Low Impact Design (LID) Retrofit, Montgomery County, Maryland

In order to comply with EPA and Maryland Department of the Environment (MDE) Municipal Separate Storm Sewer System (MS4) Permits, Montgomery County has undertaken a LID retrofit program to treat stormwater runoff from roads and other impervious facilities owned and maintained by the County.

A|I|DATA’s first involvement was in 2011, teaming with an engineering firm tasked with designing one of the earliest pilot LID projects along Arcola Avenue. A|I|DATA first performed Quality Level B utility mapping for the design team so that proposed retrofits could be placed with minimal impacts to existing utilities. We then performed Quality Level A test holes to allow the designers to precisely understand the relationship between exiting utilities and the proposed retrofits. As a result, these pilot projects were constructed with minimal delay and impact to utilities and the community and were the first of their kind to be completed.

Because of the successes of these earliest pilot projects, the County has required SUE practices to be performed as an integral part of future LID design projects to meet the aggressive MS4 Permit schedule requirements. A|I|DATA continues to provide SUE support as a member of the design team.