Westlake Chemical Partners (WLKP) 10-K2023 FY Annual report

Our business and operations are conducted through OpCo. Because we own OpCo's general partner, we have control over all of OpCo's assets and operations. As of December 31, 2023, Westlake held a 77.2% limited partner interest in OpCo and held a 40.1% limited partner interest in us (consisting of 14,122,230 common units), our general partner interest and our incentive distribution rights.

OpCo's assets are comprised of three ethylene production facilities, which primarily convert ethane into ethylene and have an aggregate annual capacity of approximately 3.7 billion pounds, and a 200-mile ethylene pipeline. OpCo derives substantially all of its revenue from these ethylene production facilities. Ethylene is the world's most widely used petrochemical in terms of volume and is a key building block used to produce a number of key derivatives, such as polyethylene ("PE") and polyvinyl chloride ("PVC"), which are used in a wide variety of end markets, including packaging, construction and transportation. Westlake's downstream PE and PVC production facilities consume a substantial majority of the ethylene produced by OpCo. OpCo generates revenue primarily by selling ethylene to Westlake and others, as well as through the sale of co-products of ethylene production, including propylene, crude butadiene, pyrolysis gasoline and hydrogen. Our sole revenue generating asset is our 22.8% limited partner interest in OpCo.

Our assets and operations are organized into a single reportable segment and are all located and conducted in the United States. See "Item 8. Financial Statements and Supplementary Data" for financial information on our operations and assets; such information is incorporated herein by reference.

Among other agreements entered into in connection with the closing of the IPO, OpCo entered into a 12-year ethylene sales agreement with Westlake, under which Westlake agreed to purchase 95% of OpCo's planned ethylene production each year, on a cost-plus basis that is expected to generate a fixed margin per pound of $0.10 (the "Ethylene Sales Agreement"). Any ethylene not sold to Westlake and all co-products that are produced by OpCo will be sold to third parties on either a spot or contract basis. OpCo also entered into a feedstock supply agreement with Westlake that supplies OpCo with ethane (and any other feedstocks) required for OpCo to produce ethylene under the Ethylene Sales Agreement (the "Feedstock Supply Agreement"). OpCo primarily uses ethane (a component of natural gas liquids, or NGLs) to produce ethylene.

As the owner of the general partner interest of OpCo, we control all aspects of the management of OpCo, including its cash distribution policy. See "—OpCo's Assets."

The following table provides information regarding OpCo's ethylene production facilities as of December 31, 2023:

Lake Charles Olefins

Within Westlake's Lake Charles site, Petro 1 and Petro 2 are connected by pipeline systems to Westlake's polyethylene plants. Westlake may use the ethylene it purchases from OpCo at its Lake Charles facilities or transfer it to its Geismar facility or its Longview facility, either through physical transportation or via exchange transactions. Westlake may also use the ethylene it purchases from OpCo with chlorine to produce ethylene dichloride and transport it via barge to Westlake's Calvert City site.

In addition, OpCo produces ethylene co-products including chemical grade propylene, crude butadiene, pyrolysis gasoline and hydrogen. OpCo sells its output of these co-products to external customers.

Calvert City Olefins

Pipeline

Technology

Ethylene Sales Agreement

Certain of the pricing components that make up the price for ethylene sold under the Ethylene Sales Agreement are modified to reflect the portion of OpCo's production capacity that is used to process Westlake's purge gas instead of producing ethylene. Costs specific to the processing of Westlake's purge gas are recovered under the Services and Secondment Agreement (as described below), and not the Ethylene Sales Agreement.

Under the Ethylene Sales Agreement, OpCo has the option to curtail up to approximately 5% of its ethylene production annually in the event OpCo reasonably determines that its sales of such ethylene to third parties during the relevant period would be uneconomic.

The Ethylene Sales Agreement provides that, if compliance with any law adopted or modified following our IPO results in OpCo incurring additional costs in excess of $500,000 in any contract year, OpCo is entitled to charge Westlake a monthly surcharge following efforts to mitigate the effects of such compliance.

Feedstock Supply Agreement

Services and Secondment Agreement

Site Lease Agreements

Omnibus Agreement

Exchange Agreement

OpCo Partnership Agreement

Investment Management Agreement

See "Liquidity and Capital Resources" in Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations" for a discussion of the Partnership's and OpCo's debt agreements with Westlake and "Interest Rate Risk" in Item 7A. "Quantitative and Qualitative Disclosures about Market Risk" for a discussion of the Partnership's interest rate contract with Westlake.

Also, see the discussion of our environmental matters contained in "Item 1A. Risk Factors" and "Item 3. Legal Proceedings" below.

We intend to satisfy the requirement under Item 5.05 of Form 8-K to disclose any amendments to our Code of Ethics and any waiver from a provision of our Code of Ethics by posting such information on our website at www.wlkpartners.com under "Investor Relations/Corporate Governance."

Risks Inherent in Our Business

Risks Relating to Our Partnership Structure

We are substantially dependent on Westlake for our cash flows. If Westlake does not pay us under the terms of the Ethylene Sales Agreement or if our assets fail to perform as intended, we may not have sufficient cash from operations following the establishment of cash reserves and payment of costs and expenses, including cost reimbursements to our general partner and its affiliates, to enable us to pay the minimum quarterly distribution to our unitholders.

Westlake may be unable to generate enough cash flow from operations to meet its minimum obligations under the Ethylene Sales Agreement if its business is adversely impacted by competition, operational problems, general adverse economic conditions or the inability to obtain feedstock. For example, lower prices of crude oil could lead to a reduction in the cost advantage for natural gas liquids-based ethylene derivatives in North America, such as Westlake's, as compared to naphtha-based ethylene derivatives. As a result, Westlake's margins and cash flows could be negatively impacted during such period. If Westlake is not able to meet its minimum payment obligations to OpCo as a result of any one or more of these factors, our ability to make distributions to our unitholders would be reduced or eliminated. The amount paid by Westlake will depend upon its ability to satisfy its minimum obligations under the Ethylene Sales Agreement and its ability and election to increase volumes above the minimums specified in the Ethylene Sales Agreement, which in turn are dependent upon, among other things, the level of polyethylene and polyvinyl chloride production at Westlake's other facilities, as well as industry capacity expansion in these downstream products in North America, a number of which have been recently completed. If Westlake is unable to generate sufficient cash flow from its operations to meet its obligations, or otherwise defaults on its obligations, under the Ethylene Sales Agreement, OpCo will not have sufficient available cash to distribute to us to enable us to pay the minimum quarterly distribution set forth in our cash distribution policy. As a result, our ability to pay the minimum quarterly distribution is based on the following factors, some of which are beyond our control:

OpCo is subject to the credit risk of Westlake on a substantial majority of its revenues, and Westlake's leverage and creditworthiness could adversely affect our ability to make distributions to our unitholders.

Westlake has not agreed with us to limit its ability to incur indebtedness, pledge or sell assets or make investments, and we have no control over the amount of indebtedness Westlake incurs, the assets it pledges or sells or the investments it makes.

These covenants may adversely affect OpCo's ability to finance future business opportunities. A breach of any of these covenants could result in a default in respect of the related debt. If a default occurred, the relevant lenders could elect to declare the debt, together with accrued interest and other fees, to be immediately due and payable and proceed against any collateral securing that debt, including OpCo and its assets. In addition, any acceleration of debt under Westlake's credit facility will constitute a default under some of Westlake's other debt, including the indentures governing its senior notes.

The ethylene sales price charged under the Ethylene Sales Agreement is designed to permit OpCo to cover the substantial majority of its operating costs, but not our public partnership and other OpCo costs, which reduce our net operating profit.

The fee structure of the Ethylene Sales Agreement may limit OpCo's ability to take advantage of favorable market developments in the future.

If OpCo is unable to renew or extend the Ethylene Sales Agreement beyond the initial 12-year term or the other agreements with Westlake upon expiration of these agreements, our ability to make distributions in the future could be materially adversely affected and the value of our units could decline.

OpCo has the right to use the real property underlying Lake Charles Olefins and Calvert City Olefins pursuant to two, 50-year site lease agreements with Westlake. If OpCo is not able to renew the site lease agreements or if the site lease agreements are terminated by Westlake, OpCo may have to relocate Lake Charles Olefins and Calvert City Olefins, abandon the assets or sell the assets to Westlake.

OpCo depends upon Westlake for numerous services and for its labor force.

OpCo's ability to receive greater cash flows from increased production may be limited by the Ethylene Sales Agreement.

Cost reimbursements due to our general partner and Westlake for services provided to us or on our behalf reduce our earnings and therefore our cash available for distribution to our unitholders. The amount and timing of such reimbursements are determined by our general partner.

Substantially all of OpCo's sales are generated at three facilities located at two sites. Any adverse developments at any of these facilities or sites could have a material adverse effect on our results of operations and therefore our ability to distribute cash to unitholders.

Because substantially all of OpCo's sales are generated at three facilities located at two sites, any such events at any facility or site could significantly disrupt OpCo's ethylene production and its ability to supply ethylene to its customers. For example, OpCo's Lake Charles facility was shut down for a significant period of time in the months of August, September and October 2020 in the aftermath of Hurricanes Laura and Delta. Any similar or other sustained disruption in OpCo's ability to meet its supply obligations under the Ethylene Sales Agreement could have a material adverse effect on our results of operations and therefore our ability to distribute cash to unitholders.

The amount of cash we have available for distribution to holders of our units depends primarily on our cash flow and not solely on profitability, which may prevent us from making cash distributions during periods when we record net income.

If we are unable to make acquisitions from Westlake or third parties on economically acceptable terms, our future growth would be limited, and any acquisitions we make may reduce, rather than increase, our cash generated from operations on a per unit basis.

If we consummate any future acquisitions, our capitalization and results of operations may change significantly, and unitholders will not have the opportunity to evaluate the economic, financial and other relevant information that we will consider in determining the application of our funds and other resources.

Many of our assets have been in service for many years and require significant expenditures to maintain them. As a result, our maintenance or repair costs may increase in the future. In addition, while we establish cash reserves in order to cover turnaround expenditures, the amounts we reserve may not be sufficient to fully cover such expenditures.

Our production facilities process volatile and hazardous materials that subject us to operating risks that could adversely affect our operating results.

All of these hazards can cause personal injury and loss of life, catastrophic damage to or destruction of property and equipment and environmental damage, and may result in a suspension of operations and the imposition of civil or criminal penalties. We could become subject to environmental claims brought by governmental entities or third parties. A loss or shutdown of operations over an extended period at any one of our three major operating facilities would have a material adverse effect on us. Through Westlake, we maintain property, business interruption and casualty insurance that we believe is in accordance with customary industry practices, but we cannot be fully insured against all potential hazards incident to our business, including losses resulting from wars or terrorist acts, among other things. In addition, certain policies may be subject to coverage limitations, which may affect the extent of any recovery thereunder. As a result of market conditions and past claims, premiums and deductibles for certain insurance policies can increase substantially and, in some instances, certain insurance may become unavailable or available only for reduced amounts of coverage. If we were to incur a significant liability for which we were not fully insured, it could have a material adverse effect on our financial position.

Our operations and assets are subject to extensive environmental, health and safety laws and regulations.

In April 2023, the EPA proposed amendments to new source performance standards for the synthetic organic chemical manufacturing industry and amendments to the national emissions standards for hazardous air pollutants for the synthetic organic chemical manufacturing industry and group I & II polymers and resins industry. These proposed amendments, among other things, would impose tougher emissions limits, additional leak detection and repair obligations, certain performance standards for the operation of flares at applicable facilities, and new fenceline air monitoring for several chemicals. Although we cannot predict the outcome or timing of EPA's final rule amendments, the amendments as proposed would require us to incur further capital expenditures and increase operating costs.

Our operations also produce greenhouse gas ("GHG") emissions, which have been the subject of increased scrutiny and regulation. In December 2015, the United States joined the international community at the 21st Conference of the Parties of the United Nations Framework Convention on Climate Change in Paris, France. The resulting Paris Agreement calls for the parties to undertake "ambitious efforts" to limit the average global temperature and to conserve and enhance sinks and reservoirs of greenhouse gases. The United States signed the Paris Agreement in April 2016, and the Paris Agreement went into effect in November 2016. In November 2019, the United States submitted formal notification to the United Nations that it intended to withdraw from the Paris Agreement. The withdrawal took effect in November 2020. However, President Biden signed an executive order on January 20, 2021 for reentry of the United States into the Paris Agreement and on February 19, 2021, President Biden formally rejoined the Paris Agreement. As part of rejoining the Paris Agreement, President Biden announced that the United States would commit to a 50 to 52 percent reduction from 2005 levels of GHG emissions by 2030 and set the goal of reaching net-zero GHG emissions by 2050. To measure progress towards this target, the Paris Agreement requires the parties to complete a global stocktake, assessing members' collective efforts and achievements in reducing GHG emissions and adapting to the impacts of climate change, every five years. On December 13, 2023, the 28th annual United Nations Climate Change Conference ("COP 28"), which was held in Dubai, issued its first global stocktake, which calls on parties, including the United States, to contribute to the transitioning away from fossil fuels, reduce methane emissions, and increase renewable energy capacity, among other things, to achieve net zero emissions by 2050. Legislation to regulate GHG emissions has periodically been introduced in the United States Congress, and such legislation may be proposed or adopted in the future. There has been a wide-ranging policy debate regarding the impact of these gases and possible means for their regulation. Some of the proposals would require industries to meet stringent new standards that would require substantial reductions in carbon emissions. The adoption and implementation of any international, federal or state legislation or regulations that restrict emissions of GHGs could result in increased compliance costs or additional operating restrictions. The EPA has adopted rules requiring the reporting of GHG emissions from specified large GHG emission sources on an annual basis including our facilities in Lake Charles and Calvert City. Various jurisdictions have considered or adopted laws and regulations on GHG emissions, with the general aim of reducing such emissions. The EPA currently requires certain industrial facilities to report their GHG emissions and to obtain permits with stringent control requirements before constructing or modifying new facilities with significant criteria pollutant and GHG emissions. As our chemical processing results in GHG emissions, these and other GHG laws and regulations could affect our costs of doing business.

We also may face liability for alleged personal injury or property damage due to exposure to chemicals or other hazardous substances at our facilities or to chemicals that we otherwise manufacture, handle or own. Although these types of claims have not historically had a material impact on our operations, a significant increase in the success of these types of claims could have a material adverse effect on our business, financial condition, operating results or cash flow.

Environmental laws may have a significant effect on the nature and scope of, and responsibility for, cleanup of contamination at our current and former operating facilities, the costs of transportation and storage of raw materials and finished products, the costs of reducing emissions and the costs of the storage and disposal of wastewater. The U.S. Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA") and similar state laws impose joint and several liability for the costs of remedial investigations and actions on the entities that generated waste, arranged for disposal of the waste, transported to or selected the disposal sites, and the past and present owners and operators of disposal sites. All such potentially responsible parties (or any one of them, including us) may be required to bear all of such costs regardless of fault, legality of the original disposal or ownership of the disposal site. In addition, CERCLA and similar state laws could impose liability for damages to natural resources caused by contamination.

Although we seek to take preventive action, our operations are inherently subject to accidental spills, discharges or other releases of hazardous substances that may make us liable to governmental entities or private parties. This may involve contamination associated with our current and former facilities, facilities to which we sent wastes or by-products for treatment or disposal and other contamination. Accidental discharges may occur in the future, future action may be taken in connection with past discharges, governmental agencies may assess damages or penalties against us in connection with any past or future contamination, or third parties may assert claims against us for damages allegedly arising out of any past or future contamination. In addition, we may be liable for existing contamination related to certain of our facilities for which, in some cases, we believe third parties are liable in the event such third parties fail to perform their obligations.

Our operations and assets are subject to climate-related risks and uncertainties.

We are subject to operational and financial risks and liabilities associated with the implementation of and efforts to achieve carbon emission reduction goals.

Failure to adequately protect critical data and technology systems could materially affect our operations.

Information technology system failures, network disruptions and breaches of data security due to internal or external factors including cyber-attacks could have material adverse impacts on our business or cause disruptions to our operations. Such disruptions could include, but are not limited to, delaying or cancelling customer orders, impeding the manufacture or shipment of products or causing standard business processes to become ineffective, or the unintentional or malicious disclosure of proprietary, confidential or other sensitive information. Cyber-attacks could include, but are not limited to, ransomware attacks, malicious software, attempts to gain unauthorized access to our systems or data or other electronic security breaches that could lead to disruptions in critical systems, unauthorized release, corruption or loss of data including protected information such as personal information of our employees, interruptions in communication, loss of our intellectual property or theft of our sensitive or proprietary technology, loss or damage to our data delivery systems, or other cybersecurity and infrastructure systems, including our property and equipment.

Westlake's and our employees, systems, networks, products, facilities and services remain potentially vulnerable to sophisticated cyber-attacks, including the additional cybersecurity risks posed by the increased use of remote networking technologies and services, and, as such, there can be no assurance that a system failure, network disruption or data security breach will not have a material adverse effect on our operations, business, financial condition, operating results or cash flow. In addition, laws and regulations governing cybersecurity, data privacy, and the unauthorized disclosure of confidential or protected information pose increasingly complex compliance challenges, and failure to comply with these laws could result in penalties and legal liability.

Our variable-rate debt exposes us to increases in interest rates, which could have a material impact on our financial position, results of operation and cash flows, and could reduce the price at which our common units trade.

The Board of Governors of the Federal Reserve System increased benchmark interest rates seven times in 2022, four times in 2023, and may further raise rates in future periods. Should interest rates increase significantly, the amount of cash required to service our debt would increase. As a result, significant increases in interest rates could have a material impact on our financial position, results of operations and cash flows.

An increase in interest rates may also cause a corresponding decline in demand for equity securities in general, and in particular, for yield-based equity securities such as our common units. A reduction in demand for our common units may cause their trading price to decline.

A terrorist attack or armed conflict could harm our business.

Our general partner has limited its liability regarding our obligations.

Our partnership agreement replaces our general partner's fiduciary duties to holders of our units.

By purchasing a common unit, a unitholder is treated as having consented to the provisions in the partnership agreement, including the provisions discussed above.

Our partnership agreement restricts the remedies available to holders of our units for actions taken by our general partner that might otherwise constitute breaches of fiduciary duty.

In connection with a situation involving a transaction with an affiliate or a conflict of interest, other than one where our general partner is permitted to act in its sole discretion, any determination by our general partner must be made in good faith. If an affiliate transaction or the resolution of a conflict of interest is not approved by our common unitholders or the conflicts committee, then it will be presumed that, in making its decision, taking any action or failing to act, the board of directors acted in good faith, and in any proceeding brought by or on behalf of any limited partner or the partnership, the person bringing or prosecuting such proceeding will have the burden of overcoming such presumption.

Our partnership agreement provides that the conflicts committee of the board of directors may be comprised of one or more independent directors. If the board of directors establishes a conflicts committee with only one independent director, your interests may not be as well served as if the conflicts committee was comprised of at least two independent directors. A single-member conflicts committee would not have the benefit of discussion with, and input from, other independent directors.

Westlake and other affiliates of our general partner may compete with us.

Pursuant to the terms of our partnership agreement, the doctrine of corporate opportunity, or any analogous doctrine, does not apply to our general partner or any of its affiliates, including its executive officers and directors and Westlake. Any such person or entity that becomes aware of a potential transaction, agreement, arrangement or other matter that may be an opportunity for us will not have any duty to communicate or offer such opportunity to us. Any such person or entity will not be liable to us or to any limited partner for breach of any fiduciary duty or other duty by reason of the fact that such person or entity pursues or acquires such opportunity for itself, directs such opportunity to another person or entity or does not communicate such opportunity or information to us. This may create actual and potential conflicts of interest between us and affiliates of our general partner and result in less than favorable treatment of us and our unitholders.

Holders of our common units have limited voting rights and are not entitled to elect our general partner or its directors, which could reduce the price at which our common units trade.

Even if holders of our common units are dissatisfied, they cannot currently remove our general partner without its consent.

Control of our general partner may be transferred to a third party without unitholder consent.

Our general partner has a call right that may require unitholders to sell their common units at an undesirable time or price.

In addition, our partnership agreement does not require us to pay any distributions at all. Accordingly, investors are cautioned not to place undue reliance on the permanence of such a policy in making an investment decision. Any modification or revocation of our cash distribution policy could substantially reduce or eliminate the amount we distribute to our unitholders. The amount of distributions we make, if any, and the decision to make any distribution at all will be determined by the board of directors, whose interests may differ from those of our common unitholders. Our general partner has limited duties to our unitholders, which may permit it to favor its own interests or the interests of Westlake to the detriment of our common unitholders.

We plan to distribute most of our available cash, which may cause our growth to proceed at a slower pace than that of businesses that reinvest their cash to expand ongoing operations. To the extent we issue additional units in connection with any acquisitions or expansion capital expenditures, the payment of distributions on those additional units may increase the risk that we will be unable to maintain or increase our per unit distribution level. There are no limitations in our partnership agreement on our ability to issue additional units, including units ranking senior to the common units. The incurrence of additional commercial borrowings or other debt to finance our growth strategy would result in increased interest expense, which, in turn, may impact the cash that we have available to distribute to our unitholders.

The holder or holders of our incentive distribution rights may elect to cause us to issue common units to it in connection with a resetting of the target distribution levels related to the incentive distribution rights, without the approval of the conflicts committee of our board of directors or the holders of our common units. This could result in lower distributions to holders of our common units.

Westlake, as the current holder of our incentive distribution rights, could exercise this reset right in order to facilitate acquisitions or internal growth projects that would not be sufficiently accretive to cash distributions per unit without such conversion. However, Westlake may transfer the incentive distribution rights at any time. It is possible that Westlake or a transferee could exercise this reset election at a time when we are experiencing declines in our aggregate cash distributions or at a time when the holders of the incentive distribution rights expect that we will experience declines in our aggregate cash distributions in the foreseeable future. In such situations, a holder of the incentive distribution rights may be experiencing, or may expect to experience, declines in the cash distributions it receives related to the incentive distribution rights and may therefore desire to be issued our common units rather than retain the right to receive incentive distributions based on the initial target distribution levels. As a result, a reset election may cause our common unitholders to experience reduction in the amount of cash distributions that they would have otherwise received had we not issued new common units to the holders of the incentive distribution rights in connection with resetting the target distribution levels.

The incentive distribution rights may be transferred to a third party without unitholder consent.

We may issue additional units without unitholder approval, which would dilute existing unitholder ownership interests.

The market price of our common units could be adversely affected by sales of substantial amounts of our common units in the public or private markets, including sales by Westlake or other large holders.

Our partnership agreement restricts the voting rights of unitholders owning 20% or more of our common units.

Unitholders may have liability to repay distributions.

Members of the investment community are increasing their focus on ESG practices and disclosures by public companies, including practices and disclosures related to climate change and sustainability, D&I initiatives and heightened governance standards. In March 2022, the SEC proposed enhanced climate-change disclosure requirements. As a result, we may continue to face increasing pressure regarding our ESG disclosures and practices. Additionally, members of the investment community may screen companies such as ours for ESG disclosures and performance before investing in our common units. Over the past few years, there has also been an acceleration in investor demand for ESG investing opportunities, and many large institutional investors have committed to increasing the percentage of their portfolios that are allocated towards ESG investments. With respect to any of these investors, our ESG disclosures and efforts may not satisfy the investor requirements or their requirements may not be made known to us. If we or our securities are unable to meet the ESG standards or investment criteria set by these investors and funds, we may lose investors or investors may allocate a portion of their capital away from us, our cost of capital may increase, and our common unit price may be negatively impacted.

Prior to our initial public offering, we requested and obtained a favorable private letter ruling from the IRS to the effect that, based on facts presented in the private letter ruling request, our income from the production, transportation, storage and marketing of ethylene and its co-products constitutes "qualifying income" within the meaning of Section 7704 of the Internal Revenue Code of 1986, as amended (the "Code"). However, no ruling has been or will be requested regarding our treatment as a partnership for U.S. federal income tax purposes. Failing to meet the qualifying income requirement or a change in current law could cause us to be treated as a corporation for U.S. federal income tax purposes or otherwise subject us to taxation as an entity.

If we were treated as a corporation for U.S. federal income tax purposes, we would pay U.S. federal income tax on our taxable income at the corporate tax rate. Distributions to our unitholders would generally be taxed again as corporate distributions, and no income, gains, losses or deductions would flow through to our unitholders. Because a tax would be imposed upon us as a corporation, our cash available for distribution to our unitholders would be substantially reduced. Therefore, treatment of us as a corporation would result in a material reduction in the anticipated cash flow and after-tax return to our unitholders, likely causing a substantial reduction in the value of our common units.

Our partnership agreement provides that if a law is enacted or existing law is modified or interpreted in a manner that subjects us to taxation as a corporation or otherwise subjects us to entity-level taxation for U.S. federal, state, local or foreign income tax purposes, the minimum quarterly distribution amount and the target distribution amounts may be adjusted to reflect the impact of that law or interpretation on us. At the state level, several states have been evaluating ways to subject partnerships to entity-level taxation through the imposition of state income, franchise or other forms of taxation. We currently own assets and conduct business in several states, most of which impose entity-level franchise or gross receipt taxes on partnerships. In the future, we may expand our operations. Imposition of similar entity-level taxes on us in other jurisdictions that we may expand to, could substantially reduce our cash available for distribution to our unitholders.

The tax treatment of publicly-traded partnerships or an investment in our units could be subject to potential legislative, judicial or administrative changes or differing interpretations, possibly applied on a retroactive basis.

If the IRS were to contest the U.S. federal income tax positions we take, it may adversely impact the market for our common units, and the costs of any such contest would reduce our cash available for distribution to our unitholders.

In the event the IRS makes an audit adjustment to our income tax returns and we do not or cannot shift the liability to our unitholders in accordance with their interests in us during the year under audit, we will generally have the ability to request that the IRS reduce the determined underpayment by reducing the suspended passive loss carryovers of our unitholders (without any compensation from us to such unitholders), to the extent such underpayment is attributable to a net decrease in passive activity losses allocable to certain partners. Such reduction, if approved by the IRS, will be binding on any affected unitholders.

Even if unitholders do not receive any cash distributions from us, unitholders will be required to pay taxes on their share of our taxable income.

A unitholder's share of our taxable income, and its relationship to any distributions we make, may be affected by a variety of factors, including our economic performance, which may be affected by numerous business, economic, regulatory, legislative, competitive and political uncertainties beyond our control, and certain transactions in which we might engage. For example, we may engage in transactions that produce substantial taxable income allocations to some or all of our unitholders without a corresponding increase in cash distributions to our unitholders, such as a sale or exchange of assets, the proceeds of which are reinvested in our business or used to reduce our debt, or an actual or deemed satisfaction of our indebtedness for an amount less than the adjusted issue price of the debt. A unitholder's ratio of its share of taxable income to the cash received by it may also be affected by changes in law.

From time to time, in connection with an offering of our common units, we may state an estimate of the ratio of U.S. federal taxable income to cash distributions that a purchaser of common units in that offering may receive in a given period. These estimates depend in part on factors that are unique to the offering with respect to which the estimate is stated, so the expected ratio applicable to other common units will be different, and in many cases less favorable, than these estimates. Moreover, even in the case of common units purchased in the offering to which the estimate relates, the estimate may be incorrect, due to the uncertainties described above, challenges by the IRS to tax reporting positions which we adopt, or other factors. The actual ratio of taxable income to cash distributions could be higher or lower than expected, and any differences could be material and could materially affect the value of the common units.

Tax gain or loss on the disposition of our common units could be more or less than expected.

A substantial portion of the amount realized from a unitholder's sale of our units, whether or not representing gain, may be taxed as ordinary income to such unitholder due to potential recapture items, including depreciation recapture. Thus, a unitholder may recognize both ordinary income and capital loss from the sale of units if the amount realized on a sale of such units is less than such unitholder's adjusted basis in the units. Net capital loss may only offset capital gains and, in the case of individuals, up to $3,000 of ordinary income per year. In the taxable period in which a unitholder sells its units, such unitholder may recognize ordinary income from our allocations of income and gain to such unitholder prior to the sale and from recapture items that generally cannot be offset by any capital loss recognized upon the sale of units.

Unitholders may be subject to limitation on their ability to deduct interest expense incurred by us.

If our "business interest" is subject to limitation under these rules, our unitholders will be limited in their ability to deduct their share of any interest expense that has been allocated to them. As a result, unitholders may be subject to limitation on their ability to deduct interest expense incurred by us.

Non-U.S. Unitholders will be subject to U.S. taxes and withholding with respect to their income and gain from owning our units.

In addition to the withholding tax imposed on distributions of effectively connected income, distributions to a non-U.S. unitholder will also be subject to a 10% withholding tax on the amount of any distribution in excess of our cumulative net income. Due to the complexity of the calculation and lack of clarity in how it would apply to us, we intend to treat all of our distributions as being in excess of our cumulative net income for such purposes and subject to such 10% withholding tax. Accordingly, distributions to a non-U.S. unitholder will be subject to a combined withholding tax rate equal to the sum of the highest applicable effective tax rate and 10%.

Moreover, the transferee of an interest in a partnership that is engaged in a U.S. trade or business is generally required to withhold 10% of the "amount realized" by the transferor unless the transferor certifies that it is not a foreign person. While the determination of a partner's "amount realized" generally includes any decrease of a partner's share of the partnership's liabilities, the Treasury Regulations provide that the "amount realized" on a transfer of an interest in a publicly-traded partnership, such as our common units, will generally be the amount of gross proceeds paid to the broker effecting the applicable transfer on behalf of the transferor, and thus will be determined without regard to any decrease in that partner's share of a publicly-traded partnership's liabilities. For a transfer of interests in a publicly traded partnership that is effected through a broker on or after January 1, 2023, the obligation to withhold is imposed on the transferor's broker. Current and prospective non-U.S. unitholders should consult their tax advisors regarding the impact of these rules on an investment in our common units.

We treat each purchaser of our common units as having the same tax benefits without regard to the common units actually purchased. The IRS may challenge this treatment, which could adversely affect the value of our common units.

We generally prorate our items of income, gain, loss and deduction between transferors and transferees of our units each month based upon the ownership of our units on the first day of each month, instead of on the basis of the date a particular unit is transferred. The IRS may challenge this treatment, which could change the allocation of items of income, gain, loss and deduction among our unitholders.

A unitholder whose units are the subject of a securities loan (e.g., a loan to a "short seller" to cover a short sale of units) may be considered to have disposed of those units. If so, such unitholder would no longer be treated for tax purposes as a partner with respect to those units during the period of the loan and may recognize gain or loss from the disposition.

We have adopted certain valuation methodologies in determining a unitholder's allocations of income, gain, loss and deduction. The IRS may challenge these methodologies or the resulting allocations, which could adversely affect the value of our common units.

A successful IRS challenge to these methods or allocations could adversely affect the timing or amount of taxable income or loss being allocated to our unitholders. It also could affect the amount of gain recognized from the sale of our common units, have a negative impact on the value of our common units or result in audit adjustments to our unitholders' tax returns without the benefit of additional deductions.

Our unitholders will likely be subject to state and local taxes and income tax return filing requirements in jurisdictions where they do not live as a result of investing in our common units.

We currently own property and conduct business in a number of states, most of which currently impose a personal income tax on individuals, and most of which also impose an income or similar tax on corporations and certain other entities. As we make acquisitions or expand our business, we may own assets or conduct business in additional states that impose similar taxes. It is our unitholders' responsibility to file all U.S. federal, foreign, state and local tax returns and pay any taxes due in these jurisdictions. Unitholders should consult with their own tax advisors regarding the filing of such tax returns, the payment of such taxes, and the deductibility of any taxes paid.

With Westlake's support, we maintain a comprehensive approach to cybersecurity and data protection, based on a risk-based, defense-in-depth strategy. Westlake follows industry standard cybersecurity frameworks, including the National Institute of Standards and Technology's Cybersecurity Framework to design, assess and update our cybersecurity strategy, controls and processes. Westlake regularly assesses industry best practices and standards and endeavors to implement them in its efforts to manage cybersecurity risk for us. The focus is on protecting our highest-value information assets, which include manufacturing systems, financial systems, and confidential, personal, and private information.

To safeguard our networks and systems, Westlake has a dedicated cybersecurity organization overseen by its Chief Information Security Officer, which operates within its information technology department overseen by its Chief Information Officer. Westlake's cybersecurity organization employs multiple security controls, such as firewalls, spam protection, web filtering, endpoint detection and response software, controlled access, vulnerability management, redundancies, patching, and regular onsite and offsite backups. Westlake's cybersecurity organization also uses a variety of processes to address cybersecurity threats related to the use of third-party technology and services, including pre-acquisition diligence, imposition of contractual obligations, and risk-based performance monitoring.

Both Westlake's Chief Information Officer and its Chief Information Security Officer have extensive experience in assessing and managing cybersecurity risks, including through decades of collective experience in information technology and cybersecurity roles of increasing responsibility both at Westlake and in prior positions. Westlake prioritizes cybersecurity awareness among employees and contractors through various training exercises, including formal programs and simulated phishing events. Westlake maintains incident response plans, playbooks, and engages third-party cybersecurity firms for simulated cyberattacks and penetration testing to identify potential risks. Westlake also has a third-party cybersecurity firm on retainer for incident assistance and response. Periodic internal self-assessments are conducted by Westlake's cybersecurity organization using the National Institute of Standards and Technology Cybersecurity Framework.

From time to time, we and OpCo experience cybersecurity threats and attempted breaches and other incidents. Westlake classifies and tracks these events based on significance and implements remediation actions that it considers appropriate to address the risks to the Partnership and OpCo relating to such incidents. Although we and OpCo have not experienced material impacts to our business strategy, results of operations or financial condition from any such incidents in the past three years, we cannot guarantee that a material incident will not occur in the future. See "Item 1A. Risk Factors—Failure to adequately protect critical data and technology systems could materially affect our operations."

The board of directors has authorized and approved our entry into the Services and Secondment Agreement and the Omnibus Agreement with Westlake, and has thereby charged Westlake's Corporate Risk and Sustainability Committee with assisting the board of directors with its oversight of cybersecurity risks, which is a component of our overall enterprise risk management program. As a result, Westlake's Corporate Risk and Sustainability Committee assists with the oversight of our cybersecurity risks. Westlake's Corporate Risk and Sustainability Committee includes directors with cybersecurity experience and expertise, primarily through supervision of information technology departments as executive officers. The board of directors also receives regular updates from Westlake's Chief Information Officer on cybersecurity risks, incidents and trends, and ongoing and planned projects impacting the Partnership and OpCo. Westlake's Chief Information Officer and our senior management receive regular status reports on the Partnership's and OpCo's cybersecurity risks from Westlake's cybersecurity organization. Further, incident updates are reported to our senior management and the board of directors as Westlake's Chief Information Officer and cybersecurity organization consider appropriate, depending on the severity of the incident.

As part of our incident response planning, Westlake also maintains cross-functional response teams involving personnel outside of its cybersecurity organization, both globally and regionally, in order to be prepared to respond to an incident.

Under the Omnibus Agreement, certain subsidiaries of Westlake have agreed to indemnify the Partnership for certain environmental and other liabilities relating to OpCo's processing facilities and related assets that occurred or existed prior to August 4, 2014.

We are a publicly-traded partnership and are not subject to federal income tax. Instead, unitholders are required to report their allocable share of our income, gain, loss and deduction, regardless of whether we make distributions.

Following the Partnership's cash distribution for the second quarter of 2017, the requirement under the Partnership's partnership agreement for the conversion of all subordinated units was satisfied. As a result, effective August 30, 2017, all of the subordinated units owned by Westlake were converted into common units on a one-for-one basis and thereafter participate on terms equal with all other common units in distributions of available cash.

The board of directors may change our cash distribution policy at any time and from time to time, and even if our cash distribution policy is not modified or revoked, the amount of distributions paid under our policy and the decision to make any distribution is determined by our general partner.

This Management's Discussion and Analysis of Financial Condition and Results of Operations should be read in conjunction with the accompanying consolidated financial statements, the notes thereto, and the other financial information appearing elsewhere in this report. The following discussion includes forward-looking statements that involve certain risks and uncertainties. See "Cautionary Statement Regarding Forward-Looking Statements" and "Item 1A. Risk Factors" included within this report.

OpCo has entered into a 12-year feedstock supply agreement (the "Feedstock Supply Agreement") with Westlake Petrochemicals LLC, a wholly owned subsidiary of Westlake, under which Westlake Petrochemicals LLC supplies OpCo with ethane and other feedstocks that OpCo uses to produce ethylene under the Ethylene Sales Agreement. For its approximately 5% merchant sales, OpCo may purchase the ethane and other feedstocks to produce ethylene and resulting co-products to sell to unrelated third parties from Westlake Petrochemicals LLC.

Our management uses a variety of financial and operating metrics to analyze our performance. These metrics are significant factors in assessing our operating results and profitability and include: (1) production volumes, (2) operating and maintenance expenses, including turnaround costs, and (3) MLP distributable cash flow and EBITDA.

The amount of profit we generate primarily depends on the volumes of ethylene and resulting co-products we are able to produce at Calvert City Olefins and Lake Charles Olefins. Although Westlake has committed to purchasing minimum volumes from us under the Ethylene Sales Agreement, our results of operations are impacted by our ability to:

Our management seeks to maximize the profitability of our operations by effectively managing operating expenses, maintenance capital expenditures and turnaround costs. Our operating expenses are comprised primarily of feedstock costs and natural gas, labor expenses (including contractor services), utility costs (other than natural gas) and turnaround and maintenance expenses. With the exception of feedstock (including natural gas) and utilities-related expenses, operating expenses generally remain relatively stable across broad ranges of production volumes but can fluctuate from period to period depending on the circumstances, particularly maintenance and turnaround activities. Our maintenance capital expenditures and turnaround costs are comprised primarily of maintenance of our ethylene production facilities and the amortization of capitalized turnaround costs. These capital expenditures relate to the maintenance and integrity of our facilities. We capitalize the costs of major maintenance activities, or turnarounds, and amortize the costs over the period until the next planned turnaround of the affected facility.

We generate a substantial majority of our revenue from the Ethylene Sales Agreement. This contract is intended to promote cash flow stability and minimize our direct exposure to commodity price fluctuations in the following ways: (1) the cost-plus pricing structure of the Ethylene Sales Agreement is expected to generate a fixed margin of $0.10 per pound, adjusting automatically for changes in feedstock costs; and (2) Westlake is committed to purchase 95% of the annual planned output, subject to a maximum commitment of 3.8 billion pounds of ethylene per year, with an option to purchase an additional 95% of actual output in excess of the planned output on a contract year basis. As a result, our direct exposure to commodity price risk is limited to approximately 5% of our total ethylene production, which is that portion sold to third parties, assuming Westlake exercises its option to purchase 95% of the over production, as well as to our co-products sales.

The table below and descriptions that follow represent the consolidated results of operations of the Partnership for the years ended December 31, 2023 and 2022. A detailed comparison of the Partnership's 2022 operating results to its 2021 operating results can be found in the Management's Discussion and Analysis of Financial Condition and Results of Operations section in the Partnership's 2022 Annual Report on Form 10-K filed March 1, 2023.

The following table presents reconciliations of MLP distributable cash flow to net income and net cash provided by operating activities, the most directly comparable GAAP financial measures, for each of the periods indicated.

The following table presents reconciliations of EBITDA to net income, income from operations and net cash provided by operating activities, the most directly comparable GAAP financial measures, for each of the periods indicated.

Investing Activities

Financing Activities

Based on the terms of our cash distribution policy, we expect that we will distribute to our partners most of the excess cash generated by our operations. To the extent we do not generate sufficient cash flow to fund capital expenditures, we expect to fund them primarily from external sources, including borrowing directly from Westlake, as well as future issuances of equity interests or debt.

The Partnership maintains separate bank accounts, but Westlake continues to provide treasury services on our behalf under the Omnibus Agreement. Our sources of liquidity include cash generated from operations, the OpCo Revolver, the MLP Revolver and, if necessary and possible under then current market conditions, the issuance of additional equity interests or debt. We believe that cash generated from these sources will be sufficient to meet our short-term working capital requirements and long-term capital expenditure requirements and to make quarterly cash distributions. Westlake may also provide other direct and indirect financing to us from time to time, although it is not obligated to do so.

In order to fund non-annual turnaround expenditures, we cause OpCo to reserve an amount for turnaround costs during each twelve-month period designed to cover future turnaround activities. Each of OpCo's ethylene production facilities requires turnaround maintenance approximately every five years. By reserving additional cash annually, we intend to reduce the variability in OpCo's cash flow. Westlake's purchase price for ethylene purchased under the Ethylene Sales Agreement includes a component (adjusted annually) designed to cover, over the long term, substantially all of OpCo's turnaround expenditures.

Our cash is generated from cash distributions from OpCo. OpCo is a restricted subsidiary under certain indentures governing Westlake's senior notes, and these restrictions limit OpCo's ability to incur additional debt, among other things. Westlake's credit facility and various indentures do not prevent OpCo from making distributions to us.

We, OpCo and Westlake are parties to an Investment Management Agreement that authorizes Westlake to invest the Partnership's and OpCo's excess cash with Westlake for durations of up to a maximum of nine months. Per the terms of the Investment Management Agreement, cash invested with Westlake earns a market return plus five basis points and Westlake provides daily availability of the invested cash to meet any liquidity needs of the Partnership or OpCo.

On January 22, 2024, the board of directors of Westlake Chemical Partners GP LLC, our general partner, approved a quarterly distribution of $0.4714 per unit payable on February 20, 2024 to unitholders of record as of February 2, 2024, which equates to approximately $16.6 million per quarter, or approximately $66.4 million per year in aggregate, based on the number of common units outstanding on December 31, 2023. We do not have a legal or contractual obligation to pay distributions on a quarterly basis or any other basis at our minimum quarterly distribution rate or any other rate.

Capital Expenditures

Cash and Cash Equivalents

As described above, we, OpCo and Westlake are parties to an Investment Management Agreement that authorizes Westlake to invest the Partnership's and OpCo's excess cash with Westlake for durations of up to a maximum of nine months. The Partnership had $94.4 million of cash invested under the Investment Management Agreement at December 31, 2023.

Indebtedness

Critical accounting estimates are those estimates made in accordance with GAAP that involve a significant level of estimation uncertainty and have had or are reasonably likely to have a material impact on our financial condition or results of operations. Our more critical accounting estimates include those related to long-lived assets, fair value estimates, goodwill impairment and environmental and legal obligations. Inherent in such estimates are certain key assumptions. We periodically update the estimates used in the preparation of the financial statements based on our latest assessment of the current and projected business and general economic environment. We believe the following to be our most critical accounting estimates required for the preparation of our financial statements.

We evaluate long-lived assets for potential impairment indicators whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable, including when negative conditions such as significant current or projected operating losses exist. Our judgments regarding the existence of impairment indicators are based on legal factors, market conditions and the operational performance of our businesses. Actual impairment losses incurred could vary significantly from amounts estimated. Long-lived assets assessed for impairment are grouped at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. Additionally, future events could cause us to conclude that impairment indicators exist and that associated long-lived assets of our businesses are impaired. Any resulting impairment loss could have a material adverse impact on our financial condition and results of operations.

The estimated useful lives of long-lived assets range from three to 40 years. Depreciation and amortization of these assets, including amortization of deferred turnaround costs, under the straight-line method over their estimated useful lives totaled $110.2 million, $121.1 million and $108.8 million in 2023, 2022 and 2021, respectively. If the useful lives of the assets were found to be shorter than originally estimated, depreciation or amortization charges would be accelerated.

We defer the costs of planned major maintenance activities, or turnarounds, and amortize the costs over the period until the next planned turnaround of the affected unit. Total costs deferred on turnarounds were $30.9 million, $6.7 million and $131.2 million in 2023, 2022 and 2021, respectively. Amortization of previously deferred turnaround costs was $25.4 million, $26.0 million and $16.5 million in 2023, 2022 and 2021, respectively. As of December 31, 2023, deferred turnaround costs, net of accumulated amortization, totaled $133.2 million. Expensing turnaround costs as incurred would likely result in greater variability of our quarterly operating results and would adversely affect our financial position and results of operations.

Additional information concerning long-lived assets and related depreciation and amortization appears in Notes 5 and 7 to the consolidated financial statements included in Item 8 of this form 10-K.

The Partnership has conditional asset retirement obligations for the removal and disposal of hazardous materials and the remediation of the cause of any such release from certain of the Partnership's manufacturing facilities. However, no asset retirement obligations have been recognized because the fair value of the conditional legal obligation cannot be measured due to the indeterminate settlement date of the obligation. Settlement of these conditional asset retirement obligations is not expected to have a material adverse effect on the Partnership's financial condition, results of operations or cash flows in any individual reporting period.

Interest Rate Risk

PricewaterhouseCoopers LLP, the independent registered public accounting firm that audited the financial statements included in this Annual Report on Form 10-K, has also audited the effectiveness of internal control over financial reporting as of December 31, 2023 as stated in their report that appears on the following page.

Opinions on the Financial Statements and Internal Control over Financial Reporting

Definition and Limitations of Internal Control over Financial Reporting

Critical Audit Matters

In connection with the IPO, the Partnership acquired a 10.6% limited partner interest in Westlake Chemical OpCo LP ("OpCo") and a 100% interest in Westlake Chemical OpCo GP LLC ("OpCo GP"), which is the general partner of OpCo. OpCo owns three ethylene production facilities and one common carrier ethylene pipeline (collectively, the "Contributed Assets"). Since the IPO, the Partnership has periodically purchased additional limited partner interest in OpCo. Most recently, on March 29, 2019, the Partnership purchased an additional 4.5% newly-issued limited partner interest in OpCo for approximately $201,445, resulting in an aggregate 22.8% limited partner interest in OpCo, effective January 1, 2019. The remaining 77.2% limited partner interest in OpCo is owned by Westlake Corporation. References to "Westlake" refer collectively to Westlake Corporation and its subsidiaries, other than the Partnership, OpCo and OpCo GP.

OpCo and Westlake entered into an ethylene sales agreement (the "Ethylene Sales Agreement") pursuant to which the Partnership generates a substantial majority of its revenue. For more information, see Note 2.

The Partnership sells ethylene production in excess of volumes sold to Westlake, as well as all of the co-products resulting from the ethylene production, including propylene, crude butadiene, pyrolysis gasoline and hydrogen, directly to third parties on either a spot or contract basis. Co-products sold to third parties are transported by rail or truck. Net proceeds (after transportation and other costs) from the sales of ethylene co-products that result from the production of ethylene purchased by Westlake are netted against the ethylene price charged to Westlake under the Ethylene Sales Agreement, thereby reducing the Partnership's exposure to fluctuations in the market prices of these co-products.

Basis of Presentation

The Partnership holds a 22.8% limited partner interest and the entire non-economic general partner interest in OpCo. The remaining 77.2% limited partner interest in OpCo is owned directly by Westlake, which has no rights to direct the activities that most significantly impact the economic performance of OpCo. As a result of the fact that substantially all of OpCo's activities are conducted on behalf of Westlake, and the fact that OpCo exhibits disproportionality of voting rights to economic interest, OpCo was deemed to be a variable interest entity. The Partnership, through its ownership of OpCo's general partner, has the power to direct the activities that most significantly impact the economic performance of OpCo, and it also has the obligation or right to absorb losses or receive benefits from OpCo that could potentially be significant to OpCo. As such, the Partnership was determined to be OpCo's primary beneficiary and therefore consolidates OpCo's results of operations and financial position. Westlake's retained interest of 77.2% is recorded as noncontrolling interest in the Partnership's consolidated financial statements.

Cash and Cash Equivalents

Allowance for Credit Losses

Inventories

Property, Plant and Equipment

Interest expense is capitalized for qualifying assets under construction. Capitalized interest costs are included in property, plant and equipment and are depreciated over the useful life of the related asset. Capitalized interest was $164, $80 and $0 for the years ended December 31, 2023, 2022 and 2021, respectively. Repair and maintenance costs are charged to operations as incurred. Gains and losses on the disposal or retirement of property, plant and equipment are reflected in the statement of operations when the assets are sold or retired.

The accounting guidance for asset retirement obligations requires the recording of liabilities equal to the fair value of asset retirement obligations and corresponding additional asset costs, when there is a legal asset retirement obligation as a result of existing or enacted law, statute or contract. The Partnership has conditional asset retirement obligations for the removal and disposal of hazardous materials from certain of the Partnership's manufacturing facilities. However, no asset retirement obligations have been recognized because the fair value of the conditional legal obligation cannot be measured due to the indeterminate settlement date of the obligation. Settlement of these conditional asset retirement obligations is not expected to have a material adverse effect on the Partnership's financial condition, results of operations or cash flows in any individual reporting period.

Depreciation is provided by utilizing the straight-line method over the estimated useful lives of the assets as follows:

Impairment of Long-Lived Assets

Impairment of Goodwill

Turnaround Costs

Concentration of Credit Risk

Revenue Recognition

The Partnership recognizes revenue and accounts receivable upon transferring control of inventories to its customers. Ethylene sold to Westlake under the Ethylene Sales Agreement is transferred to Westlake immediately after production and recognized in sales. Control of inventories sold to third parties generally transfers upon shipment to the customer. The Partnership excludes taxes collected on behalf of customers from the estimated contract price. Provisions for discounts, rebates and returns are incorporated in the estimate of variable consideration and reflected as reduction to revenue in the same period as the related sales.

The Partnership does not disclose the value of unsatisfied performance obligations because its contracts with customers (1) have an original expected duration of one year or less or (2) have only variable consideration that is calculated based on market prices at a specified date and is allocated to wholly unsatisfied performance obligations.

The Partnership generates a substantial majority of its revenue from sales to Westlake under the Ethylene Sales Agreement. The Ethylene Sales Agreement is intended to generate a long-term, fixed cash margin per pound. See Note 2 for a description of the terms of the Ethylene Sales Agreement. The Partnership's direct commodity price risk is limited to the sales to third parties. See the Partnership's consolidated statement of operations for the disaggregation of net sales to Westlake and net sales to third parties.

Transportation and Freight

Environmental Costs

Segment Reporting

Use of Estimates

Other Comprehensive Income

Recent Accounting Pronouncements

The fee for each pound of ethylene purchased by Westlake from OpCo up to the Minimum Commitment in any calendar year will equal:

The fee for the Excess Production Option, if exercised, equals OpCo's estimated variable operating costs of producing the incremental ethylene, net of revenues from co-products sales plus a $0.10 per pound margin.

The estimated operating costs and the expected future maintenance capital expenditures and other turnaround expenditures will be adjusted at the end of each year, to be applicable for the fee for the next calendar year, to reflect certain changes in forecasted costs.

Under the Ethylene Sales Agreement OpCo has the option to curtail up to approximately 5% of its ethylene production annually in the event OpCo reasonably determines that its sales of such ethylene to third parties during the relevant period would be uneconomic.

Certain of the pricing components that make up the price for ethylene sold under the Ethylene Sales Agreement are modified to reflect the portion of OpCo's production capacity that is used to process Westlake's purge gas instead of producing ethylene. Costs specific to the processing of Westlake's purge gas are recovered under the Services and Secondment Agreement (as described below), and not the Ethylene Sales Agreement.

The Ethylene Sales Agreement provides that, if compliance with any law adopted or modified following the IPO results in OpCo incurring additional costs in excess of $500 in any contract year, OpCo is entitled to charge Westlake a monthly surcharge following efforts to mitigate the effects of such matter.

The Ethylene Sales Agreement has an initial term extending until December 31, 2026 and automatically renews thereafter for successive 12-month terms unless terminated.

Feedstock Supply Agreement

The Feedstock Supply Agreement has an initial term extending until December 31, 2026 and automatically renews thereafter for successive 12-month terms unless terminated by either party; provided, however, that such agreement can only be renewed in the event the Ethylene Sales Agreement is renewed simultaneously. The Feedstock Supply Agreement may, in certain circumstances, terminate concurrently with the termination of the Ethylene Sales Agreement.

Services and Secondment Agreement

The Services and Secondment Agreement has an initial 12-year term. The Services and Secondment Agreement may be renewed thereafter upon agreement of the parties and shall automatically terminate if the Ethylene Sales Agreement terminates under certain circumstances. Westlake and OpCo each can terminate the Services and Secondment Agreement under certain circumstances, including if the other party materially defaults on the performance of its obligations and such default continues for a 30-day period.

Site Lease Agreements

Omnibus Agreement

Exchange Agreement

OpCo Partnership Agreement

Investment Management Agreement

Depreciation expense on property, plant and equipment of $84,511, $94,744 and $91,852 is included in cost of sales in the consolidated statements of operations for the years ended December 31, 2023, 2022 and 2021, respectively.

On August 4, 2014, OpCo entered into a $600,000 senior unsecured revolving credit facility agreement with Westlake (as subsequently amended, the "OpCo Revolver"). On July 12, 2022, OpCo entered into the Second Amendment (the "OpCo Revolver Amendment") to the OpCo Revolver. Prior to the OpCo Revolver Amendment, the OpCo Revolver bore interest at the London Interbank Offered Rate ("LIBOR") plus 2.0%. The OpCo Revolver Amendment, among other things, extended the maturity date of the OpCo Revolver from September 25, 2023 to July 12, 2027 and provided for the replacement of LIBOR with the Secured Overnight Financing Rate, as administered by the Federal Reserve Bank of New York ("SOFR"). Borrowings under the OpCo Revolver now bear interest at a variable rate of either (a) SOFR plus the Applicable Margin plus a 0.10% credit spread adjustment or, if SOFR is no longer available, (b) the Alternate Base Rate plus the Applicable Margin minus 1.0%. The Applicable Margin under the OpCo Revolver is 1.75%. As of December 31, 2023, outstanding borrowings under the OpCo Revolver bore interest at SOFR plus the Applicable Margin and credit spread adjustment.

On April 29, 2015, the Partnership entered into a $300,000 revolving credit facility agreement with an affiliate of Westlake (as subsequently amended, the "MLP Revolver") to fund the Partnership's purchase of an additional 2.7% newly-issued, limited partner interest in OpCo for $135,341. In 2017, the Partnership entered into an amendment to the MLP Revolver credit agreement, increasing borrowing capacity from $300,000 to $600,000. On March 29, 2019, the Partnership borrowed $123,511 under the MLP Revolver to partially fund the purchase of the additional 4.5% interest in OpCo. On July 12, 2022, the Partnership entered into the Fourth Amendment (the "MLP Revolver Amendment") to the MLP Revolver. Prior to the MLP Revolver Amendment, the MLP Revolver bore interest at a variable rate of either (a) LIBOR plus 2.0% or, if LIBOR were no longer available, (b) the Alternate Base Rate plus 1.0%. The MLP Revolver Amendment, among other things, extended the maturity date of the MLP Revolver from March 19, 2023 to July 12, 2027 and provided for the replacement of LIBOR with SOFR as the reference rate. Borrowings under the MLP Revolver now bear interest at a variable rate of either (a) SOFR plus the Applicable Margin plus a 0.10% credit spread adjustment or, if SOFR is no longer available, (b) the Alternate Base Rate plus the Applicable Margin minus 1.0%. The Applicable Margin under the MLP Revolver varies between 1.75% and 2.75%, depending on the Partnership's Consolidated Leverage Ratio. As of December 31, 2023, outstanding borrowings under the MLP Revolver bore interest at SOFR plus the Applicable Margin and credit spread adjustment. The MLP Revolver provides that the Partnership may pay all or a portion of the interest on any borrowings in kind, in which case any such amounts would be added to the principal amount of the loan. The MLP Revolver requires that the Partnership maintain a consolidated leverage ratio of either (1) during any one-year period following certain types of acquisitions (including acquisitions of additional interests in OpCo), 5.50:1.00 or less, or (2) during any other period, 4.50:1.00 or less. The MLP Revolver also contains certain other customary covenants. The repayment of borrowings under the MLP Revolver is subject to acceleration upon the occurrence of an event of default.

As of December 31, 2023, the Partnership was in compliance with all of the covenants under the OpCo Revolver and the MLP Revolver.

The weighted average interest rate on all long-term debt was 7.2% and 4.8% at December 31, 2023 and 2022, respectively.

As of December 31, 2023, the Partnership had no scheduled maturities of long-term debt until 2027. The OpCo Revolver and the MLP Revolver are scheduled to mature on July 12, 2027.

Distributions are declared subsequent to quarter end; therefore, the table below represents total cash distributions declared from earnings of the related periods pertaining to such distributions.

Net income per unit applicable to common limited partner units is computed by dividing the respective limited partners' interest in net income by the weighted-average number of common units outstanding for the period. Because the Partnership has more than one class of participating securities, it uses the two-class method when calculating the net income per unit applicable to limited partners. The classes of participating securities include common units and incentive distribution rights. Net income attributable to the Partnership is allocated to the unitholders in accordance with their respective ownership percentages in preparation of the consolidated statements of changes in equity. However, when distributions related to the incentive distribution rights are made, net income equal to the amount of those distributions is first allocated to the general partner before the remaining net income is allocated to the unitholders based on their respective ownership percentages. Basic and diluted net income per unit is the same because the Partnership does not have any potentially dilutive units outstanding for the periods presented.

The amended Partnership Agreement provides that the Partnership will distribute cash that is deemed to be operating surplus each quarter to all the unitholders, pro rata, until each unit has received a distribution of $1.2938. If cash distributions to the Partnership's unitholders exceed $1.2938 per common unit in any quarter, the Partnership's unitholders and Westlake, as the holder of the Partnership's incentive distribution rights, will receive distributions according to the following percentage allocations:

The Partnership's distribution for each quarter in the year ended December 31, 2023 did not exceed the $1.2938 per unit threshold, and, as a result, no distribution was made with respect to the Partnership's incentive distribution rights to Westlake, as the holder of the Partnership's incentive distribution rights.

Distribution Per Common Unit

Distributions per common unit for the years ended December 31, 2023, 2022 and 2021 were as follows:

On March 29, 2019, the Partnership completed the issuance and sale of 2,940,818 common units at a price of $21.40 per unit through a private placement. TTWF LP, Westlake's principal stockholder and a related party, acquired 1,401,869 common units out of 2,940,818 common units issued in the private placement.

Sales to Related Parties

Sales to related parties were as follows:

Based on OpCo's 2022 production, the Partnership recognized buyer deficiency fees of $23,835 during the year ended December 31, 2022. The buyer deficiency fee is measured periodically based upon the lower of the actual production deficiency at period end or the estimated annual production deficiency based upon OpCo's annual anticipated production. These periodic estimates are updated at the end of the year based on actual annual production. The buyer deficiency fees are classified as a component of net sales—Westlake. The buyer deficiency fee was received by the Partnership in January 2023.

OpCo declared force majeure events in 2021 related to the flash fire at OpCo's Petro 2 facility, OpCo's Petro 1 facility outage, and due to the severe winter storm. As a result of these force majeure events in 2021, the Partnership recognized revenue for a buyer deficiency fee and Shortfall in 2021 of $51,395 and of $58,906, respectively. The buyer deficiency fee is measured periodically based upon the lower of the actual production deficiency at period end or the estimated annual production deficiency based upon OpCo's annual anticipated production. These periodic estimates are updated at the end of the year based on actual annual production. The buyer deficiency fees and Shortfall are classified as a component of net sales—Westlake. The buyer deficiency fee recognized in 2021 was received by the Partnership in January 2022 and out of the total Shortfall of $58,906 recognized in 2021, $51,713 was received by the Partnership in 2022 and $7,004 was received in 2023 pursuant to the terms of the Ethylene Sales Agreement.

Cost of Sales from Related Parties

Charges from related parties in cost of sales were as follows:

Services from Related Parties Included in Selling, General and Administrative Expenses

Charges from related parties included within selling, general and administrative expenses were as follows:

Goods and Services from Related Parties Capitalized as Assets

Charges from related parties for goods and services capitalized as assets were as follows:

Receivable under the Investment Management Agreement

The Partnership's receivable under the Investment Management Agreement was as follows:

Accounts Receivable from Related Parties

The Partnership's accounts receivable from Westlake were as follows:

Accounts Payable to Related Parties

The Partnership's accounts payable to Westlake were as follows: