6.6.8.3 Packer Testing Packer testing should be undertaken during drilling to estimate the hydraulic conductivity (K) of saturated and unsaturated bedrock at discrete intervals during drilling. An estimate of K will be derived by isolating the test interval in the bedrock by inflating a packer at the top of the test interval. Packer testing will require specialized equipment and an appropriately qualified drilling contractor and a supervising hydrogeologist with experience in packer testing. Bore Development The monitoring bores must be developed by purging as part of the hydrogeological field program. The key objective is to remove fine-grained material from the aquifer and filter pack immediately surrounding the bore screen and ensure that any drilling fluid has been removed from the bore after installation. The volume of water to be evacuated from each bore will be calculated in the field and field water quality parameters, including temperature, specific conductance, and pH must be recorded during the process of purging the bore to ensure the parameters have stabilized prior to collection of a water quality sample. 6.6.8.4 6.6.8.5 Initial Water Quality Sampling A water quality sample should be collected at the end of the bore development (purging) process. The water quality samples should be field-filtered and preserved and sent to an accredited local laboratory for water quality testing. Any future water quality samples from the new (or existing) monitoring bores must be collected after the monitoring bore has been purged immediately prior to sample collection. This will ensure the groundwater sample is representative of in-situ conditions within the aquifer adjacent to the well screen (and not the standing volume of water in the bore). All groundwater level measurements, sampling, field procedures, and data management must be undertaken by a Suitably Qualified Person and in accordance with recognised Australian and Queensland standards and guidance, including AS/NZS 5667.11:1998 – Water quality – Sampling – Guidance on sampling of groundwaters. Hydraulic Testing A slug test is recommended to be completed for each completed bore to estimate the K value of the screening interval for each bore. This testing must be completed after each bore is developed and sampled. Short-term pumping tests can also be completed depending on the yield of each monitoring bore at the discretion of the hydrogeologist(s) that supervises the hydrogeological field program. 6.6.8.6 6.6.8.7 Site-Wide Water Level Survey A site-wide water level survey must be completed as part of the hydrogeological field program. This survey should include the new bores and all of the existing MB bores on site. The static groundwater level should be recorded using a water level tape (electronic sounder) relative to the top of the PVC casing for each bore. Geodetic groundwater levels can then be calculated once the top of casing elevations are surveyed by a professional surveyor. Reporting The results of the hydrogeological field program must be documented in a factual drilling report that contains detailed information and all the relevant documentation associated with the program, including the drilling method and bore installation procedures, borehole logs, bore development data, initial water level and water quality results, and photos. The report should be prepared by the hydrogeologist(s) that supervised the drilling program. 6.6.8.8
Project number: 25B061
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