JUSTICE TURNER delivered the opinion of the court:

In February 1993, petitioner, the Illinois Environmental Protection Agency (IEPA), approved a landfill closure planfor respondent, Jersey Sanitation Corporation (Jersey). In June1999, Jersey sought a supplemental permit governing facilityclosure certification. In October 1999, the IEPA granted thesupplemental permit with conditions. In January 2000, Jerseyfiled a petition for review of the permit conditions with respondent, the Pollution Control Board (Board). In December 2000,Jersey filed a motion for summary judgment, arguing the imposedconditions were unnecessary; and in June 2001, the Board grantedthe motion (Jersey Sanitation Corp. v. Illinois EnvironmentalProtection Agency, Ill. Pollution Control Bd Op. 00-82 (June 21,2001)). In August 2001, the IEPA filed a motion to reconsider,which the Board denied along with Jersey's motion to strike(Jersey Sanitation Corp. v. Illinois Environmental ProtectionAgency, Ill. Pollution Control Bd. Order 00-82 (September 20,2001)).

Pursuant to section 41(a) of the Illinois EnvironmentalProtection Act (Act) (415 ILCS 5/41(a) (West 2000)) and SupremeCourt Rule 335 (155 Ill. 2d R. 335), the IEPA brings this directreview of the Board's decision. The issues are whether the Boarderred (1) in striking the conditions imposed on Jersey's supplemental permit and (2) in reviewing the conditions which the IEPAclaims were waived by Jersey's untimely objections. In itscross-appeal, Jersey argues the Board erred in denying Jersey'smotion to strike the IEPA's motion for reconsideration based onits alleged untimely filing. We affirm the Board's decision inthe IEPA's appeal as well as its decision denying Jersey's motionto strike in Jersey's cross-appeal.

I. BACKGROUND

The Jersey landfill is a 10-acre site located in JerseyCounty, Illinois, that opened in 1967. The landfill stoppedaccepting waste in September 1992, and a final cover/vegetativelayer was applied in September 1994. In February 1993, the IEPAapproved Jersey's closure plan for the landfill and issuedsupplemental permit No. 1992-350-SP. The permit approved arevised closure and postclosure care plan and cost estimatesalong with a groundwater monitoring plan.

In June 1999, Jersey submitted an application for asupplemental permit that sought facility closure certificationand included closure and postclosure plans along with costestimates. In the application for permit, Jersey stated, inpart:

"Groundwater monitoring results will beevaluated each quarter against backgrounddata, [g]eneral [u]se [w]ater [q]uality[s]tandards, and other historic water analysis information. If a trend is believed tobe developing, more frequent sampling(e.g.[,] monthly) may be performed to substantiate or dismiss the likelihood of siteimpact. A professional engineering firmshould be retained to develop future actionsand/or plans for subsequent IEPA approval."

In October 1999, the IEPA granted Jersey supplemental permit No.1999-209-SP with conditions approving closure certification.

In January 2000, Jersey filed a petition for review ofpermit conditions with the Board, seeking review and deletion ofcertain conditions imposed by the IEPA to the 1999 supplementalpermit. Specifically, Jersey objected to the following conditions as unnecessary to accomplish the Act's purpose and inconsistent with the Board's regulations:

"A. Closure Certification

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4. Current, valid [p]rior [c]onduct[c]ertification is required to conduct post-closure care.

B. Post[c]losure Care

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6. Prior to the [IEPA] issuance of acompletion of post[]closure care certificate,the operator shall provide the following:

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b. An analysis for the 35 Ill. Adm.Code [