|
SuDS treatment train
Good SuDS design is based on a treatment train that addresses the primary requirements of both water quantity and quality. There is a range of both natural and engineered alternatives, with the optimum solution balancing issues like cost and available space with flow rates and the level of pollutant loading.
There are typically four types of pollutant found in stormwater run-off: sediments, metals, hydrocarbons and nutrients. Sediments, also known as Total Suspended Solids (TSS), include particulate matter which are typically the focus of water treatment strategies as this removes both the particles and the attached pollutants. Removal of TSS is also important from a water quantity perspective, as build-ups reduce the capacity for water storage and flow.
TSS Removal
Natural features such as ponds, swales and filter strips can be considered as solutions for sediment removal, alongside manufactured components such as silt traps and vortex separators. However, these must be installed upstream of a below-ground attenuation device and can be expensive, both in terms of capital outlay and maintenance.
Isolator Row
ADS StormTech is an underground SuDS attenuation system with built-in water quality management. Isolator Row has 2 treatment stages: gravity separation of silt and particulates and filtration through a woven geotextile fabric. Two further treatment stages can take place downstream of Isolator Row within the stone embedment surrounding the connected StormTech chambers. As flow passes through the system, pollutants can adsorb onto the stone, preventing them passing through. This material can be broken down over time by bacteria into harmless, non-polluting material.
|
|
Isolator Row has been independently tested by universities and respected industry bodies (including NJCAT) and validated to remove over 80% of TSS plus metals, hydrocarbons, phosphorus, nitrogen, and other surface water pollutants. It is easy to maintain with standard sewer cleaning equipment.
|
