Method for reducing a release of environmental contaminants through a thief hatch

Abstract

A method for reducing a release of environmental contaminants through a thief hatch is described. The method involves a step of securing a drainage conduit to a storage tank to divert environmental contaminants from a top of a storage tank to a contaminant capture area below. A further step involves positioning a riser on the drainage conduit toward the top of the storage tank. A final step involves mounting a thief hatch at a remote end of the riser.

What is claimed is: 
     
         1 . A method for reducing a release of environmental contaminants through a thief hatch, comprising,
 securing a drainage conduit to a storage tank to divert environmental contaminants from a top of a storage tank to a contaminant capture area below;   positioning a riser on the drainage conduit toward the top of the storage tank; and   mounting a thief hatch at a remote end of the riser.   
     
     
         2 . The method of  claim 1 , wherein the height of the riser is selected to reduce the likelihood that liquids flowing along the drainage conduit will reach the remote end of the rise where the thief hatch is positioned. 
     
     
         3 . The method of  claim 1 , wherein a deflector is positioned to deflect liquids flowing along the drainage conduit away from an inlet end of the riser, thereby reducing the likelihood that liquids flowing along the drainage conduit will reach the remote end of the riser where the thief hatch is positioned. 
     
     
         4 . A thief hatch assembly, comprising:
 a drainage conduit having a first end and a second end;   a coupling at the first end for connecting the drainage conduit;   a riser on the drainage conduit toward the first end; and   a thief hatch at a remote end of the riser.   
     
     
         5 . The thief hatch of  claim 1 , wherein the height of the riser is over 6 inches to reduce the likelihood that liquids flowing along the drainage conduit will reach the remote end of the rise where the thief hatch is positioned. 
     
     
         6 . The thief hatch of  claim 1 , wherein a deflector is positioned to deflect liquids flowing along the drainage conduit away from the inlet end of the riser, thereby reducing the likelihood that liquids flowing along the drainage conduit will reach the remote end of the rise where the thief hatch is positioned. 
     
     
         7 . A storage tank and thief hatch combination comprising:
 a liquid retaining storage tank having a base, a top and a peripheral sidewall;   a drainage conduit secured to the storage tank to divert environmental contaminants from a top of a storage tank down the sidewall by gravity drainage to a contaminant capture area below, the drainage conduit having a first or inlet end and a second or outlet end;   a riser positioned on the drainage conduit toward the inlet end at the top of the storage tank, the riser having a conduit communication end and a remote end; and   a thief hatch positioned at the remote end of the riser.   
     
     
         8 . The combination of  claim 1 , wherein the height of the riser is selected to reduce the likelihood that liquids flowing along the drainage conduit will reach the remote end of the rise where the thief hatch is positioned. 
     
     
         9 . The method of  claim 1 , wherein a deflector is positioned to deflect liquids flowing along the drainage conduit away from the inlet end of the riser, thereby reducing the likelihood that liquids flowing along the drainage conduit will reach the remote end of the rise where the thief hatch is positioned.