Treatment of stormwater at industrial sites can often be challenging due to the high concentrations of contaminants generated by onsite activities.

Due to the close proximity to sensitive urban Christchurch waterways, Christchurch City Council deemed first flush treatment of the hardstand areas mandatory.

AW Fraser is a manufacturing facility comprising of a copper alloy foundry, brass extrusion mill and CNC machine shop. Due to the close proximity to sensitive urban Christchurch waterways, Christchurch City Council deemed first flush treatment of the hardstand areas mandatory.

Challenges included existing pipework making for a retrofit installation of a device difficult; shallow pipe grades meaning minimal driving head to ‘push’ the stormwater through the device, proximity of device location to adjacent buildings & lastly size of catchment (4ha) meaning flow rates would be high (25.8L/s).

A small footprint, high performing filter was the solution, the Up-Flo filter comprising of 17 filter modules.

Upon rainfall commencing, the first flush (up to 25.8L/s) is directed to the Up-Flo until the water quality flow rate is achieved. At this point, stormwater is bypassed via the upstream weir diversion manhole.

Overall the installation took 2 weeks from the Contractor’s initial arrival to departure. Once the excavation was complete the Up-Flo was installed and commissioned within days.

An highly efficient and low-interfering device designed to remove 90% TSS and some heavy metals. Subsequent testing from several rain events has revealed the Up-Flo is performing as designed by removing a significant proportion for heavy metals, hydrocarbons and sediment otherwise destined for the receiving waterways.

Efficient manufacturing and economies of scale meant shorter lead times and market accepted prices. The Up-Flo filter is also a proven high quality treatment device. With a dedicated design team offering reliable and timely technical support. Onsite Engineers and Account Managers to oversee installation and assist with problem solving

Project

AW Fraser

Client

E2Environmental

Location

Christchurch

Product