Industrial Stormwater Best Management Practices
Stormwater is the water that originates from precipitation such as heavy rain or meltwater from hail or snow. Many industrial facilities introduce materials to stormwater through the outdoor storage, handling, and transfer of product materials, by-products, and waste products. These industrial products often contain pollutants such as metals, oil, and grease which negatively impact stormwater runoff. Additionally, industrial activities can cause erosion and sediment problems that also impact stormwater runoff.
Best Management Practices (BMPs) are pollution control measures designed to prevent or reduce the effects of pollutants in stormwater runoff from industrial stormwater discharges. Some BMPs are specific and well-defined, while others are general in nature. Facilities determine which BMPs to use based on permit requirements, the facility’s specific industrial materials, and the facility’s specific activities.
BMPs should be considered as a system or series of activities that may include non-structural and structural BMPs.
Non-structural BMPs are management techniques implemented through simple daily duties. The facility identifies and implements site-specific BMPs which have a direct impact on the day-to-day operations. Some of the more common non-structural BMPs include good housekeeping, eliminating and reducing exposure, management of salt and/or industrial storage piles, management of runoff including soil and erosion prevention, and dust control.
Structural BMP options vary depending on the pollutants each can treat, efficiency, maintenance issues and limitations of controls. Structural BMPs are more technical in nature and advanced technical expertise is required to make informed decisions about implementing structural stormwater BMPs. It
is suggested to consult with a licensed professional engineer early in the decision process. Common structural BMPs include sedimentation systems (e.g. retention ponds), infiltration systems (e.g. stormwater trenches), filtration systems (e.g. vegetative filters), and proprietary systems (e.g. vortex separators).
Federal regulations require stormwater discharges associated with specific categories of industrial activity to be covered under a National Pollutant Discharge Elimination System (NPDES) permit. EPA has developed a fact sheet for each of the 29 industrial sectors regulated by the NPDES permits. Each fact sheet describes the types of facilities included in the sector, typical pollutants associated with the sector, and types of stormwater control measures used to minimize the discharge of the pollutants. These BMP fact sheets are a great starting point for determining the various pollutants which cause stormwater pollution at a facility and provide BMPs that are applicable to a specific industrial facility operation.
Regular inspections of a facility’s BMPs are required by the NPDES permits. These inspections are integral in determining if structural and nonstructural BMPs are properly functioning, require maintenance, or need to be changed. Inspections also determine the accuracy of the facility’s written stormwater plan, as all observations and any changes made as a result of the inspections must be documented in the written plan.
For more information on BMPs for stormwater, check out EPA.gov or reach out to your Cornerstone Team directly.
