EVEREST GEOPHYSICS carries out routinely quality assurance and quality control (QA/QC) services for our clients. A written plan is often a cornerstone for technical projects. The plan identifies how one will get to the answers desired. For geophysics, a quality assurance plan identifies the framework of steps that will result in quality deliverables. The QA plan is a management tool based on the premise that the presentation of quality geophysical data is an important aspect of doing business. To be most effective, a QA plan is written and agreed to by managers responsible for quality geophysical data.
Geophysical customers must decide if they want to employ a rigorous QA process. There is a cost for developing the management tool for QA and therefore, geophysical customers need to decide if they are willing to pay the cost of a QA program, or if they would prefer to accept the inherent risks of proceeding without rigorous QA.
The QA process includes commitments to equipment maintenance and upgrades, as well as commitment to software, computers, and process improvements. It can include a commitment to employee training and education. QA can be a commitment to look for changes and improvements that will provide not only a cost-competitive advantage, but also a more technically sound and reliable product. For a company providing geophysical services, company management and client commitment to QA begin with these commitments. However, for geophysics, implementation is in QC.
For planning subsurface investigation and office processing programs, it is important to be aware of parameters and properties needed for design and construction, as well as to understand the geologic conditions and site access restrictions. Specific steps include the following:
- identify data needs;
- gather and analyze existing information;
- develop a preliminary site model;
- develop and conduct a site investigation; and
- develop and conduct an office processing program.
A geophysical quality control program should ensure data are optimally acquired in the field; artifacts are not introduced during processing; and the information prepared for interpretation correlates with geologic, hydrogeologic, or man-made features related to the survey objective. For the good geophysicist, the steps described below may seem simple, trivial, or just plain common sense. In reality, not every practitioner is a good geophysicist. Therefore, a good QC plan reflects the procedures that a good geophysicist, using common sense, would apply given the same level of experience, project, and objectives.