Challenge

Eastern High School, a new centre for secondary and further education in Cardiff, opened in 2018. It can accommodate 1200 school pupils and a further 320 college students.

SDS was required to effect the fast and efficient removal of surface water from the site and to ensure its safe dispersal to natural water receptors.

As works were being carried out in an environmentally sensitive location measures had to be taken to protect the existing development from pollution and damage during both demolition and construction.

Consultation with Natural Resources Wales established that there should be no water pollution into the Severn Estuary and that the scheme should include provision for regular monitoring of water quality, including visual checks.

Solution

SDS worked in close collaboration with Cambria Consulting, the appointed civil and structural engineers for the design and specification of the sub- and super-structure of the new school.

This scheme was required to treat and remove suspended solids from surface water run-off during both the demolition and construction works.

SDS Aqua-Filter™ has been installed as part of a complete water management programme, connected upstream to an Aqua-Swirl™ separator and downstream to a GEOlight® stormwater attenuation system. It provides a high level of water quality treatment through the use of an Aqua-Swirl™ chamber for pre-treatment, followed by a filtration chamber for secondary treatment.

The treatment flow rate of the Aqua-Filter™ system has been engineered to meet or exceed the local water quality treatment criteria and form an intrinsic part of the SuDS solution train. The three SDS GEOlight® geo-cellular attenuation tanks have the combined capacity to store up to 1,950m3 of treated water.

Outcome

SDS Aqua-Filter™, along with SDS Aqua-Swirl™, has the capacity to limit the amount of silts and attached pollutants from building up in the upper layers of the wider SuDS system and to mitigate against the ability of pollutant bioaccumulations to remobilise in the event of a surge of water, such as after a torrential downpour. In line with the European Water Framework Directive (WFD2015), water polished by Aqua-Filter™ can be discharged into the most sensitive of water courses.

Testimonial

“This project required stringent control of surface water quality given the sensitive nature of the receiving watercourse in a SSSI. This level of water quality treatment could not be achieved by standard proprietary installations. Following extensive investigation, we identified a solution that we were previously unaware of. Having found the answer we were looking for in SDS’s new hydrodynamic vortex separation and filtration system we are proud to have installed the UK’s very first Aqua-Filter™. Following successful pre-installation testing we are eagerly anticipating the first set of results of the system in situ.”
- Ed Hoskins, Senior Associate, Cambria Consulting Ltd.