CASE STUDYWynn Vale Dam Stormwater Harvesting

Wynn Vale Dam Stormwater Harvesting Water source:

Stormwater Harvesting collect to a Dam | Water Use:

Aquifer Storage & Recovery (ASR) to use for Irrigation and

dual reticulation | Problem: Elevated level of Turbidity, TSS,

Organic & Micro-organism control | Flow: 2 MLD

Background:Picturesque Wynn Vale Dam in Adelaide is the site for the

City of Tea Tree Gully (CTTG) Council's innovative stormwater

harvesting and reuse initiative. This Waterproofing Northern

Adelaide (WNA) project is designed to treat 400 Mega

litres of stormwater that will be extracted from the dam

every winter to go into aquifer storage.During the warmer

months, the water will be recovered by extracting it from

the aquifer for irrigation and dual reticulation purposes.

Amiad Australia was involved in this project since 2007 and has trailed a tested a number of different technologies

(exclusive to Amiad Australia) to determine the best water treatment process. Amiad Australia was contracted to install

a stormwater treatment plant to increase the quality of the water collected in the dam to the requirements for Aquifer

Storage and Recovery (ASR) as outlined in the EPA license held by CTTG.

The Challenge:It was clear from the start that this project will present challenges to both the Council and Amiad Australia

to deliver a sustainable water reuse system in a reasonably built-up urban environment. The City of Tea Gully

requests a design, which is simple in concept, utilizing off-the-shelf components as much as possible and which

will be easy to operate service, maintain and repair. The design should be reliable with key modules and spares

being readily available for the life of the equipment.

Amiad Australia designed, manufactured, installed and commissioned a 2 MLD (25 l/s) containerised water

treatment plant to treat Dam water (i.e. Stormwater Harvesting) to meet the performance requirement of the

contract. The containerised system was manufactured and tested in Amiad Australia's Melbourne factory before

it was transported to Wynn Vale Dam. This engineered solution offered many features that Amiad Australia

perfected over 30 years in the water industry in Australia.

W A T E R S Y S T E M S

The Solution:Amiad designed, manufactured, constructed, delivered and commissioned a stormwater plant. The water treatment

process consist of coagulation, rapid mixing, slow mixing, retention tank & Progressing Cavity pump, primary media

filters to capture the bulk of the suspended particles, secondary media filters to further reduce the turbidity and UV

disinfection. The essential services such as compressed air, chemical storage, eyewash/safety shower and blower is

installed inside the modified containers. The Backwash Pump is utilized to backwash Media Filters & Air –Scouring for

effective backwash. The system has various online analytical instruments for continuous monitoring and is controlled

by a PLC with a touch screen interface (HMI) for the operator.

Parameter Raw Water (Max.) Target Result

Turbidity [NTU] 64 <5 3.7

TSS [ppm] 27 <10 2

pH 6.5-9 No Set 7.36

[Hu] Colour 600 No Set

TOC [ppm] 6 <15 <6

E. Coli [coliform/100ml] 180coliform/100ml

<0coliform/100ml (95th percentile)<5 coliform/100ml (Maximum)

<0coliform/100ml (95th percentile)<5 coliform/100ml (Maximum)

EC [uS/cm²] 367

Aluminium [ppm] 0.06

Redox potential [mV] 153

The Results:Wynn Vale Dam, like other stormwater harvesting sites, presented significant challenges that influenced the

design. The main challenge was to ensure compliance with the EPA license while maximising the harvesting

potential of the plant during the winter months when run-off is at its maximum and water quality at it worst.

Amiad has successfully proven that the treated stormwater complies with the quality performance requirements.

Recent results for this season harvesting (May-September, 2012) are for a 100 ML harvested water as provided by Gary Beveridge the Technical Officer Water Resources at City of Tea Tree Gully (Client): “We are governed by our EPA licence for discharge into our approved aquifer storage wells and thus all of the product water requirements were met. Water sampling is required for every 20ML of production with no corrective action required ie. all criteria in our licence was below limits”.