In this appeal from a district court order affirming the decision of the Bureau of Land Management (BLM), Exxon Corporation challenges the Secretary of Interior’s decision to issue a right-of-way across federal land in Wyoming for Exxon’s carbon dioxide pipeline pursuant to section 28 of the Mineral Leasing Act (MLA), 30 U.S.C. § 185 (1988). Exxon argues that the right-of-way should properly have been issued under the auspices of the Federal Land Policy and Management Act (FLPMA), 43 U.S.C. § 1761(a)(2) (1988). The district court held that the agency’s decision to issue the permit under the MLA was reasonable, and therefore affirmed the decision of the BLM.
See Exxon Corp. v. Lujan,
The relevant factual background is simply stated. Exxon operates several oil and gas leases on federal lands in the LaBarge field in southwestern Wyoming. The gas stream produced from that field includes carbon dioxide, methane, nitrogen, helium, *759 and hydrogen sulfide. Exxon ships the raw gas from the LaBarge field to a processing plant at Shute Creek, where the gas is separated into its constituent elements which are marketed individually. The carbon dioxide travels by pipeline network to Rangely, Colorado, and Bairoil, Wyoming, where it is employed in tertiary oil recovery operations. 1
In these operations, an oil company injects carbon dioxide into an oil field in order to maximize its productive capacity. The mechanics of tertiary oil recovery have little impact on our analysis of the BLM’s decision. The process itself matters only because it creates commercial demand for Exxon’s carbon dioxide. The FLPMA and the MLA impose different obligations on parties holding rights-of-way under their authority. The.MLA’s provisions impose a common carrier requirement; FLPMA does not. The Exxon right-of-way was issued pursuant to the MLA. Exxon argued in district court and repeats on appeal that the common carrier requirement threatens its ability to fulfill its commercial contracts for carbon dioxide delivery. Rec., vol. I, doc. 37 at 15-16.
Following the agency’s decision to issue the right-of-way under section 28 of the MLA, Exxon sought agency review. The Interior Board of Land Appeals upheld the initial agency decision. Exxon Corp., 97 IBLA 45 (April 23, 1987). The district court upheld the decision of the IBLA. Against this background, Exxon brings this appeal, urging that the FLPMA, and not the MLA, should govern rights-of-way for carbon dioxide pipelines.
The district court’s opinion rests on its resolution of a purely legal question. As a consequence, we apply a de novo standard of review.
Anthony v. Baker,
When a court reviews an agency’s construction of the statute which it administers, it is confronted with two questions. First, always, is the question whether Congress has directly spoken to the question at issue. If the intent of Congress is clear, that is the end of the matter; for the court, as well as the agency, must give effect to the unambiguously expressed intent of Congress. If, however, the court determines Congress has not directly addressed the precise question at issue, the court does not simply impose its own construction on the statute, as would be necessary in the absence of an administrative interpretation. Rather, if the statute is silent or ambiguous with respect to the specific issue, the question for the court is whether the agency’s answer is based on a permissible construction of the statute.
See Sullivan v. Everhart,
The statutes contain complementary provisions for rights-of-way across federal lands. The MLA provides, in relevant part, that:
Rights-of-way through any Federal lands may be granted by the Secretary of the Interior or appropriate agency head for pipeline purposes for the transportation of oil, natural gas, synthetic liquid or gaseous fuels, or any refined product *760 produced therefrom to any applicant. ...
30 U.S.C. § 185(a) (emphasis added). The FLPMA authorizes the Secretary to grant rights-of-way for:
pipelines and other systems for the transportation or distribution of liquids and gases, other than water and other than oil, natural gas, synthetic liquid or gaseous fuels, or any refined product produced therefrom, and for storage and terminal facilities in connection therewith.
43 U.S.C. § 1761(a)(2) (emphasis added). In this case, the sole question is whether carbon dioxide is “natural gas” within the meaning of the two statutes so as to fall under the MLA and outside the scope of the FLPMA. 2
We must first determine whether Congress has addressed the question. Exxon contends that “natural gas” plainly does not mean carbon dioxide. If that were the case, the inquiry.would extend no farther. The plain meaning would amount to Congress’s resolution of the question at issue and the agency, like this court, would have to abide by that resolution.
Chevron;
As this court has noted before, “[t]he term ‘natural gas’ ... has various definitions within the industry.”
Aulston,
In addition to the district court and the IBLA in this case, other adjudicatory bodies have recognized the difficulty of assigning a definition to “natural gas.”
At the outset it should be noted that the term “natural gas” has two fundamentally different meanings. In the terminology of chemistry, ‘natural gas’ would mean any gas occurring naturally, including such gases as helium and carbon dioxide. The common meaning of ‘natural gas,’ however, is a mixture of hydrocarbons, each one having a different chemical composition, but each one being volatile or having a certain vapor tension.
Cortez Pipeline Co.,
Our conclusion that the terminology employed by Congress is ambiguous does not fully resolve the question asked by the first prong of the
Chevron
test. We must also “[e]mploy[] traditional tools of statutory construction” to assess whether Congress has addressed the issue.
I.N.S. v. Cardo-za-Fonseca,
When applying the first prong of the
Chevron
test in the face of decidedly ambiguous statutory language, we approach legislative history cautiously. After all, “[ljegislative history is a step removed from the language of the statute and, hence, is not entitled to the same weight.”
Miller v. C.I.R.,
Applying this standard, we conclude that the legislative history of the MLA does not establish Congress’s intention with the requisite clarity.
3
Indeed, one court has observed “[t]he legislative history indicates that the phrase ‘for the transportation of oil or natural gas’ was added to the statute solely to ensure that the statute did not govern pipelines for water and artificial gas.”
Wilderness Society v. Morton,
That is not the end of the question, however, for Exxon suggests that Congress meant “fuel” when it wrote “natural gas” and that, whatever else it may be, carbon dioxide is not fuel. The comments of Representative Mann, quoted above, illustrate the fragility of this premise. Even granting that Congress’s primary concern when it passed section 28 of the MLA was the transportation of fuel, the exclusion of carbon dioxide rights-of-way from the statute’s scope is not mandated. Moreover, that the Congressional reversal of Morton was motivated, in large part, by the nation’s need for fuel, see S.Rep. No. 93-207, 93rd Cong., 1st Sess. (1973), reprinted in 1973 U.S.C.C.A.N. 2417, 2418, does not compel such exclusion. Even under the agency’s construction, the primary concern of the MLA is fuel. Thus, Exxon’s repeated references to legislative discussions of fuel are beside the point. See Appellant’s Reply Brief at 2-4. Observing that fuel was a primary concern does not settle *762 the question of statutory scope. The question we must answer is whether the legislative history clearly announces that carbon dioxide is not “natural gas.” We are persuaded that it does not.
“[W]hen an administering agency’s interpretation of a statute is challenged, and traditional tools of statutory construction yield no relevant congressional intent, the reviewing court must determine if the agency’s construction is a permissible one.”
Salt Lake City,
Exxon argues that the deferential standard of review is not appropriate in this case because the BLM has previously issued a right-of-way pursuant to the FLPMA. “An agency interpretation of a relevant provision which conflicts with the agency’s earlier interpretation is ‘entitled to considerably less deference’ than a consistently held agency view.”
Cardoza-Fonseca,
Exxon also suggests that the action of the FERC in the Cortez Pipeline case somehow renders the agency’s decision in this case inconsistent with its past practice. In Aulston, we rejected a very similar argument in the following manner:
These wholly distinct interpretations of the word “gas” by agencies other than the Department of the Interior in these other contexts have no bearing on the Department’s interpretation of the 1914 Act or of the related Mineral Lands Leasing Act, and do not make the Department’s practice internally inconsistent.
As we have noted, the use of the term “natural gas” in the MLA is ambiguous. Therefore, neither the position advanced by Exxon nor the definition adopted by the Secretary is compelled by Congress’s usage. Implicit in our discussion of the relevant statutory language and the legislative history is the understanding that both definitions have some credence.
*763
At most, Exxon has established “that the language may bear the interpretation [it] desire[s] — not that it cannot bear the interpretation adopted by the Secretary.”
Sullivan,
Exxon also argues that, as policy, the decision of the Secretary is not sustainable. This argument attempts to establish that the construction is irrational and therefore not permissible.
See id.
at 89,
Exxon complains further that the common carrier requirement will unduly burden the carbon dioxide industry and create perverse incentives to produce artificial carbon dioxide. This strikes us as a matter more appropriately left to the agency. “When a challenge to an agency construction of a statutory provision, fairly conceptualized, really centers on the wisdom of the agency’s policy, rather than whether it is a reasonable choice within a gap left by Congress, the challenge must fail.”
Chevron,
The district court and the IBLA also concluded that the MLA was the appropriate authority for the right-of-way because the carbon dioxide is shipped after being separated from the rest of the gas stream and is therefore a “refined product produced therefrom” within the meaning of the statute.
See Exxon Corp.,
We AFFIRM the decision of the district court.
Notes
. Exxon is responsible for only one portion of the pipeline — extending from the processing plant to Rock Springs, Wyoming. The other segments of the pipeline are the responsibility of Chevron Corporation. The required rights-of-way for the other portions of the pipeline were also issued pursuant to section 28 of the MLA. Chevron did not appeal the decision to issue the rights-of-way under that statute. Rec., vol. II, doc. 17 at 2.
. Actually, the question is whether carbon dioxide is "natural gas" within the meaning of the MLA. The agency action appealed from was taken pursuant to the MLA, not the FLPMA. We consider the FLPMA only because of the parallel language in the two statutes; if we were to hold the agency action improper under the MLA, the right-of-way could only be issued under the FLPMA.
. The district court opinion in this case discusses the relevant legislative history in considerable detail.
See Exxon Corp. v. Lujan,
. Even were we to conclude that this policy marked a change of course by the agency, we would still uphold the agency’s action. The law does not require an agency to stand by its initial policy decisions in all circumstances. Instead, "an agency changing its course ... is obligated to supply a reasoned analysis for the change beyond that which may be required when an agency does not act in the first instance."
Motor Vehicle Mfrs. Ass'n v. State Farm Mutual Auto. Ins. Co.,
. The district court apparently thought it necessary to discuss the "refined product” language because it viewed the decision of the IBLA as referring to separate stages of the carbon dioxide recovery process.
Exxon Corp.,
