Structural basin

Geomorphology

Detention basin

Machine learning

Drainage basin

Geology

Watershed

Stormwater

Organic chemistry

Chemistry

Geotechnical engineering

Ecology

Denitrifying bacteria

Geography

Environmental science

Computer science

Nitrogen cycle

Surface runoff

Nitrogen

Cartography

Denitrification

Hydrology (agriculture)

Biology

Environmental Science & Technology

The nitrogen (N) cycling dynamics of four stormwater basins, two often saturated sites ("Wet Basins") and two quick draining sites ("Dry Basins"), were monitored over a ∼ 1-year period. This study paired stormwater and greenhouse gas monitoring with microbial analyses to elucidate the mechanisms controlling N treatment. Annual dissolved inorganic N (DIN) mass reductions (inflow minus outflow) were greater in the Dry Basin than in the Wet Basin, 2.16 vs 0.75 g N m-2 yr-1, respectively. The Dry Basin infiltrated a much larger volume of water and thus had greater DIN mass reductions, even though incoming and outgoing DIN concentrations were statistically the same for both sites. Wet Basins had higher proportions of denitrification genes and potential denitrification rates. The Wet Basin was capable of denitrifying 58% of incoming DIN, whereas the Dry Basin only denitrified 1%. These results emphasize the need for more mechanistic attention to basin design because the reductions calculated by comparing inflow and outflow loads may not be relevant at watershed scales. Denitrification is the only way to fully remove DIN from the terrestrial environment and receiving waterbodies. Consequently, at the watershed scale the Wet Basin may have better overall DIN treatment.

The Role of Denitrification in Stormwater Detention Basin Treatment of Nitrogen