Irrigation Scheme (NAIS)
Recycled water supplied by NWIC to our customers comes from
SA Water’s Northern Adelaide Irrigation Scheme.
The recycled water is treated at the NAIS Advanced Water Recycling Plant (AWRP) located at Bolivar, 17 km north of Adelaide. The plant has a capacity of approximately 17.5 ML/day (6 GL/year) with facility to upgrade to 12 GL/year. The recycled water has a target salinity of 1165 mg/L and is intended for crop irrigation with the highest level of treatment being suitable for commercial food crops consumed raw or unprocessed. The recycled water complies with the Australian Guidelines for Recycled Water and is approved by the South Australian Department for Health and Wellbeing.
The water is sourced from treated effluent downstream of the Bolivar secondary treatment clarifiers and is treated at the AWRP with the following processes:
Physical pre-treatment: Coagulation and flocculation with sludge removal.
Pressure Media Filtration: A pressurised media filtration system is used with filtration by means of sand and then anthracite filter media.
Disinfection and Chemical Dosing
The treated water undergoes a two stage disinfection process, using UV disinfection, pH balancing and post-treatment disinfection.
The NAIS treatment system is capable of being upgraded to twice its current capacity should demand require additional water and the system is designed to be retrofitted with Reverse Osmosis should this be required in the future.
The NAIS system is served by a number of pump stations, all remotely controlled.
AWRP Pump Station: The AWRP has several standalone pump stations are located within the Bolivar site. These are used to extract raw water and transfer within the AWRP treatment process.
Recycled Water Transfer Pump Station: This pump station transfers irrigation water from AWRP product water tank to the Two Well storage site.
DAFF Pump Station: The DAFF Pump station takes water from the existing Bolivar DAFF plant and transfers this water to the AWRP
Recycled Water Distribution Pump Station: This pump station is located at the Two Wells storage and provides water on demand to the NAIS customers.
The NAIS system has several water storage sites to provide adequate buffer capacity to meet the demand of irrigation customer’s daily needs, including:
2.5 ML tank for storage of treated water at the AWRP Bolivar site
Managed Aquifer Storage (MAR) of 3.5 GL capacity.
Two Wells water storage of 200 ML dams facility located at Porter Rd, Korunye.
Operations and integration to SA Water network
The NAIS treatment plant can operate automatically, meeting water quality requirements and demand. The start-up of the Distribution Pump Station is automatic as is the back-up generator located at this site. The additional water stored within the MAR scheme is also controlled automatically.
All infrastructure associated with the NAIS system is designed and constructed in accordance with SA Water Standards and Guidelines. The control system in linked by radio connection at each location and controlled by the NAIS SCADA control system, integrated within the SA Water SCADA system.