Ivar Singsaas

Species sensitivity distributions for suspended clays, sediment burial, and grain size change in the marine environment

Assessment of the environmental risk of discharges, containing both chemicals and suspended solids (e.g., drilling discharges to the marine environment), requires an evaluation of the effects of both toxic and nontoxic pollutants. To date, a structured evaluation scheme that can be used for prognostic risk assessments for nontoxic stress is lacking. In the present study we challenge this lack of information by the development of marine species sensitivity distributions (SSDs) for three nontoxic stressors: suspended clays, burial by sediment, and change in sediment grain size. Through a literature study, effect levels were obtained for suspended clays, as well as for burial of biota. Information on the species preference range for median grain size was used to assess the sensitivity of marine species to changes in grain size. The 50% hazardous concentrations (HC50) for suspended barite and bentonite based on 50% effect concentrations (EC50s) were 3,010 and 1,830 mg/L, respectively. For burial the 50% hazardous level (HL50) was 5.4 cm. For change in median grain size, two SSDs were constructed; one for reducing and one for increasing the median grain size. The HL50 for reducing the median grain size was 17.8 mum. For increasing the median grain size this value was 305 mum. The SSDs have been constructed by using information related to offshore oil- and gas-related activities. Nevertheless, the results of the present study may have broader implications. The hypothesis of the present study is that the SSD methodology developed for the evaluation of toxic stress can also be applied to evaluate nontoxic stressors, facilitating the incorporation of nontoxic stressors in prognostic risk assessment tools.

WEATHERING AND DISPERSION OF NAPHTHENIC, ASPHALTENIC, AND WAXY CRUDE OILS

ABSTRACT The chemical composition and physical properties of a crude oil determine the behavior of the oil and the way its properties will change when the oil is spilled at sea. Reliable knowledge ...

Experiences in Dispersant Treatment of Experimental Oil Spills

Abstract In Norway, mechanical recovery has traditionally been the preferred oil spill response technique for the past decades. More recently, the Norwegian Pollution Control Authority (SFT) has opened the door to the consideration of dispersant use in certain oil spill situations. The responsibility for planning and decision for use/non-use of dispersants lies with the oil industry/enterprise itself; their decisions are subject to review and approval by SFT. This is in accordance with the “Principle of Internal Control” on what the Authorities focuses their regulations. The new regulations for use of dispersants in Norway requires well-documented contingency plans for refineries, oil terminals and offshore installations. This change in the attitude to the use of dispersants in Norway is a result of the recent years’ progress in scientific documentation of dispersant use. Previous paper (Spill Science & Technology Bulletin 5(1) 1999 63) gives an overview of the methodologies developed for oil weathering and dispersibility studies in the laboratory forming the basis for the development of the SINTEF Oil Weathering Model, which has been extensively validated in the field. This paper gives a summary of the main findings from recent years’ dispersant field trials in the North Sea. This work forms a basis for building up an operational and effective dispersant response for specific Norwegian coastal and offshore locations/regions. Data generated from the experimental field trials have been invaluable for validation and development of numerical models for fate and response assessment of oil spills. Examples in using the quantitative model tool “Oil Spill Contingency and Response” (OSCAR) in contingency planning and Net Environmental Benefit Analyses (NEBA) of oil spill scenarios are given.

MODELING THE WATER-ACCOMMODATED FRACTION IN OSCAR2000

ABSTRACT Oil Spill Contingency and Response 2000 (OSCAR2000) is a multicomponent 3-dimensional oil spill contingency and response model tool for analysis of alternative response strategies. The mod...

Experiments at Sea with Herders and In Situ Burning (HISB)

ABSTRACT A series of experiments involving herders and ISB (designated HISB) were conducted at sea on 14th – 15th June 2016, near the Frigg Field in the North Sea. The primary objective of the expe...

Joint Industry Program on Oil Spill in Arctic and Ice Infested Waters: An Overview

SINTEF has on behalf of the oil companies Shell, Chevron, Statoil, Total and ConocoPhillips performed a pre-project for development of a R&D program for oil spill response in ice-infested and Arctic waters. AGIP KCO joined the program in 2006. The objective of the pre-project has been to propose objectives, scope of work and participants for a Joint Industry Program to develop tools and technologies for environmental beneficial oil spill response strategies in ice-infested waters. The main tasks in the pre-project have been: Preparation of a state-of-the-art report to give an overview of the R&D status within this field and form a basis for identification of future research needs as input to the JIP. Preparation of Joint Industry Program (JIP) proposal.

Deepwater Blowouts: Modeling for Oil Spill Contingency Planning, Monitoring, and Response

ABSTRACT This paper describes work in progress in the Environmental Engineering Division of SINTEFs Applied Chemistry Institute in Trondheim, Norway. The modeling work relies heavily on past and p...