That portion of a political subdivision lying within a district and having representation on the district board of directors, shall be excluded from the proposed refuse transfer or disposal system, or both, and shall not be liable for any cost incurred by said district in acquiring, constructing, operating and maintaining such system; provided, that the governing body of said political subdivision within 90 days after passage of the resolution of intention by the district to form such system, delivers to said district a certified copy of its resolution requesting exclusion from the proposed refuse transfer or disposal system, or both.