Why the logo?  

Hopf Environmental's logo is simple.  Each letter of the owner's last name is represented by an element in the periodic table.  H for hydrogen, O for oxygen, P for phosphorus, and F for fluorine.  

The number above each letter is the atomic number = the number of protons of the element.

The number below each letter is the atomic weight.  

For example, the atomic number of hydrogen is 1 (1 proton) and the atomic weight is 1.01.  The atomic number of oxygen is 8 (8 protons) and the atomic weight is 16.00, and so on.