This caches's theme will point to the various mining materials and the railways used to carry them.

You can do the complete hunt by bike (expect some steep gradients in this area) or foot for approximately 11 kilometers.
You may use your car from task 2 to task 3.

So, park your car near the start coordinates and find an information board.

Task 1:
Note the values in metric(!) tons for CO2 as ABCDE, tons for SO as FG, tons for NO as HI, tons for CO as J and the nuclear garbage in kilogrammes as KL. 
and walk to the next location near N 50° 3J.HEF' E 7° 58.(K+A+B)(C+D)(E+G)

Translation hints: carbon=Kohle, sulphur=Schwefel, nitrogene=Stick..., nuclear garbage=Atommüll
It's your decision to walk or use your car now. Each way has it's own difficulties.

Task 2:
You'll find a broken bridge nearby and some rails buried in the ground and crossing the way.
Count the iron rails (beware of the difference between tracks and rails) and associate them with M.
Then approach to task 3 at N 50° 3F.(J-M+E)(E)(I)  E 7° 58.(H)(K)(M+H)

Task 3:
This is the prettiest location for those, who like it. Look around, take some photos and enjoy it.
Sorry, it's a private property, so you cannot take a closer look.

Look for a sign as shown in picture 1. 
Note the phone number (without the dial prefix) as NPQR.
Look for a clock hanging there and note the hours the hour hand points to as RN

Task 4:
Now you can find the cache near the final coordinates N 50° 3(M+E).(N-P)(F+R)(M+L)  E 7° 58.(F+Q)(E)(F)