Stormwater four

Industrial stormwater

Stormwater carries pollutants to the storm drains, dry wells or directly into receiving waters. Industrial settings can be particularly vulnerable to unintended transport of hazardous pollutants into surface waters. As part of Phase I of the stormwater program, in addition to the requirement that large and medium MS4s must regulate industrial stormwater pollution within their jurisdiction, eleven industrial categories were required to obtain permits for their stormwater pollution.

While you may not consider your watershed to have “industrial” activities or pollutants, close review of the list of categories reveals several very common activities found in urban as well as suburban or rural settings including landfills, salvage lots and trucking facilities:

Industrial Stormwater Categories
Category One (i): Facilities with effluent limitations
Category Two (ii): Manufacturing
Category Three (iii): Mineral, Metal, Oil and Gas
Category Four (iv): Hazardous Waste, Treatment or Disposal Facilities
Category Five (v): Landfills
Category Six (vi): Recycling Facilities
Category Seven (vii): Steam Electric Plants
Category Eight (viii): Transportation Facilities
Category Nine (ix): Treatment Works
Category Ten (x): Construction Activity
Category Eleven (xi): Light Industrial Activity

(40CFR122.26(b)(14)(i)-(xi))

When possible, states prefer to include industrial stormwater requirements in existing NPDES wastewater permits. Requirements related to industrial stormwater management are often written into the narrative section of a wastewater permit following the effluent limits. In most cases, the stormwater-related section describes the stormwater management plan that must be developed. It might also describe some monitoring or reporting requirements. Industrial stormwater monitoring and reporting requirements are generally not as specific nor as frequent as the “Discharge Monitoring Reports” for wastewater NPDES permits described earlier in the chapter.

An industrial activity which doesn't already have an NPDES permit for wastewater discharge, such as an auto salvage lot, will need to seek an individual permit or apply to be covered under the state's industrial stormwater general permit. Both options will require a stormwater management plan, which may or may not have to be submitted to the state. It should require monitoring and reporting.