Cal. Health & Safety Code § 11379.8
(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:
(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.