Learnings from the Texas Nearshore Dispersant Demonstration Project

2003 ◽  
Vol 2003 (1) ◽  
pp. 341-345
Author(s):  
Don Aurand ◽  
James Clark ◽  
Robin Jamail
Keyword(s):  
Water Column ◽  
Oil Spill ◽  
Mechanical Response ◽  
Demonstration Project ◽  
Net Benefit ◽  
Corpus Christi ◽  
Dispersed Oil ◽  
Trade Offs ◽  
Response Team ◽  
Training Exercises

ABSTRACT This project defines circumstances where a dispersant demonstration might be considered for an estuarine oil spill in Texas. In seeking approval for a spill of opportunity demonstration project, we developed criteria defining a viable dispersant response for consideration by the Region VI Regional Response Team. This paper presents the criteria and their rationale developed for Galveston Bay and Corpus Christi Bay, along with the results of recent training exercises. The criteria define the size and general location of an oil spill that might be considered appropriate for a trial dispersant application, and implementation of response and monitoring within a 2-hour window from notification. They are based on descriptions and characterizations of the habitats and species at risk in coastal areas, concentration and duration of dispersed oil plumes that might be generated in a response, potential impacts of these exposures, and the environmental trade-off between implementing mechanical response and a dispersant response. Because the dilution potential is constrained in shallow water environments, spill size has significant impact on the magnitude and duration of potential exposure regimes for water column organisms. Spills of 250 bbls or less pose minimal concern for water column communities with potential net benefit to other coastal resources. The trade-offs were not so obvious for larger spills. The exposure regimes and potential impacts for water-column organisms that would be maximally exposed during a dispersant operation were compared to the exposures and potential impacts for organisms and habitats exposed to floating oil and oil stranded on shorelines, at levels that could result during a mechanical recovery operation. These potential impacts are compared on a spatial and temporal basis, and with consideration for potential rates of recovery.

OIL SPILL CLEANUP WITH DISPERSANTS: A BOOMED OIL SPILL EXPERIMENT

1981 ◽  
Vol 1981 (1) ◽  
pp. 263-268
Author(s):  
Joseph Buckley ◽  
David Green ◽  
Blair Humphrey
Keyword(s):  
Water Column ◽  
Oil Spill ◽  
Oil Spills ◽  
Sea Water ◽  
Visual Observation ◽  
Oil Droplets ◽  
Oil Boom ◽  
Dispersed Oil ◽  
Vertical Density ◽  
Oil Spill Cleanup

ABSTRACT Three experimental oil spills of 200, 400, and 200 litres (l) were conducted in October, 1978, in a semiprotected coastal area on Canada's west coast. The surface slicks were restrained with a Bennett inshore oil boom. The spilled oil was chemically dispersed using Corexit 9527, applied as a 10-percent solution in sea water and sprayed from a boat. The dispersed oil was monitored fluorometrically for some hours. Surface and dispersed oil were sampled for chemical analysis. The highest recorded concentration of dispersed oil was 1 part per million (ppm). After a short time (30 minutes), concentrations around 0.05 ppm were normal, decreasing to background within 5 hours. The concentrations were low compared to those expected for complete dispersion which, as visual observation confirmed, was not achieved. The dispersed oil did not mix deeper into the water column with the passage of time, in contrast to predicted behaviour and in spite of the lack of a significant vertical density gradient in the sea water. This was attributed to the buoyancy of the dispersed oil droplets and the limited vertical turbulence in the coastal locale of the experiment. The integrated quantity of oil in the water column decreased more rapidly than either the mean oil concentration of the cloud or the maximum concentration indicating that some of the dispersed oil was rising back to the surface. The surfacing of dispersed oil was confirmed visually during the experiment. The mixing action of the spray boat and breaker boards apparently created large oil droplets that did not form a stable dispersion. Horizontal diffusion of the dispersed oil was initially more rapid than expected, but the rate of spreading did not increase with time as predicted. The results imply that the scale of diffusion was larger than the scale of turbulence which again can be attributed to the locale of the experiment.

scholarly journals Tropical Oil Pollution Investigations in Coastal Systems [TROPICS]: A 32-year Review of Response and Recovery

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
D. Abigail Renegar ◽  
Paul Schuler ◽  
Nicholas Turner ◽  
Richard Dodge ◽  
Anthony Knap ◽  
...  
Keyword(s):  
Crude Oil ◽  
Oil Spill ◽  
Field Experiments ◽  
Oil Pollution ◽  
Environmental Benefit ◽  
Coastal Systems ◽  
Dispersed Oil ◽  
Trade Offs ◽  
Nearshore Environments ◽  
Comparative Risk

ABSTRACT In 1984, the Tropical Oil Pollution Investigations in Coastal Systems (TROPICS) experiment began in Bahia Almirante on the Caribbean coast of Panama. This study sought to compare the impacts of a severe, but realistic spill of untreated crude oil versus chemically treated (dispersed) crude oil on tropical marine reef, sea-grass, and mangrove ecosystems. The aim of the study was to identify and evaluate the environmental trade-offs of dispersant use in tropical marine and subtidal systems. As a result of continuing research at the site, the study became one of the most comprehensive field experiments examining the long-term impacts of oil and dispersed oil exposures in nearshore tropical communities. Consequently, TROPICS has been the foundational and seminal field study which served as the historical antecedent for Net Environmental Benefit Analysis (NEBA), as well as the basis for follow-on Spill Impact Mitigation Analysis (SIMA) and Comparative Risk Analysis (CRA) for oil spill planning, preparation, and response. From the initial experiment in 1984, through three decades of study and data collection visits, the coral reef, seagrass, and mangrove communities have exhibited significantly different damage and recovery regimes, depending on whether the sites were exposed to non-treated crude oil or dispersed crude oil. While this study does not definitively determine whether or not dispersants should be applied in tropical nearshore environments, it is illustrative of the environmental and ecosystem trade-offs between surface oil impacts to the shoreline, compared to water column exposure from chemically dispersed oil. This paper provides an overview of the results and observations reported in numerous previous TROPICS publications, as a progression of damage and recovery over time. With this perspective, planners and responders can use this study to predict what damages/recoveries may be expected from an oil spill incident in this environment. The results of the TROPICS experiment are examined within the context of this recent parallel research from the perspective of ongoing implications for oil spill preparedness and response.

Application of In-Situ Burning During the Mosquito Bay Oil Spill: Observations and Trade-Off Discussion

2003 ◽  
Vol 2003 (1) ◽  
pp. 307-310
Author(s):  
Charlie Henry ◽  
Stephen Thumm ◽  
John Brolin ◽  
Patrick Cuty ◽  
Jacqueline Michel
Keyword(s):  
Oil Spill ◽  
Oil Recovery ◽  
Coastal Marsh ◽  
Final Decision ◽  
Manual Response ◽  
Trade Off ◽  
Trade Offs ◽  
Response Team ◽  
Unified Command

ABSTRACT On 11 April 2001, the Unified Command received permission from the Regional Response Team (RRT6) to conduct a series of in-situ burns at an oil spill site in a remote coastal marsh adjacent to Mosquito Bay, Louisiana. Approximately 12 acres of marsh were contaminated with an estimated 1000 bbl of condensate crude oil. Because the spill was largely contained in low areas of remote interior marsh, conventional oil recovery techniques and mitigation would have caused unacceptable physical marsh impact; therefore, in-situ burning was considered the most environmentally friendly approach to minimize impact from the spill. Overall, the application of in-situ burning was considered a positive environmental trade-off since any manual response in such a sensitive marsh would involve greater negative environmental trade-offs. This paper focuses on an overview of the incident and the scientific and environmental issues that were evaluated and presented to the Unified Command in making the final decision to use in-situ burning as a mitigation technique.

COMPARATIVE FATE OF CHEMICALLY DISPERSED AND UNTREATED OIL IN THE ARCTIC: BAFFIN ISLAND OIL SPILL STUDIES 1980–1983

1985 ◽  
Vol 1985 (1) ◽  
pp. 561-569
Author(s):  
Paul D. Boehm ◽  
William Steinhauer ◽  
Adolfo Requejo ◽  
Donald Cobb ◽  
Suzanne Duffy ◽  
...  
Keyword(s):  
Water Column ◽  
Oil Spill ◽  
Large Scale ◽  
The Arctic ◽  
Baffin Island ◽  
Dispersed Oil ◽  
Beach Sediments ◽  
Chemically Dispersed Oil ◽  
Deposit Feeding

ABSTRACT Two experimental oil spill studies designed to assess the comparative short and long term fates and effects of chemically dispersed and untreated nearshore discharges in the Arctic were undertaken as part of the Baffin Island Oil Spill (BIOS) Project. The fates of oil in the water column, in subtidal and beach sediments, and in five species of filter- and deposit-feeding animals were investigated. Analytical results indicate that the discharge of the chemically dispersed oil caused a large but short-lived chemical impact on the water column (up to 50 ppm), a significant initial bio accumulation of oil, and little sediment impact. In contrast, the untreated oil, allowed to beach, did not have a significant water column impact, but did result in a large scale landfall, continual long term erosion of oil off the beach, and increasing oil levels in subtidal sediments and deposit-feeding animals.

Fabrication of a Portable Large-Volume Water Sampling System To Support Oil Spill Nrda Efforts

1999 ◽  
Vol 1999 (1) ◽  
pp. 1179-1184 ◽  
Author(s):  
James R. Payne Payne ◽  
Timothy J. Reilly ◽  
Deborah P. French
Keyword(s):  
Water Column ◽  
Oil Spill ◽  
Water Samples ◽  
Detection Limits ◽  
Water Sampling ◽  
Sampling System ◽  
Oil Droplets ◽  
Early Stages ◽  
Dispersed Oil ◽  
Dissolved Components

ABSTRACT A field-portable water-sampling system was designed and fabricated for collecting adequate volumes of seawater to meet the quantitation requirements to support Natural Resource Damage Assessment (NRDA) toxicity determinations and modeling efforts following an oil spill. This system is a significant improvement to conventional water sampling equipment and includes the ability to filter water samples at the time of collection, thereby providing critical differentiation between truly dissolved constituents and dispersed oil droplets. The system can be quickly and easily deployed from shoreline structures (piers and breakwaters) and/or vessels of opportunity to provide essential data during the early stages of a spill. Likewise, data collected with the system can be used to document dispersant effectiveness and provide information relating to seafood exposure, tainting, and toxicity issues. In many oil-spill NRDA efforts, water-column effects from dissolved components and dispersed oil droplets have not been adequately quantified or documented because: (1) samples are not obtained early enough after the spill event; (2) insufficient volumes are collected; and (3) the wrong constituents are analyzed. Generally, EPA hazardous-materials sampling approaches are followed, leading to inadequate sample sizes (e.g., 40 mL for volatile component analyses and 1-L samples for dissolved/dispersed constituents). Analytically, EPA semivolatile gas chromatography/mass spectrometry (GC/MS) SW-846 Method 8270 is often specified for polynuclear aromatic hydrocarbons (PAH). These sample sizes are not large enough to meet the detection limits required for most marine hydrocarbon analyses (de Lappe et al., 1980; Payne, 1997 and references therein), and the EPA PAH target analyte list does not include the majority of alkyl-substituted one-, two-, and three-ring aromatics that are the primary dissolved constituents actually present in the water column following an oil spill (Sauer and Boehm, 1991). As a result, water column effects are often written off as being short-lived or insignificant. Alternatively, impacts are often assessed by computer modeling efforts with limited field validation. In either event, there is inadequate profiling of the extent and duration of petroleum hydrocarbon exposure to marine organisms. Furthermore, when adequate volumes of water have been collected and the proper target analytes have been specified, provisions have not been taken to differentiate between truly dissolved components and dispersed oil droplets. Consequently, later data analyses are unreliable in their ability to reflect conditions as they actually existed during the early stages of the spill. For example, PAH analyses of unfiltered water samples are confounded by the facts that: (1) a significant, but unknown fraction of discrete oil droplets in the water column will rise to the surface with time; (2) high levels of dispersed oil droplets will raise detection limits of dissolved PAH; and (3) it is impossible to determine how much of the PAH is in the truly dissolved state where it will persist as a toxic fraction to exposed organisms and how much is simply associated with slightly less toxic oil droplets that are subject to relatively rapid removal by resurfacing. The equipment and field implementation approach described in this paper can provide samples that are not subject to the aforementioned problems.

Fundamental Aspects of the Science and Engineering of Oil Spill Dispersant Systems: An Overview of Recent Research Activities of the Gulf of Mexico Research Initiative-funded CMEDS Project

2014 ◽  
Vol 2014 (1) ◽  
pp. 721-732
Author(s):  
Tom Coolbaugh ◽  
Vijay John ◽  
Keith Johnston ◽  
Kalliat T. Valsaraj ◽  
Alon McCormick ◽  
...  
Keyword(s):  
Water Column ◽  
Oil Spill ◽  
Deep Sea ◽  
High Pressures ◽  
Liquid Droplet ◽  
Research Effort ◽  
Science And Engineering ◽  
Oil Droplets ◽  
Research Activities ◽  
Dispersed Oil

ABSTRACT Upon consideration of dispersant-related research, both before and after the Macondo Well oil release, it can be divided into two general categories: (1) the fundamentals of how dispersants work and the effects that may result from their use (e.g., physicochemical and transport characteristics of drops, bubbles, hydrates, surfactants), and (2) an applied focus that has emphasized the design of new dispersants or an enhancement of the performance of those products that are currently available. While there is an extensive amount of data relating to dispersants, a main focus has been on the demonstration of their effectiveness in bench tests and examination of the toxicity of dispersants and dispersed oil. As a result, there is a need for an enhanced understanding of dispersant and dispersed oil thermodynamics and their fate and transport, with a goal to translate the science and engineering to the development of new, effective dispersant systems. The focus of the work to be discussed addresses the following areas: Formation of small oil droplets: Widely dispersed stable oil droplets in the water column are easily accessible to microbes and therefore highly susceptible to degradation. It is important therefore, to understand the fundamental mechanisms of oil breakup and colloidal stabilization in order to develop new and effective dispersants. Dispersant-related processes under deep sea conditions: Current dispersants have been developed for surface spills. The efficacy of such formulations when applied at the high pressures and low temperatures representative of deep ocean release has not been systematically studied. Because of concomitant gas release at the discharge point, and the pressures involved, the liquid droplet is essentially a gas-expanded liquid which could behave quite differently when treated with dispersant components depending upon how they partition at the phase interfaces, i.e., gas/water, gas/oil, oil/water. Fluid mechanics of stabilized oil droplets: Droplet transport, as influenced by all thermodynamic variables of relevance under deep sea conditions, is being studied. Droplet interactions with solid particulates: A better understanding of these processes, either in marine sediments or in the water column, will help predict the environmental fate of the droplets. Development of alternative dispersants: Based on the knowledge gained with respect to the fundamentals, a key goal is the systematic translation of that understanding to the development of new and improved materials. This paper summarizes recent work of a collaborative research effort involving investigators from 22 universities, with particular emphasis on increasing the understanding of the science and engineering of oil spill dispersants.

DISPERSED OIL TRANSPORT MODELING CALIBRATED BY FIELD-COLLECTED DATA MEASURING FLUORESCEIN DYE DISPERSION

2008 ◽  
Vol 2008 (1) ◽  
pp. 527-536 ◽  
Author(s):  
Deborah P. French-McCay ◽  
Christopher Mueller ◽  
James Payne ◽  
Eric Terrill ◽  
Mark Otero ◽  
...  
Keyword(s):  
Water Column ◽  
Oil Spill ◽  
Aerial Photography ◽  
Hf Radar ◽  
Transport Modeling ◽  
Surface Currents ◽  
Near Surface ◽  
Oil Transport ◽  
Dispersed Oil ◽  
Fluorescein Dye

ABSTRACT Oil-spill fate and transport modeling may be used to evaluate water column hydrocarbon concentrations, potential exposure to organisms, and impacts of oil spills with and without dispersant use. Important inputs to transport modeling for such analyses are current velocities and turbulent dispersion coefficients. Fluorescein dye studies off San Diego, California, were used to calibrate an oil transport model by hindcasting movement and dispersion of dye. The oil spill model was then used to predict subsurface hydrocarbon concentrations and potential water column impacts if oil were to be dispersed into the water column under similar conditions. Field-collected data included surface currents calculated from high-frequency radar data (HF-Radar), near-surface currents from drifter measurements drogued at several depths (1m, 2m, 4m or 5m), dye concentrations measured by fluorescence, spreading and dye intensity measurements based on aerial photography, and water density profiles from CTD casts. As the dye plume quickly extended throughout an upper mixed layer (7–15m), the horizontal dye movements were better indicated by the drifters drogued to a depth near the middle of that layer than the HF-Radar, which measured surface (∼top 50 cm) currents (including wind drift). Diffusion rates were estimated based on dye spreading measured by aerial photography and fluorescence-depth profiles. The model used these data as inputs, modeling of wind-forced surface water turbulence and drift as a function of wind speed and direction (based on published results of fluid dynamics studies), and Stokes law for droplet rise/sinking rates, to predict oil transport and dispersion rates within the water column. Use of such diffusion rate data in an oil fate model can provide estimates of likely dispersed oil concentrations under similar conditions, which may be used to evaluate potential impacts on water column biota. However, other conditions with different patterns of current shear (due to background currents, tidal currents, and wind stress) should be examined before these results can be generalized.

FIELD MEASUREMENTS OF FLUORESCEIN DYE DISPERSION TO INFORM DISPERSED-OIL PLUME SAMPLING AND PROVIDE INPUT FOR OIL-TRANSPORT MODELING1

2008 ◽  
Vol 2008 (1) ◽  
pp. 515-525
Author(s):  
James R. Payne ◽  
Eric Terrill ◽  
Melissa Carter ◽  
Mark Otero ◽  
William Middleton ◽  
...  
Keyword(s):  
Water Column ◽  
Oil Spill ◽  
Pressure Sensors ◽  
Surface Current ◽  
Hf Radar ◽  
Concentration Data ◽  
Near Surface ◽  
Dispersed Oil ◽  
Fluorescein Dye

ABSTRACT The California Department of Fish and Game Office of Spill Prevention and Response (CA OSPR) is utilizing oil-spill fate and transport modeling to develop the time and spatial scales, and equipment needs, for a formal Dispersed Oil Monitoring Plan (DOMP). When fully implemented, the DOMP will aid in documenting hydrocarbon concentrations in the water column, potentially exposed organisms (zooplankton), and the impacts of entrained oil and dissolved hydrocarbons with and without dispersant applications. Fluorescein dye studies off San Diego, California (USA) have been completed to test the operational framework for repeated sampling of dispersed oil plumes as outlined in the DOMP, to allow evaluation of high-frequency radar (HP-Radar) for providing surface current input data to oil spill models, and to provide verification of model-predicted movement of subsurface oil (dye) by comparison with drogue movement and measured dye concentrations over three dimensions and time. Aerial photodocumentation, subsurface drogues, dye transport, and HF-Radar were used to measure near-surface current fields at varying depths. High-resolution subsurface dye-plume structure was mapped using an in situ GPS-coupled towed fluorometer equipped with pressure sensors to provide dye concentration data as a function of time, position, and depth. In addition, data from the more traditional Special Monitoring of Applied Response Technology (SMART) protocols utilized by the U.S. Coast Guard (USCG) were compared with the in situ towed-fluorometer measurements, and conventional CTD data were collected to determine the mixed layer depth, an important variable in monitoring dispersion of oil in the water column. As a result of these efforts, significant progress has been made on developing and testing sampling protocols for the DOMP, and nearly continuous and synoptic data have been obtained from seven cruises conducted over a 12-month period. These data sets (available on-line through the Coastal Response Research Center (CRRC) website: http://www.crrc.unh.edu/) are being analyzed and integrated to support oil spill model development and verification with direct applicability to spill response decision making, net environmental benefit analysis, natural resource damage assessments, and educating the spill community and public.

scholarly journals A multiscale approach to balance trade-offs among dam infrastructure, river restoration, and cost

2018 ◽  
Vol 115 (47) ◽  
pp. 12069-12074 ◽  
Author(s):  
Samuel G. Roy ◽  
Emi Uchida ◽  
Simone P. de Souza ◽  
Ben Blachly ◽  
Emma Fox ◽  
...  
Keyword(s):  
New England ◽  
River Restoration ◽  
Spatial Scales ◽  
Dam Removal ◽  
The United States ◽  
Multiscale Approach ◽  
Funding Policy ◽  
Net Benefit ◽  
Trade Offs ◽  
Aging Infrastructure

Aging infrastructure and growing interests in river restoration have led to a substantial rise in dam removals in the United States. However, the decision to remove a dam involves many complex trade-offs. The benefits of dam removal for hazard reduction and ecological restoration are potentially offset by the loss of hydroelectricity production, water supply, and other important services. We use a multiobjective approach to examine a wide array of trade-offs and synergies involved with strategic dam removal at three spatial scales in New England. We find that increasing the scale of decision-making improves the efficiency of trade-offs among ecosystem services, river safety, and economic costs resulting from dam removal, but this may lead to heterogeneous and less equitable local-scale outcomes. Our model may help facilitate multilateral funding, policy, and stakeholder agreements by analyzing the trade-offs of coordinated dam decisions, including net benefit alternatives to dam removal, at scales that satisfy these agreements.

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