Regulatory requirements are…

Regulatory requirements are posing material assessment constraints for rock that will become excess soil through crushing during removal on large infrastructure projects. Typically for these large projects, assessment and characterization of soil and/or rock is required prior to construction to support project and material mangement planning for significant volumes of soil. Once tunneling and excess soil removal has started, it is extremely challenging within construction schedules and storage limitations to characterize the crushed rock to determine reuse and/or disposal options, without any previous sample data. Environmental quality data is also required as part of the reporting requirements of the regulation to support reuse or disposal as appropriate. During initial in-situ environmental characterization and sampling programs, rock collected from boreholes is generally cored and competent, and wouldn't be crushed for sampling in a traditional investigation. However, understanding the contaminant concentrations in the crushed rock is required to support the management of the subsequent excess soils following removal. The regulation states in section 2.1 of the laboratory protocol that milling or crushing of rocks and stones is not expected to occur in the laboratory. CALA accredited labs have confirmed that they will not crush rock for analysis, particularly for volatile parameters, making it impossible to characterize tunneling soils and assess for contamination in shale prior to construction. This has been further complicated by naturally occurring benzene exceeding the ESQS in crushed rock from some shale formations. Lack of ability to obtain data to assess for, and identify, exceedances of various ESQS in crushed rock, have significant schedule and cost implications for large tunnelling infrastructure projects. Would the MECP consider providing more guidance on how crushed rock samples for tunneling projects can be collected; and amending the guidance for laboratories to allow crushing for analysis of rock samples specifically for rock that will be mechanically crushed through removal processes and become excess soils (such as shale removed via tunnelling).