This matter comes before the court as an interlocutory appealbrought pursuant to Supreme Court Rule 308 (155 Ill. 2d R. 308). In this appeal, plaintiffs seek review of the trial court's orderdenying their motion for leave to file an amended complaint. Theamended complaint sought to maintain the pending cause as a classaction. We answer the relevant certified questions presented andremand.

Plaintiffs are owners of residential property neighboring theMallard Lake Landfill. On September 24, 1997, nine plaintiffsfiled suit against Browning-Ferris Industries, the Forest PreserveDistrict of Du Page County, and E&E Hauling, Inc., the owners ofthe landfill and persons responsible for operating, maintaining,and depositing refuse at the landfill site. The complaint allegedcommon-law torts of trespass to land and temporary and continuingnuisances to plaintiffs' property arising from dirt, dust, debris,odors, and noise emanating from the landfill.

During the course of discovery, defendants produced a letterof complaint dated May 2, 1998, in which 93 signatories complainedof trespass and nuisance to their properties resulting from thelandfill. Plaintiffs contend that this letter prompted them toseek leave to file an amended complaint. Although the proposedamended complaint was premised on allegations of trespass andnuisance, as alleged in the original complaint, plaintiffs nowsought to pursue the matter as a class action.

The trial court conducted a hearing on plaintiffs' motion forleave to file the amended complaint. The motion was denied basedon findings that (1) the claims could not be brought as a classaction as a matter of law because property damage claims are tooindividualized for class treatment; (2) the class allegations wereconclusory; and (3) the motion was untimely. Plaintiffs filed amotion to reconsider. The motion was denied. However, the trialcourt granted plaintiffs leave to file a second motion for leave toamend.

On July 12, 1999, plaintiffs filed a second motion for leaveto file an amended complaint. The amended complaint was againstyled as a class action and sought certification of the followingclass of plaintiffs:

"All people owning real property located within orbounding on the following geographic area (the class area),which has been determined by encompassing the complaints madeagainst the landfill: bounded on the north by Lake Street,bounded on the east by Gary Avenue, bounded on the south bythe tracks of the Illinois Central Gulf Railroad, and boundedon the west by County Farm Road, except for the area north ofSchick Road, where Morton Road exists, in which case MortonRoad shall serve as the west border."

According to the allegations of the proposed amendedcomplaint, the exact number of class members was not known but wasbelieved to exceed 1,000 members. The complaint alleged that allthe homeowners in the class area had suffered from diminishedenjoyment and value of their properties due to noise, dust, odor,and litter blowing or moving onto their properties from thelandfill. In count I, plaintiffs alleged that defendants committedtrespass to land due to the blowing and movement of litter, debris,dust, dirt, and noxious odors from the landfill. In counts II andIII, plaintiffs alleged a temporary and continuing nuisance.

After a hearing, the trial court again denied plaintiffs leaveto amend. The court again determined that the proposed amendedcomplaint was untimely. It further determined that the claimscould not be brought as a class action because each parcel ofproperty is unique and, therefore, plaintiffs could not satisfy theelement of commonality necessary for certification of the classaction.

The trial court granted plaintiffs' motion for certificationpursuant to Supreme Court Rule 308 (155 Ill. 2d R. 308), findingthat answers to the following certified questions of law wouldmaterially advance the ultimate termination of the litigation:

"A. Whether the trial [c]ourt erred in determining theissue of commonality without receiving briefing, evidence andargument on the issue of class certification as provided forin the Illinois Code of Civil Procedure[.]

B. Whether the trial court abused its discretion when itrefused to consider additional evidence Plaintiffs firstsubmitted in support of a Motion for Reconsideration, based onthe court's determination that this material was not 'newlydiscovered evidence' because it was available at the time ofthe initial hearing[.]

C. Whether, if the trial [c]ourt misapprehended the lawin holding that the 'commonality' requirement could not bemet, [it should] have granted leave to file an amended classaction complaint where the amendments were sought within a fewmonths after plaintiffs' counsel determined the case should bepursued as a class action and on a schedule set by the court,where the amendments did not add any additional substantiveclaims, and where the parties were not yet at issue and nodepositions had yet been taken[.]

D. Whether the trial court abused its discretion indenying Plaintiffs leave to file an amended complaint, whenthey did not seek leave to amend until 18 months after thecommencement of this action and where the court determinedplaintiffs were aware of facts which would have supportedclass-action allegations almost one year before they filedsuit[.]

E. Whether the trial court abused its discretion when itdenied Plaintiffs leave to amend based on the court'sdetermination that the Plaintiffs could not proceed as a classon their claims that the landfill was a nuisance and that thelandfill's operations caused trespasses on their property[.]"

Section 2--801 of the Code of Civil Procedure (Code) addressesclass action complaints and contains the following prerequisitesfor the maintenance of a class action:

"An action may be maintained as a class action in any court ofthis State and a party may sue or be sued as a representativeparty of the class only if the court finds:

(1) The class is so numerous that joinder of all membersis impracticable.

(2) There are questions of fact or law common to theclass, which common questions predominate over any questionsaffecting only individual members.

(3) The representative parties will fairly andadequately protect the interest of the class.

(4) The class action is an appropriate method for thefair and efficient adjudication of the controversy." 735 ILCS5/2--801 (West 2000).

The trial court gave two reasons for denying plaintiffs'motion for leave to file the amended complaint. First, althoughdefendants acknowledged that the statute of limitations would notbar a separate class action suit arising from the same facts, thetrial court found that the motion for leave to amend was untimely. Second, even though a class action complaint was not even on file,the trial court found that the proposed action could not bemaintained as a class action because each parcel of land was uniqueand plaintiffs would not be able to meet the commonalityrequirement necessary for class certification.

Obviously, a class action complaint must be filed in order toproceed with a class action suit. Once a complaint is filed,section 2--801 of the Code, set forth above, contains very specificrequirements that must be satisfied before the trial courtcertifies the class and finds that the action may proceed as aclass action. One of those issues is commonality.

Nevertheless, the trial court treated the motion for leave toamend as a motion for class certification. In denying leave toamend, the trial court considered the merits of plaintiffs' caseand prejudged issues that would have been properly presented andconsidered in a motion for class certification only after thecomplaint was on file. The issue of commonality, which the trialcourt found could not be satisfied, was not properly before thecourt at the time it denied plaintiffs leave to amend.

The appropriate way to determine whether to certify a class isby a motion for class certification. At the time such a motion ispresented for hearing, the trial court may consider any matters oflaw or fact properly presented by the record, including pleadings,depositions, affidavits, answers to interrogatories, and anyevidence adduced at hearing on the motion. See Brown v. Murphy,278 Ill. App. 3d 981, 989 (1996).

At the time plaintiffs' motion for leave to amend thecomplaint was denied, the parties had not presented any evidenceconcerning the issue of commonality, as it was not an issueproperly before the court. For these reasons, we respond "yes" tocertified question A. The trial court erred in determining theissue of commonality.

Certified questions C, D, and E each address the issue ofwhether the trial court erred in denying plaintiffs leave to amendthe complaint. Questions C and D address the timing of the motionfor leave to amend, and question E, although presented as aquestion of law, addresses the issue of whether the trial courtcorrectly found that plaintiffs could not proceed as a class ontheir claims that the landfill was a nuisance and that itsoperations caused trespasses on their properties.

We first address the issue of the timing of the proposedamended complaint. While the Code sets forth requirements formaintaining a class action suit, it does not provide any specificlimitations period for bringing suit as a proposed class. Likewise, it does not contain any restrictions concerningamendments to existing complaints to add class action allegations.

Section 2--616(a) of the Code contains the followingprovisions applicable to amended pleadings:

"At any time before final judgment amendments may beallowed on just and reasonable terms, introducing any partywho ought to have been joined as plaintiff or defendant,dismissing any party, changing the cause of action or defenseor adding new causes of action or defenses, and in any matter,either of form or substance, in any process, pleading, bill ofparticulars or proceedings, which may enable the plaintiff tosustain the claim for which it was intended to be brought orthe defendant to make a defense or assert a cross claim." 735ILCS 5/2--616(a) (West 2000).

Section 2--616(b) addresses the timing of amended pleadings asfollows:

"The cause of action, cross claim or defense set up inany amended pleading shall not be barred by lapse of timeunder any statute or contract prescribing or limiting the timewithin which an action may be brought or right asserted, ifthe time prescribed or limited had not expired when theoriginal pleading was filed, and if it shall appear from theoriginal and amended pleadings that the cause of actionasserted, or the defense or cross claim interposed in theamended pleading grew out of the same transaction oroccurrence set up in the original pleading, even though theoriginal pleading was defective in that it failed to allegethe performance of some act or the existence of some fact orsome other matter which is a necessary condition precedent tothe right of recovery or defense asserted, if the conditionprecedent has in fact been performed, and for the purpose ofpreserving the cause of action, cross claim or defense set upin the amended pleading, and for that purpose only, anamendment to any pleading shall be held to relate back to thedate of the filing of the original pleading so amended." 735ILCS 5/2--616(b) (West 2000).

Defendants concede that the statute of limitations applicableto the proposed class action complaint seeking damages for trespassand nuisance caused by the landfill while in operation does not barthe proposed amended complaint. See 735 ILCS 5/13--205 (West2000). Likewise, defendants concede that the statute oflimitations would not bar plaintiffs from filing a separate classaction suit arising out of the same set of facts as set forth inthe original complaint and voluntarily dismissing the underlyingsuit if a motion for class certification was granted. Yet,defendants vigorously contend that the trial court properly deniedleave to amend the complaint because the motion was untimely. Defendants assert that plaintiffs knew sufficient facts at the timeof the initial filing to bring suit as a class action and thattheir failure to do so until two years later precludes theirattempt to amend. In support of this proposition, defendants citethis court's opinions in Trans World Airlines, Inc. v. MartinAutomatic, Inc., 215 Ill. App. 3d 622 (1991), and Ray Dancer, Inc.v. DMC Corp., 230 Ill. App. 3d 40, 48 (1992). Although this courtheld in both cases that the trial court did not abuse itsdiscretion in denying leave to amend a complaint, the cases aredistinguishable.

In Trans World Airlines, the plaintiff sought to amend acomplaint to add two new causes of action six years after theinitial filing and on the eve of trial. Not only did we considerthe extreme time lapse in affirming the denial of leave to amend but also we considered that the allegations in the proposedcomplaint were specious. See Trans World Airlines, 215 Ill. App.3d at 628. Similarly, in Ray Dancer, our affirmance of the trialcourt's order denying leave to amend the complaint was based not onthe timing but instead on the fact that the allegations set forthin the proposed amended counts failed to contain sufficient factsand did not cure the defects noted in the prior complaint. See RayDancer, 230 Ill. App. 3d at 48-49.

Here, unlike Trans World Airlines and Ray Dancer, plaintiffs'proposed amended complaint did not seek to correct a factuallydeficient complaint or add new legal theories. Instead, theproposed complaint sought to add new plaintiffs by bringing suit asa class action.

In determining whether to grant leave to amend, the trialcourt should consider the following four factors: (1) whether theproposed amendment would cure the defective pleading; (2) whetherother parties would sustain prejudice or surprise by virtue of theproposed amendment; (3) whether the proposed amendment is timely;and (4) whether previous opportunities to amend the pleading couldbe identified. Loyola Academy v. S&S Roof Maintenance, Inc., 146Ill. 2d 263, 276 (1992). One rationale expressed by the court fordenying leave to amend in the case before us was the timing. Theproposed complaint did not change or add to the legal theoriesasserted in the prior complaint. Instead, the complaint sought toadd plaintiffs. Since the statute of limitations applicable to thecauses of action asserted in the proposed amended complaint had notrun at the time plaintiffs sought leave to amend, the proposedamendment was not untimely simply because it was brought 18 monthsafter the original suit was filed. We fail to see how a complaintthat could be brought by any member of the purported class withinthe statute of limitations could be deemed untimely based merely onthe passage of time when brought by these plaintiffs. In otherwords, if an original cause could have been brought, it wouldfollow that an amendment comprising the same cause would be no lesstimely.

Timing is not the only factor the court should consider indetermining whether to grant leave to amend. As set forth inLoyola Academy, the trial court should also consider whether otherparties would be prejudiced by the proposed amendment. Althoughoral discovery had not even begun, defendants contend that pursuitof the case as a class action would complicate and delay the caseand force defendants to reassess their litigation strategy. Undoubtedly, any matter pursued as a class action is more timeconsuming and complicated and magnifies the scope of thelitigation. However, the fact that defendants may be required tolitigate a class action that was not originally filed in thisfashion does not outweigh the interests of the potential classmembers who would be prejudiced if the proposed amendment wasdenied, particularly when the statute of limitations has not run. We will not engage prematurely in a factual review of whetherthe trial court properly determined that plaintiffs could notsatisfy the element of commonality, as set forth in certifiedquestion C, or whether plaintiffs were aware of facts to supportclass action allegations one year before they filed suit, as setforth in certified question D, as these are not questions of lawproperly addressed on an interlocutory appeal brought pursuant toSupreme Court Rule 308 and are the proper subject of motions andhearings not yet heard by the trial court. 155 Ill. 2d R. 308. However, we answer "yes" to the portion of certified question Cconcerning whether the trial court abused its discretion in denyingleave to amend based on timing when the proposed amendments did notadd any additional substantive claims, the parties were not yet atissue, no depositions had been taken, and the statute oflimitations had not run. We also answer "yes" to the portion ofcertified question D concerning whether the trial court abused itsdiscretion in denying leave to amend the complaint based on thetiming.

Certified question E inquires whether the trial court abusedits discretion in denying leave to amend based on its determinationthat plaintiffs could not proceed as a class on allegationspremised upon nuisance and trespass. Again, in deciding the motionfor leave to amend the complaint, the trial court considered issuesthat were not properly before the court. When ruling on a motionfor leave to amend, it is improper for the trial court to prejudgethe merits of the proposed complaint without a pending motion todismiss the complaint. In our opinion, the trial court abused itsdiscretion in denying leave to amend based on a finding thatplaintiffs could not proceed as a class on claims for nuisance andtrespass, as this issue was not properly before the court and wouldappropriately be determined at the time plaintiffs sought classcertification. Therefore, we respond "yes" to certified questionE.

Based on our responses to certified questions A, C, D, and E,we deem it is unnecessary to address certified question B, exceptto indicate that the question presumes the procedural history ofthis cause is correct. Because the procedural history is flawed,the perspective of "newly discovered evidence" is also flawed andis not material to the correct procedure described in this opinion.

The certified questions of the circuit court of Du Page Countyare answered, and we remand this cause to the circuit court of DuPage County for further proceedings in conformance with the opinionof this court.

Certified questions answered. Cause remanded.

BOWMAN and GROMETER, JJ., concur.