When two or more counties may have joined together for the purposes of sections 70.010 to 70.090, additional counties, until the total shall have reached ten, may be admitted to participation by all such counties, including those already participating and those desiring to participate, proceeding as is provided for in sections 70.010 to 70.090 for the formation of a new agreement. If the proposition to admit additional counties shall fail to receive a majority vote of those voting thereon in any one of such counties, including those already participating and those desiring to participate, the proposition shall be deemed to have failed and the counties already participating before such proposition was submitted shall carry on in the same manner as before.