Häfla Bruk is located in the small community of Hävla in Östergötland, Sweden. The site dates back to the 17th century, while today’s industrial area is centered around the “new” manufacturing plant established in the early 19th century. Historical operations such as nail forging and horseshoe production have been replaced by a modern industrial facility producing expanded metal, grating, railings, and staircases. The company also offers automated services in sheet metal processing and laser cutting. The products are treated in Häfla Bruk’s own hot-dip galvanizing plant.

A project in two phases

The first phase of the project focuses on treating groundwater, removing metal contaminants originating both from raw materials used in production and from subsequent galvanizing processes.

Zinc contamination in the groundwater is a historical environmental liability that was first identified in 2009 in connection with a planned expansion of the site. This was followed by fifteen years of investigations before an effective treatment method could be identified.

Several wells have been drilled across the site, from which the water is pumped to the treatment facility. Initially, the flows are relatively low, with zinc and other dissolved metals as the primary contaminants.

The second phase of the project involves the treatment of industrial stormwater from precipitation, and may also include the treatment of dredged material from Lake Tisnaren. Such operations will involve significantly higher flow rates than groundwater treatment, and the facility has been designed and dimensioned accordingly from the outset.

The treatment plant includes a collection container, a process container for chemical dosing, a flocculation tank, a lamella separator with an integrated sludge scraper, a sedimentation container, pH adjustment, and equipment for sludge dewatering.

The facility is also equipped with Swedish Hydro Solutions’ cloud-based system for monitoring water quality parameters.

New technology for complex water

The water to be treated is highly complex, with elevated zinc levels and very low pH. A series of bench-scale tests led to the implementation of a new complementary treatment chemistry, thoroughly tested in Swedish Hydro Solutions’ in-house laboratory.

New equipment for dosing this environmentally friendly treatment agent was also developed specifically for the project. Häfla Bruk is the first project in Sweden where this particular treatment technology is being used.

Excellent zinc removal performance

The treatment plant has been in operation since late April 2026 and has demonstrated excellent results.

– It is a remarkably strong performance,” says Johan Magnusson of Swedish Hydro Solutions. “The plant consistently treats the water well below the regulatory limit for zinc, with a wide margin from the very start, despite fluctuations in incoming zinc concentrations. This demonstrates the robustness of the treatment process.

– We have also fine-tuned the plant throughout the project, and the trend shows that the treatment performance continues to improve, Johan concludes.

This page will be updated with measured data as the project progresses.