, and fish and shellfish are
studied to understand how the ecosystem functions, and to measure
environmental effects of MWRA pollution abatement projects.
To ensure that the bay monitoring is carried out
in a scientifically defensible manner, an independent panel
of scientists, The Outfall Monitoring Science Advisory Panel
(OMSAP), reviews monitoring data and provides advice on scientific
issues related to the discharge permit and related monitoring.
OMSAPs web page).
MWRA's goals for Boston Harbor and Massachusetts
Bay are based on concerns expressed by the public during the
planning of the Boston Harbor Project. These goals include clean
beaches, healthy marine resources, seafood safe for eating,
and protection of the natural beauty of the harbor and the bay.
on Massachusetts Bay