StormTech, the stormwater management system from Advanced Drainage Systems (ADS), is the first combined SuDS attenuation and water quality management system to obtain third party verification of mitigation indices (MIs) for treatment of stormwater runoff.
This means StormTech can satisfy the water quality requirements on appropriate projects without the need for additional treatment equipment – something virtually all other below ground SuDS attenuation systems require – resulting in significant savings on capital and operational costs.
The use of mitigation indices for stormwater treatment are detailed in The SuDS Manual from the Construction Industry Research and Information Association (CIRIA) and calculated in accordance with the British Water ‘how to’ guide, using The SuDS Manual’s Simple Index Approach and applying this to proprietary/ manufactured stormwater treatment devices.
StormTech’s independently verified results are now listed on the British Water web site and a new Mitigation Index Data Sheet is available on ADS’s UK web site.
Pollution hazards for various land uses are categorized in The SuDS Manual as very low, low, medium, or high, and come in the form of Total Suspended Solids (TSS), metals or hydrocarbons. The MIs for ADS StormTech’s Isolator Row – the inbuilt water quality treatment device – are TSS = 0.8, metals = 0.6 and hydrocarbons = 0.7, meeting the requirements for medium pollution hazard applications, such as car parks, commercial yards, delivery areas and minor roads; and the TSS requirements of high pollution hazard applications, without the need for additional treatment devices.
StormTech is a versatile and effective alternative to crates, combining arch-shaped chambers with an innovative, integrated water quality treatment system. This, the Isolator Row, provides ‘first flush’ cleansing and treatment of storm water run-off. Featuring a range of chamber sizes, StormTech has been used successfully in over 50,000 projects worldwide employing in excess of 3m units.
In addition to integral water quality management, StormTech is especially suited to applications requiring minimum cover under trafficked areas and fast construction. As units are stackable, minimal space is required for storage and transport.
StormTech fully complies with the requirements recently updated in the Design and Construction Guidance for foul and surface water sewers, meaning that water companies in England can accept StormTech when offered for adoption by developers under Section 104 Agreements in accordance with the Water Industry Act 1991, subject to any additional requirements imposed by the water company.
Additionally, structural modelling to Eurocodes has demonstrated that StormTech SuDS attenuation chambers can be installed to the minimum and maximum cover depths detailed within the standard ADS installation guidelines, originally based on US standards.
The independent verification of StormTech MIs demonstrate it meets requirements for medium pollution hazard applications and the TSS requirements of high pollution hazard applications; and can be used as a combined SuDS attenuation and water quality treatment system without the need for additional components within the treatment train.