Sec. 131.206.  INCREASE OR DECREASE OF BOND.  (a)  The amount of the bond or deposit required and the terms of acceptance of the applicant's bond or substitute collateral may be increased or decreased from time to time to reflect changes in the cost of future reclamation of land mined or to be mined.
(b)  The amount of the bond or substitute collateral may be reduced only in accordance with the provisions of Sections 131.208 through 131.213 of this code.
Acts 1977, 65th Leg., p. 2627, ch. 871, art. I, Sec. 1, eff. Sept. 1, 1977.