Ark. Code Ann. § 14-54-207

No agreement made pursuant to this subchapter shall relieve any public agency of any obligation or responsibility imposed upon it by law except that, to the extent of actual and timely performance thereof by an adjoining municipality pursuant to an agreement entered into under this subchapter or by a joint board or other legal or administrative entity created by an agreement made under this subchapter, the performance may be offered in satisfaction of the obligation or responsibility.