(a) Any person convicted of a violation of subdivision (a) of Section 11379.6, or of a conspiracy to violate subdivision (a) of Section 11379.6, with respect to any substance containing a controlled substance which is specified in paragraph (21), (22), or (23) of subdivision (d) of Section 11054, or in paragraph (1) or (2) of subdivision (d) or in paragraph (3) of subdivision (e) or in paragraph (2) of subdivision (f) of Section 11055 shall receive an additional term as follows:
(1) Where the substance exceeds three gallons of liquid by volume or one pound of solid substances by weight, the person shall receive an additional term of three years.
(2) Where the substance exceeds 10 gallons of liquid by volume or three pounds of solid substance by weight, the person shall receive an additional term of five years.
(3) Where the substance exceeds 25 gallons of liquid by volume or 10 pounds of solid substance by weight, the person shall receive an additional term of 10 years.
(4) Where the substance exceeds 105 gallons of liquid by volume or 44 pounds of solid substance by weight, the person shall receive an additional term of 15 years.
In computing the quantities involved in this subdivision, plant or vegetable material seized shall not be included.
(b) The additional terms provided in this section shall not be imposed unless the allegation that the controlled substance exceeds the amounts provided in this section is charged in the accusatory pleading and admitted or found to be true by the trier of fact.
(c) The additional terms provided in this section shall be in addition to any other punishment provided by law.
(d) Notwithstanding any other provision of law, the court may strike the additional punishment for the enhancements provided in this section if it determines that there are circumstances in mitigation of the additional punishment and states on the record its reasons for striking the additional punishment.
(e) The conspiracy enhancements provided for in this section shall not be imposed unless the trier of fact finds that the defendant conspirator was substantially involved in the direction or supervision of, or in a significant portion of the financing of, the underlying offense.