Response Guide: Understanding Underwater Electric Transmission Line Dielectric Oil Leaks

The Consumer Electronics Association reveals that, in 2017, the average U.S. household owns approximately 30 consumer electronic devices and this number has been growing tremendously annually (Pew Research Center, 2017)¹. Such devices provide the connectivity and communications that Americans have come to rely on heavily. However, as the dependence of electronic devices increases, so does a a lack of tolerance for electric outages, since the public expects a reliable electric system with the minimal chances of outages.

Although only 6% of electrical wires are located underground (Electrical Engineering Portal, 2017), the advantages of their Pipe-Type Cable (PTC) systems cannot be overstated. Underground electric transmission lines consisting of PTC's transmit power to substations delivering power to homes and businesses. PTC cables are common infrastructure, especially in major urban areas including New York City and Boston. Notably, the underground transmission cables deliver power to congested areas where overhead lines are challenging to implement. The PTC system provides critical power, which is highly reliable, faces minimal outages, and is efficient.

The underground transmission line infrastructure is becoming common pervasive, since starting in the 1970's/1980's, though some underground electric transmission lines have been in service since the 1950's. The modern high-pressure, fluid-filled (HPFF) PTC underground transmission lines consist of a steel pipe containing three high voltage surrounded by a dielectric fluid maintained at 200 pounds per square inch (Electrical Engineering Portal, 2017). The dielectric fluid prevents electrical discharges and acts as a cooling mechanism (Electrical Engineering Portal, 2017). The pumping stations monitor the pressure and temperature of the fluid. The major reason for retaining antiquated underground power transmission is the cost, since an underground 230 kV line costs 10 to 15 times the cost of an overhead line carrying the same power due to time, materials, processes, the need to include transition substations, and the use of specialized labor (Xcel Energy, n.d.).

Each electric company employs their own monitoring, inspection, and investigation system that tracks the electric current and dielectric fluid in the PTC System. Remarkably, the electrical systems have multiple indicators when a dielectric fluid leak occurs, including alarms, decreased oil and pressure levels. Problems associated with the PTC underground lines include maintenance issues and leaks, which have been on the rise, even with detection methods in place.

As the infrastructure of U.S. electrical cable systems becomes older and more challenging to maintain, we will continue to encounter dielectric oil discharges into our waterways. Accordingly, this research focuses on U.S.underwater dielectric cable leaks. Underwater dielectric cable leaks pose a unique problem because of inadequate research into resolution, lack of accessibility, dielectric fluid behaviors in water, and their increasing frequency (Reference  Appendix A Dielectric Fluid Fact Sheet).

Electrical companies offer an essential public service to the public by providing uninterrupted electrical power. However, there are significant environmental risks associated with the maintenance and replacement of the US electric delivery systems such as threats to human health, the food web, and drinking water. Mitigating the environmental risks associated with electric delivery systems requires a collaborative approach to increase our preparedness and efforts to readily respond to arising problems. This guide highlights practices to facilitate a prompt response to a specific risk and a reduction of the risk of harm to both the public and the marine environment.

It is clear that the aging electrical infrastructure needs an upgrade. Meanwhile, formulation of a plan is necessary to deal with underwater dielectric fluid leaks. Past studies of dielectric spills provides the window of opportunity for capturing valuable lessons learned and overarching themes that can shape response to future spills. With some of this infrastructure aged over 65 year problems will continue well into the future. Accordingly, this how-to guide evaluates and proposes numerous recommendations to make future responses more effective.

This capstone research serves as a planning guide for supporting response to prospective dielectric oil discharges into waterways. Dielectric spills can reach waterways through a PTC leak underwater, or from an above ground pipe that finds a pathway to the waterway through a storm drain, or from water outfall. Notably, most dielectric leaks occur on the ground and the fluid is absorbed by the soil; however, since dielectric fluid disperses when if it reaches water, the results tend to be significantly more challenging to assess and cleanup (Reference  Appendix A Dielectric Fluid Fact Sheet). For the purposes of this capstone research, all factors were assessed in order to consider the effectiveness of a dielectric spill response based on their relevance and impact.

Every spill incident will be different and pose its own set of unique challenges and variables; however, this research intends to highlight the most common best practices found through past responses. In the Recommendations section below, we focus on notification, discovery methods, sampling strategy, potential toxicity, effective clean-up strategies, and clean-up endpoints. After distilling information from past case studies, it was determined that the success of a dielectric spill response depends on three aspects: the amount of time until completion, damage to natural resources, and the cost.

In the Code of Federal Regulations (CFR) 33 U.S.C. §§ 2701, the Oil Pollution Act of 1990 (OPA 90) prohibits oil discharges or hazardous substance release into or on navigable waterways. OPA 90 regulations created standards in terms of response, liability, and compensation for oil pollution. The National Oil and Hazardous Substances Pollution Contingency Plan (NCP), 40 Code of Federal Regulations (C.F.R.) § 300 provides the framework for coordinating response actions to oil discharges and hazardous substances for all levels of government. The NCP is based on a three-tiered approach to making responses including owners/operators of facilities, Area Committees (that include local, state, federal, and non-governmental organizations), and the federal government.

Owners/operators of facilities that could pose a serious threat to the environment must prepare a Facility Response Plan (FRP) to respond to potential discharges. The National Contingency Plan uses the term “Federal On-Scene Coordinator (FOSC)” to describe the individual responsible for coordinating and directing the removal of oil discharges and hazardous substance releases. Once the FOSC is notified of a spill or discovers a spill, facts are then collected to assess the situation. The response efforts are then coordinated with local, state, and federal response agencies. For dielectric spills, it is important to mitigate the environmental threats through an intricate network of people, plans, and resources since these spills are not widely recognized.

For the purposes of this capstone project, the criteria for the selection of past responses for study are documented underwater electricity line leaks, which were chosen due to their level of difficulty with detection and performing repairs underwater with lines buried under sediment. The most notable three recorded major underwater dielectric fluid leaks are highlighted below. Each of the documented cases below released thousands of gallons of dielectric fluid into our waterways, which if not quickly mitigated, could have had negative effects on public safety through drinking water, water pollution, and damaged plant life and wildlife.

Jersey City, NJ- A dielectric oil leak was detected near Newport Marina in Jersey City, NJ due to a persistent sheening in the area. Initially, the leak detection sensor was inoperable, but later it was confirmed the leak came from the B3402_C3404 feeder line. That particular electric line provides electricity from Jersey City to lower Manhattan and therefore is a vital energy link. A shut down could have caused water intrusion into the lines and consequently would have disrupted electric supply to Manhattan. The line has had previous repairs and a permanent clamp was installed on 18 August 2017.

• Time to repair leak: 2 years

• Amount of dielectric oil released: Unknown (total amount leaked cannot be determined without a start time)

• Cost: $72 Million

Brooklyn, NY- An electric transformer containing 37,000 gallons of dielectric fluid failed, causing much of the oil to be released within the station property in addition to the East River and Lower New York Bay. The discharge caused a disturbance to the ferry traffic, as well as commercial traffic along the waterway.

• Time to repair leak: 3 Days

• Amount of dielectric oil released: 37,000 gallons released

• Cost: Unknown

Charlestown, MA- A dielectric oil leak was detected on the Mystic River in Charlestown, MA, due to a constant sheen in the area. After use of a Remote Operating Vehicle, freeze testing, and perfluorocarbon (PFC) tracer gas, it was discovered that the dielectric leak was occurring inland in Charlestown, MA. The dielectric fluid discharge was still significant enough to reach Mystic River outfall, which caused the reoccurring sheen. It is estimated that 6,870 gallons of dielectric fluid was discharged and the line was repaired.

• Time to repair leak: 28 Days

• Amount of dielectric oil released: 6,870 gallons

• Cost: Unknown

Modernizing the aging U.S. energy infrastructure to reduce dielectric fluid leaks requires time, money, and resources. An important trend to recognize is that dielectric spills have been occurring at increasing rates. The listed recommendations are overarching lessons learned that can be applied to future spills as they arise.

Timely notifications targeting the relevant bureaus with associated jurisdiction is key to a successful and efficient response between all entities including the responsible party, state and local officials as outlined in the Spill Prevention, Control, and Countermeasure (SPCC) plan. The required SPCC plan has a list of all notifications required including local, state, federal agencies associated with each PTC line.

For example, in Massachusetts the Department of Environmental Protection requires notification of any spill of 25+ gallons and/or any spill or release which poses a threat to human health or the environment. The respective state pollution response agency will most likely be the first notification made, as most dielectric spills occur on land. If any amount of dielectric oil reaches a waterway, the National Response Center (NRC) must be notified as the emergency call center for all federal/state agencies (Reference  Appendix C Support Descriptions and Roles). Additionally, the Spill Control and Countermeasures (SPCC) regulations require written notification to be made to the Environmental Protection Agency (EPA) Regional Administrator for discharges greater than 1,000 gallons into a navigable waterway. Alignment of priorities, authority, and expectations with all regulatory agencies ensures a coordinated effort in respond to the release.

Dielectric fluid spills are difficult to detect in the marine environment because they are made up of clear, colorless, and odorless fluids (Dielectric Fluids, n.d.). A variety of detection techniques are needed to find the location of leaks since underwater dielectric spills are so difficult to detect. One initial method to find an underwater cable leak is a visual inspection using a Remotely Operated Vehicle (ROV). A ROV is an underwater robot with the ability to provide underwater video and can have multiple manipulators (MASGC, n.d.). The ROV's can also be useful for undersea mapping which can provide valuable information into the cause of the leak, hazards, and behavior of the oil. If visual ROV efforts are not successful at locating the leak, other physical technological tests may need to be performed on the pipes themselves.

A freeze test isolates portions of the pipe in order to narrow down the location of an underwater leak. During this freezing method, liquid nitrogen is put into the line and the pressure on either side of the frozen place is measured. The side with the lower pressure signifies the location of the leak. Usually, multiple freeze tests are implemented to pinpoint the leak's location. Although freeze testing is an effective method of detection, advanced technology provides more efficient methods of detection.

Tracer Technology provides an advanced method to find dielectric leaks on land. In 1988, ConEdison developed a leak detector - perfluorocarbon (PFT) - into their cables, allowing for detection equipment on roving trucks to detect the location of the leak (What We Do, n.d.). The PFT is injected into the dielectric fluid lines and converts to a gas that can be detected at ground level. The PFT method is the least intrusive technology and the most effective method on land; however, the PFT detection cannot be used underwater.

Dielectric fluids are designed to have a low degradation rate and dispese when introduced to water. Dielectric oils are expected to float when released into the water and quickly spread into a thin sheen (NOAA, 2019). As seen in the photos below, recent spills have a rainbow color and older spills have a gray color. The sheens will naturally weather and degrade as the oil product breaks down. The hydrophobic nature of the product makes the product spread vastly from the point of release; therefore, the product is difficult to recover and sample (Refer to  Appendix A). As demonstrated in the case studies, the sheens are unable to be sampled using traditional sample jar methods; therefore, alternate sample techniques are needed.

Teflon nets enable an effective strategy for sampling dielectric fluids (Oil Spill Science and Technology, n.d.). To sample, a pre-treated Teflon net attached to a sampler and lowered to the oil sheen and dragged across the surface of the sheen about 60 times (Oil Spill Science and Technology, n.d.). Due to the colorless nature of the dielectric oil, the net will not be visibly oiled. After sampling, the Teflon net is put into a glass bottle and transported to a lab (Oil Spill Science and Technology, n.d.). Since different electric companies use different dielectric fluids, sampling may be necessary to identify a responsible party and identify specific dielectric fluid.

Data indicate the toxicity of dielectric fluid is low; however, there is limited data on the matter. Dielectric fluids are extremely diverse products; therefore, it is important to review the Safety Data Sheet for the specific product spilled, so that the physical properties and environmental fate and effects of the chemical constituents can be determined (NOAA, 2019). Dielectric fluid is generally a mixture of polybutenes and linear alkybenzenes (NOAA, 2019). Overall, polybuetenes and alkybenzenes have a low acute level of toxicity to humans and aquatic wildlife (US National library of Medicine Haz-Map). Although dielectric fluids have low toxicity, there are other environmental effects that can be caused by dielectric fluids.

Dielectric fluids pose an exposure risk to waterfowl. Dielectric fluid can coat the bird's feathers, rendering them unable to regulate their body temperature or fly (NOAA, 2019). Dielectric fluids are designed to be persistent and stable compounds, which then pose a significant threat to the waterfowl (NOAA, 2019). Overall, there is little information on the fate of environmental and toxicological information regarding dielectric fluids in the marine environment.

Dielectric fluid spills do not behave like traditional oils; therefore, the clean-up methods need to be adapted accordingly. Since dielectric fluid spreads so thin on water, clean-up methods become labor intensive. Tests in large tanks showed that they can be effectively removed from the water surface using drum and disk skimmers, at rates about 5 times higher than that of diesel (NOAA, 2019). Additionally, organic absorbents have proven to be a successful clean-up method for dielectric fluids. Examples of organic absorbents include: kapok fiber, cattail fiber, rice husk, wood chips, and coconut husk (Khan, 2004). In accordance with regulations, organic sorbents need approval to be used in navigable waterways by the National Contingency Plan Product Schedule Subpart J (EPA, 2019). Although the organic absorbents are an effective cleanup method, the products vary with availability and oil recovery effectiveness.

One of the most difficult decisions to be made on an oil spill is when cleanup methods should conclude. The clean-up endpoints need to be determined early in the response, so the clean-up methods can be selected to meet those clean-up decision endpoints. Generally, clean-up endpoints determined in order to minimize exposure hazards for human health, speed the recovery of impacted areas, and reduce the threat of additional or prolonged natural resource impacts (Michel, J., & Benggio, B., 1999). As a best practice, the NOAA Shoreline Assessment Manual can be used as a guide for determining clean-up decision endpoints. Additionally, an example dielectric spill endpoint decision memo is included in  Appendix D.

The period of time until a response to a dielectric oil cable leak occurs incorporates many different aspects of the response. Additionally, the amount of time it takes to repair a dielectric cable leak has a direct correlation to the amount of product discharged. The total amount of dielectric oil spilled needs to be calculated using specific information on cable size, leak hole size, fluid properties, and water depths.⁴ Remarkably, the rate at which dielectric oil is discharged in a leak has historically been very slow, but if the duration of the detection/repairs is long, then the impacts from the amount of oil could be substantial even for a small leak.

Given the speed of today's technology, it may seem absurd that it would take months to fix a leak. However, dielectric cable spill repair can be very complex because these vital lines provide critical electricity to major metropolitan areas. Additionally, when these lines are underwater, they are buried five to six feet under sediment. Therefore, once a leak is detected underwater, the location of the cable break may not be in the exact position of the dielectric fluid detection. Therefore, finding a dielectric leak is similar to finding a needle in a haystack; it is a very labor-intensive process.

While the investigative work is underway on the leaking dielectric cable lines, the highly pressurized lines cannot be shut-off since they would then experience water intrusion. Water intrusion into an electrical line would render the whole line unsafe and it could require line replacement. Electric companies have a mandatory regulatory obligation to provide utility to the public. Hence, an electric company's priority is to protect the energy grid and the cost/benefit analysis of a dielectric oil leak can result in inaction.

The best recovery method for cleaning up dislectric leaks does not necessarily remove most of the oil from the water. The common method for containing floating dielectric oil from the marine environment is through using a boom. The boom creates collection areas by using wind and current to corral the oil into one place where it can be removed. The performance ranges from excellent in calm, low current waters to poor in high wave, wind, and current conditions (Exxon Mobile, 2015). Once the dielectric oil is collected, oil can then be removed by using skimmers and an absorbent material called sorbent boom.

An effective boom clean-up strategy requires a sophisticated logistical framework in addition to equipment. Booming methods require booms, skimmers or sorbents, boats, trained crew, anchors, vacuum trucks, and a way of replacing the sorbent boom. In sensitive environments, the equipment required to do manual removal of oil can be more damaging to the environment than letting the natural processes degrade the oil. Clean-up objectives should take into consideration the speed of the natural recovery in affected areas (Michel, J., & Benggio, B., 1999). Removal efforts should only be implemented when it will speed up natural recovery of affected resources. Otherwise, natural recovery is preferable (Michel, J., & Benggio, B., 1999).

Numerous factors can affect the cost of an oil spill; the most important being geographic location. Each undersea area will have its specific geographic differences and available of resources. Since underwater electric lines provide electricity to urban areas, the costs to get equipment and personnel onsite are usually low. However, if the dielectric oil is in a location that affects the transportation or a location that is very visible to the public, response costs can greatly increase. Other factors that can drastically change costs are the need for excavation of a site to get to the leak location or sites that are contained and therefore are easy to manage. Based on the dielectric oil type, the costs for the clean-up of dielectric spills are generally far more economical than heavy crude oil spills that are highly visible and have an extensive clean-up process if the oil reaches the shoreline.

Different clean-up strategies for dielectric spills will also change the overall cost of the spill. Notably, mechanical methods (such as using a sorbent boom) that have significant logistical needs drive costs up, while other methods such as using vacuum trucks to pick up oily water can keep costs down. Lastly, the amount of oil spilled will drive up the cost factors. This relates back to the time component. Generally speaking, the longer the spill continues, the higher the costs.⁵

When an underwater dielectric incident triggers a response, there are many subject matter experts that can provide services. Coordination and participation of local, state, federal agencies, and private industry is key to a successful response. There a several special teams that are available to provide support including the following:

In an effort to address the underwater dielectric fluid leaks, this paper presented generalized best practices based on extensive past case study actions. Based on information from past case studies, it was determined that the success of a dielectric spill response depends on three variables: the amount of time until completion, damage to natural resources, and cost minimization. Another contributing factor to the success of a response is the ability to utilize the best practice techniques of notification, discovery methods, sampling strategy, potential toxicity, effective clean-up strategies, and clean-up endpoints. The research concludes that by acknowledging that these spills will be reoccurring until upgrades and increased maintenance improves upon our aging infrastructure.

In short, the infrastructure, some of which dates back to the 1950's, is going to generate problems in the future. The U.S. electrical infrastructure is a vital service provided to the public. However, further research and coordinated efforts are necessary in order to upgrade the electrical infrastructure and minimize dielectric fluid spills. The combination of aging infrastructure and the frequency of the dielectric spills has become a topic of conversation for regulators and environmentalists.. In conclusion, a more proactive stance needs to be taken against PTC spills as opposed to the current reactive process.

Reference: Hazardous Materials Response Special Teams Capabilities and Contact Handbook

Department of Interior (DOI)

• 1) Office of Emergency Management (OEM): The office of OEM can provide expertise for the Department's emergency management responsibilities through programs, functions, and supporting activities to prevent, protect against, mitigate the effects of, respond to, and recover from all hazards. The office of OEM can be useful if there are trustee concerns including historic properties, tribes, National Parks etc.

National Oceanic and Atmospheric Administration (NOAA)

• 1)Scientific Support Coordinator (SSC): The NOAA SSCs are part of NOAA's Office of Response and Restoration. NOAA SSCs are interdisciplinary scientific teams that support the Federal On-Scene Coordinator, and respond to oil and chemical spills in U.S. waters. NOAA SSCs help the On-Scene Coordinator make timely operational decisions. The team is headquartered at NOAA's campus in Seattle; however, members are located around the country to represent the team at spills, drawing on the team's spill trajectory estimates, chemical hazards analyses, and assessments of the sensitivity of biological and human-use resources. OR&R staff members also represent NOAA on the National Response Team and Regional Response Teams.

U.S. Coast Guard (USCG):

• 1) National Response Center (NRC):The NRC is a part of the federally established National Response System and staffed 24 hours a day by the U.S. Coast Guard. It is the designated federal point of contact for reporting all oil, chemical, radiological, biological and etiological discharges into the environment, anywhere in the United States and its territories. The NRC also takes maritime reports of suspicious activity and security breaches within the waters of the United States and its territories. Reports to the NRC activate the National Contingency Plan (NCP) and the federal government's response capabilities. It is the responsibility of the NRC staff to notify the pre-designated On Scene Coordinator assigned to the area of the incident and to collect available information on the size and nature of the release, the facility or vessel involved, and the party(ies) responsible for the release. The NRC maintains reports of all releases and spills in a national database. The NRC can be contacted at 800-424-8802.

• 2) National Strike Force (NSF):Units of the NSF maintain the capability to support incident management operations, and specialized response capabilities. The Atlantic Strike Team, located at Joint Base McGuire-Dix-Lakehurst, is one of three strike teams of the NSF. AST is a vital national asset comprised of a unique, highly trained cadre of Coast Guard professionals who maintain and rapidly deploy with specialized equipment and incident management skills, including maritime environmental response, weapons of mass destruction (WMD), and Chemical, Biological, Radiological, and Nuclear (CBRN) response. The Public Affairs Information Assist Team (PIAT), also operates under the National Strike Force. The AST can be dispatched via communications with the District 5 command center, Critical Incident Reporting, and/or via the NSF command center (NSFCC) at 252-331-6000.

• 3) Coast Guard Incident Management Assist Team (IMAT):The IMAT, also part of the NSF, is designed to support tactical incident responses. This team represents the highest level of ICS experience and qualifications in the Coast Guard and its members are available upon request to assist operational or incident commanders during significant contingencies. The IMAT may be requested through the District 5 command center, Critical Incident Reporting mechanisms, and/or via the NSFCC.

• 4) Coast Guard Public Information Assist Team (PIAT): The PIAT, is also a part of the NSF, is responsible for assisting OSCs in meeting the demands for public information during a response.

U.S. Environmental Protection Agency (EPA)

• 1)Facilities: Enforces regulations on Spill prevention, control, and countermeasure (SPCC) which establish requirements for transportation related facilities that could be reasonably expected to discharge oil into navigable waters. The SPCC Plan must address all relevant spill protection, control, and countermeasures necessary.

• 2) Environmental Response Team (ERT): Capable of conducting on-site health and safety assessments (including chemical, biological and physical treatment and monitoring) to determine if immediate threats to personnel safety exist. Coast Guard commanders who have reason to suspect threats to physical safety exist should contact the ERT via the National Response Center (NRC) at 1-800-424-8802 or EPA's Emergency Operations Center.

• 1) Departments of Environmental Protection (DEP): DEP's administer the state's environmental protection, conservation, and emergency response efforts.

• 2) Offices of Emergency Management (OEM): OEM is the lead state agency for coordination of comprehensive emergency preparedness, training, response, recovery and mitigation services.

• 1) Fire Departments: Some municipal fire departments have specialized HAZMAT units. State/municipal HAZMAT capabilities should be coordinated through the cognizant state office of emergency management or regional operations/dispatch center.

• 2) Emergency Medical Services (EMS): Local EMS organizations are responsible for responding to requests for medical assistance, depending upon the severity of the incident in terms of number of casualties and extent of exposure.

• 3) Harbormaster:Local harbormasters are usually employed by the town in which the harbor is located. They may be part of the local law enforcement agency or may have powers delegated to them directly by the town or city council. Harbormasters may be able to readily facilitate movement of vessels within the harbor and clear dock space as needed for the response.

• 1) Electric Companies: The Electric Companies have a vested interest in the transmission of electricity to the public. The Electric Companies can provide critical information on dielectric fluid systems and transmission stations. It is in the mutual interests of both groups to work together on these complicated incidents

Name of Requester: MSSR2 Omar Borges, USCG

Federally Defined Response Area: Boston Harbor

Product Spilled: DF 100

Effective date of proposal:

Subj: DECISION MEMO REGARDING THE MITIGATION OF ENVIRONMENTAL THREATS FROM THE MYSTIC RIVER DIELECTRIC SPILL UNIFIED COMMAND

The Unified Command is comprised of entities or agencies, which have jurisdictional responsibilities during response to an incident. In this case the governing authorities are the U.S. Coast Guard, Federal on Scene Coordinator for the Coastal Zone, Massachusetts Department of Environmental Protection, State on Scene Coordinator and the Responsible Party Eversource Energy as defined in 40 Code of Federal Regulations 300.5.

END POINT GUIDING PRINCIPLES

Shoreline treatment or shoreline cleanup endpoints are specific criteria assigned to a segment or unit of oiled shoreline or river bank that are used to define when sufficient treatment effort has been completed for that segment or unit. In effect, the endpoints are the practical definition of ‘clean’ for that particular segment of shoreline in that particular spill. The selection of appropriate and practical end points is part of the net environmental benefit evaluation in the decision process that is conducted during the development of the shoreline treatment plan. Endpoints affect the selection of response strategies and tactics, provide a target for the operations team, and are a standard against which the achievement of treatment can be compared so that closure can be achieved.

INCIDENT ENDPOINTS

MAN-MADE STRUCTURES - PILINGS, SEAWALLS, SHEET-PILE (NONPOROUS OR LOW POROSITY OBJECTS):

Structures shall be free of bulk oil and not produce a sheen under all weather conditions.

Oil stains that cannot be removed easily will remain to weather and degrade naturally.

It may not be feasible to remove impacted media with heavier (non-sheening) oil in some inaccessible areas.

No sheen on the water surface under all weather conditions.

MAN-MADE STRUCTURES - RIPRAP AND LARGE OBJECTS:

Oiled riprap shall be free of bulk oil and not produce a sheen under all weather conditions.

Oil stains that cannot be removed without an inordinate level of effort will be allowed to weather and degrade naturally.

Some inaccessible patches of oil may not be feasible to remove.

No sheen on the water surface under all weather conditions.

MIXED SEDIMENT/GRAVEL/COBBLE SHORELINES:

Oiled shorelines shall be free of bulk oil and not produce a sheen under all weather conditions.

No sheen on the water surface under all weather conditions.

OUTFALL:

The area shall be free of recoverable and potentially mobile oil.

No sheen on the water surface under all weather conditions.

Approval: (check one) Yes______ No_____

Federal on Scene Coordinator

___________________________________________________________.

State on Scene Coordinator

___________________________________________________________.

Incident Commander

___________________________________________________________.

Responsible Party

___________________________________________________________.