.

Mr. Justice REHNQUIST delivered the opinion of the Court.

    The United States seeks review of a decision of the United States Court of Appeals for the Tenth Circuit that a proceeding for the assessment of a "civil penalty" under Sec. 311(b)(6) of the Federal Water Pollution Control Act (FWPCA) is a "criminal case" within the meaning of the Fifth Amendment's guarantee against compulsory self-incrimination.  We granted certiorari and now reverse.

    At the time this case arose, Section 311(b)(3) of the FWPCA prohibited the discharge into navigable waters or onto adjoining shorelines of oil or hazardous substances in quantities determined by the President to be "harmful".   Section 311(b)(5) of the Act imposed upon "any person in charge of a vessel or of an onshore facility or an offshore facility" to report any discharge of oil or a hazardous substance into navigable waters to the "appropriate agency" of the United States Government.  Should that person fail to supply such notification, he or she was liable to a fine of not more than $10,000 or imprisonment of not more than one year.  Section 311(b)(5) also provided for a form of "use immunity", specifying that "notification received pursuant to this paragraph or information obtained by the exploitation of such notification shall not be used against any such person in any criminal case, except a prosecution for perjury or for giving a false statement."  33 U.S.C. Section 1321(b)(5).

    Section 311(b)(6) provided for the imposition of a "civil penalty" against "any owner or operator of any vessel, onshore facility, or offshore facility from which oil or a hazardous substance is discharged in violation" of the Act.  In 1975, that subsection called for a penalty of up to $5,000 for each violation of the Act.  In assessing penalties, the Secretary of the appropriate agency was to take into account "the appropriateness of such penalty to the size of the business of the owner or operator charged, the effect on the owner or operator's ability to continue in business, and the gravity of the violation ... ."  U.S.C. Section 1321(b)(6).

    According to Section 311(k) of the Act, funds collected from the assessment of penalties under Section 311(b)(6) were to be paid into a "revolving fund" together with "other funds received under this section" and any money appropriated to the revolving fund by Congress.  +++  Money contained in this fund was to be used to finance the removal, containment, or dispersal or oil and hazardous substances discharged into navigable waters and to defray the costs of administering the Act.  +++  Another section of the Act allowed the United States Government to collect the costs of removal, containment, or dispersal of a discharge from the person or corporation responsible for that discharge in cases where that person or corporation had been identified.  +++

    On or about march 23, 1975, oil escaped from an oil retention pit at a drilling facility located near Enid, Oklahoma, and eventually found its way into Boggie Creek, a tributary of the Arkansas River System.  At the time of the discharge, the premises were being leased by respondent L.O. Ward, who was doing business as L.O. Ward Oil and Gas Operations.  On April 2, 1975, respondent Ward notified the regional office of the Environmental Protection Agency (EPA) that a discharge of oil had taken place.  Ward later submitted a more complete written report of the discharge, which was in turn forwarded to the Coast Guard, the agency responsible for assessing civil penalties under Section 311(b)(6).

    After notice and opportunity for hearing, the Coast Guard assessed a civil penalty against respondent in the amount of $500.  Respondent filed an administrative appeal from this ruling, contending, inter alia, that the reporting requirements of Section 311(b)(5) of the Act violated his privilege against compulsory self-incrimination.  The administrative appeal was denied.

. . .

    Prior to trial, the District Court rejected Ward's contention that the reporting requirements of Section 311(b)(5), as used to support a civil penalty under Section 311(b)(6), violated his right against compulsory self-incrimination.  The case was tried to a jury, which found that Ward's facility did, in fact, spill oil into Boggie Creek.  The District Court, however, reduced Ward's penalty to $250 because of the amount of oil that had spilled and because of its belief that Ward had been diligent in his attempts to clean up the discharge after it had been discovered.

    The United States Court of Appeals for the Tenth Circuit reversed.  +++  Although admitting that Congress had labelled the penalty provided for in Section 311(b)(6) as civil and that the use of funds collected under that section to finance the administration of the Act indicated a "remedial" purpose for the provision, the Court of Appeals tested the statutory scheme against the standards set forth in Kenney v. Mendoza-Martinez, 372 U.S. 144, +++, and held that Section 311(b)(6) was sufficiently punitive to intrude upon the Fifth Amendment's protections against compulsory self-incrimination.  It therefore reversed and remanded for further proceedings in the collection suit.

    The distinction between a civil penalty and a criminal penalty is of some constitutional import.  The Self-incrimination Clause of the Fifth Amendment, for example, is expressly limited to "any criminal case.  ..."  Similarly, the protections provided by the Sixth Amendment are available only in "criminal explicitly limited to one context or the other, have been so limited by decision of this Court.  +++

    This Court has often stated that the question whether a particular statutorily-defined penalty is civil or criminal is a matter of statutory construction.  +++  Our inquiry in this regard has traditionally proceeded on two levels.  First, we have set out to determine whether Congress, in establishing the penalizing mechanism, indicated either expressly or impliedly a preference for one label or the other.  +++  Second, where Congress has indicated an intention to establish a civil penalty, we have inquired further whether the statutory scheme was so punitive either in purpose or effect as to negate that intention.  +++  In regard to this latter inquiry, we have noted that "only the clearest proof could suffice to establish the unconstitutionality of a statute on such a ground."  +++

    As for our first inquiry in the present case, we believe it was quite clear that Congress intended to impose a civil penalty upon persons in Ward's position.  Initially, and importantly, Congress labelled the sanction authorized in Section 311(b)(6) a "civil penalty," a label that takes on added significance given its juxtaposition with the criminal penalties set forth in the immediately preceding subparagraph, Section 311(b)(5).  Thus, we have no doubt that Congress intended to allow imposition of penalties under Section 311(b)(6) without regard to the procedural protections and restrictions available in criminal prosecutions.

    We turn then to consider whether Congress, despite its manifest intention to establish a civil, remedial mechanism, nevertheless provided for sanctions so punitive as to "transform[] what was clearly intended as a civil remedy into a criminal penalty."

+++

    Without setting forth here our assessment of each of the seven ... factors, we think only one, .., aids respondent.  That is a consideration of whether "the behavior to which [the penalty] applies is already a crime [.]"   In this regard, respondent contends that Section 13 of the Rivers and Harbors Act of 1899, 33 U.S.C. Section 407, makes criminal the precise conduct penalized in the present case.  Moreover, respondent points out that at least one federal court has held that Section 13 of the Rivers and Harbors Act defines a "strict liability crime," for which the government need prove no scienter.  +++  According to respondent, this confirms the lower court's conclusion that this fifth factor "falls clearly in favor of a finding that [Section 311(b) (6)] is criminal in nature."

+++

    While we agree that this consideration seems to point toward a finding that Section 311(b)(6) is criminal in nature, that indication is not as strong as it seems at first blush.  We have noted on a number of occasions that "Congress may impose both a criminal and civil sanction in respect to the same act or omission." +++

. . .

    In sum, we believe that the factors set forth in Mendoza-Martinez, while neither exhaustive nor conclusive on the issue, are in no way sufficient to render unconstitutional the congressional classification of the penalty established in Section 311(b)(6) as civil.  Nor are we persuaded by any of respondent's other arguments that he has offered the "clearest proof" that the penalty here in question is punitive in either purpose or effect.

    Our conclusion that Section 311(b)(6) does not trigger all the protections afforded by the Constitution to a criminal defendant does not completely dispose of this case.  Respondent asserts that, even if the penalty imposed upon him was not sufficiently criminal in nature to trigger other guarantees, it was "quasi-criminal", and therefore sufficient to implicate the Fifth Amendment's protection against compulsory self-incrimination.  +++

. . .

    The question before us, then, is whether the penalty imposed in this case, although clearly not "criminal" enough to trigger the protections of the Sixth Amendment, the Double Jeopardy Clause of the Fifth Amendment, or the other procedural guarantees normally associated with criminal prosecutions, is nevertheless "so far criminal in [its] nature" as to trigger the Self-Incrimination Clause of the Fifth Amendment.  Initially, we note that the penalty and proceeding considered in Boyd were quite different from those considered in this case.  Boyd dealt with forfeiture of property, a penalty that had absolutely no correlation to any damages sustained by society or to the cost of enforcing the law.  +++  Here the penalty is much more analogous to traditional civil damages.  Moreover, the statute under scrutiny in Boyd listed forfeiture along with fine and imprisonment as one possible punishment for customs fraud, a fact of some significance to the Boyd court.  +++  Here, as previously stated, the civil remedy and the criminal remedy are contained in separate statutes enacted 70 years apart.  The proceedings in Boyd also posed a danger that the appellants would prejudice themselves in respect to later criminal proceedings.  +++  Here, respondent is protected by Section 311(b)(5), which expressly provides that "notification received pursuant to this paragraph or information obtained by the exploitation of such notification shall not be used against any such person in any criminal case, except [for] prosecution for perjury or for giving a false statement."  33 U.S.C. Section 1321(b)(5).

    More importantly, however, we believe that in the light of what we have found to be overwhelming evidence that Congress intended to create a penalty civil in all respects and quite weak evidence of any countervailing punitive purpose or effect it would be quite anomalous to hold that Section 311(b)(6) created a criminal penalty for all other purposes.  We do not read Boyd as requiring a contrary conclusion.

We conclude that the penalty imposed by Congress was civil, and that the proceeding in which it was imposed was not "quasi-criminal" as that term is used in Boyd v. United States, supra.  The judgment of the Court of Appeals is therefore reversed.