Okla. Admin. Code § 252:515-9-73

Current through Vol. 41, No. 19, June 17, 2024

Section 252:515-9-73 - Monitoring frequency

(a)Semi-annual monitoring required. Groundwater from each monitoring well shall be sampled and analyzed at least semi-annually during the active life of the facility and any required post-closure monitoring period.

(b)Alternative frequency authorized. The DEQ may, on a case-by-case basis, approve alternative sampling and analysis frequencies in the approved detection monitoring program.

(1)All constituents. An alternative frequency for repeated sampling and analysis for all constituents may be approved. The following shall be considered:

(A) lithology of the aquifer and unsaturated zone;

(B) hydraulic conductivity of the aquifer and unsaturated zone;

(C) groundwater flow rates;

(D) minimum distance between upgradient edge of the facility unit and downgradient monitoring well screen; and

(E) resource value of the aquifer.

(2)Individual constituents. An alternative sampling and analysis frequency for one or more individual constituents may be approved. In addition to the considerations of (1) of this Subsection, the following shall be considered:

(A) the mobility, stability, and persistence of the constituents or their reaction/degradation products in the unsaturated zone beneath the disposal facility;

(B) the detectability of the waste constituents, and reaction/degradation products in the groundwater; and

(C) the concentration or values and coefficients of variation of the constituents in the groundwater background.

(c)Minimum alternative monitoring frequency. Alternative detection monitoring frequencies shall not be less than annual during the active life, but may be less than annual during the post-closure monitoring period.

Okla. Admin. Code § 252:515-9-73

Added at 20 Ok Reg 1151, eff 6-1-03