Wyoming Administrative Code
Agency 020 - Environmental Quality, Dept. of
Sub-Agency 0009 - Solid Waste Management
Chapter 3 - INDUSTRIAL LANDFILL REGULATIONS
Section 3-9 - Monitoring Standards

(1.) Site-specific field measurements, and information about the specific solid wastes to be disposed at the facility or unit; and

(2.) Contaminant fate and transport predictions, which maximize contaminant migration and consider impacts on human health and the environment.

(1.) Industrial landfills which ceased receiving solid wastes before January 1, 1998;

(2.) Industrial landfills which do not receive very small quantity generator (VSQG) hazardous wastes; or

(3.) Industrial landfills which accept less than twenty tons of solid waste per day (annual average) for disposal, have no evidence of existing groundwater contamination, serve communities that have no practicable solid waste management alternatives and are located in an area that receives less than or equal to twenty-five inches of precipitation annually.

(1.) Number, spacing, and orientation of the individual solid waste units at the facility;

(2.) Hydrologic setting;

(3.) Site history and design; and

(4.) Type of solid waste accepted at the individual solid waste units.

(1.) Deletes a constituent because the operator shows that it is not likely to be present in the solid waste disposed at the facility;

(2.) Establishes an alternate list of inorganic indicator parameters in lieu of some or all of the heavy metals, if the alternative parameters provide a reliable indication of inorganic releases from the facility or unit, considering the following factors:

(3.) Determines that a different, but no less frequent than annual, monitoring schedule is appropriate, considering the following factors:

(1.) Notify the Administrator in a written report with supporting documentation and place a copy of the report in the facility operating record within fourteen days and start assessment monitoring within ninety days; or

(2.) Demonstrate to the Administrator that the statistically significant increase over background is not due to the solid waste disposal facility or unit, but that the difference is due to another source of pollution, error in sampling, analysis or statistical evaluation, or natural variation in groundwater quality. The operator shall prepare a report documenting this demonstration and, following approval by the Administrator, place the report in the operating record for the facility. If the report is approved, the operator shall continue detection monitoring. If, after ninety days, a successful demonstration is not made, the operator must initiate an assessment monitoring program.

(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 the facility and the downgradient groundwater monitoring well(s);

(5.) Classification of the aquifer under Chapter 8 of the Water Quality Rules; and

(6.) Nature (fate and transport) of any constituents detected under assessment monitoring.

(1.) Within fourteen days, notify the Administrator in a written report and place a copy of the report in the operating record identifying the Appendix B constituents that have been detected;

(2.) Within ninety days, and on at least a semiannual basis thereafter, resample all groundwater monitoring wells, conduct analyses for all constituents required under detection monitoring of this Section, and for all Appendix B constituents that have been detected under assessment monitoring, and record their concentrations in the operating record. At least one must be collected from each groundwater monitoring well during each sampling event under this paragraph. The Administrator may approve an alternate sampling frequency, no less than annual, considering the factors in paragraph (b)(i)(E)(III) of this Section;

(3.) Establish background concentrations for any constituents detected for the first time; and

(4.) Request in writing that the Administrator establish groundwater protection standards for all constituents detected.

(1.) Characterize the nature and extent of the release by installing additional groundwater monitoring wells as necessary;

(2.) Install at least one additional groundwater monitoring well at the facility boundary downgradient of the release and sample the groundwater monitoring well in accordance with paragraph (b)(i)(E)(IV)(2.) of this Section;

(3.) Notify all persons who own or reside on the land that directly overlies any part of a plume of contamination that migrated off-site; and

(4.) Initiate an assessment of corrective measures within ninety days; or

(5.) Demonstrate to the Administrator in writing that the contamination was caused by another source or resulted from an error in sampling, analysis or statistical evaluation, or from natural variation in groundwater quality. The operator shall prepare a report documenting this demonstration, and following approval by the Administrator, place the report in the operating record. If a successful demonstration is made, the operator must continue monitoring under the assessment monitoring program, or may return to detection monitoring if all Appendix B constituents are at or below background. Until a successful demonstration is made, the operator must comply with paragraph (b)(i)(E)(VIII) of this Section including initiating an assessment of corrective measures under Section 13 of this Chapter.

(1.) For constituents where a maximum contaminant level (MCL) has been promulgated, the MCL for that constituent;

(2.) For constituents for which MCLs have not been promulgated, the background concentration; or

(3.) For constituents for which the background level is higher than the MCL or health-based level established under subsection (b)(i)(E)(X), the background concentration.