California Code of Regulations
Title 14 - Natural Resources
Division 2 - Department of Conservation
Chapter 4 - Development, Regulation, and Conservation of Oil and Gas Resources
Subchapter 1 - Onshore Well Regulations
Article 4 - Underground Injection Control
Section 1724.7.2 - Liquid Analysis

(a) Liquid analysis required under this article shall include testing for all of the following: total dissolved solids; total petroleum hydrocarbon as crude oil; major cations (Ca, Mg, Na, K, Fe, Mn, Sr, B); major anions (CI, SO4, HCO3, CO3, Br, I); total alkalinity and hydroxide; electrical conductance; pH; and temperature.

(b) The Division may require testing for additional constituents on a project-specific basis. Any additional constituents shall be listed in the Project Approval Letter for the project.

(c) To ensure the liquid analysis required under Section 1724.7(a)(2)(B) is representative of the reservoir liquid in its native condition, if feasible the liquid analyzed shall be either sampled from the injection zone itself prior to commencement of any injection into the reservoir or sampled from an analogous reservoir that has not already received injection fluid. The representative sample shall be recovered after all completion and drilling fluid has been circulated from the wellbore.

(d) To ensure the liquid analysis required under Sections 1724.7(a)(3)(H) and 1724.10(d) is representative of the liquid actually injected, the liquid to be analyzed shall be sampled after all additives (if any) are added to the liquid, and after all treatment or separation processes (if any).

(e) Liquid analysis required under this article shall be performed by a laboratory that is certified by the State Water Resources Control Board environmental laboratory accreditation program. The performing laboratory shall submit the data and analysis to the Division directly, using a digital format.