Seasonal hydrological and water quality performance of individual and in-series stormwater infrastructures as treatment trains in cold climate

Abstract

The performance of stormwater treatment trains and of their individual green infrastructures was evaluated near Montreal, Canada. Three treatment trains were studied: Train 1 – five bioretention cells in series with a wet retention pond; Train 2 – an infiltration trench in series with a dry detention pond; and Train 3 – Train 2 in series with a wet retention pond. A total of 47 rain events were monitored to quantity the hydrological performance, while water quality samples were taken during 24 rainfall events. During the summer, the bioretention cells led to a reduction in runoff volumes varying from 8 to 100%. Overall, the three studied treatment trains and all of the individual infrastructures, except for the dry pond, provided reductions in the mean concentrations of total suspended solids, chemical oxygen demand, total nitrogen and total phosphorous. Results also showed that the use of a train of stormwater infrastructures can be more effective to reach Quebec's legislated targets than single infrastructures, but only if the infrastructures are sequenced properly. Indeed, the addition of a dry basin at the end of Train 2 affected negatively the removal efficiency of the four studied contaminants.

Scientific Evidence behind the Ecosystem Services Provided by Sustainable Urban Drainage Systems

“…Dfb. This facilitation provided diminutions in the concentration of total suspended solids, COD, total nitrogen, and total phosphorous [46].…”

“…Dfb. Bioretention cells are able to retain suspended solid, COD, total nitrogen, and total phosphorous [46] (in some cases a special treatment is necessary [103]), naphthalene [104], microplastics [105], benzotriazole (depending on temperature, and salinity can be desorbed) [106], and metals [91].…”

“…Underground stormwater detention chambers provide similar levels of stormwater treatment as wet detention ponds and avoid thermal contamination of aquatic habitats [192]. The use of a train of stormwater infrastructure (including detention ponds) can be more effective in removing total suspended solids, COD, total nitrogen, and total phosphorous, but only if the infrastructure is sequenced properly [46]. The concentration of suspended solids and total nitrogen also decrease in these ponds because of their sedimentation [176].…”

“…There are variations between summer and winter in the settlement of some salt components [243]. Retention ponds are effective in reducing the mean concentrations of total suspended solids, COD, total nitrogen, and total phosphorous [46], but removal of vegetation in stormwater retention ponds degrades water quality [211].…”

“…Climate Change and thermal control: Large surface water storage SUDS have a warming effect [158,255] on their immediate surroundings and can sometimes emit greenhouse gases [211] Regulation Services. Water Quality: Pervious pavement [38,39], infiltration trenches [23], bioretention systems [46,75,91,99,100,[104][105][106][107][108], green swale [102], infiltration pond [38,150], detention pond [102,155,158,187,[189][190][191][192] (although their efficiency of nitrate removal in detention deposits varies seasonally [188]), retention pond [46,205], and artificial wetland [266] have demonstrated good efficacy at removing pollutants. However, the absence of vegetation in some techniques can degrade water quality [211].…”