Accessing Data

The State DOT Portal includes two tools for accessing BMP performance data: Retrieve BMP via map and Transportation BMP Summary analysis.

To access data using the map interface,

  1. Apply data filters as needed and then zoom to a BMP study icon of interest.
  2. Click on the icon to activate a summary pop-up box that identifies the BMP site name, location, category, and provides links to PDF reports and data as follows:
    1. Summary report: contains BMP study watershed and design information.
    2. Flow & precip. summary: contains hydrologic statistics such as the regional climate information, monitored storm events, and measured discharge volumes.
    3. Photos: site photos, schematics, or other drawings provided by the data supplier.
    4. Stats Analysis: select parameter from the drop-down menu to access the water quality performance monitoring data and generate summary statistics for the study.

To access using the summary analysis tool,

  1. Select a parameter group and an individual parameter (required; see Terms and Definitions below).
  2. Select one or more BMP categories (optional; see Terms and Definitions below).
  3. Select a Site Type (optional; see Terms and Definitions below).
  4. Select an EPA Rain Zone (optional; see Terms and Definitions below).
  5. Change the Average Annual Daily Traffic (AADT) range selector (optional; currently disabled due to limited AADT data).
  6. Click Submit.

After clicking submit, summary statistics and graphs of the queried data are produced. The queried data may also be downloaded for independent analyses.

NOTE: The summary analysis tool will only produce summary statistics if there is adequate data for analysis. A less restrictive query may be required to generate statistics.

For additional information on the underlying data contained in the BMPDB, refer to the User’s Guide for BMP Data Entry Spreadsheets.

Terms and Definitions

Parameter Groups

Biological – fecal indicator bacteria and pathogens.

General – common water quality, geochemical, and oxygen demanding parameters.

Metals – total and dissolved metals parameters.

Nutrients – nitrogen and phosphorus parameters.

Organics – pesticides and other organic chemicals.

Other – unique analyses not included in other categories.

PCBs – polychlorinated biphenyls.

Radionuclides – radioactive elements.

Solids – settleable, suspended, dissolved, and volatile solids.

Toxicity – parameters used in toxicity tests.

Note:  additional data related to particle size distribution can be obtained in the downloadable Access database but is not retrievable through the summary statistics tool.

BMP Categories

Grass Strip – also called buffer strips, are vegetated areas designed to accept sheet flow or conveyed via flow spreaders.

Bioretention – also called rain gardens, are shallow, landscaped areas with engineered soils, with or without underdrain systems.

Grass Swale – also called bioswales, are shallow grass-lined channel with zero, or little, bottom width designed for shallow flow.

Composite – provided to enable users to enter data for other BMP types not included in the BMP Database.

Detention Basin – also called extended detention basins or ponds, are designed to completely empty at some time after stormwater runoff ends.

Green Roof – also known as vegetated roofs or eco-roofs are constructed of a lightweight soil media, underlain by a drainage layer, and an impermeable membrane that protects the building structure.

Infiltration Basin – a basin that can capture a given stormwater runoff volume and infiltrate it into the ground.

LID – Low Impact Development (LID) is an overall site design approach that is intended to mimic pre-development hydrology using dispersed on-site controls such as swales and bioretention.

Media Filter – a facility that uses some form of a granular media, most commonly sand, to filter pollutants from stormwater.

Other – provided to enable users to enter data for other BMP types not included in the BMP Database.

Permeable Friction Course – an open-graded bituminous mixture placed over an impervious base.

Percolation Trench/Well – also known as infiltration trenches, can be generally described as a ditch filled with porous media designed to encourage rapid percolation of runoff.

Retention Pond – commonly known as “wet ponds” because they have a permanent pool of water and may or may not include an extended live storage component.

Rainwater Harvesting – from simple residential cisterns (rain barrels) that collect runoff from a single residential rooftop to advanced rainwater harvesting systems that can be supplemented with potable water and used for toilet flushing, irrigation systems, car washing and other non-potable use.

Wetland Basin – similar to a retention pond (with a permanent pool of water) with more than 50 percent of its surface covered by emergent wetland vegetation.

Wetland Channel – a channel or swale that stays permanent wet and supports dense wetland vegetation.

Note:  many types of manufactured treatment devices are also contained in the downloadable Access Database but are not currently accessible in the Summary Statistics tool due to on-going work related to subcategorization of manufactured treatment devices.

DOT Site Types

Borrow Pit – a location where natural deposits, such as fill dirt, sand, gravel, or rock is excavated for use in roadway construction or maintenance.

Highway – a publicly-accessible major road, thoroughfare, or freeway designed to efficiently route vehicles through and between cities.

Maintenance Station – a facility or yard owned by a DOT for storing and maintaining materials and equipment.

Not Applicable – this selection is used when a DOT site type does not apply to the BMP study.

Parking Facility – lots and structures where vehicles park.

Rest Stop – dedicated areas next to highways for travelers and truck drivers to take a break from driving.

Service Plaza – similar to a rest stop, but may include fueling stations, convenience stores, and restaurants.

Stockpile – an area used solely for the storage of materials used for roadway construction and maintenance.

Unspecified – the BMP study has inadequate metadata to classify the site type.

Urban Roadway – roads within urban areas not classified as highway and may include low traffic roads and arterial streets. Rural Roadway – roads located in areas with limited development and storm sewer infrastructure.

EPA Rain Zone Map

EPA Rain Zone Map
EPA Rain Zone Map (source: R. Pitt et al 2004. The National Stormwater Quality Database)