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Firefighting Drill Foam Leachate Remediation
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Water treatment .
Challenge
Challenge
Location
Sweden
Application
Treatment and recirculation of firefighting training water
Industry
Emergency Services
Capacity
Treatment capacity: up to 6 m³/h Buffer tank volume: 250 m³ Treated water storage: 650 m³
Performance
PFAS11, PFAS21 & PFAS22: >99% reduction Anionic, cationic and non-ionic surfactants reduced to near or below detection limits
Solution facts.
Mellifiq delivery:
Containerized treatment solution for PFAS reduction,
surfactant removal, and recirculation of firefighting
training water
Introduction.
Containerized leachate water treatment solution to manage fire quenching foam surfactants, heavy metals and surfactants.
A municipal fire and rescue service operates a dedicated fire training facility where training activities generate water containing firefighting foam additives, surfactants, PFAS compounds and heavy metals. The facility required a robust treatment solution capable of handling varying water quality and intermittent flows while meeting project-specific water quality requirements.
Mellifiq delivered a containerized treatment system combining Sealed Reactor Electrocoagulation (SRE), filtration, ozonation and activated carbon adsorption for advanced treatment of the collected training water.
The problem.
Firefighting training activities generate contaminated water containing foam additives, surfactants, PFAS compounds and other substances associated with live fire training. The collected water can vary significantly depending on training activities and operating conditions.
The surfactant load represented a particular challenge. Characterization of the training water showed concentrations of 82 mg/L anionic surfactants, 1,700 mg/L cationic surfactants and 120 mg/L non-ionic surfactants. PFAS11 was measured at 27 ng/L, while PFAS21 and PFAS22 were measured at 29 ng/L.
The treated water was also required to meet defined project and environmental requirements. These included target values for surfactants and PFAS, as well as stormwater guideline values for parameters including copper, zinc, oil index and suspended solids. The treatment system therefore needed to provide stable treatment performance while handling intermittent flows, varying water quality and seasonal operating conditions. The plant also had to be installed outdoors and integrated with existing tanks and infrastructure.
The solution.
Mellifiq delivered a prefabricated, containerized treatment plant with a capacity of 6 m³/h, integrated with the facility’s existing 250 m³ buffer tank and 650 m³ treated-water reservoir. The first container carries the SRE electrocoagulation stage, consisting of three SRE reactors followed by an OptiFloc™ flotation unit.
In the reactors, contaminants are destabilized and form flocs, which are then removed through flotation. The second container houses the polishing treatment system. Water passes through sand filtration, ozonation and activated carbon adsorption before being directed to the treated-water reservoir or back through the treatment process when required. Ozonation oxidizes residual organic compounds, while activated carbon provides additional adsorption of remaining contaminants.
Adapted to varying operating conditions
Due to seasonal variations in operating conditions and contaminant loads, the system is equipped with three operational modes: low demand during spring and autumn, high demand during peak training periods, and winter mode. During peak periods, the system automatically adjusts operation to accommodate maximum flow conditions.
Evaluation.
Performance testing was conducted to verify the system’s ability to reduce key contaminants while supporting recirculation of training water and compliance with project-specific water quality requirements under real operating conditions.
The treatment process demonstrated substantial reductions across multiple contaminant groups associated with firefighting training water. Surfactant concentrations were reduced to levels supporting compliance with the project-specific water quality requirements established for the treated water. Laboratory analyses confirmed compliance with the specified surfactant requirements. Anionic surfactants were reduced to <0.023 mg/L, while cationic and non-ionic surfactants were reduced below their respective reporting limits of 0.25 mg/L and 0.20 mg/L.
| Parameter | Before Treatment | After Treatment | Reduction | Required Water Quality* |
| Anionic Surfactants | 82 mg/L | <0.023 mg/L | >99% | 0.04 mg/L |
| Cationic Surfactants | 1700 mg/L | <0.25 mg/L | >99% | 0.25 mg/L |
| Non-Ionic Surfactants | 120 mg/L | <0.20 mg/L | >99% | 0.20 mg/L |
| PFAS11 | 27 ng/L | <0.2 ng/L | >99% | 8.5 ng/L |
| PFAS21 | 29 ng/L | <0.2 ng/L | >99% | 8.5 ng/L |
| PFAS22 | 29 ng/L | <0.2 ng/L | >99% | 9.4 ng/L |
Laboratory analyses also confirmed highly effective PFAS removal, with PFAS11, PFAS21, and PFAS22 concentrations reduced from approximately 27–29 ng/L to below the analytical detection limit of 0.2 ng/L. Overall, the implementation demonstrated stable treatment performance across a broad range of contaminants associated with firefighting training activities. Effective PFAS and surfactant removal supported the recirculation of training water while meeting project specific water quality requirements. The project demonstrates how integrated treatment technologies can support sustainable water management in demanding operational environments.
*Project-specific water quality requirements established by the client as part of the project specification and supporting analytical documentation
