S.C. Code Regs. § § 61-107.19.V.E.258.54

Current through Register Vol. 48, No. 10, October 25, 2024

Section 61-107.19.V.E.258.54 - Detection Monitoring Program

a. Detection monitoring is required at all Class Three landfill groundwater monitoring wells defined in Sections258.51.a. (1) and a. (2). At a minimum, a detection monitoring program shall include the monitoring for the constituents listed in Appendix IV of this part.

(1) The Department may delete any of the Appendix IV monitoring parameters for a Class Three landfill if it can be shown that the deleted constituent(s) are not reasonably expected to be contained in or derived from the waste contained in the landfill.

(2) The Department may require additional groundwater monitoring parameters for routine monitoring based on the chemical and physical nature of the waste stream received by the landfill and any analytical data for the waste streams provided by the permittee.

b. The monitoring frequency for all constituents listed in Appendix IV to this part shall be at least semiannual during the active life of the facility and the post-closure care period. At least one sample from each well (background and downgradient) shall be collected and analyzed during each sampling event.

c. The Department may specify an appropriate alternative frequency for repeated sampling and analysis for Appendix IV constituents during the active life and the post-closure care period. The alternative frequency during the active life shall be no less than semiannual. The alternative frequency shall be based on consideration of the following factors:

(1) Lithology of the aquifer and unsaturated zone;

(2) Hydraulic conductivity of the aquifer and unsaturated zone;

(3) Groundwater flow rates;

(4) Minimum distance between upgradient edge of the Class Three landfill and downgradient monitoring well screen (minimum distance of travel); and,

(5) Resource value of the aquifer.

d. If the permittee determines, pursuant to Section258.53.g., that there is a statistically significant increase over background for one or more of the metals listed in Appendix IV, or above the MCL or PQL, as applicable, for any volatile organic compound (VOC) listed in Appendix IV at any monitoring well at the boundary specified in Section258.51.a. (2), the permittee shall:

(1) Within 14 days of this finding, notify the Department;

(2) Within 14 days of this finding, place a notice in the operating record indicating which constituents have shown statistically significant changes from background levels;

(3) Within 30 days of this finding, resample the monitoring well(s) in question for Appendix IV to determine the validity of the data; and,

(4) If the data are validated by resampling, establish an assessment monitoring program meeting the requirements of Section258.55. within 90 days except as provided for in paragraph d.5 of this section.

(5) The permittee may demonstrate that a source other than a Class Three landfill caused the contamination or that the statistically significant increase (SSI) resulted from error in sampling, analysis, statistical evaluation, or natural variation in groundwater quality. A report documenting this demonstration shall be certified by a qualified professional, submitted to the Department for approval, and placed in the operating record. If a successful demonstration is made and documented, the permittee may continue detection monitoring as specified in this section. If, after 90 days, a successful demonstration is not made, the permittee shall initiate an assessment monitoring program as required in Section258.55.

e. The permittee shall submit to the Department on or before the anniversary date of issuance of the permit, an annual report certified by a qualified professional containing all of the analytical and statistical analysis performed at the site for the previous year as a result of the requirements of this Part. The annual report shall contain the following:

(1) The results of all analytical testing performed at the site during the previous year, and any applicable data concerning sampling and analysis of monitoring wells at the site;

(2) A determination of the technical sufficiency of the monitoring well network in detecting a release from the facility as required by Section258.51.;

(3) The determination of groundwater elevations, groundwater flow directions and groundwater flow rates as specified in Section258.53.d. Groundwater flow directions shall be based upon interpretation of a potentiometric map prepared utilizing the groundwater elevations measured at the site;

(4) A summary of the results of the statistical analysis performed in accordance with Sections258.53.g. and 258.53.h.; and,

(5) Recommendations for any necessary actions regarding the groundwater monitoring system.

f. The results of all chemical analysis of groundwater samples taken during routine monitoring shall be submitted to the Department within 60 days of sample collection. On sampling events where an annual report is to be submitted to the Department, the annual report shall satisfy this requirement.

S.C. Code Regs. § 61-107.19.V.E.258.54