Retention ponds, also called holding ponds, are storm water basins that include a permanent pool for water quality treatment and additional capacity for temporary storage. Holding ponds typically trap course sediment and, while they do not achieve significant groundwater recharge or volume reduction, they can be effective for pollutant removal and peak rate mitigation.
Holding ponds improve runoff quality through settling, water reduction, chemical and biological decomposition, and absorption. They are relatively effective at reducing many common pollutants including total suspended solids, heavy metals, total phosphorus, total nitrogen, and pathogens. The pollutant removal effectiveness varies by season and may be affected by the age of the pond.
Our QISPs will perform a detailed site evaluation and accompanying action plan to determine whether and where your facility has the requisite space to implement a retention pond.