Dispersants Man
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- BSEE · Bureau of Safety and Environmental Enforcement
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- Guidance
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- Unknown
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- Emergency ResponseEnvironment
Summary
User manual for the Estimated Dispersant System Potential calculator, a planning tool for estimating aircraft and vessel dispersant application capability.
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Themes: emergency response, environment.
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Estimated Dispersant System Potential (EDSP) Calculator User Manual
The ERSP, EBSP, and EDSP Calculators are intended as planning tools for estimating the potential of different oil spill response systems to mitigate (recover, burn or disperse) discharged oil relative to one another. These planning tools are NOT intended to be used as models for calculating system performance during an actual oil spill, which is affected by many factors such as the distribution of oil on the water surface, oil weathering, and other ambient on-scene conditions which are not included in these Calculators.
Prepared by BSEE and Genwest Systems, Inc.
February 2016
Contents 1. Introduction ......................................................................................................................... 4 1a. The EDSP Calculator’s Purpose and Intended Use ..................................................... 5 1b. Dispersant Application System Components................................................................ 6 2. Assumptions and Limitations as a Planning Tool ................................................................ 9 2a. General Assumptions..................................................................................................10 2b. Additional EDAC assumptions and scenario: ..............................................................11 3. EDSP Calculator Inputs .....................................................................................................13 3a. Mobilization/Cascading Inputs ....................................................................................14 3b. Scenario Inputs ...........................................................................................................16 3c. Dispersant Spraying Operations Inputs .......................................................................17 3d. Effective Daily Application Capacity (EDAC) Input ......................................................21 3e. Platform Inputs............................................................................................................24 4. EDSP Calculator Outputs ...................................................................................................43 4a. Results for Each Operating Period ..............................................................................44 4b. Results per Sortie for a Complete Payload Application ...............................................45 4c. Aircraft Sortie Timeline Components ...........................................................................45 4c. Results when using the EDAC button .........................................................................46 5. Using the EDSP Calculator ................................................................................................48 5a. Calculating EDSP using an Aircraft .............................................................................48 5b. Variations in Aircraft Spray 1 Scenario ........................................................................51 5c. Calculating EDSP using a Vessel ...............................................................................57 5d. Variations in Vessel Spraying Scenarios .....................................................................60 6. Equations Used in Calculations ............................................................................................65
1. Introduction Dispersants are fluid chemicals that bond to oil molecules and separate them from water molecules, thus breaking up the oil. The result is tiny oil droplets that can biodegrade and disperse more quickly than a mass of oil.
The Estimated Dispersant System Potential (EDSP) Calculator developed in this project is Revision 1 of the Dispersant Mission Planner 2 (DMP2). The basic dispersant application algorithms remain the same. The programming environment used for the DMP2 is no longer supported. A document highlighting the major differences between the DMP2 and the EDSP Calculator can be found at www.genwest.com/genwest_publications.
The Calculator accounts for the performance of an aircraft or vessel dispersant application system as it sprays dispersant on an oil slick. The Calculator generates an “Estimated Dispersant System Potential” (EDSP) value for two Operating Periods following the discharge of an oil spill. The Calculator takes into account the time necessary to mobilize the system and the time needed to cascade the system from its home base to the incident staging site, if necessary. There is separate logic for aircraft platforms and vessel platforms that determines what is displayed for the two operating periods.
The EDSP Calculator is an HTML file, EDSP-160225.html, which runs in the following web browser versions:
PC (Win-XP, Win-7 and Win-8 environments) IE - 9, 10, 11 or greater Chrome 38 or greater Firefox 31 or greater Safari 5.1 or greater
Mac (OS 10.6 and greater) Safari 8.0 or greater Chrome 38 or greater Firefox 35 or greater
You can download the EDSP Calculator from the BSEE website. The “build” or version date of the calculator appears after the calculator name in the format – yymmdd.html (see Figure 7). This date stamp can verify that you are working with the latest version of the calculator.
This User’s Guide provides guidance to the user on the various data inputs that must be entered into the EDSP Calculator regarding the dispersant application configuration being evaluated, and further explains the Calculator results.
The EDSP Calculator was developed by Genwest Systems, Inc. under GSA Contract GS-00F-0002W, BSEE Order No. E12-PD-00012 in consultation with BSEE and the United States Coast Guard.
1a. The EDSP Calculator’s Purpose and Intended Use The EDSP Calculator is primarily a planning tool for estimating the potential for dispersant application on spilled oil by defined dispersant application systems. It estimates the potential of a single system and does not address the total potential or number of systems that would be necessary for a plan. You can use the Calculator to evaluate the potential of a dispersant application system for different spill planning situations
Estimated Dispersant System Potential (EDSP), a regulatory measure of a dispersant system’s potential ability to treat oil.
Effective Daily Application Capacity (EDAC), a regulatory measure of how much dispersant can be applied by a dispersant application platform that is used in conjunction with U.S. Coast Guard regulated oil spill response plans. The EDAC assumptions and scenario can be found in Section 2b.
Operational spill planning, where users are not constrained to EDAC values and assumptions.
To use the Calculator, you enter information about an aircraft or vessel dispersant application system, such as its swath, on-board dispersant storage capacity, and pump rates, and you describe the circumstances of its operation, such as cascading information and transit distance to the oil spill area and speed (see Section Three, EDSP Calculator Inputs). The Calculator then estimates the amount of dispersants that can be applied and the amount of oil that the system could treat during each of the first two days after a spill occurs (see Section Four, EDSP Calculator Outputs). These estimates of the oil treated are termed the “Estimated Dispersant System Potential” (EDSP) for the given dispersant application system configuration. The use of the calculator tool in both spill modes is further demonstrated and explained in Section Five, Using the EDSP Calculator.
The EDSP Calculator was developed with the intent of reinforcing incentives for creating and acquiring more effective dispersant application systems, and in addition, evaluating the potential of a dispersant application system to meet various regulatory planning requirements. Experimentation with the Calculator is helpful in understanding the effects of different configurations on a system’s treatment potential, and may provide incentives for developing more effective dispersant application systems.
1b. Dispersant Application System Components The EDSP Calculator was designed as a planning tool for estimating the potential of aircraft and vessel dispersant application systems. The major components of a dispersant application system include a dispersant storage tank, a pump system to move liquid dispersant from the storage tank to the distribution system, a power source, spray arms, and nozzles. Figure 1 below identifies the major components of a dispersant application system:
Figure 1. Dispersant Application System Components.
Below are short descriptions of the various components of a dispersant application system:
Delivery platform aircraft or vessel –This is the supporting platform for all the components of a dispersant application system including the following: dispersant tanks, dispersant pumps, delivery piping and manifolds, spray arms, and nozzles.
Onboard dispersant storage – Includes tankage built into or carried on the delivery platform to hold the dispersant. A payload is defined as a complete fill of the tank.
Pump – The pump transfers the dispersant from the tank through piping and manifolds to nozzles on the spray arms. The pump rate and nozzle configurations are adjusted to
deliver the dispersant at the desired dosage. Check the platform spray chart to insure that it can deliver the desired dosage and calculated pump rate.
Spotter aircraft - While not shown in Figure 1, spotter aircraft can be considered to be part of the “system” for dispersant application. Aerial delivery platforms necessarily fly low and at these altitudes oil slicks are difficult to see. The spotter aircraft assists in spill detection, tracking, alignment of the dispersant platform with the oil slick, and application-determination of “spray on” and “spray off.”
The following are photographs of some dispersant application platforms:
Figure 2. DC-4
Figure 3. C-130 Hercules
Figure 4. Helicopter with Dispersant Spray Bucket
Figure 5. Large Dispersant Vessel
Figure 6. Small Dispersant Vessel
2. Assumptions and Limitations as a Planning Tool
The EDSP Calculator was developed to provide a distribution-rate, system-based estimate of daily dispersant application. The calculator accommodates a broad range of dispersant system configurations and addresses response activities including the accessing, spraying, and treatment of oil. The Calculator also accounts for the transiting of a dispersant application system to and from a staging area for reloading of dispersant and fuel. The goal was to provide a computer tool that could facilitate the calculation of a “Planning Standard”, not a “Performance Measure”.
The ERSP, EBSP, and EDSP Calculators are intended as planning tools for estimating the potential of different oil spill response systems to mitigate (recover, burn or disperse) discharged oil relative to one another. These planning tools are NOT intended to be used as models for calculating system performance during an actual oil spill, which is affected by many factors such as the distribution of oil on the water surface, oil weathering, and other ambient on scene conditions which are not included in these Calculators.
The following is a list of assumptions and limitations inherent to the design of the EDSP Calculator, that are readily acknowledged as conditions accepted in order to keep the Calculator a simple and easy to use planning tool:
2a. General Assumptions Ambient Conditions: Estimates made by the Calculator assume that conditions are generally conducive to effective dispersant application operations. Its output is designed to serve as a guide for planning the deployment of dispersant application systems and estimating their delivery potential. System Downtime: No downtime due to maintenance or repair is considered. Oil and dispersant types: The Calculator does not differentiate outputs based on the type of oil or product being treated nor the type of dispersant being used. The Calculator assumes that the oil in question for the scenario, spray system, and dispersant being used is dispersible commensurate with expected efficiency and effectiveness ranges. Success of Dispersion: The EDSP Calculator does not provide information relating to the ultimate success of chemical dispersion of oil, but rather only the estimated potential volume of oil treated. Oil Thickness on the Water: For the purposes of planning and comparing spray systems, the Calculator does not assume any specific oil slick thickness will be encountered, however, an oil slick thickness of 0.004 inches (0.094 mm) is equivalent to the thickness of oil that would be treated by spraying dispersant at a dosage rate of 5 gallons per acre with a dispersant to oil ratio of 1:20. Dosage: The Dispersant Aircraft Capability Forms (see Figure 24) do not contain explicit dosage capability values or ranges. Every aircraft platform in the EDSP database can deliver the regulatory dosage of 5 gallons of dispersant for each acre sprayed. Other dosage values used in the EDSP may not be actually achievable and should be verified with the platform operator before use. The Use of Default and Alternate Values: The Calculator, and its default values for many of the key inputs, is intended to be “conservative” in nature. In some cases, a dispersant application system’s tested performance will be able to exceed the default values for specific inputs. Plan holders or OSROs may submit requests for the use of alternate values in the Calculator to the appropriate regulatory agency. The regulatory agencies will consider each request based on the merits of the documentation provided. Operators should expect that the use of approved alternate values may be subject to validation efforts by regulators with plan holders and OSROs being required to satisfactorily demonstrate the practical viability of these values during equipment verification visits and PREP equipment deployment exercises. Incident Briefing: All dispersant application platforms will hold an incident briefing for 45 minutes prior to departing the staging site to commence the first spray sortie. Normally this briefing will only occur in Operating Period1 (OP1), however, for a platform that cascades into the scenario and arrives for its first sortie in a subsequent OP that initial briefing will occur in the OP that contains the first operational spraying sortie. Check-in Time: Check-in time of 10 minutes with spotter aircraft occurs at the beginning of each sortie for aircraft platforms.
Side Overlap and Gaps: Spray passes will not be precise in the real world. There will be side overlap and gaps in the spray pattern between passes in some cases, as application platforms will strive to only spray areas containing oil, which usually will not be continuous and uniform in nature on the water’s surface. No side overlap or gaps are assumed in the Calculator. Resupply On Scene: When “Resupply On Scene” is set to “Yes” for vessel- based application systems, dispersants will be resupplied onsite at the spill location to the platform and application system, either when the payload of dispersant is completely applied during spraying operations, or when the operating period is completed, whichever occurs first. Resupply at the Staging Site: When “Resupply On Scene” is set to “No” (which is the default setting) for vessel-based spray application systems, the vessel will resupply its dispersant payload at the staging site. This will require the spraying vessel to transit between the spill site and the staging site, similar to aircraft operations, whenever more dispersant payload is needed. When “Resupply On Scene” is set to “No”, if a vessel has less than one half of its dispersant payload left onboard when the OP ends, the platform will immediately transit back to the staging area to resupply. However, if the vessel has more than one half of its payload remaining onboard at the end of the OP, the platform will stay at the spill site between operating periods and will commence spraying the remainder of the payload at the beginning of the next operating period. Loading in between Operating Periods: At the end of each Operating Period it is assumed that aircraft-based spray systems will reload dispersant and fuel before the next Operating Period begins.
2b. Additional EDAC assumptions and scenario: “Platform” inputs are reset and locked to default values The Dispersant-to-Oil Ratio (DOR) is 1:20. Five gallons of dispersant will be applied to each acre (46.8 liters/hectare). The pass length for the oil slick to be treated is 4 nautical miles (7.4 km) long in the direction of spraying. Aircraft platforms have 12 hours of time available for Operating Period 2 dispersant operations, not including the last transit back to the primary dispersant staging site. Cascading of aircraft and vessels from out-of-area requires entries for the platform/dispersant mobilization time, cascade distance, and platform dispersant payload status (loaded or empty). Cascading reduces the Operating Period resulting in the use of Adjusted Operating Period 1 for EDSP calculations. Aircraft platforms will be allowed to apply dispersants in both directions. Spotter aircraft are assumed on-scene waiting for dispersant spray platforms.
Aircraft platforms will be allowed to refuel and load dispersants at the same time except for USAF Reserve C-130 H. Transit distance for vessel response plans is measured from the primary dispersant staging site (or closest dispersant staging site for plans with multiple staging sites) to the furthest spill site 50 NM off shore within a Captain of the Port (COTP) zone. Transit distance for facility response plans is measured from the primary dispersant staging site to the facility. Weather: Visibility greater than 3 statute miles (4.83 kilometers)* Ceiling greater than 1000 feet (304.8 meters)* No wind (0 mph) No precipitation Mild temperatures 40-80 degrees F (4.4 – 26.7 degrees Celsius) *Visible Flight Rule (VFR) conditions are required at the spill site for aircraft to apply dispersants and are assumed for all flight operations, including cascading from home base to staging airports and for transit to and from the spill site. VFR flight requires 30 minutes of fuel reserve on the aircraft.
3. EDSP Calculator Inputs This section provides a general description, and in many cases, amplifying guidance, for each of the input fields and the variables that a user must enter into the Calculator. The graphic below is an illustration of the input screen that a user will see and use to enter their dispersant system information into the Calculator.
Figure 7. EDSP Calculator Input Screen
Name of Simulation: Entry field for the name or other form of identifier for the dispersant application system (up to 48 characters).
Simulation Details: Enter configuration details including the type of platform, skimmer, pump, and boom being used and other key information to identify this simulation.
The EDSP Calculator inputs have been grouped into five overall categories: Mobilization/Cascading, Scenario, Dispersant Spraying Operations, Effective Daily Application Capacity (EDAC), and Platforms
3a. Mobilization/Cascading Inputs
Figure 8. Mobilization/Cascading Input Screen
Mobilization Time: As resources are ordered at the onset of an oil spill response, each individual dispersant platform and/or dispersant stockpile will need a time period for activation and mobilization. Enter the time necessary for activation and mobilization to include all activity necessary to get the resource moving. Use the greater of the platform mobilization time or the dispersant stockpile mobilization time for use in the EDSP unless the platform will be cascading with payload If the platform is cascading with payload, use the mobilization time for the spray platform. Mobilization Time should be based on:
o Dispersant stockpiles must be available onsite or already loaded onboard the spray platform before it can depart for its first dispersant spraying sortie. For situations where a platform is cascading to a staging site without payload, mobilization times for dispersant stockpiles should be calculated based on the distance from the stockpile location to the selected dispersant operations staging site using applicable transit routes and speeds. For situations where a spray platform is departing from its home base to conduct sortie operations, if dispersants are not already
onsite, stockpile mobilization times must be calculated from the dispersant storage location to the spray platform’s home base. The default transit speed for moving dispersant stockpiles to staging sites is 35 mph over land or 100 kts when moving stockpiles by air. o Dispersant oil spill removal organizations should use the time specified in their contract for activation and mobilization of dispersant spraying platforms, or the time listed in other documentation that has been deemed acceptable by the appropriate regulatory agency. o For situations where activation and mobilization
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