In today’s increasingly stringent Water Sensitive Urban Design (WSUD) we often become lost in the maze of high technology stormwater treatment solutions when often a simple cost efficient effective solution may provide the best long-term outcome.
Ecosol was approached by AECOM the principal consulting engineers for the innovative, eco-friendly St Clair development a joint venture between AVJennings and Urban Pacific to propose a cost-efficient, easy to maintain and effective stormwater treatment solution to protect the inlet ponds and wetlands at St Clair.
The St Clair precinct is designed to be an innovative ecoefficient, water-wise development with aquifers creating an evergreen landscape and waterways fed by the Torrens River including lagoons and wetlands, allowing rainwater catchment, treatment and re-use within parklands and street gardens. Located 8km west of the Adelaide CBD and 5km from the beach the 64 hectare development will consist of approximately 22 hectares of green, open space, parklands and lagoons and will ultimately become home to some 3000 residents.
In consultation with AECOM, the City of Charles Sturt and the principal civil contractor Bardavcol it was determined that the Ecosol Net Guard provided the most appropriate solution. The product was selected predominately for its primary treatment efficiency and practical ease of installation and more importantly easy, safe and cost-efficient maintenance. It was determined that the simplicity of the system would ensure regular cleaning would be undertaken at minimal cost. Often stormwater treatment systems are installed based purely on their performance specifications with little consideration to ongoing cleaning requirements or costs. In this instance, maintenance played a major part in the final product selection.
In February 2013 Ecosol was engaged to supply 14 complete Ecosol Net Guard systems to be installed on all stormwater inlets feeding the central inlet ponds and wetland.
Whilst the Ecosol Net Guard is predominately designed as primary treatment system targeting gross pollutants conveyed in urban stormwater flows it was also recognised that the removal of finer constituents occurs as these particles attach to the surface of the larger particles and additionally the body of pollutant retained within the system forms a media also further contributing to the retention of smaller particles typically conveyed in stormwater. Additionally, the system needed to be able to operate in a partially submerged (inundated) environment and also be able to be easily cleaned in such an environment without using costly specialised cleaning equipment.
Each system was custom designed and built to the individual drainage lines on which it was to be installed, providing essential pre-screening of all stormwater flows entering the inlet ponds and wetlands within St Clair.
The design was required to have minimal surface footprint thereby not impacting on the aesthetics of the streetscape but must also have adequate access for easy on-site monitoring and maintenance.
The installed Ecosol Net Guards consisted of a pre-cast concrete pit that houses a strong stainless steel frame and removable heavy-duty UV stabilised polyethylene filtration net (either 50mm or 115mm apertures) that can be easily lifted out using a small crane truck.
The unit was designed to continue capturing gross pollutants until the net reaches its designed holding capacity, or in the event of a major rain event, when excess flows are designed to simply overtop the system. This facility helps eliminate any adverse hydraulic impact or potential for flooding during peak flow storm events. Ecosol was extremely proud to be the preferred solution provider of its stormwater treatment products for such an innovative green development. Further Ecosol has agreed with its client to provide training on the management, monitoring and cleaning of its systems to ensure they continue to perform to their designed specification.