In Lewis v. Seventeenth Dist. Agricultural Assn. (1985) 165 Cal. App. 3d 823, a case decided 13 years before the recent amendment to section 15125 of the Guidelines, this court affirmed a judgment ordering cancellation of contracts for auto racing at the Nevada County Fairgrounds. The flat track built in 1958 had been converted to a banked track in 1973 to accommodate higher powered modified stock cars. However, no environmental review was conducted when the track was upgraded. ( Lewis, supra, 165 Cal. App. 3d at p. 826.) We rejected the racing association's contention that the track was categorically exempt from CEQA review as an existing facility. (Lewis, supra, at pp. 825, 829.) The exemption did not apply because, under an exception set forth in section 15300.2, subdivision (c) of the Guidelines, the increased racing activity since 1973 had a significant effect on the environment due to the "unusual circumstances" that the track was located next to a residential area. ( Lewis, supra, at pp. 828-829.) In his concurring opinion, Justice Blease explained that the categorical exemptions involved categories of projects that "normally do not work an adverse change in the environmental conditions preceding the project." ( Id. at p. 836 (conc. opn. of Blease, J.).) He stated that as a general proposition, "the conditions of the environment that preceded the project were the baseline against which to measure the adverse environmental change." (Ibid.) Since there had been no environmental review when the track was modified in 1973, the categorical exemption could not be applied. ( Id. at p. 838 (conc. opn. of Blease, J.).)