Potentially, if he has the qualifying year with the Canadian company, the knowledge is specific to the company's protocol, and the U.S. affiliate rather than the mine controls and supervises his work. The placement contract is the document that decides the last point.
The client site is allowed; client control is not
An L-1B worker may be stationed primarily at an unaffiliated company's location, and long-term environmental monitoring is a legitimate reason to be there. What the statute forbids is an arrangement that amounts to labour for hire: one where the client principally controls and supervises the worker, or where the placement is not connected to a product or service requiring the petitioner's specialized knowledge. Both conditions are read from the documents, chiefly the service contract and the petition's description of supervision.
If the affiliate's project manager assigns the sampling schedule, reviews the data and signs the reports while the mine provides access and safety induction, the placement is in connection with the affiliate's service. If the mine's environmental superintendent directs him daily, the affiliate is renting out a technician. Before anyone files, read the contract with that test in mind and fix the clauses that put control in the wrong hands.
Hypothetical example: A medical-device manufacturer plans to place its calibration-process specialist at an unaffiliated hospital laboratory. The first review should mark every contract clause that concerns task assignment, performance review, equipment custody and substitution. The signed service agreement settles whether the affiliate retains control; a polished support letter cannot repair contrary contract language.
The company should also identify the proprietary deliverable, the specialist's qualifying year abroad, and the person at the affiliate who will supervise the work. If the laboratory needs ordinary staff augmentation, the L-1B route is not the right description of the arrangement.