The opinion of the court was delivered by: Justice Buckley
Northwest Mosquito Abatement District (District) appeals an Illinois State Labor Relations Board (Board) decision that issued a certificate of representation naming Teamsters Local 714 (Union) as the exclusive bargaining unit for District employees. The District filed this timely petition for direct review and maintains: (1) the Board incorrectly found that the District employed the jurisdictional minimum of 35 employees, as required by section 3(n) of the Illinois Public Labor Relations Act (Act)(5 ILCS 315/1 et seq (West 1993)); (2) the Board erred in concluding that the District's field supervisors were not supervisors under section 3(r) of the Act; and (3) the Board erred by refusing to consider evidence offered by the District after the petition was filed. For the following reasons, we affirm the decision of the Board.
The relevant facts are as follows: The District is a local government unit organized under the Mosquito Abatement District Act 70 ILCS 1005/1 et seq. (West 1994) that provides mosquito control services for northwest Cook County. It is the duty of the District to find and kill mosquito larvae, and spray the adult mosquito population. The District is a public employer within the meaning of the Act. See 5 ILCS 315/3(o)(West 1996).
The District is governed by a five-member board of trustees. At all times relevant to this case, the director was Glenn Levinson (Levinson), and the assistant director was Mike Szyska (Szyska). The four department heads were: chief of internal services Dave Baker, chief of drainage Mark Baker, entomologist Donald Oemick, and chief of field operations Szyska. The District also employed an office manager, an assistant chief of internal service, three mechanics, an auto service worker and three field supervisors. *fn1 Working with the field supervisors were the roughly 54 seasonal field employees who inspect and treat water sources and take part in mosquito abatement programs during the summer months (mid-May to mid-August).
Ninety percent of the seasonal workers are college students or individuals of college age. Every December, the District's assis-tant director asks the field supervisors to provide him with a list of seasonal employees who worked for the District the prior season and should be rehired. The director then sends job applications to those individuals in December.
In March or April, the District places advertisements in local newspapers seeking additional seasonal workers for the coming season. To qualify for seasonal employment with the District, an applicant must have a valid driver's license and no driving-under- the-influence convictions, no more than one speeding ticket in the last two years, no more than three minor moving violations in the past three years, and not more than one moving violation in the past six months. The seasonal employees are also required to obtain a pesticide operator's license from the Illinois Department of Agriculture. New hires are entitled to a grace period that allows them to obtain the license while working for the District. The license is valid for three years, but rehires may renew their licenses if sponsored by a field supervisor. Both rehires and new hires must apply for employment with the District but, unlike new hires, rehires do not have to interview.
Prior to the summer of 1996, the District sent applications to 46 of the 54 seasonal workers who had worked the previous year. The District then hired 63 seasonal employees for the 1996 mosquito season, 28 of whom were rehires with between one and six years of experience.
During the nine-month off season, the field supervisors survey and check mosquito sources, compile lists and records of potential mosquito sources, redraft maps to reflect mosquito sources, attend policy meetings and engage in continuing education concerning mosquito abatement and public health. Then, during the summer months, the field supervisors train seasonal employees, monitor work and assign equipment. They also maintain seasonal employees' work records and evaluate their performance. The field supervisors have the authority to reward seasonal employees, approve overtime and initiate disciplinary measures.
On January 28, 1997, the Union filed a petition for representation seeking to form a bargaining unit consisting of the District's assistant to the chief of internal services, the field supervisors, the mechanics and the auto services worker. The seasonal employees were not part of the proposed bargaining unit.At a hearing on the petition on February 27, 1997, the District and the Union stipulated to the following: (1) of the 13 District employees, five were either managers, supervisors or confidential employees under the Act and were not "public employees"; (2) five others were public employees under the Act; and (3) the Union is a labor organization under the Act. Assistant director Szyska testified for the District at the hearing. He stated that each summer the District hires about the same number of seasonal employees, approximately 54. For the summer of 1996, the District hired 63 seasonal employees, 28 of whom were rehired from the prior summer. Szyska further stated that even though it is not standard procedure, if a new employee's performance is satisfactory, he/she may be told he/she will be rehired the next summer. In December of 1996, Szyska sent 46 applications to seasonal employees from the previous summer and offered them employment for the upcoming summer. The number of applications sent out to former employees may vary by as much as 10, but the number of people reapplying for seasonal employment also varies.
Field supervisor John Blankenberg testified for the Union. According to Blankenberg, many seasonal employees worked for the District for two or more summers. He stated that the employment records showed approximately half of all seasonal employees were rehired from a previous summer. Mechanic Frank Hernandes also testified for the Union. He stated that 20 seasonal employees worked at his shop in Hoffman Estates and of those 20 employees, 15 had been rehired from the summer of 1995.
On June 13, 1997, the administrative law Judge (ALJ) issued a recommended decision and order finding that the seasonal employees were public employees according to the meaning provided in the Act. The ALJ concluded that the District had more than 35 employees and, therefore, the Board had jurisdiction over the District. In addit-ion, the ALJ found that the field supervisors were not supervisors within the meaning provided in the Act.
On June 23, 1997, the District filed a motion to supplement the administrative record and to reconsider. The District sought to supplement the record with an affidavit of acting director Szyska stating that the District had received 20 employment applications from prior seasonal employees but only rehired eight. Then, on June 27, 1997, the District filed its exceptions to the ALJ's recommended decision and order.
On August 26, 1997, the Board issued a final decision and order affirming the ALJ's recommendations. The Board found that the seasonal workers were not "short-term" employees within the meaning of the Act because the majority of the seasonal employees had a reasonable assurance of rehire by the District in subsequent years, they were not required to interview for the job and many former employees had already obtained a pesticide operator's license. The Board also found that the field supervisors were not supervisors under the Act since they did not spend the preponderance of their employment time engaged in supervisory duties. Furthermore, the Board determined there was no conflict of interest in including the field supervisors in a bargaining unit because the seasonal employees were not members of the unit.
As a final matter, the Board also denied the motion to supplement the record with Szyska's affidavit because the affidavit sought to introduce evidence of facts occurring after the petition for representation was filed. The Board ruled that the significant date for determining whether an employer is covered by the Act is the date the petition for representation is filed.
On September 23, 1997, the Union was elected exclusive bargaining representative of a bargaining unit consisting of the assistant to the chief of internal services, the mechanics, the auto services worker and the field supervisors. On October 7, 1997, the Board issued a certificate of representation certifying the Union as the exclusive representative of the bargaining unit.
On appeal, the District challenges the Board's decision to certify the Union as the exclusive representative of a bargaining unit. Judicial review of the Board's decision is governed by the Administrative Review Law (735 ILCS 5/3-101 (West 1996) (40 ILCS 5/18-164 (West 1996)), and extends to all questions of law and fact presented by the record. 5 ILCS 315/9(i)(West 1996); County of Cook v. Licensed Practical Nurses Ass'n, 284 Ill. App. 3d 145, 152 (1996). In reviewing the Board's decision to certify the Union as the exclusive representative of the bargaining unit, this court should not reweigh the evidence but, instead, should determine whether the Board's decision was contrary to the manifest weight of the evidence. City of Freeport v. Illinois State Labor Relations Board, 135 Ill. 2d 499, 507 (1990); Licensed Practical Nurses Ass'n, 284 Ill. App. 3d at 152.
Under the manifest weight of the evidence standard, the Board's findings of fact are prima facie true and correct. 735 ILCS 5/3-110 (West 1996); Chief Judge of the Circuit Court v. American Federation of State, County & Municipal Employees, Council 31, 153 Ill. 2d 508, 514 (1992). A decision is contrary to the manifest weight of the evidence only when, after viewing the evidence in a light most favorable to the agency, the court determines that no rational trier of fact could have agreed with the agency's decision. Chief Judge of the Circuit Court, 153 Ill. 2d at 514. Thus, the Board's ...