Research Idea Details

Research Idea Scope

I. Problem Statement:

There is increasing evidence that nutrients are major constituents in highway runoff. This varies with the area of ROW as well as the vegetation types and adjacent land use. However, many of the states with large agricultural economic bases are finding it increasingly difficult to deal with nutrients in their runoff. Current preference for managing nutrients is the development of wet ponds or artificial wetlands. These are both expensive to construct as well as maintain. This is particularly true in areas where the natural hydrology makes maintaining a permanent water pool difficult with out supplemental water.

Recent work in the area of bioretention seem to offer great promise for being able to remove nutrients from stormwater without maintaining a permanent water pool.

Most of the work that has been done however has been for relatively small drainage basins such as parking lots. This work needs to be extended to the larger scale of the highway environment to determine the practical limits of contributing drainage basins, the relative life of the bioretention vegetative system, the cost of construction and maintenance.

Given the apparent performance and the potential difference in cost of wet ponds in arid or semi-arid areas of the country this work can offer substantial savings in meeting stormwater management mandates.

II. Research Objective:

The following tasks need to be performed as part of the research:

1. A review and summary of literature on bioretention for stormwater treatment
2. An evaluation of optimum contributing drainage basin size for the use of bioretention structures.
3. An evaluation of effectiveness in regionally different climates.
4. A cost analysis for the design, installation, and maintenance of bioretention structures for stormwater treatment.
5. Guidelines for the design and use of bioretention structures for stormwater treatment.