Bold & Gold

What is it?

Bold & Gold is a biosorption activated media (BAM) for pollution control developed by the Stormwater Management Academy at the University of Central Florida. It can be used to achieve nitrogen and phosphorus reduction in stormwater, wastewater and agricultural applications such as retention basins, swales and rain gardens, urban gardens and tree wells, pervious pavement, green roofs, filter strips and more. Bold & Gold is composed of a patented blend of mineral materials, sand, and clay.

How is it being used?

No projects that used Bold & Gold were found in Ontario. However, it has been used for projects such as a commercial green roof in Florida, an upflow filter chamber following a detention pond and a subsurface upflow wetland filter for nutrient removal. Filtration Media Specifications and Typical Cross Sections are provided on the Bold & Gold website.

Benefits

The results of a study by Hood, Chopra, and Wanielista provided promising results for the use of Bold & Gold for phosphorus removal. In field scale testing, Bold & Gold had a 71% removal efficiency of total phosphorus. This was compared to sandy soil which had many negative values, indicating significant leaching of total phosphorus from the sod. The average Soluble Reactive Phosphorus (phosphorus that is readily available to plants and algae) removal efficiency was 95%. Overall, the Bold & Gold system performed much better when compared to a sandy soil bio-filtration system.

Surface runoff from at-grade surfaces, resulting from rain or snowmelt events.

Ground depression acting as a flow control and water treatment structure, that is normally dry.

A shallow constructed channel, often grass-lined, which is used as an alternative to curb and channel, or as a pretreatment to other measures. Swales are generally characterized by a broad top width to depth ratio and gentle grades.

Mineral particles which are smaller than 2 mm, and which are free of appreciable quantities of clay and silt. Coarse sand usually designates sand grains with particle size between 0.2 and 0.02 mm.

1. A mineral soil separate consisting of particles less than 0.002 millimeter in equivalent diameter. 2. A soil texture class. 3. (Engineering) A fine-grained soil (more than 50 percent passing the No. 200 Sieve) that has a high plasticity index in relation to the liquid limit. (Unified Soil Classification System).

A thin layer of vegetation and growing medium installed on top of a conventional flat or sloped roof, also referred to as living roofs or rooftop gardens.

The temporary storage of stormwater to control discharge rates, and allow for sedimentation.

A body of water smaller than a lake, often artificially formed.

A vegetated area such as a bog, fen, marsh, or swamp, where the soil or root zone is saturated for part of the year.

The technique of removing pollutants from runoff as it infiltrates through the soil.

The technique of removing pollutants from runoff as it infiltrates through the soil.

A shallow constructed channel, often grass-lined, which is used as an alternative to curb and channel, or as a pretreatment to other measures. Swales are generally characterized by a broad top width to depth ratio and gentle grades.

Surface runoff from at-grade surfaces, resulting from rain or snowmelt events.