Litigation In the ordinary conduct of our business, we are from time to time subject to lawsuits, investigations and claims, including environmental claims and employee-related matters. Although we cannot predict with certainty the ultimate resolution of lawsuits, investigations and claims asserted against us, including civil penalties or other enforcement actions, we do not believe that any currently pending legal proceeding or proceedings to which we are a party will have a material adverse effect on our financial statements. Certain environmental matters that have or may result in penalties or assessments are discussed below in the " Environmental, Health and Safety" section of this note. One of our Alon subsidiaries was the defendant in a legal action related to an easement dispute arising from a purchase of property that occurred in October 2013. In June 2019, the court found in favor of the plaintiffs and assessed damages against such subsidiary totaling $6.7 million , which is included as of June 30, 2020 in accrued expenses and other current liabilities on the accompanying condensed consolidated balance sheet. Self-insurance Delek records a self-insurance accrual for workers compensation claims up to a $4.0 million deductible on a per accident basis, general liability claims up to $4.0 million on a per occurrence basis and medical claims for eligible full-time employees up to $0.3 million per covered individual per calendar year. We also record a self-insurance accrual for auto liability up to a $4.0 million deductible on a per accident basis. We have umbrella liability insurance available to each of our segments in an amount determined reasonable by management. Environmental, Health and Safety We are subject to extensive federal, state and local environmental and safety laws and regulations enforced by various agencies, including the EPA, the United States Department of Transportation, the Occupational Safety and Health Administration, as well as numerous state, regional and local environmental, safety and pipeline agencies. These laws and regulations govern the discharge of materials into the environment, waste management practices, pollution prevention measures and the composition of the fuels we produce, as well as the safe operation of our plants and pipelines and the safety of our workers and the public. Numerous permits or other authorizations are required under these laws and regulations for the operation of our refineries, renewable fuels facilities, terminals, pipelines, underground storage tanks, trucks, rail cars and related operations, and may be subject to revocation, modification and renewal. These laws and permits raise potential exposure to future claims and lawsuits involving environmental and safety matters which could include soil and water contamination, air pollution, personal injury and property damage allegedly caused by substances which we manufactured, handled, used, released or disposed of, transported, or that relate to pre-existing conditions for which we have assumed responsibility. We believe that our current operations are in substantial compliance with existing environmental and safety requirements. However, there have been and will continue to be ongoing discussions about environmental and safety matters between us and federal and state authorities, including notices of violations, citations and other enforcement actions, some of which have resulted or may result in changes to operating procedures and in capital expenditures. While it is often difficult to quantify future environmental or safety related expenditures, we anticipate that continuing capital investments and changes in operating procedures will be required for the foreseeable future to comply with existing and new requirements, as well as evolving interpretations and more strict enforcement of existing laws and regulations. As of June 30, 2020 , we have recorded an environmental liability of approximately $112.9 million , primarily related to the estimated probable costs of remediating or otherwise addressing certain environmental issues of a non-capital nature at our refineries, as well as terminals, some of which we no longer own. This liability includes estimated costs for ongoing investigation and remediation efforts for known contamination of soil and groundwater. Approximately $6.6 million of the total liability is expected to be expended over the next 12 months, with most of the balance expended by 2032 , although some costs may extend up to 30 years. In the future, we could be required to extend the expected remediation period or undertake additional investigations of our refineries, pipelines and terminal facilities, which could result in the recognition of additional remediation liabilities. Crude Oil and Other Releases We have experienced several crude oil and other releases involving our assets. There were no material releases that occurred during the six months ended June 30, 2020 , and five releases that occurred throughout the year 2019. Cleanup operations and site maintenance and remediation efforts on these and other releases are at various stages of completion. The majority of the remediation efforts for these releases are substantially complete or have received regulatory closure. With the exception of the Sulphur Springs release defined below, we expect regulatory closure in 2020 for the release sites that have not yet received it. On October 3, 2019, a finished product release involving one of our pipelines occurred near Sulphur Springs, Texas (the "Sulphur Springs Release"). Cleanup operations and site maintenance and remediation on this release have been substantially completed where such costs incurred totaled $7.1 million during 2019. During the three and six months ended June 30, 2020 , we incurred approximately $0.1 million and $0.3 million of additional costs related to final clean-up of this release, respectively. The release is currently in boom maintenance. Ground water monitoring wells were installed in the second quarter of 2020. We expect to conduct quarterly ground water monitoring for at least a year. Additionally, we will be conducting creek bed sediment sampling in the third quarter of 2020. We have filed suit in January 2020 against a third party contractor, seeking damages related to this release. We have not received notification that any legal action with respect to fines and penalties will be pursued by the regulatory agencies. Expenses incurred for the remediation of these crude oil and other releases are included in operating expenses in our consolidated statements of income. Letters of Credit As of June 30, 2020 , we had in place letters of credit totaling approximately $204.6 million with various financial institutions securing obligations primarily with respect to our commodity transactions for the refining segment and certain of our insurance programs. There were no amounts drawn by beneficiaries of these letters of credit at June 30, 2020 .