If information on the building is not readily available, check with code officials, permitting agencies, and your building’s engineer about the building’s stormwater treatment system and how well it performs. 

In order to comply with this path, your building must implement specific best management practices (BMPs). These are found in Chapter 4, Part 2, Urban Runoff, of the EPA Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters, January 1993 (EPA 840B92002). Alternatively, your building should follow the BMPs outlined by your local government if they represent the more stringent option.  

Try to locate the project in a building that has a stormwater management system meeting LEED requirements. Constructed wetlands, filtering systems, bioswales, retention basins, or other systems that remove suspended solids from stormwater, will contribute to meeting credit requirements. If your project is in an urban environment, the building can install a detention tank that collects rainwater for reuse. Systems must remove at least 80% of the site’s average annual total suspended solids (TSS) and 40% of the site’s total phosphorus (TP).

Refer to LEED-NC SSc6.2 for detailed requirements and documentation.

Option 2, Path 3: Stormwater Design—Quality Control

If the plan does not meet the requirements, consider working with building management and the civil engineer to revise the plan and add features or performing work to improve infiltration, or install onsite storage and reuse mechanisms. These can be expensive to retroactively install, however.

If there is no formal stormwater management plan, work with a civil engineer to identify stormwater management features and confirm the pre- and post-development discharge rates.

Refer to the stormwater management plan or consult with your building’s civil engineer to learn the site’s imperviousness. If it is less than 50% impervious, the stormwater management plan must equalize the pre- and post-development peak discharge rates and quantities from the one-year, 24-hour, design storm. If your site has more than 50% impervious cover, the plan must reduce the volume of stormwater runoff by 25% from the 1½-year, 24-hour, design storm. 

Request a copy of the stormwater management plan, if there is one, listing the best management practices implemented for onsite treatment or onsite storage of stormwater. 

Select a building that has implemented stormwater collection and reuse, infiltration, or other quantity-control measures, with rates that meet the LEED requirements.