National Contingency Plan Product Schedule Research Articles

Comparative Toxicity of Oil Spill Herding Agents to Aquatic Species.

Chemical herding agents are surfactant mixtures used to coalesce spilled oil and increase slick thickness to facilitate mechanical recovery or in situ burning. Only two herders are currently listed on the United States' National Oil and Hazardous Substances Pollution Contingency Plan or National Contingency Plan product schedule for potential use in spill response: the surface collecting agents Siltech OP-40™ and ThickSlick 6535™. Toxicity data for spill response agents are frequently available only for two estuarine species, mysid shrimp (Americamysis bahia) and inland silversides (Menidia beryllina), and are particularly limited for herding agents. Toxicity can vary over several orders of magnitude across product type and species, even within specific categories of spill response agents. Seven aquatic species were tested with both Siltech OP-40™ and ThickSlick 6535™ to evaluate acute herder toxicity and relative species sensitivity. The toxicity assessment included: acute tests with A. bahia and M. beryllina, the freshwater crustacean Ceriodaphina dubia, and the freshwater fish Pimephales promelas; development of the echinoderm Arbacia unctulate; and growth of a freshwater alga Raphidocelis subcapitata and marine alga Dunaliella tertiolecta. Siltech acute toxicity values ranged from 1.1 to 32.8 ppm. ThickSlick acute toxicity values ranged from 2.2 to 126.4 ppm. The results of present study show greater toxicity of Siltech compared to ThickSlick with estimated acute hazard concentrations intended to provide 95% species protection of 1.1 and 3.6 ppm, respectively, on empirical data and 0.64 and 3.3 ppm, respectively, with the addition of interspecies correlation data. The present study provides a greater understanding of species sensitivity of these two oil spill response agents. Environ Toxicol Chem 2022;41:1311-1318. © 2022 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Comparative Toxicity of Oil Spill Response Agents and Crude Oils to Five Species of Aquatic Test Species

The majority of aquatic toxicity data for petroleum products has been limited to a few intensively studied crude oils and Corexit chemical dispersants, and toxicity testing in two standard estuarine test species: mysids (Americamysis bahia) and inland silversides (Menidia beryllina). This study compared the toxicity of three chemical dispersants (Corexit EC9500A®, Finasol®OSR 52, Accell Clean®DWD), two less studied agents (CytoSol® surface washing agent; Gelco200® solidifier), and three crude oils differing in hydrocarbon composition (Dorado, Endicott, Alaska North Slope). Consistent with listings on the U.S. National Contingency Plan Product Schedule, general rank order toxicity was greatest for dispersants and lowest for the solidifier. The results indicate that freshwater species can have similar sensitivity as the conventionally tested mysids and silversides, and that the sea urchin (Arbacia punctulata) appears to be a reasonable addition to increase taxa diversity in standardized oil agent testing.

Characterization of the effectiveness of a hydrocarbon liquid solidifier

Solidifiers are dry, granular hydrophobic polymers that form physical bonds with hydrocarbons by molecular interactions (hydrogen bonding, London forces), and are used to immobilize hydrocarbon spill propagation and dispersion. CIAgent© is a non-toxic, proprietary polymer blend listed as an “Oil Solidifier” on the EPA's National Contingency Plan Product Schedule for use on hydrocarbon spills in the navigable waterways of United States. CIAgent solidifies the liquid hydrocarbons through a rapid transformation into a cohesive rubber-like inert mass upon contact and retains the liquid for easier removal and disposal. The objective of this paper is to determine the effectiveness of the solidifier with a variety of hydrocarbon liquids that could be encountered in an oil spill scenario. The effectiveness of the solidifier was characterized in terms of the application rate, temperature change, solubility parameters and solidification time for a variety of hydrocarbon liquids (e. g., gasoline, diesel fuel, crude oil) that could be encountered by measuring the heat of solidification using a solution calorimeter. A thermogram was obtained and the heat of solidification was calculated using the temperature difference upon solidification. The temperature change and the degree of swelling in the solidifier were used to determine the solubility parameter of the solidifier (6.77 Hildebrands). The heat of solidification value was used to determine the ease and speed of the solidification of the hydrocarbon liquids. Solidification times ranged from 40 to 120 s for the liquids tested. The average application ratio in weight of solidifier to weight of hydrocarbon ranged was 3.35.

Toxicity of oil spill response agents and crude oils to five aquatic test species

The majority of aquatic toxicity data for petroleum products has been limited to a few intensively studied crude oils and Corexit chemical dispersants, and acute toxicity testing in two standard estuarine test species: mysids (Americamysis bahia) and inland silversides (Menidia beryllina). This study compared the toxicity of two chemical dispersants commonly stock piled for spill response (Corexit EC9500A®, Finasol®OSR 52), three less studied agents (Accell Clean®DWD dispersant; CytoSol® surface washing agent; Gelco200® solidifier), and three crude oils differing in hydrocarbon composition (Dorado, Endicott, Alaska North Slope). Consistent with listings on the U.S. National Contingency Plan Product Schedule, general rank order toxicity was greatest for dispersants and lowest for the solidifier. The results indicate that freshwater species can have similar sensitivity as the conventionally tested mysids and silversides, and that the sea urchin (Arbacia punctulata) appears to be a reasonable addition to increase taxa diversity in standardized oil agent testing.

Comparative Laboratory-Scale Testing of Dispersant Effectiveness of 23 Crude Oils Using Four Different Testing Protocols*

A controlled laboratory study was conducted to measure the dispersion effectiveness of Corexit 9500 on 23 different crude oils. This study was a part of a larger project initiated by the Bureau of Safety and Environmental Enforcement (BSEE) testing 20 oils to compare the predictive value of laboratory dispersant effectiveness tests with their larger scale test conducted at Ohmsett, BSEE’s national oil spill response test facility located in Leonardo, NJ. The test used in this study was the Baffled Flask Test (BFT), which is planned for adoption as EPA’s official testing protocol for listing commercial dispersant products on the National Contingency Plan Product Schedule, replacing the current Swirling Flask Test (SFT) [1]. In addition, the results of 3 additional oils, the 2 used in the SFT and BFT as currently written plus another reference oil, are presented. The temperature used for the tests was 15°C, to match the temperature used at Ohmsett. The dispersion effectiveness ranged from 3.4% to 93%. The BFT is a laboratory test with results that are inversely correlated with oil viscosity and therefore has predictive value in the decision to use a dispersant in the event of a spill.

Update on Developing and Commercializing Oil Herders for In-Situ Burning

ABSTRACT Since the 2011 Conference (Buist et al. 2011 and Buist and Nedwed 2011), work on advancing oil herding agents for in-situ burning (ISB) has focused on three areas:Obtaining regulatory approvals for their use in North America;Developing an application system for use in a helicopter; and,Researching the effectiveness of herders for rapid-response ISB in open water. Desmi-AFTI worked in conjunction with S.L. Ross Environmental Research to get approval to use herders in North American waters. The proscribed test data from an accredited laboratory in Louisiana on three candidate herding agents (also called surface collecting agents) was submitted to the U.S. EPA for approval to list them on the National Contingency Plan (NCP) Product Schedule. Two herders have been placed on the list and are now commercially available. These two can be used, with the FOSC's concurrence, for spill response operations in U.S. waters. Samples of all three herders have been sent to Environment Canada, along with all the EPA test data, for their consideration. Quantities (200 L) of the two herders listed on the NCP Product Schedule have been produced and are stockpiled at Desmi-AFTI in Buffalo, NY. An application system, consisting of a pump, controls and reservoir has been designed to be placed inside an appropriate helicopter. It incorporates a reel-able hose that is used to lower the application nozzle to the correct height above the water for herder application. Dry land, static trials were conducted in September 2013 and helicopter flight trials are planned for summer and fall 2014. A back-pack sprayer system for herder application from a small vessel is available off-the-shelf, with only minor modifications required for cold-temperature use. The US Department of the Interior's Bureau of Safety and Environmental Enforcement sponsored a series of laboratory and Ohmsett experiments to see whether herders could contract oil slicks in wave conditions in open water. The results showed that the monolayer of each of the two best herders will survive for more than 45 minutes in a calm sea. The presence of breaking or cresting waves rapidly disrupts the herder monolayer and the oil slick resulting in the production of many small slicklets from the herded slick and the re-spreading of the oil to thin slicks. The monolayer survives for considerable periods of time in a swell condition, but the constant stretching and contracting of the herded slick results in elongating the oil slick and slowly breaking the slick into smaller segments. Testing of the helicopter application system with a herding agent on a 10 m3 experimental crude oil release in drift ice is planned for spring 2015. Further laboratory study of the approved herders is also planned with the goals of better understanding their toxicity and biodegradation and the window of opportunity for their effective use on weathered, emulsified and waxy oils.

Determining the dispersibility of South Louisiana crude oil by eight oil dispersant products listed on the NCP Product Schedule

We recently conducted a laboratory study to measure the dispersion effectiveness of eight dispersants currently listed on the National Contingency Plan Product Schedule. Results are useful in determining how many commercial dispersant products would have been effective for use on South Louisiana crude oil in the Deepwater Horizon oil spill. The test used was a modification of the Baffled Flask Test (BFT), which is being proposed to replace the current Swirling Flask Test (SFT). The modifications of the BFT in this study included use of one oil rather than two, increasing replication from 4 runs to 6, and testing at two temperatures, 5°C and 25°C. Results indicated that temperature was not as critical a variable as the literature suggested, likely because of the low viscosity and light weight of the SLC. Of the eight dispersants tested, only three gave satisfactory results in the laboratory flasks at both temperatures.

Oil Spill Dispersant Effectiveness Protocol. II: Performance of Revised Protocol

The current U.S. Environmental Protection Agency (EPA) protocol for testing the effectiveness of dispersants for use in treating oil spills on the open water, the swirling flask test (SFT), has been found to give widely varying results in the hands of different testing laboratories. Part I addressed the sources of the ambiguities in the EPA SFT and the development of a new test referred to as the baffled flask test (BFT). In this part of the series, further experiments were conducted for estimating the repeatability of three operators in determining the effectiveness of 18 dispersants by both the EPA SFT and the BFT methods. Overall statistical analysis of the results indicated that the coefficient of variation by the BFT was only 7.8% compared to 21.9% for the EPA SFT. The mean percent effectiveness of the EPA SFT was only 19.7% as compared to 64.6% for the BFT. Proposed selection criteria for screening of dispersants for listing on the National Contingency Plan Product Schedule have been developed.

The Baffled Flask Test for Dispersant Effectiveness: A Round Robin Evaluation of Reproducibility and Repeatability

After two previous investigations demonstrated that the baffled flask test was an effective and reproducible method for screening the effectiveness of dispersant products in the laboratory, the US Environmental Protection Agency decided that before the new protocol could be considered for replacement of the swirling flask test, it would have to be subjected to an interlaboratory round robin investigation. This paper describes how the round robin evaluation was carried out and presents repeatability and reproducibility calculations that demonstrate the superiority of the new method over previous methods. Probabilities for passing various threshold levels of effectiveness values were computed, and the results will be used by the Agency to develop final pass–fail decision rules for dispersant manufacturers wishing to have their products listed on the national contingency plan product schedule.

Development of a Rational Oil Spill Dispersant Effectiveness Protocol

ABSTRACT Chemical dispersants are used in oil spill response operations to enhance the dispersion of oil slicks at sea as small oil droplets in the water column. To be considered for use, the dispersants must be listed in the National Contingency Plan (NCP) Product Schedule. Since 1994, dispersants were required to pass an effectiveness test known as the Swirling Flask Test (SFT), which is described in Appendix C of 40 CFR 300. Listing of a dispersant on the NCP Product Schedule is contingent on the dispersant being at least 45% effective in dispersing South Louisiana crude (SLC) and Prudhoe Bay crude (PBC) oils as measured and calculated by the test. Shortly after adopting the SFT, the U.S. Environmental Protection Agency (EPA) began to receive complaints that the test was too rigorous and few dispersants that were previously listed on the NCP Product Schedule could achieve the 45% effectiveness criterion. Additionally, the SFT has been found to give widely varying results in the hands of different testing laboratories. A redesign of the test flask, which is characterized as being baffled with a stopcock at the bottom for undisturbed sample collection, is considered to be necessary to accomplish reproducibility within operators and between operators. This paper presents the development of a revised procedure for dispersant effectiveness testing, called the Baffled Flask Test (BFT), and reports the reproducibility of the revised procedure by three independent operators. It also details the development of pass/fail selection criteria. Experimental results are presented comparing the repeatability of the SFT and BFT methods with three operators determining the effectiveness of 18 dispersants on SLC and PBC oils. Statistical analysis of the results indicated that the overall mean effectiveness of the SFT for all 18 dispersants was only 19.7% compared to 64.6% by the BFT and the coefficient of variation for the SFT was 21.9% versus only 7.8% for the BFT.

USING THE SELECTION GUIDE FOR SPILL COUNTERMEASURES TECHNOLOGIES IN RESPONSE DECISION MAKING AND PLANNING

ABSTRACT As part of national response priorities, On-Scene Coordinators (OSCs) and Incident Commanders should use all appropriate containment and removal tactics, including the use of products listed on the National Contingency Plan (NCP) Product Schedule, in a coordinated manner to ensure a timely, effective response that minimizes adverse impacts to the environment (40 CFR § 300.317). To facilitate greater understanding of these products and technologies, a Selection Guide was developed to evaluate their potential benefits and identify appropriate situations for their use. Although the NCP Product Schedule and Notebook provide information on regulated spill response products, the decision maker needs additional information presented clearly in a concise format that clarifies how these products can affect the spilled oil and the environment once applied. The Selection Guide provides a spill response tool that gives OSCs and other decision makers an easy-to-use source of technical information on spill response countermeasures that are regulated by the NCP, including alternate sorbents, bioremediation agents, dispersants, elasticity modifiers, emulsion treating agents, in situ burning on land and on water, shoreline pre-treatment agents, solidifiers, surface-collecting agents (herders), surface-washing agents, and firefighting foams, as well as potential response strategies for “unusual” spill response conditions (i.e., fast-water booming strategies, non-floating oil strategies, and water intake monitoring). The Selection Guide facilitates easy comparison among product categories, as well as aids decision makers in determining the best response strategy or product for a particular issue that “traditional” response tools do not seem to address completely. The Selection Guide has been developed under the Work Plan of the Region III Spill Response Countermeasures Work Group, in cooperation with the Region IV Regional Response Team (RRT). This document is applicable for inland and coastal areas and is intended for use during actual spill incidents and pre-spill planning efforts. This information also assists decision makers in evaluating vendor requests to use their products.

Using the Pieces to Solve the Puzzle: A Framework for Making Decisions About Applied Response Technologies

ABSTRACT The National Contingency Plan (NCP) Product Schedule, the Applied Response Tool Evaluation System (ARTES), and the Selection Guide for Oil Spill Applied Technologies (Selection Guide) are information and evaluation resources that, used together, provide spill response decision makers with a comprehensive framework to assess the potential uses and effects of applied response technologies either during an oil spill emergency or in advance. The applied response technologies addressed by these response tools include fastwater booming strategies, nonfloating oil strategies, water-intake monitoring, alternative sorbents, bioremediation agents, dispersants, elasticity modifiers, emulsion treating agents, firefighting foams, in situ burning on land and inland waters, solidifiers, surface-collecting agents, surface-washing agents, and shoreline pretreatment agents. The U.S. NCP regulates the use of any chemical/biological product as a spill response tool. In most instances, decision makers are aware of these information resources, but many government and industry users are unclear on the relationship among the three, that is, what does each do, how are they similar and/or different, and how can each be used in relation to the others. To make a well-reasoned decision, decision makers need to understand the functions of each. This paper provides an overview of the NCP Product Schedule, which is a regulatory requirement for considering the use of biological and chemical additives on oil spills in the United States, and how the Product Schedule can be used in conjunction with decision aids, like ARTES and the Selection Guide, to select the proper response products and strategies for oil spills. The paper reviews the functions, limitations, and flexibility of each component in this decision framework and discusses ways to use all three information resources to reason through when the use of applied response tools might be ecologically appropriate.

USING EXISTING DATA TO MAKE DECISIONS ABOUT CHEMICAL COUNTERMEASURE PRODUCTS

ABSTRACT The use of chemical countermeasure products (CCPs) (i.e., dispersants, herding agents, emulsion-treating agents, solidifiers, elasticity modifiers, and shoreline-cleaning agents) in treating oil spills has been hindered in the United States by the perceived lack of data or apparent conflicting data claims concerning their effectiveness and toxicity. Recognizing that important data exist, such as in the technical bulletins for the National Contingency Plan Product Schedule, an expert workshop was convened to achieve consensus on (1) the adequacy of existing effectiveness and toxicity data and (2) how best to interpret and use those data to enhance oil spill planning and response. Through a deliberative process, consensus was reached in three topic areas: environmental effects, effectiveness, and decision making. Discussions emphasized dispersants because considerable information is available on them, but other CCPs were considered. The following conclusions were reached: (1) there is a dispersed oil concentration threshold below which no ecological effects are expected in open marine waters; (2) there is a low probability that meaningful monitoring data will be available within the response period; (3) multiple applications should be encouraged; and (4) a recommended outline for a reference document on implementing dispersant prespill planning should be developed. This paper summarizes the conclusions in each of the topic areas, including the rationale for the experts consensus and prespill planning needs.

THE NATIONAL CONTINGENCY PLAN PRODUCT SCHEDULE DATABASE

ABSTRACT The U.S. Environmental Protection Agency's Emergency Response Division maintains the National Contingency Plan Product Schedule Database that allows users to view and compare product data quickly and efficiently. The current word processing format of the NC? Product Schedule Notebook does not allow for the rapid and efficient searching of toxicity and effectiveness data. Rapid access to NCP product data is vital to on-scene coordinators during the early stages of spills. The NCP Product Schedule Database provides the user with a mechanism to quickly view and/or print product data, comparison reports, and product lists.