TMDL/NPDES GEODATABASE
HOWARD COUNTY, MD
McCormick Taylor worked with Howard County to develop a centralized geodatabase to better organize, store, and report the data required by MDE in accordance with Howard County’s NPDES MS4.
THE CHALLENGE
Howard County had an existing BMP database of nearly 5,000 records stored in a non-spatial SQL database used by their inspectors. Based on MDE’s latest guidance at the time, required attribute fields (e.g., BMP type, as-built date, watershed, impervious acres treated), each BMP was filled in by reviewing available as-built plans, or through calculations using desktop GIS tools. Additionally, while reviewing the as-built plans, over 1,000 BMPs were identified on plans that were not currently in the county’s database of BMPs.
Development of this geodatabase included a massive cleanup of existing data, migration of data from disparate data sources into a single geodatabase, and the development of a web-based front end to access the database.
HOW WE HELPED
McCormick Taylor developed a centralized geodatabase to store county NPDES permit related information, including BMP facilities and their drainage areas, outfalls, and monitoring (physical, biological, and chemical) sites, etc.
We reviewed as-built plans to make updates to approximately 6,000 BMP facility data records and added approximately 1,000 records that were not currently in the database. McCormick Taylor also outlined drainage areas for approximately 2,000 of those BMPs, and is developing a web application. This will make it easier for the county to digest the database.
RESULTS
The county’s NPDES geodatabase is now flexible enough to store all data in one central location. This new geodatabase provides data to MDE in any format required, including Attachment A format for the annual report submittal; Historical BMP cleanup format as requested for input into the Chesapeake Bay Model; or to future proof the database as new guidance documents continue to be released.