Arkansas does not allow local jurisdictions like cities or counties to collect a local sales tax. The Arkansas state sales tax of 6.5% is applicable statewide. You can view the sales tax rates for various cities in Arkansas here.
Equitable adjustment is a term of art that includes an adjustment to fee, and the target. minimum, and maximum fees should not be increased in this case for what I hope are obvious reasons. The adjustment should be limited to the effect of the new wage determination on wages and fringes.
An annual review of assets and a timely provision of modest additions to reserve accounts will go a long way toward smoothing earnings and preventing what could be a substantial loss in the current period resulting from accumulated unforeseen reversals impacting one fiscal period.