National Stormwater Quality Database

The National Stormwater Quality Database (NSQD) is an urban stormwater runoff characterization database developed under the direction of Dr. Robert Pitt, P.E., of the University of Alabama and the Center for Watershed Protection under support from the U.S. Environmental Protection Agency. Originally released in 2001, followed by several updates by Dr. Pitt and Dr. Alexander Maestre (also at University of Alabama), it has recently moved to a new long-term home as a companion project to the International Stormwater BMP Database. The NSQD is being maintained as a separate stand-alone database, serving as an important resource for municipal stormwater managers and researchers who are seeking urban runoff characterization data. It can be searched for water quality data based on land use, state, and EPA Rain Zone, along with several other criteria. The NSQD is available from this website, and a new web application has been developed to accommodate custom data extraction queries. In 2018, Dr. Pitt completed his most recent analysis of the NSQD, accessible here.
Download the NSQD
The NSQD Version 4.02 (last updated January 2015) can be downloaded in two formats containing the same information:
  1. NSQD Version 4.02 Excel Spreadsheet (original format)
  2. NSQD Version 4.02 Access Database (new format)
An Overview of Data Elements in the NSQD can be downloaded a href="/Docs/Data Elements Overview NSQD_v4.02_2015.pdf">here
Access the NSQD Data Extraction and Analysis Tool

The new NSQD Data Extraction and Analysis Tool can be accessed here.

The purpose of this tool is to enable users to conduct initial data exploration enabling quick assessment of the type of data available for more in-depth analysis. Users are encouraged to download the full database for purposes of formal data analysis so that metadata accompanying sample results is properly considered during analysis. Additional features may be added to the data extraction tool in the future.
NSQD History

In 2001, the University of Alabama and the Center for Watershed Protection were awarded a U.S. Environmental Protection Agency, Office of Water 104(b)3 grant to collect and evaluate stormwater data from a portion of the NPDES (National Pollutant Discharge Elimination System) MS4 (municipal separate storm sewer system) stormwater permit holders. In 2008, the NSQD was updated with additional data under continued 104(b)3 support from the EPA. These stormwater quality data and site descriptions were collected and reviewed to describe the characteristics of national stormwater quality, to provide guidance for future sampling needs, and to enhance local stormwater management activities in areas having limited data. The monitoring data collected over nearly a ten-year period from more than 200 municipalities throughout the country have a great potential in characterizing the quality of stormwater runoff and comparing it against historical benchmarks. This project is creating a national database of stormwater monitoring data collected as part of the existing stormwater permit program, providing a scientific analysis of the data, and providing recommendations for improving the quality and management value of future NPDES monitoring efforts. Version 4.02 contains data from more than 9,000 events from about 200 municipalities throughout the country, representing multiple land uses.

Additional background and previous NSQD papers and analyses can be accessed here.