The Icely Road Treatment Plant is designed to treat up to 525 L/s of raw water delivered from Suma Park Pump Station and to produce a supply of filtered, ozonated and chlorinated potable water for use in Orange.
The major process equipment incorporated in the plant are:
- Four horizontal clarifiers
- Eight gravity filters
- Chemical dosing equipment for Aluminium Chlorohydrate, Soda Ash, Polymer, Fluoride, Chlorine and Ozone
- Rapid mix flocculation equipment
- Clear water pumping equipment
- Ozone generation equipment
- Three biologically activated carbon (BAC) filters
Raw water delivered to the plant from Suma Park Pump Station is dosed with ozone prior to the inlet of the plant. It is also dosed with Aluminium Chlorohydrate in the inlet pipe. It then enters the flash mixing tank via the raw water inlet valve.
Polymer is dosed at the flash mixing tank through a diffuser. A variable speed, high speed mixer provides initial mixing of the chemicals in the flash mixing tank.
Click the image to read the Water Treatment Process – Icely Road Treatment Plant brochure
The water then flows through a six compartment flocculation tank, fitted with variable speed flocculators, to the inlet channel feeding the four clarifiers. The flocculated water enters the clarifiers through a baffle distributor board and flows horizontally along the clarifiers. Clarified water flows into a collection channel at the end of the clarifiers. This water is then distributed to the eight gravity filters.
The water then passes through the filters and into a common filtered water channel, and then into the clear water cellar tank. Fluoride is dosed into the cellar.
The filtered water is then transferred from the cellar via three clear water pumps to the primary ozonation tank where it is dosed with ozone and detained for a minimum of 16 minutes. It then passes through the three BAC filters and into the clear water tank where it is then transferred via two clear water pumps to the 20ML storage reservoir. Chlorine is dosed at the inlet to this reservoir and soda ash is dosed downstream of the reservoir to adjust the pH if required.
The water is then gravity fed into the town reticulation system.
| Chemical | Purpose |
|---|---|
| Polyaluminium Chlorohydrate | This is a coagulant which is added for the flocculation process which is where very small suspended particles in the water contact each other and form larger particles called floc, which then settle. |
| Polymer | This is added to aid the coagulation process and help the floc particles form faster and larger to aid settling. |
| Soda Ash | This is added for pH correction to bring the pH of the water up to the desried level (when required). |
| Fluoride | This is added to the water for dental hygiene. |
| Chlorine | This is added to the water for the disinfection or pathogens eg. bacteria and viruses. |
| Ozone | This is a secondary disinfectant that is also capable of removing pathogens eg. viruses and Giardia as well as taste and odour molecules. |
| Potassium Permanganate | This is sometimes added to the raw (untreated) water if there are high levels of iron and manganese present |
Tests carried out on the water
The daily tests carried out on the water include: pH, fluoride levels, chlorine residuals, turbidity and manganese levels. These tests are carried out on both the raw and treated water daily to ensure that the water filtration process is working correctly and that the water quality is within the Australian Drinking Water Guidelines.
There are also tests that are carried out weekly such as bacteriological, fluoride levels, iron levels, manganese levels and aluminium levels from designated sites around the reticulation system.
