Aрpellants Robert and Ellen Amos, along with seventeen other Glynn County property owners, 1 have taken this interlocutory appeal from the district court’s order denying their motions for class certification and preliminary injunction. Ap-pellees, Glynn County Board of Tax Assessors, along with several other Glynn County agencies, 2 in turn, cross-appeal from the district court’s denial of their motion to dismiss for lack of subject matter jurisdiction. Because we conclude that the Tax Injunction Act stripped the district court of subject matter jurisdiction over this lawsuit, we REVERSE the district court’s denial of the appellees’ motion to dismiss, VACATE its order denying class certification and preliminary injunction, and REMAND for further proceedings consistent with this opinion.
I.
The essential background and procedural facts are these. The appellants own residential property on St. Simons Island, an upscale coastal development located in Glynn County, Georgia. This lawsuit arises out of a grievance they have with the way Glynn County assessed their ad valorem property taxes in the year 2000. Glynn County’s system for assessing property taxes and adjudicating assessment disputes is complex, and we therefore begin with an overview of that system.
The Glynn County Board of Commissioners, the governing body of the county, appoints the Glynn County Board of Tax Assessors (the “Board”), which is responsible for assessing the county’s property taxes. To that end, the Board appoints a Chief Tax Appraiser, whose office conducts the actual assessments. The Board must complete its review of the Chief Tax Appraiser’s assessments by June 1 of each year, at which point the Board must notify any taxpayers whose assessments have been changed within five days. See O.C.G.A. § 48-5-302.
A taxpayer who is dissatisfied with the Board’s reassessment of his property may appeal through the process set forth in O.C.G.A. § 48-5-311. The first step in that process is to appeal to the Board itself within 30 days of the date of the notice. See O.C.G.A. § 48-5-306(b)(2). The Board *1252 has 180 days to decide the appeal. See O.C.G.A. § 48-5-311(e)(3). If the Board fails to decide an appeal within 180 days or decides not to change the taxрayer’s assessment, the taxpayer’s appeal is automatically forwarded to the Board of Equalization (“BOE”). See id. In addition, if the Board changes the taxpayer’s assessment but the taxpayer is still unsatisfied, he may appeal to the BOE by notifying the Board within 21 days of the date the Board sends notice of its decision. See O.C.G.A. § 48 — 5—311(e)(2)(C).
The BOE is a quasi-judicial entity responsible for adjudicating tax appeals in the county. See O.C.G.A. § 48-5-311. There are two such boards of equalization in Glynn County. Each is composed of three members and has jurisdiction over all property tax appeals involving questions of taxability, valuation, entitlement to homestead exemptions, or uniformity of tax valuation within the county. See O.C.G.A. § 48-5-311(e)(l)(A). Within 15 days of receiving notice of an appeal, the BOE must set a date for a hearing to be held within 20 to 30 days of the date of the notification of the hearing. See O.C.G.A. § 48-5-311(e)(6).
Notably, once the Board of Equalization returns its decision, the taxpayer may further appeal to Glynn County Superior Court, where he is entitled to de novo review of all of his claims. See O.C.G.A. § 48-5-311(g)(l), (3). If the issues on appeаl are purely legal, the taxpayer is entitled to a bench trial within 40 days of filing his appeal. See O.C.G.A. § 48-5-311(g)(4)(A). If the taxpayer’s appeal contains fact questions, he is entitled to a jury trial at the first term following the filing of his appeal. See id. From the Superior Court, the taxpayer may appeal upward through the state court system and eventually petition the United States Supreme Court for certiorari review.
Meanwhile, the Board provides the assessments to the Glynn County Tax Commissioner, an independently elected official, who compiles the assessments into a digest and delivers the digest to the State Revenue Commissioner by August 1 each year for examination and approval. Once the State Revenue Commissioner approves the digest, Glynn County is permitted to send out tax bills for the year. Any taxpayer who is in the process of appealing his assessment when the tax bills are sent out is only required to pay 85% of his assessed value and is entitled to a full refund with interest should his actual property tax turn out to be less than he paid. See O.C.G.A. § 48-5-311(e)(6)(D)(iii).
Unfortunately, Glynn County’s entire tax assessment scheme has not been working well for close to a decade. In theory, all real property in the county should be reassessed at market value every year. But in practice, the Board has not performed a county-wide reassessment since 1995. In the interim, the Board has reassessed certain properties in the county several times, while neglecting to reassess other properties at all. According to the Board, the properties that are reassessed are chosen based on a “sales price ratio study.” The study collects sale prices for recently sold properties in the county and compares the sale prices to the former assessment values of the property. The Board uses this information to determine which neighborhood’s properties have market values that are most out of line with their assessed values and selects these neighborhoods for reassessment. In 2000, the Board used this method to pick 3,855 properties for reappraisal out of 37,000 eligible residential properties in the county. The appellants’ properties were among the 3,855 properties selected. 3
*1253 Although, from the Board’s perspective, the system is designed to promote equality by selecting the most wrongly valued properties for reappraisal, the appellants believe it penalizes them for living in neighborhoods with ever escalating sales prices. They contend that the Board’s method unconstitutionally places a disproportionate share of the county tax burden on their shoulders. On May 30, 2001, the appellants filed this class action lawsuit in the United States District Court for the Southern District of Georgia, pursuant to 42 U.S.C. § 1983, claiming that Glynn County’s tax scheme violated the Fifth and Fourteenth Amendments to the Constitution by denying them due process and equal protection. As relief, they sought a declaratory judgment and permanent in-junctive relief barring the appellees from using the allegedly unconstitutional 2000 tax digest in the collection of ad valorem taxes. Specifically, the plaintiffs say that the Board engaged in “piecemeal or spot reappraisals and reassessments of residential property” without addressing uniformity throughout Glynn County, and returned a non-uniform assessment of real property for the year 2000.
However, this was not the first time that the property owners of St. Simons Island had asked for such an injunction. In
Haller v. Glynn County Bd. of Assessors,
Case No. 00-01246 (Ga.Super.Ct.2000), two of the appellants, Haller and Dewhurst, purporting to act on behalf of the same class of property owners, brought suit in Glynn County Superior Court, Georgia, pursuant to 42 U.S.C. § 1983, raising the same federal constitutional challenge and seeking the same injunctive relief barring the Board from applying the 2000 tax digest of Glynn County. The Glynn County Superior Court granted that injunction, restraining appellees from billing or collecting taxes on the parcels of Glynn County real property which were reassessed in 2000 in an amount greater than their 1999 value, but its order was later reversed by the Georgia Supreme Court in
Glynn County Bd. of Tax Assessors v. Haller,
The Georgia Supreme Court held that the plaintiffs had an adequate remedy at law with which to challenge the perceived constitutional infirmities in the 2000 tax digest, and specifically that O.C.G.A. § 48-5-311 et seq., provided the plaintiffs with an altogether sufficient mechanism for appellate review of their tax assessments. The Georgia Supreme Court framed its holding in these terms:
The United States Supreme Court has held that state courts may not award either declaratory or injunctive relief against state taxes under section 1983 when there is an adequate legal remedy. Similarly, we have held that a superior court should not grant an injunction in a tax case when state law provides an adequate remedy at law. O.C.G.A. § 48-5-311 provides a statutory appeals process for taxpayers to challenge a property tax assessment based on the issues of taxability, uniformity, and value. Nothing in the statute prohibits taxpayers from challenging a board’s method of conducting spot reassessments as lacking in uniformity, appealing an unfavorable ruling to the county board of equalization, and appealing the equalization board’s ruling to the superior court, if necessary. Because O.C.G.A. § 48-5-311 provides the Glynn County taxpayers with an adequate remedy at law, we hold that the trial court erred in granting them injunctive relief.
Id. at 701 (footnotes omitted).
Two months after suffering that defeat, and without petitioning for certiorari review from the United States Supreme Court, appellants Haller and Dewhurst, along with seventeen other St. Simons Island property owners brought this suit in *1254 federal district court. The appellees moved to dismiss, arguing that under the Tax Injunction Act of 1937, 28 U.S.C. § 1341, the federal district courts are stripped of jurisdiction and may “not enjoin, suspend or restrain the assessment, levy or collection of any tax under State law where a plain, speedy and efficient remedy may be had in the courts of such State.” 28 U.S.C. § 1341. The appellees also argued, in the alternative, that basic principles of federalism and comity should deter a federal court from interfering with state tax administratiоn where there is an adequate state remedy, especially when the highest court of the state has already held that the state law remedy was in fact adequate.
On August 27, 2001, after conducting extensive evidentiary hearings on the jurisdictional question, the district court denied the motion, concluding that the appeals process provided by O.C.G.A. § 48-5-311 4 is neither plain, speedy, nor efficient, and that accordingly, the Tax Injunction Act did not strip the district court of the power to entertain the suit. The appellees first petitioned this Court, pursuant to 28 U.S.C. § 1292(b), for permission to take an interlocutory appeal from the district court’s denial of their motion. We denied their petition on the ground that reviewing the Georgia state remedy to determine whether it was “plain, speedy, and efficient” was too fact-intensive an inquiry for interlocutory review under § 1292(b). See Glynn County Bd. of Tax Assessors v. Amos, No. 01-90048 (11th Cir. Nov. 2, 2001) (order denying petition for interlocutory appeal); Revenue Comm’r of the State of Georgia v. Amos, No. 01-90049 (11th Cir. Nov. 2, 2001) (order denying petition for interlocutory appeal).
The case went back to the distriсt court, which on September 12, 2002, denied the appellants’ motion for a preliminary injunction and class certification. The district court concluded that the taxpayers were not entitled to a preliminary injunction because they had failed to show: (1) a substantial likelihood of success on the merits; (2) that the threatened injury to them outweighed the damage the proposed injunction would cause to the appellees; or (3) that if issued, the injunction would not be adverse to the public interest.
See Four Seasons Hotels and Resorts, B.V. v. Consorcio Barr, S.A.
In this interlocutory appeal, the taxpayers argue that the district court should have granted the preliminary injunction because the inequality in the tax assessment scheme was inexcusably unjust *1255 and violated the United States Constitution, they have been irreparably harmed and the public interest would not be dis-served by the entry of injunctive relief. They also contend that the district court wrongly decided important evidentiary issues, which led to an incorrect decision on class certification. The appellees, on the other hand, say that the district court erred as a matter of law by entertaining the taxpayers’ claims at all, because the taxpayers had a “plain, speedy, and efl> dent” remedy under state law and their suit was therefore barred by the Tax Injunction Act. 5 As for the merits, appellees say the district court properly denied the preliminary injunction and class certification under Rules 23 and 65 of the Federal Rules of Civil Procedure.
II.
The limitation imposed by the Tax Injunction Act is jurisdictional.
See Colonial Pipeline Co. v. Collins,
When reviewing the district court’s denial of a motion to dismiss for lack of subject matter jurisdiction, “we review
de novo
the district court’s interpretation and application of the statutory provisions concerning the court’s subject matter jurisdietion, and review for clear error the district court’s factual findings with respect to jurisdiction.”
United States v. McPhee,
The Tax Injunction Act provides that “[t]he district courts shall not enjoin, suspend or restrain the assessment, levy or collection of any tax under State law where a plain, speedy and efficient remedy may be had in the courts of such State.” 28 U.S.C. § 1341. Accordingly, we have held that “the Tax Injunction Act will bar the exercise of federal jurisdiction if two conditions are met: (1) the relief requested by the plaintiff will ‘enjoin, suspend, or restrain’ a state tax assessment and (2) the state affords the plaintiff a ‘plain, speedy and efficient remedy.’ ”
Williams v. City of Dothan,
The Supreme Court has held that “the ‘plain, speedy and efficient’ exception requires the ‘state-court remedy [to meet] certain
procedural
criteria.’ ”
California v. Grace Brethren Church,
The Supreme Court’s stringent interpretation of the exception is well founded. The Tax Injunction Act “was first and foremost a vehicle to limit drastically federal district court jurisdiction to interfere with so important a local concern as the collection of taxes.”
Rosewell,
If federal declaratory relief were available to test state tax assessments, state tax administration might be thrown into disarray, and taxpayers might escape the ordinary procedural requirements imposed by state law. During the pendency of the federal suit the collection of revenue under the challenged law might be obstructed, with consequent damage to the State’s budget, and perhaps a shift to the State of the risk of taxpayer insolvency. Moreover, federal constitutional issues are likely to turn on questions of state tax law, which, like issues of state regulatory law, are more properly heard in the state courts.
Grace Brethren,
This jurisdictional restraint emerges from “[t]he scrupulous regard [of the federal courts] for the rightful independence of state governments ... and a proper reluctance to interfere by injunction with their fiscal operations.”
Matthews v. Rodgers,
Rosewell
and
Grace Brethren
are primary examples of the “reluctance of the federal courts to interfere with the operation of state tax systems if the taxpayer ha[s] available an adequate remedy in the state courts.”
Grace Brethren,
In
Grace Brethren,
the Supreme Court reiterated the stringent standard of
Rosewell
that “[i]n order to ... be faithful to the congressional intent ‘to limit drastically’ federal-court interference with state tax systems, we must construe
narrowly
the ‘plain, speedy, and efficient’ exception to the Tax Injunction Act.”
Properly, our circuit has taken no more lenient a view of the “plain, speedy, and efficient” exception than the Supreme Court. Explaining that “[s]tate remedies must only meet certain ‘minimal procedural criteria,’ ” we have held that “a reviewing court should eschew any analysis of their substantive sufficiency so long as a complainant has some opportunity to raise his constitutional objections.”
Colonial,
In determining whether a state remedy is “plain, speedy, and efficient” under the act, we turn first to the state statutory language.
See generally, Colonial,
The Georgia Supreme Court has already ruled that O.C.G.A. § 48-5-311, the very tax system at issue in this case, “provides the Glynn County taxpayers with an adequate remedy at law.”
Glynn County,
Although the question of whether a state remedy satisfies the Tax Injunction Act is a federal question, and therefore the district court was not bound by the Georgia Supreme Court’s decision, the state’s highest court’s legal conclusions about state law are “persuasive” authority.
Julius v. Johnson,
The district court, nonetheless, rejected the Georgia Supreme Court’s opinion, and found that instead of providing a “plain, speedy, and efficient” remedy, O.C.G.A. § 48-5-311 was a “bureaucratic maze” of “delays” and “inadequate relief,” and as a result, the appellants “have simply been unable to and will continue to be unable to effectuate a change through the state process.” District Court Opinion at 14-15. As such, it held that .the taxpayers had no “plain, speedy, and efficient” remedy at *1259 state law, and jurisdiction was therefore proper in federal district court. Based on our review of the text of O.C.G.A. § 48-5-311 et seq., the record, and unambiguous case precedent, we disagree.
The district court began its analysis with the “plain” prong, taking notice of the Supreme Court’s admonition in
Rosewell
that “uncertainty concerning a State’s remedy may make it less than ‘plain’ under 28 U.S.C. § 1341.”
We disagree with the district court’s judgment that the state court remedy was not “plain” because it failed to guarantee a county-wide injunction against the tax digest. In the first place, a state remedy need not provide for county-wide injunctive relief in order to be “plain” under the Act. The Supreme Court has held that “at the time that it passed the Tax Injunction Act, Congress was well aware that refund procedures were the sole remedy in many States for unlawfully collected taxes.”
Grace Brethren,
Indeed, as the Fifth Circuit has held, “[t]here is no indication that Congress intended that the lower federal courts would provide supplemental relief whenever a litigant does not receive all the relief he seeks in state court.”
Redd v. Lambert,
But the district court’s analysis of the “plain” prong is erroneous in any event, because a county-wide reassessment is in fact a form of relief available under Georgia state law. O.C.G.A. § 48-5-311 provides:
If in the course of determining an appeal the county board of equalization finds reason to believe that the property involved in an appeal or the class of property in which is included the property involved in an appeal is not uniformly assessed with other property included in the digest, the board shall request the *1260 respective parties to the appeal to present relevant information with respect to that question. If the board determines that uniformity is not present, the board may order the county board of tax assessors to take such action as is necessary to obtain uniformity, except that, when a question of county-wide uniformity is considered by the board, the board may order a partial or total county-wide revaluation only upon a determination by a majority of all the members of the board that the clear and convincing weight of the evidence requires such action. The board of equalization may act pursuant to this paragraph whether or not the appellant has raised the issue of uniformity.
O.C.G.A. § 48-5-311(d)(2). On its face, this statute provides that the taxpayers may raise their county-wide concerns about uniformity to the BOE and the BOE may order county-wide relief.
The district court nevertheless posited four reasons why, under O.C.G.A. § 48-5-311, the taxpayers may not be able obtain “plain” county-wide injunctive relief on their constitutional claims: (1) a citizen’s review board such as the BOE is incapable of making the judicial determination contemplated by the Supreme Court in Rose-well; (2) the BOE’s power to order a county-wide reassessment is purely discretionary; (3) even if the BOE orders a county-wide reassessment, it is powerless to enforce its order; and (4) a taxpayer would not be able to appeal county-wide claims to supеrior court if the BOE granted him individual relief.
The district court’s first concern is easily dispensed with. As discussed, a taxpayer may appeal rulings of the BOE to Glynn County Superior Court, where he is entitled to
de novo
review.
See
O.C.G.A. § 48 — 5—811(g)(1), (3). The Supreme Court has found state remedies to satisfy the Tax Injunction Act, even where a taxpayer must first exhaust administrative remedies.
See Grace Brethren,
The district court’s second concern was that the BOE’s power to order a countywide recount is purely discretionary. It based this finding on the statutory language: “[i]f the board determines that uniformity is not present, the board
may
order the county board of tax assessors to take such action as is necessary to obtain uniformity.” O.C.G.A. § 48-5-311(d)(2) (emphasis added). In
Noble v. Joint City-County Bd. of Tax Assessors,
like in this case, the taxpayers did not allege that their property was overvalued.
See
The district court’s next concern was that the BOE is powerless to enforce its orders, even when it dеcides to grant them. As evidence, the district court points out that the Board failed to reassess all of St. Simons Island and Sea Island, despite an order from the BOE to do so. However, the record reveals that if the Board disobeys the BOE’s order, the BOE is free to pursue a mandamus action in court against the Board to enforce its order. For example, in 1997, the BOE of Douglas County, Georgia, ordered its Board to perform a county-wide revaluation of all land in Douglas County, after finding a lack of uniformity. After the Douglas County Board refused to do so, the Douglas County BOE petitioned the Douglas County Superior Court for a writ of mandamus to force the Board to obey its order. Mandamus was promptly granted. See Smith v. Salvo, Case No. 97-CV-618 (Ga.Super.Ct., 1997) (unpublished decision). The superior court found that the Board was “under a clear legal duty to comply with the provisions of the order of the Board of Equalization” and therefore the petitioners were “entitled to the issuance of an Order of Mandamus Absolute compelling [the Board of Assеssors] to carry out and complete the county-wide revaluation of land.” Id.
As
ad valorem
taxpayers directly affected by the BOE’s order to revalue Glynn County’s real property, we see no reason why the appellants in this case would not be able to bring a similar mandamus action in superior court. And since the Board has a “clear legal duty to comply with the provisions of the order” under state law, we can discern no reason why their suit would not be successful. Notably, however, the appellants have never attempted such action. The district court was concerned that “it is most uncertain whether a mandamus action brought by Plaintiffs in Superior Court would meet with dismissal on the basis of
[Glynn County].”
This, though, misapprehends the Georgia Supreme Court’s decision in
Glynn County.
In that case, as discussed
supra,
the Georgia Supreme Court found that § 1983 injunctive relief would not lie because “O.C.G.A. § 48-5-311 provides the Glynn County taxpayers with an adequate remedy at law.”
Glynn County,
The district court’s last concern was that “it is entirely possible that a taxpayer may receive a favorable ruling from the Board of Equalization with respect to an individual property assessment without an order of county-wide revaluation.” District Court Opinion at 23. The district court worried that such an outcome might prevent the taxpayer from appealing the county-wide issues to superior court. Moreover, the district court noted that even if the taxpayer could appeal to superior court, “relief may not be granted by the superior court on a county-wide basis because it is unable to enter a declaratory judgment or issue an injunction in light of the [Glynn County ] decision.” Id.
With respect to the first issue, the statute makes clear that taxpayers may appeal to the BOE “matters of uniformity of assessment of their property with other properties located within such municipality.” O.C.G.A. § 48 — 5—311(e)(1)(B). Once the taxpayer has raised the uniformity issue with the BOE, the statute explains that if he is unsatisfied with his result, he “may appeal decisions of the county board of equalization ... to the superior court of the county in which the property lies.” O.C.G.A. § 48 — 5—311(g)(1). Nothing in the state’s detailed statute suggests that a taxpayer may only appeal adverse decisions of the BOE with respect to individual assessments, and cannot appeal other adverse decisions. To the contrary, the broad lаnguage of the statute allowing the taxpayer to “appeal decisions,” without limiting what sorts of decisions, says quite the opposite. We believe the district court’s legal conclusion that taxpayers can only appeal rulings on individual valuations is unfounded. Moreover, the district court’s finding that a superior court could not grant declaratory or injunctive relief in a properly filed case on the basis of
Glynn County
misapprehends
Glynn County.
The Georgia Supreme Court in that case held only that taxpayers could not circumvent the process laid forth in O.C.G.A. § 48-5-311, not that if they properly followed that process, injunctive relief would be denied to them.
See Glynn County,
In short, the four reasons offered for why taxpayers cannot obtain county-wide injunctive relief do not reflect the legal options readily available to the taxpayers under the process set forth in O.C.G.A. § 48-5-311. The taxpayers have simply failed to comprehensively pursue these options. Moreover, we emphasize again that even if county-wide injunctive relief were actually unavailable to the taxpayers under Georgia law, it would still not prevent the state remedy from being “plain” for purposes of the Tax Injunction Act. Supreme Court precedent is unambiguous that a state court remedy may be “plain,” even where the sole relief afforded by the state is an individual refund, and such a remedy is undisputedly available here.
See Grace Brethren,
*1263
Turning to whether the remedy was “speedy” under the Act, the Supreme Court has given only limited guidance as to how “speedy” a remedy must be for purposes of the Tax Injunction Act. In
Rosewell,
the Supreme Court held that a state remedy procedure that took two years to complete was sufficiently “speedy.”
See
In this case, the state statute itself manifests a strong concern for the speedy adjudication of claims. It requires the taxpayer to file an appeal to the Board within 30 days of the Board’s original notice, and requires the Board to decide the appeal within 180 days of receipt of the filing. See O.C.G.A. § 48-5-311(b)(2), (e)(3). If the Board fails to adjudicate the claim within 180 days (or if it does adjudicate the claim but the taxpayer appeals to the BOE within 21 days), the appeal is automatically forwarded to the BOE. See O.C.G.A. § 48-5-311(e)(2)(C), (3). The BOE itself must schedule a hearing within 15 days of receiving notice of the appeal, and it must conduct that hearing within 20 to 30 days. If the taxpayer wishes to appeal the BOE decision to state superior court, the superior court must hear the case as a bench trial within 40 days, or with a jury at the first term following the filing of the appeal. Simply put, O.C.G.A. § 48-5-311 is comprehensively concerned with the speedy resolution of taxpayer appeals.
Even if two years were an outer boundary, moreover, the district court clearly erred in finding that “[tjhe evidence in this case shows that the length of time to resolve a tax appeal on average far exceeds the two-year delay at issue in Rosewell.” District Court Opinion at 25. The district court based this finding on an exhibit purporting to list the appeals still pending in the Tax Commissioner’s database as of July 25, 2001. The district court said that the exhibit, “shows 404 appeals pending for the years 1992-1999, including 48 appeals from 1994, 172 appeals from 1995, and 81 appeals from 1996.” 9 Id. From this, the district court concluded that the *1264 average length of- time for an appeal to be completed was more than two years.
The calculations that yielded this average are not altogether apparent from the court’s opinion, but it appears as if the district court used only those appeals still pending in 2001 and did not include those appeals that had already been resolved. In other words, the district court’s calculation seems based only on a small, biased sample of the aggregate. Without knowing how many appeals were filed in each year and how long those appeals took to be resolved, there is no way of computing the average length of time for appeals. For example, the district court found that as of July 2001, there were 81 appeals still pending from 1996. But the district court made no finding as to how many appeals were originally filed in 1996, nor how many of those appeals were quickly resolved. Perhaps there were thousands of appeals filed in 1996 and they were all resolved within one year, and only 81, for some reason (here unexplained), remained pending. On this record, we cannot tell. By including only 81 appeals that were still pending in 2001 (i.e., the ones that took the longest to resolve) the district court used an obviously inaccurate method for determining the average length of time for a tax appeal.
Indeed, a review of this record suggests that while at most some 404 appeals were still pending in 2001 from 1992-1999, that figure may be only a small fraction of the total appeals that were already resolved. Steve Fentriss, the Deputy Chief Appraiser for Glynn County, testified that there were as many as 12,395 appeals filed between 1994 and 2000 total. See R-39, Exhibit B, Affidavit of Steve Fentriss. The calculus of an “average” did not account for the thousands of appeals that were timely resоlved.
In short, we are not satisfied that the average length of appeal actually exceeded two years, nor that we can answer that question based only on a review of the number of appeals still pending as of 2001. But even if the district court’s calculus was accurate, Rosewell did not set two years as the maximum time frame for appeals. Nor did the district court make any findings as to what caused the delays in the appeals it cited. Lastly, and importantly, the appellants have failed to show that they themselves have experienced repeated prolonged delays in the appeals process despite the vigilant pursuit of their claims on their part. Simply put, this record does not establish that the appeals process embodied in O.C.G.A. § 48-5-311 is not “speedy” for purposes of the Tax Injunction Act.
Finally, the district court held that the remedy was not “efficient.” A remedy will be deemed “efficient” where it “imposes no unusual hardship ... requiring ineffectual activity or an unnecessary expеnditure of time or energy.”
Rosewell,
Finally, we note that our holding in this case applies to the application of O.C.G.A. § 48-5-311 in Glynn County in the taxable year 2000. We do not rule out the possibility that other Georgia counties at other times may fail to apply O.C.G.A. § 48-5-311 in a “plain, speedy, and efficient” manner and thus lift the bar to federal jurisdiction. We hold simply, based on our textual review of the Georgia scheme, this record, and case precedent, that the Glynn County tax appeals system both facially and as applied to these plaintiffs was “plain, speedy, and efficient.” 11 *1266 Accordingly, we REVERSE the district court’s order denying the appellee’s motion to dismiss, VACATE the district court’s order denying class certification and a preliminary injunction, and REMAND for further proceedings consistent with this opinion.
REVERSED IN PART, VACATED IN PART, AND REMANDED.
Notes
. The other seventeen property owners are George Cashin, Mary Cashin, Marcia De-whurst, Kenneth Enney, Elizabeth Enney, Le-ían Haller, Jean Helck, Patricia Hinerman, William Jens, Helene Jens, Helen Katz, Billy Moore, Marianne Moore, George Paulding, Jr., Edward Stuart, Margaret Stewart, and Laura Williams.
. The other appellees are the Glynn County Board of Equalization, Glynn County Tax Commissioner, Glynn County Board of Commissioners, Glynn County Board of Education, and the City Commission of the City of Brunswick. The Glynn County Board of Education and City Commission of the City of Brunswick have not joined in the cross-appeal.
. The appellants are also referred to in this opinion as the "taxpayers.”
. The appeals process described in O.C.G.A. § 48-5-311 lays out the entire system of appeals for Georgia’s ad valorem property tax system. In addition to the basic features of the system, described supra, the statute fully еxplains the establishment, composition, responsibilities, and powers of boards of equalization. See O.C.G.A. §§ 48-5-311(a)-(d). It also describes the time frame in which participants (both taxpayers and county officials) must perform their responsibilities under the system. See O.C.G.A. §§ 48-5-3 ll(e)-(g). The statute further lays out the particulars of submitting tax disputes to arbitration, and the regulations involved in appealing adverse decisions from a board of equalization to Glynn County Superior Court. See id.
. Although we originally denied the appellees' petition to review the district court's denial of their motion to dismiss, this Court has an unqualified duty to review the district court's subject matter jurisdiction if the cause of action is before the court on an issue that otherwise qualifies for interlocutory review.
See Tamiami Partners Ltd. ex rel. Tamiami Dev. Corp. v. Miccosukee Tribe of Indians of Fla.,
. In
Bonner v. City of Prichard,
. In
Colonial,
we held that the 1988 amendments to Georgia's
ad valorem
tax system "so significantly altered the assessment and appeals process,” that our prior cases on the subject "remain binding only to the extent to which their underlying premises were left unchanged by the 1988 amendments.”
. The appellants argue in their brief that even if they obtain relief from the BOE or superior court, such relief might not come until after the State Revenue Commissioner has already examined the tax digest and given it final approval. Although this may be true, it does not stand as an obstacle to adequate relief. In the Douglas County case, the BOE did not obtain a mandamus to force a recompilation of the tax digest until after the State Revenue Commissioner had already approved the tax digest. Notwithstanding the State Revenue Commissioner’s approval, the tax digest was recompiled pursuant to court order. See R-10, 130 (Testimony of Larry Griggers, Director of Property Tax Division, Georgia Department of Revenue).
. The district court obtained these figures for pending appeals from Record Exhibit 33 and we will accept them for purposes of our dis *1264 cussion. However, we note our concern with their reliability. Florence Dees, Glynn County Tax Commissioner, who compiled Exhibit 33, testified on cross-examination as follows:
Q: So [Exhibit] 33 does not adequately represent the number of pending appeals at any level prior to the year 2000, correct?
A: It just represents the difference on my system that has not been addressed.
A comprehensive review of her testimony reveals that the 404 supposedly pending appeals were actually 404 appeals that may still have been pending or may also just have erroneously remained on the tax commissioner’s system after having already been concluded in one manner or another. Other evidence suggests that a maximum of 293 appeals were still pending at the time. See R-39, Exhibit B, Affidavit of Steve Fentriss. Still other record evidence purports to shоw that a maximum of 155, pre-2000 cases were still pending at the time. See R-38, Affidavit of Billy Moore.
. Having determined that the appellants had a "plain, speedy, and efficient” remedy under state law, and that the Tax Injunction Act therefore barred their suit, we need not decide whether principles of comity would have dictated a similar result.
. Although perhaps unnecessary in light of our broader holding in this case, we also hold that the
Rooker-Feldman
doctrine bars appellants Haller and Dewhurst from arguing that their remedy was inadequate under the Tax Injunction Act.
Rooker-Feldman
provides that federal courts, other than the United States Supreme Court, do not have jurisdiction to review the final judgments of state courts.
See Rooker v. Fidelity Trust Co.,
Here, Haller and Dewhurst were indisputably parties to the Georgia Supreme Court's
Glynn County
decision and that decision resolved the merits of their § 1983 class action suit conclusively. Moreover, Haller and De-whurst had ample opportunity to raise their federal claims in state court, and indeed did so, having later obtained review by the Georgia Supreme Court and having had the opportunity to petition the United States Supreme
*1266
Court for certiorari review had they so chosen. Finally, as our discussion makes clear, the Georgia Supreme Court adjudicated the central issue in this case in
Glynn County,
when it held that “O.C.G.A. § 48-5-311 provides the Glynn County taxpayers with an adequate remedy at law.”
