California Code of Regulations › Title 23 - Waters › Division 3 - State Water Resources Control Board and Regional Water Quality Control Boards › Chapter 15 - Discharges of Hazardous Waste to Land › Article 5 - Water Quality Monitoring and Response Programs for Waste Management Units › Section 2550.11 - Unsaturated Zone Monitoring and Response Provisions for Class I Land Treatment Units

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a) A
				  discharger required pursuant to the provisions of this article to conduct
				  unsaturated zone monitoring at a land treatment unit shall comply with the
				  unsaturated zone monitoring and response provisions of this section in
				  conjunction with all other unsaturated zone monitoring and response provisions
				  of this article.
(b) The discharger
				  shall monitor the soil and soil-pore liquid to determine whether constituents
				  of concern migrate out of the treatment zone.
(c) The regional board shall specify the
				  monitoring parameters and constituents of concern to be monitored in the waste
				  discharge requirements. The monitoring parameters to be monitored are those
				  specified pursuant to subsection
				  2550.8(e) of this
				  article for detection monitoring and subsection
				  2550.9(e)(2) of
				  this article for evaluation monitoring. The constituents of concern to be
				  monitored are those specified in the water quality protection standard
				  specified for each monitoring and response program. The constituents of concern
				  to be monitored shall include the constituents, including hazardous
				  constituents, that must be degraded, transformed, or immobilized in the
				  treatment zone of the land treatment unit.
(d) The regional board may require monitoring
				  for principal hazardous constituents (PHCs) in lieu of the constituents
				  specified under subsection (c) of this section. PHCs are hazardous constituents
				  contained in the wastes to be applied at the unit that are the most difficult
				  to treat considering the combined effects of degradation, transformation, and
				  immobilization. The regional board may establish PHCs if the regional board
				  finds based on waste analyses, treatment demonstrations, or other data that
				  effective degradation, transformation, or immobilization of the PHCs will
				  assure treatment at at least equivalent levels for the other hazardous
				  constituents in the wastes.
(e) The
				  discharger shall install an unsaturated zone monitoring system that includes
				  soil monitoring using soil cores and soil-pore liquid monitoring using
				  appropriate devices such as lysimeters capable of acquiring soil-pore liquid
				  samples. The unsaturated zone monitoring system shall consist of a sufficient
				  number of sampling points at appropriate locations and depths to yield samples
				  that:
(1) represent the quality of background
				  soil-pore liquid quality and the chemical makeup of soil that has not been
				  affected by a release from the treatment zone; and
(2) indicate the quality of soil-pore liquid
				  and the chemical makeup of the soil below the treatment
				  zone.