Regulatory Framework
3.13 Environmental Risk Evaluation Criteria
In addition to fulfilling requirements on individual and societal risk to people, ac- tivities that introduce additional risks to the environment need to meet acceptance
criteria for environmental risk as well. Damage to the environment can be expressed at different levels such as organism level, population level, habitat level complete ecosystem level, or global level (as for CO2) and several environmental compo- nents can be damaged. Environmental risk assessment is about making estimates of harm to plant and animal life and to the ecosystem integrity that can later be com- pared to previously agreed risk acceptance criteria. However, due to practicality, environmental risk analysis for a complete ecosystem is normally not performed, in particular not to decide on an RCO to be implemented on a ship, which in general is allowed to trade globally. The risk is rather assessed for vulnerable single compo- nents within the environment, e.g. stock of specific species or habitats. These serve as risk indicators and this is normally considered to be sufficient in order to estimate the environmental risk.
In a report published by GESAMP in 2001 it was made clear that the major threats to the marine environment came from activities on land. In comparison, the environmental pressure on the oceans due to shipping was believed to have de- creased over the past decade. Nevertheless, the environmental risk stemming from shipping activities should not be trivialized, and the following sections of this chap- ter will discuss issues related to environmental risk and shipping.
Environmental impacts from shipping activities may be caused by regular (both legal and illegal) and accidental releases. The regular releases (of e.g. CO2,NOX, sewage or garbage) are not considered here in a risk context, as the estimation of quantities of regular releases may be done without involving the use of risk assess- ment, and the estimation of consequence is no different from releases from other sources. Risk assessment for regular releases is only relevant if the system is not defined as the ship, and the analysis go into analysing short and long term effects on the environment, habitat, biodiversity etc. For accidental releases, however, risk assessment is as relevant as for accidents threatening safety of crew and passen- ger. Figure 3.12 illustrates the most important emissions and discharges from tanker ships in operation.
At IMO there has so far not been any application of FSA for environmental con- sequences. Therefore there has not been any detailed discussion on environmental risk criteria based on real analysis.
Early on there were some debate in the Joint MSC MEPC working group on FSA on environmental risk criteria and it seems that the tendency has been to favour the use of some cost effectiveness criteria for the risk control options that are con- sidered. For oil-spills this would imply that the criterion would be for example a
$/tonnes of accidental release of oil (and other pollutants) prevented. Information could be the cleanup and compensation costs from spills in the past, or it could be based on willingness to pay studies. Both methods were suggested in Mathiesen and Skjong (1996).
An example of willingness to pay for preventive measures may be identified by studying the cost and benefits of OPA 90 and other risk control options that have been implemented in the past. For OPA 90 this has been done by US Coastguard, (Speares 1991). The total costs has been estimated to $11 billion and the reduction
Fig. 3.12 Emissions and discharges from ships in service (tankers)
of accidental release was estimated to 1.2 million barrels, 9,167 $/barrel or about 57,660 $/tonnes.
Based on a review of cleanup costs, estimates of environmental damages, and ap- plying an insurance factors of 1.5 (reflecting the willingness to pay more for preven- tion than paying for the cleanup and living with the environmental consequences), Skjong et al. (2005) proposed a Cost of Averting a Tonne of oil Spill (CATS) of
$60.000.
Of this the average cost of cleanup is $16.000, the average environmental costs is $24.000 based on review of available literature. The sum is thus $40.000. With an insurance factor of 1.5 (from insurance statistics), this results in a CATS of $60.000.
This is close to the willingness to pay in line with OPA90.
The debate on which criteria to use has not come yet to a conclusion. However, there are already a number of FSAs that have used the suggested CATS value. The debate seems now to go in two different directions, complicating the use of one single CATS number to multiple values, namely:
• Dependent on spill size
• Dependent on accident type (grounding, collision etc.)
• A combination
At time of writing this section, it is not clear what will be the end result.
Societal risk acceptance of environmental damages from shipping is not yet pro- posed. And, to effectively apply a cost-effectiveness criterion related to environmen- tal protection, societal risk acceptance and the associated ALARP area need to be defined. Risk evaluation criteria related to the protection of the environment are not
yet agreed at IMO. Thus, no proposal concerning the acceptability of the societal risk of environmental damages from oil transport by tankers exists.
McGregor (2007) suggested an ALARP region for oil spills of tankers based on information from US pipeline requirements. He presented an ALARP area using historical data relating to oil spills of AFRAMAX tankers. His assessment is based on a consequence function which is linearly dependent on oil spill size, thus, view- ing large spills as relatively less important. This is based on the recommendation from the US Marine Board (2001) which indicated that the relationship between spill size and environmental consequence is nonlinear. Introducing the relationship of consequences and oil spill size (C=1 equals 1892 m3of oil), McGregor pre- sented his proposal using oil outflow as parameter and the newly proposed criterion has a much gentler slope than the usual slope of -1. This reflects the opinion that large spills are relatively less severe than smaller spills.
Sames and Hamann (2008) explored how an ALARP area could be fitted to existing oil-spill data under the assumption that current maritime oil transport by tankers – defined by 1990–2006 data – is JUST acceptable and cost-effective risk control options should be implemented. By fitting the ALARP boundaries to larger spills, spills smaller than 20 tonnes are considered negligible, i.e., no design or rule changes should be targeting these spills. The second approach considered ratio of CAF and CATS is used to translate the ALARP boundaries for oil tankers from the FN-diagram. The resulting ALARP boundaries render maritime oil transport ef- fectively unacceptable as spills larger than 1000 tonnes are in the intolerable area.
Only by introducing a spill-size dependent value of CATS, this second approach was shown to deliver a meaningful result. They concluded that that the presently avail- able historic data are not sufficient to evaluate the environmental risk of oil tankers or to demonstrate the appropriateness of the proposed ALARP area.