United States: Ninth Circuit Holds Air Emissions Not Covered By CERCLA

Last Updated: August 2 2016
Article by Duke K. McCall, III and Douglas Hastings

Decision finds operator of a lead and zinc smelter not liable as an "arranger" under CERCLA for aerial deposition of heavy metals.  

On July 27, a panel of the US Court of Appeals for the Ninth Circuit unanimously held in Pakootas v. Teck Cominco Metals1 that aerial deposition of hazardous substances does not constitute a "disposal" giving rise to arranger liability under Section 107 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).2 Relying heavily on precedent and textual analysis, the court concluded that the statutory term "disposal" does not include a scenario in which hazardous substances end up in soil or water after being initially discharged into the air. The court therefore dismissed claims by the State of Washington and Native American tribes alleging that Teck Cominco Metals, the operator of a lead and zinc smelter in Canada, was liable for heavy metal contamination in the Upper Columbia River basin in Washington caused by its aerial emissions.


CERCLA imposes liability on several different categories of individuals or entities, one of which is "any person who. . .arranged for disposal. . .of hazardous substances."3 So-called "arranger liability" is a nebulous concept that has been explored in many judicial opinions, but no previous opinion had addressed the precise question of whether aerial emissions constitute a disposal. "Disposal" under CERCLA is defined by cross-reference to the Resource Conservation and Recovery Act (RCRA), which defines the term as the discharge, deposit, injection, dumping, spilling, leaking, or placing of any solid waste or hazardous waste into or on any land or water so that such solid waste or hazardous waste or any constituent thereof may enter the environment or be emitted into the air or discharged into any waters, including ground waters.4

Teck owns a lead and zinc smelting facility in British Columbia, Canada. As part of its regular operations, Teck discharged a heavy-metal-containing waste product referred to as "slag" from the facility into the Columbia River, and components of that slag traveled downstream to the United States. It also emitted heavy metals into the air, which were carried by air currents into the United States. The plaintiffs initially brought an action seeking to hold Teck liable for contamination caused by its discharge of slag, but later amended their complaint to add liability based on air emissions.

Teck moved to dismiss the air emissions portion of the complaint, arguing that CERCLA imposes no liability for the discharge of hazardous substances through air. The plaintiffs countered that their complaint properly alleged "deposition" of hazardous substances, thus meeting CERCLA's definition of a disposal. The district court agreed with the plaintiffs and denied Teck's motion, reasoning that a disposal giving rise to arranger liability occurred when the hazardous substances emitted into the air were deposited onto land or water in the Upper Columbia River Basin. Noting the novelty and importance of the issue, however, the district court certified it for interlocutory appeal to the Ninth Circuit.

The Ninth Circuit's Decision

In reversing the district court, the Ninth Circuit relied heavily on two prior Ninth Circuit opinions. The first such precedent, Center for Community Action & Environmental Justice v. BNSF Railway5 held that particulate emissions into the air from diesel fuel did not constitute disposal of waste under RCRA. The Center for Community Action court reasoned that air emissions did not meet the regulatory definition of "disposal" in part because the definition requires substances to be introduced to a "land or water" through "discharge, deposit, injection, dumping, spilling, leaking, or placing." The court found it particularly significant that the definition did not include the word "emit." The court noted that the US Congress knew how to use "emit" to refer to air emissions, as it did later in the same definition when it noted that materials first disposed onto a land or water may later be "emitted into the air." Given that CERCLA incorporates RCRA's definition of "disposal," Teck had emphasized Center for Community Action in its briefing and had unsuccessfully moved for the district court to reconsider its opinion in light of that ruling. The Pakootas court found that Center for Community Action's interpretation did not "absolutely foreclose" a different interpretation for CERCLA purposes. But it nonetheless found Center for Community Action's analysis of RCRA's identical statutory language persuasive and did not identify any grounds for distinguishing the analysis under CERCLA.

The second precedent relied upon by the Ninth Circuit, Carson Harbor Village, Ltd. v. Unocal Corp.6 did not involve air emissions—instead, it addressed the migration of substances in previously contaminated soil onto another property through natural processes. The Carson Harbor court held that such passive migration did not constitute a disposal under CERCLA. The Pakootas court considered that holding dispositive, finding that treating air emissions as a disposal would be inconsistent with Carson Harbor's conclusion that the term "deposit" in the statutory definition is "akin to 'putting down' or 'placement'" and its statement that "nothing in the context of the statute or the term 'disposal' suggests that Congress meant to include chemical or geologic processes or passive migration." The Pakootas court also found that accepting aerial depositions as "disposals" would implicate the Carson Harbor court's concern with creating a definition of disposal so broad that it would erode defenses under CERCLA, such as the innocent landowner defense.

The Ninth Circuit in Pakootas also used dictionaries to analyze the plaintiffs' argument that aerial deposition of metals could properly be considered the "deposit" of hazardous substances. The court found that the plaintiffs' interpretation was "reasonable enough" under dictionary definitions of the term and even observed that it "might be persuaded to adopt it" if the court was "writing on a blank slate." But the court did not consider the dictionary analysis strong enough to depart from Center for Community Action and Carson Harbor. Likewise, the court found nothing in legislative history that justified a different interpretation. It therefore concluded that it was compelled by precedent to hold that air emissions do not give rise to arranger liability under CERCLA.  


The Ninth Circuit's decision is a significant development in CERCLA law that changes how many practitioners and courts have seemingly understood arranger liability for aerial emissions. As the Pakootas district court observed, "it appears to have been treated as a given" in prior cases that CERCLA liability attaches when "hazardous substances from aerial emissions are disposed of into or on any land or water of a CERCLA facility." And, as the State of Washington further pointed out in its brief before the Ninth Circuit, CERCLA liability has already been imposed at a number of smelter sites where nearby land has been contaminated at least in part by aerial deposition.

Going forward, potentially responsible parties (PRPs) at CERCLA sites will be able to rely on Pakootas to contest their liability for response costs or natural resource damages related to contamination caused by aerial deposition. A potential challenge with such arguments is that, in the Upper Columbia River and many other sites, contamination deposited through air emissions may have commingled with contamination discharged through the dumping of slag or other means. It will be interesting to see how courts, including the Pakootas district court, deal with delineating the contamination resulting from aerial deposition and the contamination stemming from other disposals.

The Pakootas decision will also affect several other provisions of CERCLA in addition to arranger liability. As the Ninth Circuit observed, the term "disposal" appears throughout CERCLA, including in the definition of a "facility," the definition of a "release," and the definition of other categories of PRPs. The Ninth Circuit's ruling could therefore impact, for example, whether a site that has been contaminated by aerial emissions is considered to be a facility within the meaning of CERCLA.

Given the significant impacts of the Pakootas decision, it seems likely that the plaintiffs will petition the US Supreme Court for certiorari. If the Supreme Court ultimately decides to hear the case, it will represent the Court's first consideration of arranger liability under CERCLA since its 2009 landmark decision in Burlington Northern & Santa Fe Ry. Co. v. United States,7 in which the Supreme Court both limited the scope of arranger liability and recognized the divisibility defense to CERCLA liability.


1 No. 15-35228 (9th Cir. 2016)

2 42 U.S.C. § 9607

3 42 U.S.C. § 9607(a)(3) (emphasis added)

4 42. U.S.C. § 6903

5 764 F.3d 1019 (9th Cir. 2014)

6 270 F.3d 863 (9th Cir. 2001)

7 556 U.S. 599 (2009)

This article is provided as a general informational service and it should not be construed as imparting legal advice on any specific matter.

To print this article, all you need is to be registered on Mondaq.com.

Click to Login as an existing user or Register so you can print this article.

Similar Articles
Relevancy Powered by MondaqAI
In association with
Related Topics
Similar Articles
Relevancy Powered by MondaqAI
Related Articles
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Registration (you must scroll down to set your data preferences)

Mondaq Ltd requires you to register and provide information that personally identifies you, including your content preferences, for three primary purposes (full details of Mondaq’s use of your personal data can be found in our Privacy and Cookies Notice):

  • To allow you to personalize the Mondaq websites you are visiting to show content ("Content") relevant to your interests.
  • To enable features such as password reminder, news alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our content providers ("Contributors") who contribute Content for free for your use.

Mondaq hopes that our registered users will support us in maintaining our free to view business model by consenting to our use of your personal data as described below.

Mondaq has a "free to view" business model. Our services are paid for by Contributors in exchange for Mondaq providing them with access to information about who accesses their content. Once personal data is transferred to our Contributors they become a data controller of this personal data. They use it to measure the response that their articles are receiving, as a form of market research. They may also use it to provide Mondaq users with information about their products and services.

Details of each Contributor to which your personal data will be transferred is clearly stated within the Content that you access. For full details of how this Contributor will use your personal data, you should review the Contributor’s own Privacy Notice.

Please indicate your preference below:

Yes, I am happy to support Mondaq in maintaining its free to view business model by agreeing to allow Mondaq to share my personal data with Contributors whose Content I access
No, I do not want Mondaq to share my personal data with Contributors

Also please let us know whether you are happy to receive communications promoting products and services offered by Mondaq:

Yes, I am happy to received promotional communications from Mondaq
No, please do not send me promotional communications from Mondaq
Terms & Conditions

Mondaq.com (the Website) is owned and managed by Mondaq Ltd (Mondaq). Mondaq grants you a non-exclusive, revocable licence to access the Website and associated services, such as the Mondaq News Alerts (Services), subject to and in consideration of your compliance with the following terms and conditions of use (Terms). Your use of the Website and/or Services constitutes your agreement to the Terms. Mondaq may terminate your use of the Website and Services if you are in breach of these Terms or if Mondaq decides to terminate the licence granted hereunder for any reason whatsoever.

Use of www.mondaq.com

To Use Mondaq.com you must be: eighteen (18) years old or over; legally capable of entering into binding contracts; and not in any way prohibited by the applicable law to enter into these Terms in the jurisdiction which you are currently located.

You may use the Website as an unregistered user, however, you are required to register as a user if you wish to read the full text of the Content or to receive the Services.

You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these Terms or with the prior written consent of Mondaq. You may not use electronic or other means to extract details or information from the Content. Nor shall you extract information about users or Contributors in order to offer them any services or products.

In your use of the Website and/or Services you shall: comply with all applicable laws, regulations, directives and legislations which apply to your Use of the Website and/or Services in whatever country you are physically located including without limitation any and all consumer law, export control laws and regulations; provide to us true, correct and accurate information and promptly inform us in the event that any information that you have provided to us changes or becomes inaccurate; notify Mondaq immediately of any circumstances where you have reason to believe that any Intellectual Property Rights or any other rights of any third party may have been infringed; co-operate with reasonable security or other checks or requests for information made by Mondaq from time to time; and at all times be fully liable for the breach of any of these Terms by a third party using your login details to access the Website and/or Services

however, you shall not: do anything likely to impair, interfere with or damage or cause harm or distress to any persons, or the network; do anything that will infringe any Intellectual Property Rights or other rights of Mondaq or any third party; or use the Website, Services and/or Content otherwise than in accordance with these Terms; use any trade marks or service marks of Mondaq or the Contributors, or do anything which may be seen to take unfair advantage of the reputation and goodwill of Mondaq or the Contributors, or the Website, Services and/or Content.

Mondaq reserves the right, in its sole discretion, to take any action that it deems necessary and appropriate in the event it considers that there is a breach or threatened breach of the Terms.

Mondaq’s Rights and Obligations

Unless otherwise expressly set out to the contrary, nothing in these Terms shall serve to transfer from Mondaq to you, any Intellectual Property Rights owned by and/or licensed to Mondaq and all rights, title and interest in and to such Intellectual Property Rights will remain exclusively with Mondaq and/or its licensors.

Mondaq shall use its reasonable endeavours to make the Website and Services available to you at all times, but we cannot guarantee an uninterrupted and fault free service.

Mondaq reserves the right to make changes to the services and/or the Website or part thereof, from time to time, and we may add, remove, modify and/or vary any elements of features and functionalities of the Website or the services.

Mondaq also reserves the right from time to time to monitor your Use of the Website and/or services.


The Content is general information only. It is not intended to constitute legal advice or seek to be the complete and comprehensive statement of the law, nor is it intended to address your specific requirements or provide advice on which reliance should be placed. Mondaq and/or its Contributors and other suppliers make no representations about the suitability of the information contained in the Content for any purpose. All Content provided "as is" without warranty of any kind. Mondaq and/or its Contributors and other suppliers hereby exclude and disclaim all representations, warranties or guarantees with regard to the Content, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. To the maximum extent permitted by law, Mondaq expressly excludes all representations, warranties, obligations, and liabilities arising out of or in connection with all Content. In no event shall Mondaq and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use of the Content or performance of Mondaq’s Services.


Mondaq may alter or amend these Terms by amending them on the Website. By continuing to Use the Services and/or the Website after such amendment, you will be deemed to have accepted any amendment to these Terms.

These Terms shall be governed by and construed in accordance with the laws of England and Wales and you irrevocably submit to the exclusive jurisdiction of the courts of England and Wales to settle any dispute which may arise out of or in connection with these Terms. If you live outside the United Kingdom, English law shall apply only to the extent that English law shall not deprive you of any legal protection accorded in accordance with the law of the place where you are habitually resident ("Local Law"). In the event English law deprives you of any legal protection which is accorded to you under Local Law, then these terms shall be governed by Local Law and any dispute or claim arising out of or in connection with these Terms shall be subject to the non-exclusive jurisdiction of the courts where you are habitually resident.

You may print and keep a copy of these Terms, which form the entire agreement between you and Mondaq and supersede any other communications or advertising in respect of the Service and/or the Website.

No delay in exercising or non-exercise by you and/or Mondaq of any of its rights under or in connection with these Terms shall operate as a waiver or release of each of your or Mondaq’s right. Rather, any such waiver or release must be specifically granted in writing signed by the party granting it.

If any part of these Terms is held unenforceable, that part shall be enforced to the maximum extent permissible so as to give effect to the intent of the parties, and the Terms shall continue in full force and effect.

Mondaq shall not incur any liability to you on account of any loss or damage resulting from any delay or failure to perform all or any part of these Terms if such delay or failure is caused, in whole or in part, by events, occurrences, or causes beyond the control of Mondaq. Such events, occurrences or causes will include, without limitation, acts of God, strikes, lockouts, server and network failure, riots, acts of war, earthquakes, fire and explosions.

By clicking Register you state you have read and agree to our Terms and Conditions