I recommend, at a minimum, a short course in environmental site assessment and risk assessment. Visit and talk with, not to get a job, but to see what potential exists in your area, a local environmental engineering firm that does this kind of work.
I recommend talking with a remediation company, preferably one that tackles projects (such as landfill caps, slurry cut-off walls, excavations) requiring heavy equipment. If you're familiar with heavy equipment and their production rates you may be able to find a position as an estimator. From there, you'll be learning the procedures and methods involved in this field through on-the-job training, and can also get exposure to environmental engineering firms.
Get a county application for 3rd party engineers. In Georgia we must also pass the Residential Building Examiner test and take a Soil Erosion course. The county will refer jobs where they want an engineer's opinion. And I would refrain from doing home inspection type work and stick to projects that require engineering input.
Phase I's can be very good for bringing in business, as banks usually have them done before a property is purchased and developed. Phase I's are eyes-and-ears only, and can be done by any competent, moral individual. It's just a lot of footwork, but it'll get you in the field. Lord forgive my use of apostrophes. It just looked better.
Use your talents and expertise in the mining field and apply it to get a foot in the door. Manay large companies that deal in Environmental remediation have many departments with different kinds of engineers. At my company, we have Civil, Environmental, Geotechnical, and Structural. The fundamentals of remediation design can be learned in a class or 2. Your experience in the engineering field and project management sense should be more important than knowledge of the subject.
In the western U.S., remediation of abandoned mines is becoming an ever-expanding field. Consider applying at a large consulting firm that deals with abandoned mines or has large state or federal mine remediation contracts, such as Tetra Tech or Golder Associates. They might be happy to have someone with your background, even with relatively little remediation experience.
From there you would have opportunities to expand in other fields or areas, but it is a way to get your foot in the door.
