Full opinion text
ORDER MOLLOY, Chief Judge. I. Introduction Defendants W.R. Grace and Co., a Connecticut corporation (“Grace”), and current and former Grace employees Alan R. Stringer, Henry A. Eschenbach, Jack W. Wolter, William J. McCaig, Robert J. Bet-tacchi, 0. Mario Favorito and Robert C. Walsh, are charged by a ten-count Indictment with crimes arising from Grace’s operation of a vermiculite mine near Libby, Montana (the “Libby Mine”). The Defendants are charged with conspiracy to violate the Clean Air Act and to defraud the United States in violation of 18 U.S.C. § 371 (Count I); violation of the Clean Air Act, 42 U.S.C. § 7413(c)(5)(A) (Counts II, III and IV); wire fraud in violation of 18 U.S.C. §§ 1343, 2 (Counts V and VI); and Obstruction of Justice in violation of 18 U.S.C. §§ 1505, 2 (Counts VII, VIII, IX and X). The charges relate to the Defendants’ alleged role in the release and distribution throughout the Libby area of asbestos contaminated vermiculite. Several motions to dismiss have been filed by the Defendants. They are: (1) Defendants’ joint motion pursuant to Rule 8(a), Fed.R.Crim.P., to dismiss Count I of the Indictment as duplicitous (dkt # 248); (2) Defendants’ joint motion pursuant to Rule 7(c), Fed.R.Crim.P., to dismiss Counts I through IV of the Indictment for failure to allege a required element, i.e., that the Defendants were aware that their conduct in violation of the Clean Air Act was unlawful (dkt # 250); (3) Defendants Grace, Stringer, Wolter and Bettacchi’s motion to dismiss Counts II through IV of the Indictment for failure to allege breach of an emissions standard (dkt # 254); (4) Defendants Grace, Stringer, Wolter and Bettacchi’s motion to dismiss Counts II through IV of the Indictment for failure to sufficiently apprise the Defendants of the nature of the offense charged (dkt # 255); (5) Defendant Grace’s motion to dismiss Counts II through IV of the Indictment on statute of limitations and duplicity grounds (dkt # 249); and (6) Defendants Grace, Stringer, Wolter and Bettacchi’s motion to dismiss Counts V and VI for failure to state an offense (dkt ##252, 253). The government opposes all of the motions, but has filed its own motion to dismiss Counts V and VI for failure to allege the required element of materiality. The government’s motion to dismiss the wire fraud counts is granted and Counts V and VI are dismissed for the reasons set forth below. Furthermore, the Statute of Limitations has run on some aspects of other charges so that the proof will be limited as set forth and explained in this Order. II. Background common to all pending motions Count I of the Indictment charges: That beginning on or about 1976, and continuing until on or about 2002, at Libby, and other locations within and without the District of Montana, the defendants, W.R. GRACE, ALAN R. STRINGER, HENRY A. ESCHEN-BACH, JACK W. WOLTER, WILLIAM J. McCAIG, ROBERT J. BET-TACCHI, O. MARIO FAVORITO, and ROBERT C. WALSH, and others known and unknown to the grand jury did knowingly combine, conspire and agree among themselves and others: OBJECTS OF THE CONSPIRACY a. To knowingly release and cause to be released into the ambient air a hazardous air pollutant, namely asbestos, and at the time knowingly placed persons, including: families of employees of W.R. GRACE Libby vermi7 culite mining and processing operations; residents of Libby, Montana and surrounding communities in Lincoln County; and others in imminent danger of death or serious bodily injury in violation of 42 U.S.C. § 7413(c)(5)(A). b. To defraud the United States and others by impairing, impeding, and frustrating the governmental functions of the United States, including the United States Environmental Protection Agency (EPA) and the Department of Health and Human Services, specifically, the National Institute for Occupational Safety and Health (“NIOSH”); being federal agencies responsible for administering federal laws and regulations designed to protect public health and safety and the environment in violation of 18 U.S.C. § 371. Count II charges: That beginning on or about November 15, 1990, and continuing until the present, at Libby, within the State and District of Montana, defendant W.R. GRACE did knowingly release and caused to be released into the ambient air a hazardous air pollutant, namely, asbestos, and at the time, knowingly placed another person, namely the residents of the town of Libby and Lincoln County in imminent danger of death or serious bodily injury by providing and distributing asbestos contaminated vermiculite material to the community; and by causing defendant W.R. GRACE employees and their personal effects to be contaminated with asbestos, in violation of 42 U.S.C. § 7413(c)(5)(A), 18 U.S.C. § 2. Count III charges: That beginning on or about December, 1993, and continuing until on or about June 15, 2000, at Libby within the State and District of Montana, the defendants, W.R. GRACE, ALAN R. STRINGER, JACK W. WOLTER, and ROBERT J. BETTACCHI did knowingly release and caused to be released into the ambient air a hazardous air pollutant, namely, asbestos, and at the time knowingly placed another person in imminent danger of death or serious bodily injury by selling real property known as the “Screening Plant” to the Parker family, in violation of 42 U.S.C. § 7413(c)(5)(A), 18 U.S.C. § 2. Count IV charges: That beginning on or about November 15, 1990, and continuing until on or about the summer of 2000, at Libby within the State and District of Montana, the defendants, W.R. GRACE, ALAN R. STRINGER, JACK W. WOL-TER, and ROBERT J. BETTACCHI did knowingly reléase and caused to be released into the ambient air a hazardous air pollutant, namely, asbestos, and at the time knowingly placed another person in imminent danger of death or serious bodily injury by leasing a property known as the “Export Plant” to the Burnetts and selling the property known as the “Export Plant” to the City of Libby, in violation of 42 U.S.C. § 7413(c)(5)(A), 18 U.S.C. § 2. Count V charges: That from on or about November, 1992 and continuing until late April, 2000, at Libby, within the State and District of Montana, the defendants W.R. GRACE, ALAN R. STRINGER, JACK W. WOL-TER, and ROBERT J. BETTACCHI, having devised or intending to devise a scheme or artifice to defraud that is to obtain money from the Parkers and to avoid liability by selling property known as the “Screening Plant” to the Parkers without disclosing the health hazard associated with tremolite asbestos contamination on the property, did for the purpose of executing said scheme, on April 12, 2000 transmit or cause to be transmitted by means of wire, communications in interstate or foreign commerce, namely, a Letter of Intent, describing defendant W.R. GRACE’S plan for cleaning the “Screening Plant” and the compensation the Parker’s would receive, in violation of 18 U.S.C. § 1343 and 18 U.S.C. § 2. Count VI charges: That from on or about 1994 and continuing until late July, 2000, at Libby, within the State and District of Montana, defendants W.R. GRACE, JACK W. WOLTER and ALAN R. STRINGER having devised or intending to devise a scheme or artifice to defraud, that is to avoid liability by selling and subsequently purchasing properties known as the “Mine site” and “Flyway” from KD’C, Inc., did for the purpose of executing said scheme, on July 12, 2000, transmit or cause to be transmitted by means of wire, communications in interstate or foreign commerce, wiring instructions directing the transmission of payment for the purchase of KDC, Inc. stock, in violation of 18 U.S.C. § 1343 and 18 U.S.C. § 2. III. Analysis A. Defendants’ joint motion to dismiss Count I of the Indictment as duplicitous The Defendants invoke Rule 8(a), Fed. R.Crim.P., to dismiss Count I of the Indictment as duplicitous. They argue that Count I charges two distinct conspiracies, one spanning the years 1976 through 1995 and consisting of criminal acts done in the course of operating the Libby Mine and for the purpose of maintaining the mine as a going concern, and a second conspiracy occurring from 1999 until 2002 consisting of criminal acts done for the purpose of covering up the earlier conspiracy. 1. Background Count I of the Indictment contains the following paragraphs relevant to the Defendants’ motion to dismiss that count as duplicitous: 72. It was a purpose of the conspiracy to conceal and misrepresent the hazardous nature of the tremolite asbestos contaminated vermiculite, thereby enriching defendants and others. 73. It was a purpose of the conspiracy to increase profits and avoid liability by misleading the government and preventing the government from using its authorities to protect against risks to human health and the environment associated with the manufacture, processing, distribution, commerce, use, handling, disposal, and release of tremolite asbestos contaminated vermiculite. MANNER AND MEANS OF THE CONSPIRACY The following manner and means, among others, were used by the defendants to effectuate and perpetuate the conspiracy set forth above: 74. It was part of the conspiracy that the defendants obtained knowledge of the hazardous nature of the tremolite asbestos contaminated vermiculite through various means, including, but not limited to: scientific testing and analysis, including animal studies; epidemiological studies of employees; employee medical screening and examinations; employee medical record reviews; collection and evaluation of a deceased employee’s lung tissue; review of employee death certificates; conducting employee morbidity and mortality studies; employee autopsy reviews; review of medical and scientific literature; reviewing reports from insurance carriers; and reviewing employee worker’s compensation claims. 75. It was part of the conspiracy that the defendants obtained knowledge of the propensity of tremolite asbestos contaminated vermiculite, when disturbed, to release fibers into the ambient air (also known as “friability”) through various means, including, but not limited to: product testing, including attic simulation and vermiculite materials handling tests (“drop tests”); and air and bulk sampling at the Libby Mine and other defendant W.R. GRACE facilities in and around Libby, Montana, at defendant W.R. GRACE owned and licensed expansion plants, at the facilities of customers using vermiculite materials, and at the Libby High School track. 76. It was part of the conspiracy that the defendants concealed the full extent of their knowledge of the hazardous nature and friability of the tremolite asbestos contaminated vermiculite from employees of defendant W.R. GRACE Libby vermiculite mining and processing operations; families of employees of defendant W.R. GRACE Libby vermiculite mining and processing operations; industrial customers of defendant W.R. GRACE Libby vermiculite products; employees of industrial customers of defendant W.R. GRACE Libby vermiculite products; residents of Libby, Montana and surrounding communities in Lincoln County, Montana; and government authorities. 77. It was part of the conspiracy that the defendants obstructed, impeded, and frustrated the governmental authorities by withholding information regarding the hazardous nature and friability of the tremolite asbestos contaminated vermiculite and asserting that the Libby Mine operations and Libby vermiculite posed no risk to public health and safety and the environment. * * * 79. It was part of the conspiracy that the defendants sold and leased tremolite asbestos contaminated real property and withheld information about the contamination from the purchasers of the property. 82. It was part of the conspiracy that the defendants falsely described, concealed from, and failed to reveal to the government the hazardous nature and friability of the tremolite asbestos in the Libby vermiculite and the health hazards associated with exposure to tremol-ite asbestos. 83. It was part of the conspiracy that the defendants obstructed, impaired, impeded, and misled EPA during the course of EPA’s emergency response to the asbestos contamination in and around Libby, Montana. The “Overt Acts” portion of the Indictment charges the following conduct relevant to the pending motion: (1) In 1976, Defendant Eschenbach compiled a study which described the incidence of lung disease among Grace employees at the Libby Mine (Indictment, ¶ 84). (2) Grace commissioned a study in 1976 intended to test the effects of tremol-ite asbestos on hamsters. A preliminary draft of the report concluded that the number of hamster deaths was evidence that tremolite asbestos caused cancer (¶¶ 85-88). (3) Grace commissioned a review of employee x-rays in 1977 to determine the risks posed by exposure to tremolite and the benefits of improved dust controls at the Libby Mine. The review found “numerous cases of asbestos disease” among Grace employees (¶¶ 89-92). (4) Grace conducted an internal audit in 1981 which included a review of employee x-rays. The audit revealed a 38.4% incidence of lung abnormalities for employees working from 1976 though 1980 and concluded that each additional year of tremolite exposure adds 1.5% to the incidence of lung abnormality (¶¶ 93-97). (5) In 1980, Grace learned of lung problems among employees at O.M. Scott, a processing facility in Ohio that handled ore from the Libby mine. In 1983, a doctor who studied O.M. Scott employees informed Grace executives that the health problems there were caused by exposure to Grace’s vermiculite (¶¶ 98-102). (6) In 1982, Grace commissioned a mortality study which included that an excessive number of employees at the Libby Mine had died of cancer of the respiratory system (¶¶ 103-04). (7) Beginning in 1980, in response to a statement by NIOSH representatives that the agency was interested in conducting an epidemiological study at the Libby Mine, Grace executives sought to dissuade NIOSH through obstruction and other means (¶¶ 105-114). (8) From 1977 through 1982, Grace conducted in-house testing to determine whether tremolite fibers were released into the air from its commercial and consumer products (¶¶ 115-27). (9) Grace failed to provide certain of the studies and tests described above in response to requests by the EPA pursuant to the Toxic Substances Control Act.. Grace failed to fully respond to such requests in 1983, 1986 and 1992 (¶¶ 128-32). (10) In the early nineties, Grace began exploring options for the sale of its Libby properties, including the mine site. After prospective buyer 3M declined the purchase because of “potential environmental problems,” Defendant Stringer wrote a memo to Defendant Wolter providing this analysis of Grace’s position: For the same reasons that 3M would not buy the mine, I doubt any other large corporation will come forward with an offer to buy the entire property. If Grace is going to be able to transfer all of the future responsibilities and liabilities to someone else, they are going to have to be willing to sell to some small organization. (¶¶ 150-55). (11) Grace sold its Screening Plant property to Lincoln County residents Mel and Lerah Parker in 1993. In 1994, Grace sold the Libby Mine site and other properties to Kootenai Development Company (KDC). Grace donated its Export Plant property to the City of Libby in 1994-95 (¶¶ 156-68). (12) In 2000, knowing that the EPA’s Superfund Emergency Response Team was negotiating with KDC to use the mine site to return contaminated materials removed from the Libby community, Grace paid $2.3 million to regain control of the mine site. Grace then denied the Superfund Emergency Response Team access to the mine site (¶¶ 169-72). (13) From 1999 through 2002, Grace and Defendant Stringer made a series of false and misleading statements in response to EPA CERCLA 104(e) requests and engaged in other acts intended to obstruct the EPA investigation into asbestos contamination in Libby (¶¶ 173-84). 2. Discussion The duplicitous argument about Count I is based on the premise that because the two objects of the charged conspiracy (i.e., release of asbestos into the air and concealment of the known dangers of asbestos-contaminated vermiculite) were fully accomplished when Grace ceased Libby operations in 1992 and sold its Libby properties in 1995, there are two different conspiracies charged in one count. Defendants say the conduct charged from 1999 through 2002 was not contemplated or agreed upon by the members of the “first” conspiracy and as such constitutes a separate conspiracy to cover up the earlier illegal conduct. The distinction advanced by the Defendants is important from their perspective because it would likely mean that the “first” conspiracy, spanning the years 1976 to 1995, is time-barred due to the five-year statute of limitations applicable to conspiracies charged under 18 U.S.C. § 371. In such a scenario the only actionable conduct would be the “second” conspiracy beginning in 1999, in which only Defendants Grace and Stringer are alleged to have committed overt acts. The prosecution argues that Count I charges a single agreement to achieve all of the criminal ends alleged in Count I, including false statements and obstruction in response to the EPA investigation undertaken years after Grace closed the Libby Mine. a. Legal standard An indictment is duplicitous where a single count joins two or more distinct offenses. United States v. Ramirez-Martinez, 273 F.3d 903, 913 (9th Cir.2001) (citation omitted). Rule 8(a), Fed. R.Crim.P. provides: The indictment may charge a defendant in separate counts with 2 or more offenses if the offenses charged — whether felonies or misdemeanors or both — are of the same or similar character, or are based on the same act or transaction, or are connected with or constitute parts of a common scheme or plan. The requirement that multiple offenses be charged in separate counts is intended to eliminate the constitutional problems created when two or more offenses are joined in a single count. “A duplicitous indictment compromises a defendant’s Sixth Amendment right to know the charges against him, as well as his Fifth Amendment protection against double jeopardy.” United States v. King, 200 F.3d 1207, 1212 (9th Cir.1999). A duplicitous indictment also carries with it the risk of a non-unanimous verdict on the duplicitous count. United States v. Aguilar, 756 F.2d 1418, 1420 n. 2 (9th Cir.1985). i. Test for assessing claims of duplicity In deciding whether an indictment is duplicitous, “[t]he court limits its review to a reading of the indictment itself to determine tvhether it may be read to charge a single violation.” King, 200 F.3d at 1212 (citing Aguilar, 756 F.2d at 1422) (emphasis added). Instead of using the limited review prescribed in King, the Defendants urge the Court to employ the “overall agreement/relevant factors” test set forth in United States v. Gordon, 844 F.2d 1397 (9th Cir.1988), to determine whether the conduct charged in Count I constitutes two distinct conspiracies. A hard look at the case law shows that King’s limited review is the applicable test at this stage of the case. In Gordon, the defendants were accused of conspiring to rig bids for military hardware contracts. 844 F.2d at 1398-1400. During the investigation into the defendants’ conduct, the defendants destroyed documents and took other steps intended to avoid detection of their wrongdoing. Id. The defendants were convicted on Count I of the indictment, which charged them with: conspiracy to commit offenses against and to defraud the United States of America as follows: 1. To defraud the United States of America and in particular the United States Navy of its program for the design, development, construction and distribution of military hardware under the Trident Ballistic Missile Program administered honestly, fairly and free from corruption, deceit, dishonesty and kickbacks; 2. To conceal, cover up; and obstruct an investigation by this Grand Jury into that wrongdoing. Id. at 1401. In Gordon, the defendants argued that Count I of the indictment was duplicitous. The appeals panel began its analysis of the argument by stating the test for duplicity: “Our task is solely to assess whether the indictment can be read to charge only one violation in each count.” Id. at 1400 (citing United States v. Mastelotto, 717 F.2d 1238, 1244 (9th Cir.1983)). The court held that the defendants had waived their objection to the form of the indictment because they failed to raise the issue of duplicity prior to trial as required by Rule 12(b)(2), Fed. R.Crim.P. 844 F.2d at 1400. Nonetheless, the court went on to consider whether the conduct charged in Count I of the Gordon case constituted two conspiracies: In this case Gordon first raised the duplicity issue in his Rule 29 motion at the close of the government’s case-in-chief and he has not made any showing of good cause. We conclude that appellants have «waived an objection to the form of the indictment and their right to force the government to divide Count I into two separate conspiracy counts. Appellants, however, have a right under Article III, sec. 2 and the sixth amendment to a unanimous jury verdict. This constitutional claim was not waived. Id. at 1400-01 (emphasis in original) (citation omitted). In analyzing the defendants’ constitutional claim, the Gordon panel considered “whether there was one overall agreement among the various parties to perform various functions in order to carry out the objectives of the conspiracy.” Id. at 1401 (quoting United States v. Moran, 759 F.2d 777, 784 (9th Cir.1985)). The Gordon court then listed the relevant factors to be considered in determining the existence of such an overall agreement: the nature of the scheme; the identity of the participants; the quality, frequency and duration of each conspirator’s transactions; and the commonality of times and goals. Id. at 1401 (citing United States v. Arbelaez, 719 F.2d 1453, 1457 (9th Cir.1983)). It is this “overall agreement/relevant factors” test that the Defendants argue should apply in this case. But, as was discussed at the hearing on this motion, there is a distinct procedural difference between Gordon and the situation confronted here. The structure of the Gordon opinion belies the Defendants’ contention that the overall agreement/relevant factors test applies at this stage. The Gordon court expressly stated that it was not considering an objection to the form of the indictment, and made clear that objections to the form were to be resolved pursuant to the “limited review” test. Instead, the Gordon court was assessing whether the defendants were subjected to the risk of a non-unanimous jury verdict. The relevant factors test it employed in making that assessment is markedly of a different character than the limited review test associated with pretrial challenges for duplicity. This distinction is apparent from the Gordon court’s application of the relevant factors test, for which the court relied upon a review of the evidence at trial. 844 F.2d at 1401 (“The evidence does not show that the parties contemplated or discussed any plans for a coverup.”). At the pretrial stage, during which a challenge to the form of the indictment must be raised under Rule 12(b)(2), it is impossible for the court to consider the evidence heard at trial. Other Ninth Circuit cases confirm that the overall agreement/relevant factors test advanced by the Defendants does not apply to their current motion to dismiss. In United States v. Zemek, 634 F.2d 1159, 1167 (9th Cir.1980), defendants charged with racketeering argued that the evidence adduced at trial demonstrated that conduct charged as a single conspiracy was in fact two distinct conspiracies. The reviewing court applied the overall agreement/relevant factors test and, like the Gordon court, looked to the evidence at trial for its application. Id. at 1167-68 (“The evidence revealed a continuing relationship among participants organized in a hierai'chical pattern.”). The Zemek opinion contains no mention of a duplicity argument at either the trial or appellate stage. In United States v. Jabara, 618 F.2d 1319 (9th Cir.1980) which the Gordon court cites as authority for the “overall agreement” portion of its test, defendants convicted of a narcotics conspiracy claimed that the evidence adduced at trial showed that the conduct charged as one conspiracy was in fact several conspiracies. Id. at 1327. The reviewing court looked for an “overall agreement” between the defendants and determined based on the evidence at trial that such an agreement existed. Id. at 1328. As in Zemek, there is no mention of a duplicity challenge. These cases reveal more than a nominal distinction between the “limited review” test and the “overall agreement/relevant factors” test. The latter applies in those cases where the government has charged a single conspiracy but the defendant alleges a variance between the charge and the proof at trial because the proof has shown that the conduct charged constitutes more than one conspiracy. In such cases, the “overall agreement/relevant factors” test is used to determine whether the conduct charged constitutes only one conspiracy. By contrast, the “limited review” test is used when the defendant is making a pretrial objection under Rules 12(b)(2) and 8(a) to the form of the indictment as duplicitous. Unlike the overall agreemeni/relevant factors test, the duplicity inquiry necessarily proceeds without reference to the evidence at trial. “In reviewing an indictment for duplicity, our task is not to review the evidence presented at trial to determine whether it would support charging several crimes rather than one, but rather solely to assess whether the indictment itself can be read to charge only one violation in each count.” United States v. Martin, 4 F.3d 757, 759 (9th Cir.1993) (quoting United States v. Yarbrough, 852 F.2d 1522, 1530 (9th Cir.1988)). If Count I can be read to charge only one violation, the Defendants’ motion to dismiss Count I as duplicitous will be denied. ii. Remedies available upon a finding of duplicity If duplicity is established, a trial court may (1) allow election, provided the defendant is not prejudiced thereby and the election does not alter the nature of the charge, or (2) dismiss the offending count. Aguilar, 756 F.2d at 1423. Another option is to address the duplicitous indictment by instructing the jury that all members are required “to agree as to which of the distinct charges the defendant actually committed.” Ramirez-Martinez, 273 F.3d at 915. b. When acts of concealment may be viewed as acts in furtherance of a conspiracy In deciding whether the indictment can be fairly read to charge only one offense, it is helpful to refer to case law discussing the circumstances under which acts of concealment may be considered part of the original scheme. Both parties cite the Supreme Court’s decision in Grunewald v. United States, 353 U.S. 391, 77 S.Ct. 963,1 L.Ed.2d 931 (1957), in support of their positions. In Grünewald, the defendants were charged with conspiring to defraud the government by taking bribes from companies under investigation by the Bureau of Internal Revenue in exchange for using their influence with Bureau officials to procure “no prosecution” rulings for their beleaguered clients. 353 U.S. at 394-95, 77 S.Ct. 963. A congressional investigation into the defendants’ wrongdoing began in 1951, two years after the last of the “no prosecution” rulings was obtained and the last bribes were paid in 1949. Id. at 395-96, 77 S.Ct. 963. In response to the investigation, the defendants doctored records, warned their clients not to talk and attempted to influence witness testimony. Id. When the defendants were eventually charged in 1954 with conspiracy to defraud the United States, the charged conduct included their post-1951 efforts at concealment. Id. at 394 n. 3, 77 S.Ct. 963. The defendants argued on appeal that the conspiracy count was barred by the three-year statute of limitations because the acts done to conceal the conspiracy were not part of the original agreement, meaning the last act in furtherance of the conspiracy took place in 1949, well outside the statute of limitations. Id. at 397-98, 77 S.Ct. 963. The government argued that although the main objective of the conspiracy was to obtain the “no prosecution” rulings, the conspiracy necessarily inelud-ed a subsidiary agreement to conceal the conspiracy. Id. at 398, 77 S.Ct. 963. Quoting its opinion in Krulewitch v. United States, 336 U.S. 440, 69 S.Ct. 716, 93 L.Ed. 790 (1949), the Grünewald Court rejected the government’s argument: Conspirators about to commit crimes always expressly or implicitly agree to collaborate with each other to conceal facts in order to prevent detection, conviction and punishment. Thus the (Government’s) argument is that even after the central criminal objectives of a conspiracy have succeeded or failed, an implicit subsidiary phase of the conspiracy always survives, the phase which has concealment as its sole objective. We cannot accept the Government’s contention. 353 U.S. at 400, 77 S.Ct. 963 (quoting Krulewitch, 336 U.S. at 444, 69 S.Ct. 716). The Grünewald Court went on to state: The crucial teaching of Krulewitch and [Lutwak v. United States, 344 U.S. 604, 73 S.Ct. 481, 97 L.Ed. 593 (1953) ] is that after the central criminal purposes of a conspiracy have been attained, a subsidiary conspiracy to conceal may not be implied from circumstantial evidence showing merely that the conspiracy was kept a secret and that the conspirators took care to cover up their crime in order to escape detection and punishment. As was there stated, allowing such a conspiracy to conceal to be inferred or implied from mere overt acts of concealment would result in a great widening of the scope of conspiracy prosecutions, since it would extend the life of a conspiracy indefinitely. Acts of covering up, even though done in the context of a mutually understood need for secrecy, cannot themselves constitute proof that concealment of the crime after its commission was part of the initial agreement among the conspirators. 353 U.S. at 401-02, 77 S.Ct. 963. In holding that the government sought to infer an agreement to conceal from “elements which will be present in virtually every conspiracy case, that is, secrecy plus overt acts of concealment,” the Court observed, “[tjhere is not a shred of direct evidence in this record to show anything like an express original agreement among the conspirators to continue to act in concert in order to cover up, for their own self-protection, traces of the crime after its commission.” Id. at 404, 77 S.Ct. 963. The Court nonetheless left open the possibility that acts of concealment might be included as part of an original conspiratorial agreement. By no means does this mean that acts of concealment can never have significance in furthering a criminal conspiracy. But a vital distinction must be made between acts of concealment done in furtherance of the main criminal objectives of the conspiracy, and acts of concealment done after these central objectives have been attained, for the purpose only of covering up after the crime. 353 U.S. at 405, 77 S.Ct. 963. Ninth Circuit cases applying Grünewald have delineated those circumstances in which acts of concealment may be viewed as furthering the main criminal objectives of a conspiracy. In United States v. Finlay, 55 F.3d 1410 (9th Cir.1995), the defendant was convicted of two conspiracies to defraud the United States. The first occurred between January and October of 1987 and involved a series of undocumented illegal shipments of nuclear materials by the defendant’s company. Id. at 1412. The second conspiracy occurred between August and November of 1987 and had as its objective to defraud the government by obtaining through false statements the reinstatement of the company’s license to possess radioactive materials, which had been suspended when the Nuclear Regulatory Commission (NRC) learned of two of the illegal shipments. Id. The last of the illegal shipments occurred on August 18, 1987. Id. at 1413. The NRC discovered two of the illegal shipments that same month. Despite the company’s efforts to persuade the NRC not to impose a penalty, the NRC suspended the company’s license on September 21, 1987. Id. Two weeks later, on October 5, 1987, the company filed a “request for recision or relaxation of order” with the NRC in hopes of having its license reinstated. Attached to the request were false documents which the company submitted as evidence that the illegal shipments were supported by proper documentation. Id. The defendant was indicted on September 16, 1992. On appeal, the defendant argued that the conspiracy to make illegal shipments ended with the last illegal shipment in August of 1987 and that prosecution of that conspiracy was time-barred because of the five-year statute of limitations. Id. at 1415. The government disagreed, arguing that the submission of false documents on October 5, 1987 was done in furtherance of the conspiracy to make illegal shipments. The court, applying the Supreme Court’s decision in Grünewald, concluded that the falsification of documents after the shipments were complete was nonetheless part of the main criminal object of the smuggling conspiracy: The main conspiracy charged in Count I of the indictment in our case was a conspiracy to defraud the United States. The submission of the false documents prepared for the Johnston Island shipments was part of the main conspiracy to defraud the United States by concealing from the NRC the violation of its rules governing shipments. The conspiracy, as charged, embraced both the illegal shipments and the illegal absence of documentation and false documentation. It was an essential part of this conspiracy to continue to mislead the NRC and for that purpose on October 5 the false documentation was submitted. As the main conspiracy continued through the commission of this overt act, prosecution was not barred by the statute of limitations. That the false documents also played a part in the second conspiracy to get back the license does not mitigate their use to further the goal of the first conspiracy. Id. at 1415-16. By contrast, in United States v. Vowiell, 869 F.2d 1264 (9th Cir.1989), the Ninth Circuit held that acts taken by a co-conspirator to help escaped prison inmates avoid capture were not a part of the original conspiracy to assist escape. The defendant in Vowiell was charged with conspiracy to assist in the escape of several fellow inmates. Following the escape, which took place on April 16, 1986, the escapees were transported to various hideouts over the next several days. Id. at 1265. On April 20, four days after the escape, the defendant told a fellow inmate/co-conspirator that the escapees needed to move from their current hideout because law enforcement was closing in. Id. at 1266. The inmate then relayed the defendant’s statement to her brother, a co-conspirator on the outside, so that the brother could get the message to the escapees. Id. The brother testified for the government at the defendant’s trial and recounted the instructions to relocate which he had received from the defendant by way of his sister. The trial court held the sister’s hearsay statement admissible as a co-conspirator statement under Rule 802(d)(2)(E), Fed.R.Evid. Id. ' The defendant argued on appeal that the sister’s statement relaying his instructions to the escapees was inadmissible because it was not made in furtherance of the conspiracy to assist escape. The Ninth Circuit agreed, holding that the escape which was the object of the conspiracy was completed when the escapees had successfully fled “beyond immediate active pursuit.” Id. The Court stated: Any further assistance could have, at most, constituted harboring or concealing. [The sister], however, was not charged with that offense. Nor did the conspiracy charged in the indictment encompass such harboring. Further, there was no evidence that [the sister] agreed to assist the escapees beyond leaving the prison confines and making a getaway to some kind of refuge. No ongoing assistance seems to have been contemplated.- Id. What these cases show is that acts taken to conceal a criminal conspiracy will be considered acts in furtherance of the conspiracy when the acts of concealment were contemplated by the original conspiratorial agreement and carried out in furtherance of the main criminal objectives of the charged conspiracy. As the Ninth Circuit stated in United States v. Walker, 653 F.2d 1343 (9th Cir.1981), Id. at 1347 (quoting United States v. Kissel, 218 U.S. 601, 607, 31 S.Ct. 124, 54 L.Ed. 1168 (1910)). The Walker court went on to write: “Where there is evidence that the conspirators originally agreed to take certain steps after the principal objective of the conspiracy was reached, or evidence from which such an agreement may reasonably be inferred, the conspiracy may be found to continue.” 653 F.2d at 1350 (quoting United States v. Hickey, 360 F.2d 127, 141 (7th Cir.1966)). [T]he mere continuance of the result of a crime does not continue the crime-.... But when the plot contemplates bringing to pass a continuous result that will not continue without the continuous cooperation of the conspirators to keep it up, and there is such continuous cooperation, (the conspiracy continues). In light of this authority, it is now necessary to examine Count I of the Indictment in this case to determine whether it may be fairly read to charge only one offense. The measure of that answer lies with King and Aguilar, and must be confined to a review of the Indictment. This means that rather than looking for evidence, what is examined is whether there are allegations that the conspirators originally agreed to take certain steps after the principal objective of the conspiracy was reached, or allegations from which such an agreement may reasonably be inferred. c. The conspiracy charged in Count I The Defendants argue that Count I contains allegations of one conspiracy ending in 1995 and a second conspiracy to conceal beginning in 1999. This argument is based on a mischaracterization of the objects of the conspiracy charged in Count I, in particular the object of defrauding the United States. The Defendants argue that Count I charges them with conspiring to “defraud federal regulatory agencies in order to keep the mine operating and to avoid further regulation of Grace’s Libby vermiculite products.” Defs.’ Op. Br., pp. 13-14. This narrow view of the purpose of the defrauding conspiracy as solely to maintain the mining operation as a going concern allows the Defendants to claim that the conspiracy was complete upon closure of the mine: “At that point, of course, the Defendants could no longer conceal scientific research and mislead Government agencies in order to continue operation of the mine without government interference. In other words, the objective of defrauding the government to facilitate the Libby operation was complete.” Id. at 15. Contrary to the Defendants’ view, the defrauding conspiracy charged in Count I is fairly aimed at both facilitation of the Libby Mine as a going concern and avoidance of liability for the Defendants’ actions. That the conspiracy charged contained a “liability avoidance” component is clear from the language of Count I, which reads, It was a purpose of the conspiracy to increase profits and avoid liability by misleading the government and preventing the government from using its authorities to protect against risks to human health and the environment associated with the manufacture, processing, distribution, commerce, use, handling, disposal, and release of tremolite asbestos contaminated vermiculite. Indictment, ¶ 73 (emphasis added). There is no dispute that acts such as withholding information from the government about the dangers of exposure to Libby vermiculite and obstructing government plans to conduct health studies of the Libby miners further the goal of keeping up the mine as a profitable business. The question is whether, on a fair reading, those acts also further the purpose of liability avoidance. Many of the overt acts which Defendants argue relate exclusively to the goal of maintaining a profitable mining concern free of regulation can also be fairly read to be intended in part to avoid liability. Withholding information and obstructing government investigation has the direct benefit of preventing potentially burdensome regulation which might require the company to follow costly safety procedures. But those tactics would also benefit the company by keeping damaging information from those who might seek to hold the company liable for their injuries. Information given to the government might filter down to Grace employees or employees of Grace’s industrial customers, who in turn might seek to hold Grace liable for asbestos-related health problems. Moreover, withholding information about the dangers of processed ore prevents the possibility that the government might (as it eventually did) require that processed ore disposed of within the Libby community be removed at the company’s expense. The sale of the Libby Mine site to KDC in 1994 may also prove that liability avoidance was a goal of the charged conspiracy well before the Superfund investigation began in 1999. Before the sale to KDC, Grace allegedly negotiated with several other companies, including 3M, to sell the mine site. The Indictment alleges that in 1993 Defendant Stringer wrote Defendant Wolter a memo summarizing Grace’s sales options and offered this conclusion: For the same reasons that 3M would not buy the mine, I doubt any other large corporation will come forward with an offer to buy the entire property. If Grace is going to be able to transfer all of the future responsibilities and liabilities to someone else, they are going to have to be willing to sell to some small organization. Indictment, ¶ 155. Grace’s mining and milling operations had concluded at the time this memo was allegedly written. Even so, the allegations show Defendants continued to act to avoid liability after the mine had ceased as a going concern. This allegation undermines the Defendants’ argument that the defrauding conspiracy was aimed solely at keeping the mine operating and that the conspiracy ended when Grace shut down its operation. A fair reading of Paragraph 155, in conjunction with Paragraph 73 and the Indictment’s allegations that Grace withheld information from the government and others, allows the reasonable inference that liability avoidance was a goal of the charged conspiracy from the beginning. On this reading, the acts of concealment taken in response to the EPA’s Superfund investigation from 1999 through 2002 were merely a continuation of the conspiracy to defraud the government in order to avoid liability. In this regard, the Defendants’ conduct in response to the Superfund investigation is analogous to the concealment efforts of the smugglers in Finlay after the NRC learned of the illegal shipments. In Finlay, the court held that the conspiracy embraced both illegal shipments and the illegal absence of proper documentation, and that it was therefore an essential part of the conspiracy to continue to mislead the NRC by submitting false documents months after the shipments were complete. 55 F.3d at 1415. In this case, the defrauding objective of the charged conspiracy embraced both facilitation of the mining operation and avoidance of liability for the harmful effects of Libby vermiculite ore on people and property. It was arguably an essential part of the charged conspiracy to continue to mislead the EPA to avoid liability resulting from the Superfund investigation. The court in Vowiell held that acts constituting harboring were not done in furtherance of a conspiracy to escape where (1) the conspiracy as charged did not encompass harboring and (2) there was no evidence that the conspirators agreed to provide ongoing assistance to the escapees once they had left the prison confines and made a getaway. 869 F.2d at 1268. By contrast, the conspiracy charged in this case expressly names liability avoidance as a purpose in Paragraph 73 and includes direct and circumstantial allegations from which one may fairly infer that the genesis of the liability avoidance goal occurred long before the EPA’s Superfund investigation in 1999. As a result, this case does not present the scenario forbidden by the Supreme Court in Grünewald, whereby an agreement to conceal is inferred “merely because the conspiracy is kept a secret, and merely because the conspirators take steps to bury their traces.” 353 U.S. at 405, 77 S.Ct. 963. Count I can be fairly read to charge a single offense, i.e., a conspiracy with the dual purposes of violating the Clean Air Act and defrauding the government in order to facilitate operation of the Libby Mine and avoid liability for the effects of asbestos-contaminated vermiculite on humans and the environment. The Ninth Circuit’s test for duplicity has not been satisfied by the arguments put forth here. d. The Defendants’ constitutional rights The Defendants also contend that Count I violates their rights under the Fifth and Sixth Amendments to the United States constitution, specifically their Fifth Amendment protection against double jeopardy and their Sixth Amendment right to know the charges against them and to be free from the risk of a non-unanimous jury verdict. These concerns are addressed by the Ninth Circuit’s test for duplicity, which is designed to protect against violations of those rights. See King, 200 F.3d at 1212 (“A duplicitous indictment compromises a defendant’s Sixth Amendment right to know the charges against him, as well as his Fifth Amendment protection against double jeopardy.”). Satisfaction of King’s test for duplicity therefore negates any concern relating to those constitutional protections. There is one remaining constitutional claim. Defendants argue that Count I subjects them to the risk of a non-unanimous jury verdict. The argument or assertion is premature. By their motion, Defendants have objected to the form of the Indictment as duplicitous. If the argument fails and the form of the Indictment is proper, the case can go forward without injury to the Defendants’ constitutional rights because the proper presentation of the charge is all that is required at this stage. If the proof at trial shows that the conduct charged in Count I does in fact constitute two distinct conspiracies, steps can be taken to protect the Defendants from the risk of a non-unanimous verdict. Such steps might include curative instructions to the jury, special interrogatories to insure unanimity, or the dismissal of all or part of the offending count. No violation of the Defendants’ constitutional rights results from the denial of their motion to dismiss Count I for duplicity. Accordingly, the Defendants’ joint motion to dismiss Count I of the Indictment as duplicitous is denied. B. Defendants’ joint motion to dismiss Counts I through IV of the Indictment for failure to allege knowledge of unlawful conduct Defendants move to dismiss Counts I through IV of the Indictment for failure to allege a required element, i.e., that the Defendants were aware that their conduct in violation of the Clean Air Act was unlawful. The United States opposes the motion and argues that the knowing endangerment provision of the Clean Air Act (42 U.S.C. § 7413(c)(5)) does not require proving that an accused knew that his actions were unlawful at the time of the offense. None of Counts I through IV contains an allegation that the persons charged knew that their conduct in violation of the Clean Air Act was unlawful. 1. Legal standard “[A]n indictment is sufficient if: (1) it contains the elements of the offense charged and fairly informs a defendant of the charge against which he must defend; and (2) it enables him to plead an acquittal or conviction in bar of future prosecutions for the same offense.” United States v. Hill, 279 F.3d 731, 741 (9th Cir.2002) (citing Hamling v. United States, 418 U.S. 87, 117, 94 S.Ct. 2887, 41 L.Ed.2d 590 (1974)); see also Fed.R.Crim.P. 7(c)(1). Failure to allege a required element of the charged offense is a fatal flaw requiring dismissal. United States v. Du Bo, 186 F.3d 1177, 1179 (9th Cir.1999) (“[I]f properly challenged prior to trial, an indictment’s complete failure to recite an essential element of the charged offense is not a minor or technical flaw subject to harmless error analysis, but a fatal flaw requiring dismissal.”). In interpreting a statute to determine what are the required elements, courts should look first to the language of the statute, and second to the legislative history. United States v. Weitzenhoff, 35 F.3d 1275, 1283 (9th Cir.1994). A court should seek to “give effect to the plain, common-sense meaning of the enactment without resorting to an interpretation that defies common sense.” United States v. Bonilla-Montenegro, 331 F.3d 1047, 1051 (9th Cir.2003) (internal quotation marks omitted). The plain language of the statute is to be ignored only when a literal interpretation of the statute would thwart the purpose of the statutory scheme and lead to an absurd result. County of Santa Cruz v. Cervantes, 219 F.3d 955, 960 (9th Cir.2000). Courts should also reject any interpretation that would render another statutory provision surplusage or a nullity. Id. at 961. Resort to the legislative history for aid in interpreting a statute is only appropriate when the terms of the statute are ambiguous. Burlington N. R.R. Co. v. Oklahoma Tax Comm’n, 481 U.S. 454, 461, 107 S.Ct. 1855, 95 L.Ed.2d 404 (1987) (“Unless exceptional circumstances dictate otherwise, when we find the terms of a statute unambiguous, judicial inquiry is complete.” (internal quotation marks omitted)). 2. Statutory language The relevant section of the Clean Air Act provides: Any person who knowingly releases into the ambient air any hazardous air pollutant listed pursuant to section 7412 of this title or any extremely hazardous substance listed pursuant to section 11002(a)(2) of this title that is not listed in section 7412 of this title, and who knows at the time that he thereby places another person in imminent danger of death or serious bodily injury shall, upon conviction, be punished by a fine under Title 18, or by imprisonment of not more than 15 years, or both. Any person committing such violation which is an organization shall, upon conviction under this paragraph, be subject to a fine of not more than $1,000,000 for each violation. 42 U.S.C. § 7413(c)(5)(A). The next sub-paragraph sets forth a test for satisfaction of the knowing endangerment requirement for individual defendants: In determining whether a defendant who is an individual knew that the violation placed another person in imminent danger of death or serious bodily injury— (i) the defendant is responsible only for actual awareness or actual belief possessed; and (ii) knowledge possessed by a person other than the defendant, but not by the defendant, may not be attributed to the defendant; except that in proving a defendant’s possession of actual knowledge, circumstantial evidence may be used, including evidence that the defendant took affirmative steps to be shielded from relevant information. 42 U.S.C. § 7413(c)(5)(B). The Defendants contend that the phrase “knew that the violation” in § 7413(c)(5)(B) adds an additional element to the offense set forth in § 7413(c)(5)(A), i.e., that the individual defendant knew that his conduct was unlawful. 3. Discussion Interpretation of § 7413(c)(5) begins with a reading of the statutory language to see whether the words have a plain and unambiguous meaning. Section 7413(c)(5)(A) requires a knowing release of a hazardous air pollutant leading to knowing endangerment, both of which are charged in Counts I through IV. The Defendants contend that § 7413(c)(5)(B) must be read to add as a required element that an individual defendant acted with knowledge that his conduct was unlawful. The government correctly characterizes the Defendants’ motion as reading a required mental state of willfulness into § 7413(c)(5). See Cheek v. United States, 498 U.S. 192, 201, 111 S.Ct. 604, 112 L.Ed.2d 617 (1991) (“[T]he standard for the statutory willfulness requirement is the ‘voluntary, intentional violation of a known legal duty.’ ”). Because the statute does not expressly require willfulness, the question for the Court is whether the statute is ambiguous with respect to the required mental state, thereby requiring resort to the legislative history to settle the dispute. The Defendants’ tenuous reading of § 7413(c)(5)(B) cannot obscure the plain meaning of the statute. When read as a whole, § 7413(c)(5)(B) is intended to give added content to the knowing endangerment requirement with respect to individual defendants. There is no articulated reasonable basis to assume that § 7413(c)(5)(B) is intended to change the required mental state explicitly set forth in the previous subparagraph. In support of their position, the Defendants urge the Court to compare the Clean Air Act to two other environmental statutes, the Resource Conservation and Recovery Act (“RCRA”), 42 U.S.C. §§ 6901-7000 (2000), and the Clean Water Act (“CWA”), 33 U.S.C. § 1251-1387 (2000). Both statutes contain knowing endangerment provisions similar to § 7413(c)(5)(A) and provisions defining responsibility similar to § 7413(c)(5)(B). In a provision analogous to § 7413(c)(5)(B), the RCRA provides, “In determining whether a defendant who is a natural person knew that his conduct placed another person in imminent danger....” 42 U.S.C. § 6928(f)(2) (emphasis added). Similarly, the CWA provides, “[I]n determining whether a defendant who is an individual knew that his conduct placed another person in imminent danger....” 33 U.S.C. § 1319(c)(3)(B)(emphasis added). The crux of the argument is that Congress’ use of the phrase “knew that the violation” in § 7413(c)(5)(B) rather than the phrase “knew that his conduct” demonstrates an intention to require a different mental state than the knowing standard that is required for the RCRA and CWA. The argument is unpersuasive. Congress is aware of the construction courts will give to various terms with respect to the required mental state, and Congress is able to explicitly require the mental state of willfulness when it wishes to do so. In Cheek, in which the Supreme Court discussed the proper construction of tax statutes requiring willfulness, the Court began by stating the general common law rule that ignorance of the law is no defense to a criminal prosecution. 498 U.S. at 199, 111 S.Ct. 604. The Court acknowledged, however, that in the tax context, the law can be so complex that an ordinary citizen cannot be expected to know all of his duties and obligations. Id. at 199-200, 111 S.Ct. 604. In such cases, the Court wrote, Congress has deemed it appropriate to require the heightened mental state of willfulness: Congress has accordingly softened the impact of the common-law presumption by making specific intent to violate the law an element of certain federal criminal tax offenses. Thus, the Court almost 60 years ago interpreted the statutory term “willfully” as used in the federal criminal tax statutes as carving out an exception to the traditional rule. 498 U.S. at 200, 111 S.Ct. 604. Congress chose not to use the term “willfully” in § 7413(c)(5)(A) and this suggests that Congress did not intend for the Clean Air Act to depart from the traditional rule that ignorance of the law is not a defense to prosecution. In the context of public welfare statutes such as the Clean Air Act, the Supreme Court has established a presumption against construing statutes to require that the defendant knew that his conduct was unlawful. “[Wjhere ... dangerous or deleterious devices or products or obnoxious waste materials are involved, the probability of regulation is so great that anyone who is aware that he is in possession of them or dealing with them must be presumed to be aware of the regulation.” United States v. Int’l Minerals & Chem. Corp., 402 U.S. 558, 565, 91 S.Ct. 1697, 29 L.Ed.2d 178 (1971). In Weitzenhoff, the Ninth Circuit applied the Supreme Court’s rule in International Minerals to hold that the Clean Water Act was a public welfare statute of the type contemplated by International Minerals, because the CWA was “clearly designed to protect the public at large from the potentially dire consequences of water pollution.” 35 F.3d at 1286. Accordingly, the Weitzenhoff court concluded that the CWA requires that a defendant act knowingly, and does not impose upon the government the higher standard of willfulness. Id. That the Clean Air Act is a public welfare statute under the International Minerals definition further undermines the Defendants’ contention that § 7413(c)(5) contains an element of willfulness. Moreover, the interpretation advanced by the Defendants in support of their position would render another provision of § 7413 a nullity. Section 7413(h) provides in part, Except in the case of knowing and willful violations, for purposes of paragraphs (1), (2), (3), and (5) of subsection (c) of this section the term “a person” shall not include an employee who is carrying out his normal activities and who is acting under orders from the employer. That section provides a shield from criminal liability under § 7413(c)(5) for non-managerial employees who commit violations in the course of their normal employment activities while acting under orders from an employer. By virtue of the exception in § 7413, an employee whose conduct otherwise satisfies the elements set forth in § 7413(c)(5)(A) will not be liable unless the government can prove the additional element of willfulness. In other words, an employee who is “just following orders” from his employer is not criminally liable under the Clean Air Act unless the government can prove that the employee knew that his conduct was unlawful. The interpretation advanced by the Defendants would render § 7413(h) meaningless. If the Defendants are correct, and all violations of § 7413(c)(5) require that the defendant knew his conduct was unlawful, there is no reason to designate willfulness as the heightened standard applicable to employees acting on the instructions of their employer. Because Congress established a willfulness standard for such employees, it strongly suggests that Congress intended something less than willfulness to be required for violations of § 7413(c)(5). The Defendants’ interpretation of § 7413(c)(5) is unpersuasive because it would render the exception provision in § 7413(h) a nullity. See Cervantes, 219 F.3d at 961. The language and structure of § 7413 do not reveal an ambiguity with respect to the requisite mental state for criminal liability of § 7413(c)(5). There is as a result no reason to refer to the legislative history for guidance as the Defendants suggest. See Newton v. Sec’y of Health and Human Services, 70 F.3d 1114, 1115 n. 2 (9th Cir.1995) (“[T]he statute itself is perfectly clear, so resort to legislative history is neither called for nor appropriate.”). Moreover, resort to legislative history does nothing to bolster the Defendants’ position. The plain language of the Clean Air Act indicates that it is not a required element of § 7413(c)(5) that the defendant know that his conduct is unlawful. This interpretation is supported by the structure of the statute, the Supreme Court’s presumption against a willfulness standard in interpreting public welfare statutes, and the statute’s legislative history. The De