Industrial stormwater requirements are contained in national pollutant discharge elimination system (NPDES) permits; the critical element in such permits is development and implementation of a stormwater pollution prevention plan (SWPPP). These compliance tips cover key points that are sometimes overlooked in company SWPPPs and related compliance activities.
Except in a relatively few cases where individual NPDES permits are either requested or required, SWPPPs are developed under provisions in stormwater general permits issued by either EPA (for Idaho, New Mexico, Massachusetts, New Hampshire, Indian Country, most territories, and some federal facilities) or the states, acting with federal authority. Facility owners/operators submit a notice of intent (NOI) to be covered by the general permit to their permitting agency.
Since general permits issued by U.S. EPA or the states may differ in details, no single compliance guide will cover all requirements. However, the great majority of provisions that have proven successful in controlling industrial stormwater pollution are common in all general permits. This commonality has allowed EPA to issue general directions for affected industry.
According to EPA, Developing Your Stormwater Pollution Prevention Plan: A Guide for Industrial Operators was written “generically to make it applicable to as many industrial permits as possible.”
Who Must Comply
The Clean Water Act (CWA) does not explain at length which industrial facilities are subject to NPDES permitting for stormwater. The Act simply states that permitting is required for “discharges associated with industrial activity.”
To clarify the situation, EPA issued a list of 11 categories of stormwater discharges associated with industrial activity that must be covered under a NPDES permit, unless excluded under the federal no-exposure provision at 40 CFR 122.26(g).
(Originally included in the category list, construction activity (Category x) was shifted to a separate regulatory program because of significant differences with activities conducted at industrial facilities; construction activities are also not entitled to the no-exposure provision available to other industrial categories.)
The categories are:
- Category i: facilities subject to federal stormwater effluent discharge standards at 40 CFR Parts 405-471
- Category ii: heavy manufacturing (e.g., paper mills, chemical plants, petroleum refineries, and steel mills and foundries)
- Category iii: coal and mineral mining and oil and gas exploration and processing
- Category iv: hazardous waste treatment, storage, or disposal facilities
- Category v: landfills, land application sites, and open dumps with industrial wastes
- Category vi: metal scrap yards, salvage yards, automobile junkyards, and battery reclaimers
- Category vii: steam electric power generating plants
- Category viii: transportation facilities that have vehicle maintenance, equipment cleaning, or airport deicing operations
- Category ix: treatment works treating domestic sewage with a design flow of 1 million gallons a day or more
- Category xi: light manufacturing (e.g., food processing, printing and publishing, electronic and other electrical equipment manufacturing, and public warehousing and storage)
These categories are further divided into sectors. EPA’s 2008 multi-sector general permit (MSGP) regulates dis¬charges from a subset of 29 different industrial sectors. Also, states typically issue general permits for one or related groups of sectors.