Chemical injection is a specialised field of in situ remediation technology and is one of the core techniques employed by InSite for the treatment of impacted soil and groundwater.
InSite is an industry leader in the application of a range of chemical injection strategies, including:
In situ chemical oxidation (ISCO)
Oxygen release compounds (ORC)
In situ chemical reduction (ISCR) reagents
These strategies are selected and tailored to site-specific conditions to achieve targeted remediation outcomes efficiently and effectively.
InSite owns and operates its full suite of chemical injection equipment, including skid-mounted and modular mixing hoppers and tanks, variable speed pumps, hoses, well heads, manifolds, flow gauges, safety equipment, and monitoring instrumentation. Owning all plant and equipment in-house allows for rapid mobilisation, flexible system configuration, and full operational control.
Our chemical injection services include:
Procurement and safe storage of chemicals
Mixing and preparation of reagents
Controlled chemical application
Monitoring of groundwater parameters to assess performance and optimise outcomes
At a site under construction in the southern suburbs of Melbourne, InSite carried out an in situ chemical reduction (ISCR) injection program to remediate residual contamination associated with historical dry-cleaning activities. The works were undertaken during active construction, requiring careful planning and execution to integrate remediation activities with site development.
The project involved the application of ISCR reagents using InSite’s specialised chemical injection equipment. Key activities included:
Application of 34,000 litres of mixed EHC© ISCR reagent to 13 injection wells
Use of InSite’s skid-mounted chemical mixing and injection unit to prepare and deliver the reagent
Preparation of reagent batches of approximately 950 litres, comprising ELS™ Microemulsion, EHC© liquid mix, and potassium bicarbonate, mixed with water
Simultaneous injection into up to four wells to maximise coverage and efficiency
Adaptation of injection pressures to suit site conditions, including pressure injection at approximately 100 kPa in tight geological zones to ensure reagent distribution
The project presented several technical considerations:
Tight Geology – Low permeability zones required the use of controlled pressure injection to achieve effective subsurface distribution of reagents.
Active Construction Site – Remediation activities had to be carefully coordinated with concurrent construction works to avoid disruption and ensure safety.
Complex Reagent Mixing – Accurate batching and chemical handling were critical to maintain the effectiveness of the ISCR treatment.
The ISCR injection program was successfully completed, delivering targeted reagent volumes to the required subsurface intervals. The controlled injection approach ensured effective distribution of the reagents, laying the groundwork for ongoing in situ treatment of contamination in line with the site’s remediation strategy.
34,000 litres of ISCR reagent injected across 13 wells
Use of InSite’s in-house skid-mounted chemical mixing and injection unit
Multi-chemical batching and simultaneous injection into multiple wells
Adaptation to challenging geological conditions using controlled pressure injection
Integration of remediation works within an active construction environment
InSite managed an in situ chemical oxidation (ISCO) injection program at a vacant service station site in suburban Perth. The works included the procurement and safe storage of chemicals, mixing, injection, and the monitoring of reagent and groundwater parameters to support targeted subsurface remediation.
The project involved multiple ISCO injection events using sodium persulphate and sodium hydroxide reagents. Key activities included:
Procurement and safe storage of chemicals
Mixing and preparation of reagents on site
Injection and monitoring of reagent and groundwater parameters
Four ISCO injection events conducted over a two-month period
Injection of 5,400 kg of sodium persulphate and 9,000 litres of sodium hydroxide solution into 15 injection wells
Establishment of a secured works compound with temporary fencing, bollards, and bunting
Setup of temporary power supply, clearly defined hot zone, emergency shower and eyewash station, site administration office, and crib area
The project required careful management of chemical handling, logistics, and safety:
Safe chemical storage and handling were critical to meet regulatory and site safety requirements.
Coordinating multiple injection events within a short time frame required efficient batching, equipment management, and operational planning.
Establishing secure and compliant on-site infrastructure was essential for maintaining safety and environmental protection throughout the works.
The ISCO injection program was delivered safely and efficiently over the two-month period, with all reagent volumes successfully injected and monitored. The secure compound setup and structured site management allowed InSite to complete the works with no incidents and to regulatory and client expectations.
Four ISCO injection events over two months
5,400 kg of sodium persulphate and 9,000 litres of sodium hydroxide injected
Secure on-site compound established with clear safety zones and emergency facilities
Comprehensive chemical handling, mixing, and monitoring program
Safe and efficient delivery of in situ chemical oxidation works
InSite was engaged to undertake a program of simultaneous chemical injection and multi-phase extraction at a former service station site in Perth, Western Australia. The site presented several operational challenges, including restricted access, a narrow plant setup area, neighbouring retail and commercial businesses that remained operational throughout the works, and constant through-traffic in the injection zone from an adjacent four-lane highway.
The works involved a six-day pulsed chemical injection program combined with groundwater extraction to target contamination within the source zone. Key activities included:
Injection of 4,350 kg of sodium persulphate and 33,325 litres of hydrogen peroxide using InSite’s specialised chemical injection unit
Pulsed injection of each chemical to ensure full activation within the source zone
Implementation of pressure relief systems and constant monitoring to maintain safety and control during injection
One day of multi-phase extraction before and after the injection program, as well as throughout the injection works
Removal of 44,200 litres of contaminated groundwater from the site during the extraction phase
The project required careful planning and execution to manage multiple operational constraints:
Restricted Access – Limited plant area required precise equipment placement and workflow coordination.
Traffic Management – The proximity to a busy four-lane highway required detailed traffic control and site safety measures.
Business Continuity – Neighbouring retail and commercial operations continued throughout the works, requiring minimal disruption and clear communication.
Chemical Handling – Pulsed injection of reactive chemicals required pressure relief systems and continuous monitoring to ensure safe operation.
The combined chemical injection and multi-phase extraction program was completed safely and efficiently within the planned schedule. Pulsed injection ensured effective activation and distribution of reagents, while multi-phase extraction removed significant volumes of contaminated groundwater. The program successfully addressed site contamination within the operational constraints, with no safety incidents or disruption to neighbouring businesses.
Six-day pulsed chemical injection program using sodium persulphate and hydrogen peroxide
Multi-phase extraction before, during, and after injection works
Safe and controlled injection using pressure relief systems and monitoring
44,200 litres of contaminated groundwater removed
Successful delivery under tight access, high-traffic, and operationally complex conditions
