Hennig-Olsen Is secures outstanding discharge water quality



Norway’s largest ice cream supplier is safely discharging wastewater into local fjord with a Grundfos BioBooster treatment plant.

Hennig-Olsen Is (Hennig-Olsen Ice Cream) is the largest supplier of ice cream in Norway, producing over 30 million litres of frozen desserts every year. Established in 1924, the family owned company today has over 200 employees and a Norwegian market share of 50 %.


The situation

With great products comes great responsibility. That includes the obligation to ensure an environment-friendly production. In the making of ice cream, process wastewater is produced, mainly from the clean-in-place (CIP) system. Previously, the Hennig-Olsen Is plant’s process wastewater was collected in pump pits with a simple fat separator and pumped into the municipal sewer.

In 2016, new requirements of reducing organic loads to the municipal sewer sent Hennig-Olsen Is searching for a pretreatment solution. But instead of a pretreatment solution only, Grundfos suggested a complete wastewater treatment system that would allow Hennig-Olsen Is to discharge treated process wastewater directly to the local fjord. This would also open the door to a possibility for Hennig-Olsen Is to reuse water within their own production.


The solution

The benefits of the complete treatment system in terms of both economy and sustainability were clear to Hennig-Olsen Is, and as a result they went with the solution suggested by Grundfos.

In 2018 the full process water treatment plant was delivered to Hennig-Olsen Is by Grundfos as a complete turnkey solution including pretreatment units, biological system, UF membrane, sludge treatment and climate shield building, all combined in a BioBooster treatment system.

Based on a Membrane BioReactor technology (MBR) and using a Grundfos ceramic UF filtration method, the BioBiooster treatment system is designed to cope with varying hydraulic and organic loads from the production. That combined with the compact and modular design of the BioBooster system, makes it the perfect fit for the very limited space at the Hennig-Olsen Is plant.

In addition to this, SCADA control monitoring combined with online quality sensors ensures operational robustness and reduced man-hours as constant output from the Grundfos BioBooster unit provides the necessary flexibility to meet the fluctuating demand in Hennig-Olsen Is’ production.


The outcome

Hennig-Olsen Is’ new BioBooster treatment system removes all solids, organics and nutrients from the plant’s process water and has proven to be able to treat the water to a level that supersedes the authorities’ discharge requirements:

Water quality parameters in the treatment plant:

Water parameter Raw process wastewater Treated water Discharge requirements
Total COD, mg/L 4100 < 30 75
BOD5, mg/L 2000 < 3 10
Ammonium-N, mg/L   0,04 N/A
Total Phosphorus, mg/L 8,5 0,01 0,4
Suspended solids, mg/L 848 < 2 5
pH 11 7,5 6,8-8,5


After the installation of the Grundfos BioBooster wastewater treatment system, Hennig-Olsen Is is now discharging its treated wastewater to the local Kristiansand fjord. Thanks to the advanced UF filtration method used in the treatment system, the quality of the water discharged to the recipient is superior by being free of micropollutants, such as bacteria and microplastics – an achievement that would not have been possible with conventional technology.

Furthermore, the plant is prepared to be combined with a Reverse Osmosis (RO) filtration system (remineralisation units and disinfection system) to produce high-quality water for the purpose of reuse. This add-on will allow Hennig-Olsen Is to reuse the treated water in the actual production, i.e. for CIP and other utility purposes.

To Bård Schefte, Senior Project Manager at Hennig-Olsen Is, the benefits of decentralized wastewater treatment are clear:

"Being able to discharge our treated process water directly to the fjord means that we don’t have to worry about water purification in the future. Even if we increase our production, we won’t be limited by the capacity of the municipal sewer or increasing water purification prices, and even better, we will eventually be able to reuse our process wastewater, saving us money and protecting the environment"


Industrial wastewater treatment and reuse


Kristiansand, Norway


Hennig-Olsen Is

From the opening of Henning Olsen Is' water treatment plant in Kristiansand, Norway.

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