6. Environmental Liabilities and Expenditures

Occidental’s operations are subject to stringent federal, state, local and foreign laws, and regulations related to improving or maintaining environmental quality. The laws that require or address environmental remediation, including the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and similar federal, state, local and foreign laws, may apply retroactively and regardless of fault, the legality of the original activities or the current ownership or control of sites. OPC or certain of its subsidiaries participate in or actively monitor a range of remedial activities and government or private proceedings under these laws with respect to alleged past practices at operating, closed and third-party sites. Remedial activities may include one or more of the following: investigation involving sampling, modeling, risk assessment or monitoring; cleanup measures including removal, treatment or disposal of hazardous substances; or operation and maintenance of remedial systems. These environmental proceedings seek funding or performance of remediation and, in some cases, compensation for alleged property damage, punitive damages, civil penalties, injunctive relief and government oversight costs.

As of September 30, 2017, Occidental participated in or monitored remedial activities or proceedings at 148 sites. The following table presents Occidental’s environmental remediation reserves as of September 30, 2017. The current portion of $131 million is included in accrued liabilities and the noncurrent portion of $732 million is included in deferred credits and other liabilities — other. The reserves are grouped as environmental remediation sites listed or proposed for listing by the United States Environmental Protection Agency on the CERCLA National Priorities List (NPL sites) and three categories of non-NPL sites — third-party sites, Occidental-operated sites and closed or non-operated Occidental sites.

	Number of Sites	Reserve Balance (in millions)
NPL sites	34	$	458
Third-party sites	69	164
Occidental-operated sites	15	108
Closed or non-operated Occidental sites	30	133
Total	148	$	863

As of September 30, 2017, Occidental’s environmental reserves exceeded $10 million each at 16 of the 148 sites described above, and 88 of the sites each had reserves of $1 million or less. Based on current estimates, Occidental expects to expend funds corresponding to approximately half of the current environmental reserves at the sites described above over the next three to four years and the balance at these sites over the subsequent 10 or more years. Occidental believes its estimable amount of reasonably possible additional losses beyond those liabilities recorded for environmental remediation at these sites could range up to $1.1 billion. The status of Occidental’s involvement with the sites and related significant assumptions, including those sites indemnified by Maxus Energy Corporation (see further discussion below), has not changed materially since December 31, 2016.

When Occidental acquired Diamond Shamrock Chemicals Company (DSCC) in 1986, Maxus Energy Corporation (Maxus), formerly a subsidiary of YPF S.A. (YPF), agreed to indemnify Occidental for a number of environmental sites, including the Diamond Alkali Superfund Site (Site) along a portion of the Passaic River. On June 17, 2016, Maxus and several affiliated companies filed for Chapter 11 bankruptcy in Federal District Court in the State of Delaware. Prior to filing for bankruptcy, Maxus defended and indemnified Occidental in connection with cleanup and other costs associated with the sites subject to the indemnity, including the Site. Occidental is pursuing Maxus’ current and former parent companies, YPF and Repsol, as the alter egos of Maxus, to recover all indemnified costs, which will include costs to be incurred at the Site.

In March 2016, the EPA issued a Record of Decision (ROD) specifying remedial actions required for the lower 8.3 miles of the Lower Passaic River. The ROD does not address any potential remedial action for the upper nine miles of the Lower Passaic River or Newark Bay. During the third quarter of 2016, and following Maxus’s bankruptcy filing, Occidental and the EPA entered into an Administrative Order on Consent (AOC) to complete the design of the proposed cleanup plan outlined in the ROD at an estimated cost of $165 million. The EPA announced that it will pursue similar agreements with other potentially responsible parties.

Occidental has accrued a reserve relating to its estimated allocable share of the costs to perform the design and the remediation called for in the AOC and the ROD, as well as for certain other Maxus-indemnified sites. Occidental’s accrued estimated environmental reserve does not consider any recoveries for indemnified costs. Occidental’s ultimate share of this liability may be higher or lower than the reserved amount, and is subject to final design plans and the resolution of Occidental’s allocable share with other potentially responsible parties. Occidental continues to evaluate the costs to be incurred to comply with the AOC, the ROD and to perform remediation at other Maxus-indemnified sites in light of the Maxus bankruptcy and the share of ultimate liability of other potentially responsible parties. In June 2017, the court overseeing the Maxus bankruptcy approved a Plan of Liquidation (Plan) to liquidate Maxus and create a trust to pursue claims against YPF, Repsol and others to satisfy claims by Occidental and other creditors for past and future cleanup and other costs. In July 2017, the court-approved Plan became final and the trust became effective. Among other responsibilities, the trust will pursue claims against YPF, Repsol and others and distribute assets to Maxus’ creditors in accordance with the trust agreement and Plan.