Industrial Stormwater Permit Guide

Compliant Condition

Raw material stockpile - Properly Covered
This is an example of a stockpile of materials that has been securely covered to prevent stormwater from entering the environment either through natural pathways (i.e., absorption, flow to rivers and streams, etc.) or through engineered storm sewer systems.

Photo courtesy of Tetra Tech, Inc.

This is an example of a stockpile of materials that has been securely contained to prevent stormwater from entering the environment either through natural pathways (i.e., absorption, flow to rivers and streams, etc.) or through engineered storm sewer systems without being pre-treated.

This is an example of a structure that can be used to secure even very large stockpiles of materials from stormwater exposure.

Non-Compliant Condition

Pile of Metal Turnings - Not Covered, No Containment

Scrap metal stockpile - No cover
Stockpiles of materials should be securely covered and/or a containment system should be in place that prevents stormwater from entering the environment either through natural pathways (i.e., absorption, flow to rivers and streams, etc.) or through engineered storm sewer systems without being pre-treated.

Raw steel stored uncovered, without secondary containment. Adjacent to a water body.
The problem here is that it's right next to the stream without any BMP to buffer contaminants getting into the stream.

Stockpile With Poor Containment and No Cover
The problem here is that containment is inadequate for the pile and the stormwater flow path. The pile should either be covered or the containment system should be redesigned so that the material is not carried away by stormwater.

Aggregate Storage Piles - Not Covered, No Containment

Compost Stockpiles - Not Covered, No Containment

Photos courtesy of Tetra Tech, Inc.