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Wastewater Treatment Engineering (Design & Construct): Service

Wastewater Treatment Engineering (Design and Construction)

We have over 25 years of wastewater treatment design and construction experience including primary, secondary and tertiary treated water. Our design strategies are based on our client’s needs, desired water quality, footprint, energy and overall efficiency.


Primary treatment systems remove solids and gross contaminants from wastewater streams through physical and chemical methods to improve water quality for either discharge to sewer or in preparation for secondary and tertiary treatment.

For primary treatment we could use any of the following items depending on the application:  

Sedimentation and grit separation

Waste streams that have heavy silt or sand loading can required sedimentation or grit separation equipment to reduce mechanical stress and heavy maintenance and operational costs.


Screening is an important function in any wastewater operation as it can deal with debris and other materials that can cause blockages and create issues with plant reliability. We have a number of different types of screens including inclined rotary screens, static screens, wedge wire screens, vibrating screens.

Oil water separators

Certain waste streams can have free oil present in their operation. The presence of oil can create issues through emulsification, saponification and can hinder biological activity. In situations where significant quantities of oil are present it is best to remove oil through simple oil skimming devices or more advanced oil separation equipment like lamella oil water separators. iH2OM have a range of products that can assist in the removal and recovery of oil.  

Balancing and agitation

Wastewater treatment plants operate optimally when adequate balancing and agitation is allowed for. Balance tanks need to be properly sized and made of suitable materials of construction with safe access for ongoing maintenance and inspection. Agitation allows wastewater to be homogenised and this can be achieved through recirculation, aeration, mixers or a multitude of other methods.

Chemical dosing equipment

Suitable selection of dosing equipment for pH control, coagulant and flocculant delivery is essential for reliability and control.  

Instrumentation for monitoring & control

Instrumentation plays a vital role in ensuring your wastewater treatment plant operates effectively. Instrumentation provides information and feedback to our clients that can improve reliability and more effective control. We have developed iH2OM Real Time Wastewater (WW) that can allow critical parameters to be monitored and controlled on a simple platform that can provide feedback 24/7 for our clients 

Polymer make up and dilution systems

Polymer dilution and activation is critical to the performance of WWTP’s. iH2OM has utilised its own R&D to develop a range of liquid and powder polymer make-up systems. The systems range in size from 1000LPH for small applications, to over 20000LPH for larger applications.

Chemical handling systems

Safety is at the forefront of our design and chemical handling for small and large volumes alike. We have a number of chemical handling and bunding systems from 15L, 250L, 1000L IBC Bunds, 5000L-10000L and beyond. We commonly customise design and build bunds and chemical storage systems to suit individual needs.

Dissolved air flotation (DAF)

Our systems are designed for a flowrate 1m3/hr up to 250m3/hr and can be made of the following materials, 304SS, 316SS, duplex, triplex and polyethylene upon request. We have co-current for standard applications and counter-current DAF deigns for higher efficiency applications. Our DAF designs are flexible, and we can allow for multiple reaction tanks for pre and post-DAF dosing and control.  

Clarification systems

Our sizing ranges from 1m3/hr up to 10,000m3/hr. We have several different designs for traditional up flow, horizontal flow and lamella designs for smaller footprint applications. 

Sludge dewatering equipment

Sludge produced from chemical treatment and can be voluminous and costly to dispose of. Sludge dewatering or sludge thickening can be applied using suitable technologies to reduce sludge volumes. iH2OM has extensive experience with screw presses, belt presses, filter presses, centrifuges, vacuum filters, gravity filters and bag dewatering systems.


Secondary treatment

Using biological processes to remove organic matter present in wastewater. The biological processes we have expertise in include aerobic and anaerobic treatment.

Aerobic Treatment 

Aerobic processes utilise oxygen to breakdown organic material to remove phosphorus and nitrogen. This type of treatment includes activated sludge process, sequencing batch reactors SBR, membrane bio reactors (MBR), moving bed biofilm reactors (MBBR).

Anaerobic Treatment 
Anaerobic treatment is a process where wastewater or material is broken down by micro-organisms without oxygen. Anaerobic digestion is a typical anaerobic process.

Tertiary Treatment

Process involves additional treatment after secondary treatment to reduce organics, turbidity, nitrogen, phosphorous, metals and pathogens. Typical treatment processes can involve coagulation, filtration, activated carbon adsorption, reverse osmosis and disinfection.


iH2OM utilises biological modelling software to accurately determine design processes and suitable sizing. All of our treatment operations can be managed by our iH2OM REAL TIME™ Online System.

For further information on wastewater treatment engineering, contact us today
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