Delft University of Technology
Faculty Mechanical, Maritime and Materials Engineering
Transport Technology

M.J. van Wijngaarden Mors op het oppervlaktewater. Een model ter beoordeling van de effectiviteit van morsmaatregelen
Masters thesis, Report 2006.TL.7100, Transport Engineering and Logistics.

During the handling of bulk solid materials, some material is spilled. This material ends up in the air, the bottom or the water. This emission can be harmful for the environment. Rijkswaterstaat and the stevedore OVET B.V. recently entered into a discussion about the amount of bulk solid material that may fall into the surface water during handling. These discussion results into the foundation of a project group, with Rijkswaterstaat, 12 stevedores, TU Delft and some other companies. One of the tasks of this group is to develop a tool that assesses the effectiveness of emission measures based on spillage reduction and costs.

This report presents a tool to assess the effectiveness of emission measures, especially for the direct emission of bulk solid material into the surface water. This tool can be used by Rijkswaterstaat and the stevedores. For the realization of this model it is necessary to answer the next questions: To answer these questions investigation was done. Legislation about emission was studied and also the emission of dust particles into the air was investigated. Risk assessment models were investigated and a new risk assessment model was developed. As a case û study the spillage problem of OVET B.V. was analyzed with this tool.

All the European emission legislation should be based on the council directive 96/61/EC concerning integrated pollution prevention and control (IPPC directive). This directive prescribes that all the emission control measures should be based on the best available techniques. It also says that every permit should include emission limit values. At the moment this is not the case.

From the analysis of various risk assessment models it is shown that a firm model should contain risk estimation as well as risk evaluation. In the case of the spillage model the estimation deals with the amount and the harmfulness of the spillage. To give this an expression, the term "spillage impact" is introduced. This term makes clear how much spillage takes place somewhere and it makes clear, how harmful the spillage is.

There are two problems in practice. At first in most cases the amount of spillage is not exactly known. Rough estimations suggests that, depending on the type of bulk solid material, 0,1 to 0,001 mass percent of the grab volume falls from a grab into the surface water during a grab cycle. Secondly the harmfulness of bulk solid materials into the surface water is not known. The problem is that the harmfulness of some elements, like metals, is known, but harmfulness of bulk solid material itself is not.

The evaluation part of the model should answer the question why a measure should be taken or not. To answer this question, it is important to determine a reasonableness criterion. This criterion makes clear if it is reasonable to take a measure or not. According to the IPPC directive the best available techniques should be used. To determine if a measure is reasonable the costs and effectiveness are important. In the model the costs and effectiveness are put together into the cost effectiveness methodology to help to make the decision.

To be able to use the model the following should be determined: The amount of spillage should be measured by collecting the material from the pontoon. The harmfulness of bulk solid materials should be determined by analyzing the material. The costs and effectiveness of various measures should be gathered by the stevedores.

Reports on Transport Engineering and Logistics (in Dutch)
Modified: 2006.12.06; , TU Delft / 3mE / TT / LT.