MEMORANDUM OPINION AND ORDER
NORDBERG, District Judge.
This case is before the court on the defendant Riverside’s motion to stay the proceeding pending resolution of Riverside’s two state court actions. For the following reasons, this court grants the motion to stay on the basis of
Pullman
and
Colorado River
abstention principles.
I. Facts
On November 21,1986, the United States Environmental Protection Agency (USEPA) filed this suit against Riverside Laboratories, Inc. (Riverside), pursuant to section 113(b)(2) of the Clean Air Act, 42 U.S.C. § 7413(b)(2) (1982) (Act). Under the Act, the USEPA must establish “national ambient air quality standards” (NAAQS) for pollutants, such as ozone, that “cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare____”
Id.
§ 7408(a)(1)(A). In order to implement, maintain, and enforce the NAAQS, each state is required to develop and submit for USEPA approval a comprehensive regulatory strategy known as a “state implementation plan” (SIP).
Id.
§ 7410(a)(1). The SIP includes regulations for emissions limitations that specify the amount of each pollutant that lawfully can be emitted. Each state is free to choose whatever emissions limitations it deems appropriate, provided that its SIP complies with the minimum standards set by the NAAQS.
See Train v. Natural Resources Defense Council, Inc.,
421 U.S. 60, 79, 95 S.Ct. 1470, 1482, 43 L.Ed.2d 731 (1975) (“[S]o long as the ultimate effect of a State’s choice of emission limitations is compliance with the national standards for ambient air, the State is at liberty to adopt whatever mix of emission limitations it deems best suited to its particular situation.”).
Once the USEPA approves the SIP, it has the power under section 113(b) to bring enforcement actions in United States District Court against violators of the SIP.
As a prerequisite to such an enforcement action, however, the USEPA must first issue a “notice of violation” (NOV) to both the alleged violator and the state authorities. 42 U.S.C. § 7413(a)(1).
If after thirty days the violation continues unabated, the USEPA then can bring suit in federal court.
In this case the pertinent regulations, adopted by the Illinois Pollution Control Board (IPCB) and approved by the USEPA, govern the emission of volatile organic compounds (VOC’s) — substances that contribute to the formation of ozone. These regulations include, in part, VOC emissions limitations for paper coating and fabric coating operations.
See
Ill.Admin.Code tit. 35, § 215.204(c), (e) (1985). On April 19, 1985, the USEPA issued an NOV to Riverside, notifying the defendant that its Geneva, Illinois, facility was in violation of these regulations.
The USEPA claims that it then engaged in extensive negotiations with Riverside regarding the alternatives available to correct the alleged violations.
On October 22, 1986, Riverside filed suit in Illinois Circuit Court against the Illinois Environmental Protection Agency (IEPA), seeking a declaratory judgment that its operating permit was valid because its facility was not and never was intended to be classified as a “paper coating” operation within the meaning of the Illinois regulation.
Riverside also alleges that prior to the adoption of the paper coating regulation, the IEPA itself did not consider Riverside to be a paper coater. Consequently, Riverside claims, it was not given notice and an opportunity to be heard at the IPCB hearings conducted to determine the economic impact of the regulation; nor was Riverside able to submit proposed amendments or alterations to the regulation or to file a timely appeal with the Illinois Appellate Court as a party adversely affected or threatened by the regulation. The categorization of Riverside as a paper coater, the defendant contends, would therefore violate its procedural due process rights.
After Riverside filed its state court declaratory action, the USEPA filed this suit in federal court, seeking injunctive and monetary relief for Riverside’s alleged violations of the Illinois SIP.
On April 3, 1987, the IEPA refused to renew Riverside’s operating permit, in part on the ground that Riverside was a paper coater and was not in compliance with the applicable regulation. Riverside then appealed the IEPA’s decision to the IPCB on May 7, 1987. Thus, the issue whether Riverside is a paper coater is now before two state tribunals — the Illinois Circuit Court and the IPCB — as well as before this court. The
issue whether Riverside has violated the fabric coating regulation, on the other hand, is before this court only.
II. Analysis
When a federal district court has subject matter jurisdiction over a case, it has a “ ‘virtually unflagging obligation’ ” to exercise that jurisdiction.
Illinois Bell Tel. Co. v. Illinois Commerce Comm’n,
740 F.2d 566, 569 (7th Cir.1984)
(quoting Colorado River Water Conservation Dist. v. United States,
424 U.S. 800, 817, 96 S.Ct. 1236, 1246, 47 L.Ed.2d 483 (1976)). The judge-made doctrine of abstention, by which a federal district court declines to exercise or postpones the exercise of its jurisdiction, is an “ ‘extraordinary and narrow exception to the duty of a District Court to adjudicate a controversy properly before it.’ ”
Colorado River,
424 U.S. at 813, 96 S.Ct. at 1244
(quoting County of Allegheny v. Frank Mashuda Co.,
360 U.S. 185, 188, 79 S.Ct. 1060, 1063, 3 L.Ed.2d 1163 (1959)). Abstention is proper only “‘in the exceptional circumstances where the order to the parties to repair to the State court would clearly serve an important countervailing interest.’ ”
Id. (quoting County of Allegheny,
360 U.S. at 189, 79 S.Ct. at 1063).
The Supreme Court has recognized several forms of abstention.
Riverside claims that three abstention principles apply to this case:
Pullman, see Railroad Comm’n v. Pullman Co.,
312 U.S. 496, 61 S.Ct. 643, 85 L.Ed. 971 (1941);
Colorado River;
and
Burford, see Burford v. Sun Oil Co.,
319 U.S. 315, 63 S.Ct. 1098, 87 L.Ed. 1424 (1943).
A.
Pullman Abstention
Pullman
abstention is appropriate “‘in cases presenting a federal constitutional issue which might be mooted or presented in a different posture by a state court determination of pertinent state law.’ ”
Colorado River,
424 U.S. at 814, 96 S.Ct. at 1244
(quoting County of Allegheny,
360 U.S. at 189, 79 S.Ct. at 1063);
see also Lynk v. LaPorte Superior Court No. 2,
789 F.2d 554, 567-68 (7th Cir.1986)
(“[Pullman
abstention] authorizes, and in appropriate cases directs, a district court to withhold decision of a federal constitutional issue pending determination in state court of an issue of state law which may, depending on how it is resolved, moot the constitutional issue.”).
Pullman
abstention was designed to avoid “unnecessary federal constitutional challenges to state laws, thereby avoiding needless friction between the state and federal governments.”
Wynn v. Carey,
582 F.2d 1375, 1380 (7th Cir.1978).
For a federal court to invoke
Pullman
abstention, three elements must be present: (1) There must be an unclear or unsettled state law; (2) this state law must be susceptible to a narrowing interpretation by a state court; and (3) this narrowing construction should render unnecessary the federal court’s determination of the federal constitutional issue. In addition, because the abstention doctrine is “rooted in equity,” a court should balance “the need for clarification [of the uncertain state law] ... against the effects of abstaining.”
Id.
at 1381. If the federal court decides that
Pullman
abstention applies, it retains jurisdiction over the case pending state court decision of the state law issue; if disposition of the state issue does not resolve the controversy, the federal court can reassert its jurisdiction and rule on the federal constitutional issue.
Moses v. County of Kenosha,
826 F.2d 708, 710 (7th Cir.1987) (per curiam).
This court concludes that
Pullman
abstention is appropriate in this case. First, there exists a state law — the Illinois SIP — that is unclear in its application to Riverside’s manufacturing operations. The USEPA argues that the SIP is not state law, but rather is federal law that the USEPA can interpret and enforce independent of any state court construction. This argument, however, is contrary to Seventh Circuit precedent. In
Bethlehem Steel Corp. v. Gorsuch,
742 F.2d 1028, 1035-36 (7th Cir.1984), the court held that the USE-PA cannot make an SIP more stringent
than intended by the state without following the procedures set out in the Clean Air Act.
See also Riverside Labs., Inc. v. United States,
No. 86 C 9890, slip op. at 3 (N.D.Ill. Mar. 5, 1987) [Available on WEST-LAW, 1987 WL 7836] (“[T]he Federal Clean Air Act merely provides the authority for the state to enact the SIP. The SIP retains its character as state law.”). Because “claims based on the scope and application of the SIP are essentially ones of state law,”
id.,
the USEPA’s right to enforce the SIP in federal court depends upon the Illinois courts’ interpretation of the regulation. If the state courts rule that the regulation does not apply to Riverside, the USE-PA cannot make the regulation more stringent by enforcing it against Riverside.
Next, this unclear state law is “susceptible” to a narrowing interpretation that could obviate decision on a federal constitutional question: if the state courts hold the regulation inapplicable to Riverside, the federal procedural due process issue would be mooted. The USEPA claims, however, that the SIP is not “susceptible” to a narrowing interpretation because it is “unlikely” that the state courts will find the paper coating regulation inapplicable to Riverside. To support this argument, the USE-PA contends that the state courts will adhere to a basic principle of administrative law and defer to the IEPA’s interpretation that Riverside is a paper coater. Riverside disagrees, arguing that the state courts will not defer to the IEPA’s determination because it is plainly erroneous and inconsistent with its prior interpretation of the regulation as being inapplicable to Riverside.
See Homemakers N. Shore, Inc. v. Bowen,
832 F.2d 408, 412 (7th Cir.1987) (“When an agency waffles without explanation, taking one view one year and another the next, ... [c]ourts are correspondingly less willing to accept the agency’s latest word as authoritative; maybe it is no better and no more enduring than the last warble.”)
(citing Skidmore v. Swift & Co.,
323 U.S. 134, 140, 65 S.Ct. 161, 164, 89 L.Ed. 124 (1944)).
This court need not predict with certitude the outcome of the state proceedings. Rather, the court’s only task is to determine whether the state law is “susceptible” to a narrowing construction — that is, whether a state court “might,”
see Colorado River,
424 U.S. at 814, 96 S.Ct. at 1244, or “could,”
see Board of Educ. v. Bosworth,
713 F.2d 1316, 1321 (7th Cir.1983), narrowly construe the law so as to render moot the federal constitutional issue. Given that the IEPA — the body that promulgated the regulation — at first apparently did not consider Riverside to be a paper coater, as well as the fact that until April 3, 1987, the IEPA issued Riverside operating permits without classifying it as a paper coater, it certainly is possible that the state courts could find the regulation inapplicable to Riverside.
Finally, the equities in this case militate in favor of
Pullman
abstention. Unlike the typical
Pullman
abstention case, in which there are no parallel state proceedings and the federal court orders the parties to begin anew in the state courts,
in this case there already are two ongoing state proceedings. The USEPA’s interest — if any — in premature enforcement of the regulation (that is, before the state courts have determined its applicability to Riverside) is outweighed by the state’s interest in initially interpreting the scope of its own SIP. Moreover, the existence of the USEPA’s concurrent authority to enforce the SIP does not necessarily make abstention inappropriate, especially when, as in this case, a state court interpretation
could obviate, decision of a federal constitutional issue.
See United States v. Interlake, Inc.,
429 F.Supp. 193, 197 (N.D.Ill.1977).
B.
Colorado River Abstention
Reinforcing
Pullman
abstention in this case are elements of
Colorado River
abstention,
which applies when there are parallel federal and state proceedings. As a general rule, “ ‘the pendency of an action in the state court is no bar to proceedings concerning the same matter in the Federal court having jurisdiction____’”
Colorado River,
424 U.S. at 817, 96 S.Ct. at 1246
(iquoting McClellan v. Carland,
217 U.S. 268, 282, 30 S.Ct. 501, 505, 54 L.Ed. 762 (1910)). Nevertheless, parallel actions may lead to what the Seventh Circuit has termed “ ‘a grand waste of efforts by both the courts and parties____’”
Illinois Bell,
740 F.2d at 569
(quoting Microsoftware Computer Sys., Inc. v. Ontel Corp.,
686 F.2d 531, 538 (7th Cir.1982)). Federal courts, therefore, have exercised their discretion to stay proceedings pending resolution of parallel state court actions, provided that certain “exceptional circumstances” are present. Abstention in these situations is based not on “considerations of proper constitutional adjudication and regard for federal-state relations,” but on considerations of “ ‘[w]ise judicial administration, giving regard to conservation of judicial resources and comprehensive disposition of litigation.’”
Colorado River,
424 U.S. at 817, 96 S.Ct. at 1246
(quoting Kerotest Mfg, Co. v. C-O-Two Fire Equip. Co.,
342 U.S. 180, 183, 72 S.Ct. 219, 221, 96 L.Ed. 200 (1952)). If a federal court abstains because of parallel state proceedings, the principles of res judicata and collateral estoppel would apply to any subsequent proceeding, so long as the state court action adequately protected the parties’ rights.
See Lumen Constr., Inc. v. Brant Constr. Co.,
780 F.2d 691, 697 (7th Cir.1985) (“ ‘Re-determination of issues is warranted if there is reason to doubt the quality, extensiveness, or fairness of procedures followed in the prior litigation.’ ”)
(quoting Montana v. United States,
440 U.S. 147, 164 n. 11, 99 S.Ct. 970, 979 n. 11, 59 L.Ed.2d 210 (1979)).
Colorado River
and its progeny have enumerated the following factors that a federal court should consider in deciding whether to abstain: (1) Whether the state or federal court has assumed jurisdiction over property; (2) the geographical inconvenience of the federal forum; (3) the desirability of avoiding piecemeal litigation; (4) the order in which jurisdiction was obtained by the concurrent forum; (5) the source of the governing law — state or federal; (6) the adequacy of the state court action to protect the federal plaintiff’s rights; (7) the relative progress of the state and federal proceedings; and (8) the presence or absence of concurrent jurisdiction.
See Colorado River,
424 U.S. at 818, 96 S.Ct. at 1247;
see also Moses H. Cone Memorial Hosp. v. Mercury Constr. Corp.,
460 U.S. 1, 23-26, 103 S.Ct. 927, 941-42, 74 L.Ed.2d 765 (1983);
Lumen,
780 F.2d at 694.
Unlike
Pullman
abstention,
Colorado River
abstention does not require the presence of an unsettled state law issue that might moot a federal constitutional question. The procedural consequences, on the other hand, are similar. Although
Colorado River
involved a dismissal of the federal case, and the Court in
Cone
reserved decision on whether a dismissal or stay would be appropriate, 460 U.S. at 28;
see also Arizona v. San Carlos Apache Tribe,
463 U.S. 545, 570 n. 21, 103 S.Ct. 3201, 3215 n. 21, 77 L.Ed.2d 837 (1983), the Seventh Circuit has held that a stay is normally the preferred choice.
See Lumen,
780 F.2d at 698 (“This Court ... has consistently held that the proper procedure is to stay. A dismissal, even without prejudice, creates a risk that the federal plaintiff will be time-barred from reinstating his federal suit if
the state proceeding does not result in a final decision on the merits.”)
(citing Bosworth,
713 F.2d at 1322;
Evans Transp. Co. v. Scullin Steel Co.,
693 F.2d 715, 717-18 (7th Cir.1982)).
In this case, several factors militate against
Colorado River
abstention: Neither court has assumed jurisdiction over property; the federal forum is not geographically inconvenient; and the state and federal suits were filed at approximately the same time.
Nevertheless, the decision whether to abstain under
Colorado River
“ ‘does not rest on a mechanical checklist, but on a careful balancing of the important factors as they apply in a given case____’”
Illinois Bell,
740 F.2d at 570
(quoting Cone,
460 U.S. at 16, 103 S.Ct. at 937).
The salient factors here are the predominance of the state law issue (the interpretation of Illinois’ SIP); the possibility of avoiding an unnecessary decision of a federal constitutional issue; the fact that the state court proceedings have progressed further on the merits than those in federal court; and the avoidance of duplicative litigation. Absent a stay of the federal action, this court could be determining the extent of Riverside’s liability under the paper coating regulation before the Illinois courts have had the opportunity to determine its applicability to Riverside. If this court concludes that the regulation is applicable to Riverside, and the state tribunals would have decided otherwise, the effect would be to make the SIP more stringent than the state originally intended — a result contrary to the Seventh Circuit’s holding in
Bethlehem Steel.
The fact that the federal suit also involves the fabric coating regulation, and hence that the federal and state actions are not precisely parallel, does not change the decision to abstain in this case.
See Hickey v. Duffy,
827 F.2d 234, 246 (7th Cir. 1987) (Flaum, J., concurring) (In considering the piecemeal-litigation factor, the court should determine whether there is a “ ‘substantial likelihood that the state litigation will dispose of all claims presented] in the federal case.’ ”)
(quoting Lumen,
780 F.2d at 695). First, it is this court’s understanding, based upon the statements of counsel for both parties in open court, that the bulk of the federal case concerns the paper coating regulation and that a state court decision holding the paper coating regulation inapplicable to Riverside would, as a practical matter, dispose of the federal suit.
See Ingersoll Milling Mach. Co. v. Granger,
833 F.2d 680, 686 (7th Cir.1987) (emphasizing pragmatic concerns in dealing with
Colorado River
abstention).
Second, the duplicative-litigation factor is not dispositive, for the fact that this court may avoid an unnecessary decision of a constitutional issue bears heavily on the decision.
See Colorado River,
424 U.S. at 818, 96 S.Ct. at 1246
{“[In
]
the absence of weightier considerations of constitutional adjudication and state-federal relations,
the circumstances permitting the dismissal of a federal suit due to the presence
of a concurrent state proceeding for reasons of wise judicial administration are considerably more limited than the circumstances appropriate for [other forms of] abstention.”) (emphasis added).
Third, this court is not dismissing the federal case, but rather is simply ordering a stay of the proceeding pending the outcome of the state court litigation. If necessary, this court can reassert its jurisdiction to determine the extent of Riverside’s liability under the SIP.
See Lumen,
780 F.2d at 698 (A stay allows a federal court “to retain jurisdiction in case the state court action does not meet its anticipated end. A stay has the additional advantage of bringing the case back before the same federal judge if a determination is needed as to the preclusive effects of the state judgment or decisions.”).
Finally, the state court action, even though a declaratory action and not an enforcement proceeding, is adequate to protect the federal plaintiff’s rights. If the state courts find the regulation inapplicable, the USEPA may not enforce it against Riverside; and if the state courts find the regulation does apply to Riverside, then this court will reassert its jurisdiction and proceed with the USEPA’s federal enforcement action.
See also Riverside Labs.,
slip op. at 4 (Riverside should be allowed to use favorable outcome in state court as res judicata defense to federal suit: “The state is the proper entity to determine the scope and application of its own regulations. The USEPA must then enforce what the state has decreed.”). There is no indication that the state court proceedings have been stalled or unreasonably delayed. Thus, there is no need at this point for the court to exercise jurisdiction in order to protect the USEPA’s rights.
C.
Burford Abstention
Burford
abstention applies when the state has a unified scheme for review of its administrative orders and federal judicial review would have a disruptive effect on the state’s efforts to establish a coherent policy on a matter of substantial public concern.
Evans v. City of Chicago,
689 F.2d 1286, 1295 (7th Cir.1982);
Cash Currency Exch., Inc. v. Shine (In re Cash Currency Exch., Inc.),
37 B.R. 617, 629 (N.D.Ill.1984),
aff'd,
762 F.2d 542, 556 (7th Cir.),
cert. denied sub nom. Fryzel v. Cash Currency Exch., Inc.,
474 U.S. 904, 106 S.Ct. 233, 88 L.Ed.2d 232 (1985). Factors to consider in deciding whether to abstain under
Burford
are the presence of a complex and important issue of traditional state concern; the creation of a specialized state agency and the consequent superior competence of state tribunals; the possibility of disruption to the state’s administrative scheme by the mere exercise of federal judicial review; and the need for coherent state doctrine in the area.
See Adams v. Attorney Registration & Disciplinary Comm’n of the Supreme Court,
600 F.Supp. 390, 396 (N.D.Ill.1984),
aff'd on other grounds,
801 F.2d 968 (7th Cir.1986).
Burford
abstention, unlike that under either
Pullman
or
Colorado River,
requires neither unclarity in a state law nor parallel state proceedings. Moreover, the procedural consequences of
Burford
abstention are different: under
Burford,
the court normally dismisses
— rather than stays — the federal proceeding and thereby relegates the federal issue to state court.
See, e.g., Wynn,
582 F.2d at 1383.
Thus, the only federal review of federal issues is that of the United States Supreme Court reviewing the decision of the state supreme court.
See, e.g., McNeese v. Board of Educ.,
373 U.S. 668, 673, 83 S.Ct. 1433, 1436,10 L.Ed.2d 622 (1963) (“Thus we have stayed the hands of a Federal District Court when it sought to enjoin enforcement of a state administrative order enforcing the state law, since any federal question would be reviewed when the case came here [the United States Supreme Court] through the hierarchy of state courts.”)
{citing Burford).
This court concludes that
Burford
abstention would be inappropriate in this case. The Illinois SIP, although state law that should be interpreted initially by the state courts, may be enforced in federal court. Thus, the SIP is not a matter of specialized and purely local concern, but rather an issue of both federal and state concern: although the state initially develops the SIP, the USEPA must approve it; only then may the SIP be enforced independently by both the USEPA and the state authorities. Abstention on
Burford
grounds in these cases effectively would preclude USEPA enforcement in federal court, for the only federal review would be that of the United States Supreme Court —a result clearly at odds with the Act’s federal enforcement provision.
III. Conclusion
This case is not a textbook example of either
Pullman
or
Colorado River
abstention. Nevertheless, the different forms of abstention “are not rigid pigeonholes into which federal courts must try to fit cases. Rather, they reflect a complex of considerations designed to soften the tensions inherent in a system that contemplates parallel judicial processes.”
Pennzoil Co. v. Texaco, Inc.,
— U.S.-, 107 S.Ct. 1519, 1526 n. 9, 95 L.Ed.2d 1 (1987). In essence, this case merits
Pullman
abstention with a
Colorado River
twist: staying the proceedings in the federal suit will avoid not only the possibility of unnecessary resolution of a federal constitutional issue, but will also avoid duplicative litigation on a state law issue — an issue that currently is being considered by two state tribunals.
See Inter-lake,
429 F.Supp. at 198. For these reasons, this court grants the defendant’s motion to stay the federal enforcement action pending resolution of the state court proceedings.