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Flierman Techniek



The family firm Flierman Techniek in Colmschate is involved in soil drilling, water treatment and pumping systems. Not all Dutch enterprises source their drinking water from a water company. Some, particularly livestock farming and the recreation sector, tap their own groundwater.

This groundwater has to be treated to make it safe as drinking water for humans or animals. Groundwater used for industrial processes also has to be upgraded to meet minimum safety standards, as does water for nurseries, gardens, laundries, offices and laboratories.

In conventional treatment plants springwater is pumped up, enriched with oxygen, filtered and chemicals sometimes added to further purify it.

Fermanox (the system that Flierman Techniek employs) works differently. Water is treated when it is still in the ground, which acts as a natural filter. The Fermanox process enriches the water with oxygen from the air. Due to the presence of oxygen, iron and manganese are oxidized into a solid form and released back into the ground. At the same time, the ammonium level is significantly lowered. This means much more water can be treated, extracted and used.


Fermanox is highly effective. Very high concentrations of iron and manganese in the water can be reduced to very low amounts. The system is not cheap to install, but it repays itself within a few years. Maintenance costs are extremely low because there is no filter that has to be rinsed. Also, Fermanox is energy efficient; the system can save thousands of euros a year.

Complete package

Flierman Technique can handle the entire water treatment process, from initial soil analysis up to and including annual maintenance of the system. Fermanox is most suitable for sandy soils and gravel beds, so most of Flierman Techniek’s customers are in the east and middle of The Netherlands. One new customer is a Belgian hospital which wants to heat its building by geothermal means. The quality of the groundwater was not good enough, but

after Fermanox treatment it will be. This paves the way for potential new markets.

Future standard

Flierman Techniek placed the first Fermanox installations in 1992, for farms at first, later for industry and recreation. Large-scale installations have now been installed in the food supply industry, including abattoirs, at a thermal spa complex and at one of the biggest swimming pools in The Netherlands.

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