This article argues in favor of stricter regulation to the wash
water resulting from the Exhaust Gas Cleaning System aboard
ships. These systems are also known as scrubbers. The
International Maritime Organization (IMO) has required the
shipping industry to reduce the fuel oil sulfur limit to 0.5%, and
in emission control areas to 0.1%. To achieve this reduction, ship
owners use scrubbers to comply with this regulation, which
essentially cleans the fuel. However, the current legal framework
of scrubber wash water lacks certainty due to two reasons. The
first reason is uncertainty in the law, because it is not clear from
the IMO Guidelines whether scrubber wash water is considered
as pollution by vessel operation under MARPOL or pollution by
dumping under the London Convention. The second reason is
uncertainty in science. It is also not clear whether the current
levels of materials allowed to be discharged in scrubber wash
water are harmful to the environment. This is demonstrated in
contradictory scientific reports submitted to the IMO.
This article attempts to answer two interrelated questions.
First, how does the law deal with legal uncertainty? Second, how
does the law deal with the questions related to scientific
uncertainty? Hence, this article is divided into four main parts.
The first part presents the legal problems raised regarding
scrubber wash water. This includes uncertainty in the law,
uncertainty in science, and how they overlap. The second part
tackles the solution for uncertainty in the law. It resorts to the
general rules of marine pollution and argues that pollution by
dumping is the applicable regime. The third part presents a
solution for the uncertainty in science from the legal perspective,
which includes both policy and judicial solutions. For the policy
solution, this article argues in favor of adopting the precautionary
principle. As for the judicial solution, this article adopts guidance
from a case decided by the International Court of Justice to set
the borders between law and science. This article concludes by
presenting a hypothesis for addressing the uncertainty in the law
and uncertainty in science surrounding the issue of scrubber wash
water and whether it is harmful to the environment.