Environmental Engineering Reference
In-Depth Information
for improved bilge water separations. A primary reason for this lack of interest by the
scientiic community is that, from a practical point of view, there is little incentive to
develop new technology. Bilge water is most often discharged in international waters
where enforcement and monitoring is typically nonexistent. Naval ships have sovereign
immunity from environmental regulations and thus do not have to comply with MARPOL
standards. Special areas with higher regulatory standards do exist in ports and environ-
mentally sensitive bodies of water; however, shipboard bilge water storage capacity is gen-
erally suficient to allow for temporary holding and eventual discharge once a vessel is
back in the open ocean or at dock. Another dificulty for research and development activ-
ity is the lack of bilge water samples or standardized protocols to allow for measurements.
To date, there has not been a comprehensive study of bilge water composition, leaving an
extensive void in the general understanding of these waste streams. The constant move-
ment of ships in the open ocean makes such studies logistically dificult. Lack of samples
is compounded by the fact that there is little interest by the shipping industry to conduct
these investigations.
However, there are factors that may help spur high-technology development in the area
of bilge water management. The irst is the growing size of the shipping industry and
the number of vessels being deployed worldwide. Larger and more numerous ships lead
to larger total discharges, and thus increased scrutiny of environmental impact. Cruise
ship operators garner the most attention because of their greater visibility by the general
public and operation in scenic regions. Fines have been assessed against cruise ship opera-
tors stemming from observed discharges. In one of the largest incidents, in 2002, Carnival
Corp. pleaded guilty to six felony counts related to oily discharges in the Caribbean and
seas off Florida between July 1998 and January 2001. The company paid $US 18 million in
ines and agreed to establish an environmental compliance department.
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Such incidents
led to advocacy groups petitioning the US Environmental Protection Agency (EPA) Region
9 to established a No Discharge Zone off the coast of California.
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Beginning in March
2012, all large vessels of 300 gross tons or greater are prohibited from discharging any
water into navigable waters within 3 miles from shore. These relatively small, yet extreme,
measures may be indicative of future regulatory steps taken by governments and inter-
national agencies. Impetus for new technology will increase if a large to mid-size navy
or shipping company creates a goal of improved bilge water discharge for the purposes
of environmental stewardship. The US armed forces are moving in such a direction. The
National Defense Authorization Act of 1996 amended Section 312 of the Federal Water
Pollution Control Act requiring the US Secretary of Defense and the Administrator of
the EPA to develop uniform national discharge standards for vessels. Only Phase I of III
has been completed to date. Phase I, established in 1999, identiied and characterized 39
discharges (new 40 CFR part 1700), 25 needing control. The Phase I rule determines the
type of vessel discharges that require control by marine pollution control devices, which
include surface bilge water-oil water separator discharge. Phase II, establishing standards
for discharges is still undergoing review. Phase III, implementing technology to meet stan-
dards, lies in the future. If seagoing organizations and naval forces insisted on improved
bilge water management, the market would be in excess of a $US 1 billion annually offer-
ing incentives to academic and industrial researchers.
Nanotechnological developments have occurred tangentially via the goal of improved
separation methods for the petroleum industry where oil-water separation is an impor-
tant process. In many respects, treatment of bilge water has much in common with treat-
ment of produced water, which may help drive innovations. Of the technologies reported
within this review, physical separators represent the only technology that is widely
