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Chapter 5
Source Control BMPs
2.0 Structural Source
Controls
Site operations and potential pollution source
control needs should be considered early in the
planning and design process. This will reduce
the load of pollutants into stormwater and may
also facilitate site operations and reduce
maintenance requirements for on-site
treatment BMPs. Representative questions
that should be considered prior to finalizing
the site layout include:
1. What materials are stored on-site?
2. How are these materials handled and
moved through the site?
3. What on-site operations take place that
could potentially cause materials to enter the storm sewer system?
4. Where and how might these materials enter the storm sewer?
Photograph 5-1. This commercial materials storage area drains directly
to a storm drain. Effective site design would have located this storage
area away from a storm drain and directed runoff to a landscape bed or
provided additional covering and containment that would both protect the
material and reduce pollutant loading to the storm sewer.
5. How can storage and handling areas and drainage facilities be designed to reduce pollutant loading?
Is it feasible to cover these areas?
6. When a spill occurs, how and where will it be controlled and contained? Are structural spill
containment measures needed? What is the relationship between these areas and planned treatment
BMPs (Chapter 2) for the site?
Use good judgment when planning your site and consider BMP Fact Sheets S-1 Covering of Storage and
Handling Areas and S-2 Spill Prevention, Containment and Control early in the planning and design
process. Structural source control measures must also be combined with appropriate employee training.
For example, if a covered structure and spill containment area are constructed at an industrial site, but
employees conduct operations subject to spills (e.g., drum storage) in other portions of the site, the
structural BMP will not be effective.
3.0 Procedural Source Control BMPs
Procedural BMPs are actions or procedures that can be implemented to reduce pollutant loading. These
practices are critical at stormwater "hotspots," but can also be effective when behavior change in
residential areas occurs over entire watersheds. Examples of stormwater hotspots and the operations that
cause pollution at hotspots are provided in the inset on the following page and in Table 5-2.
3.1 Municipal Operations
Communities regulated under Phase 1 or Phase 2 of the NPDES program are required to develop a
program to:
November 2010 Urban Drainage and Flood Control District 5-3
Urban Storm Drainage Criteria Manual Volume 3