Evaluation of 10-year management measure

Published March 18, 2025

Well, that 10 years is actually 25 years. Because the company we're talking about started controlling groundwater contamination with zinc on its own property in Brabant around the year 2000. After some time, it became clear to the company that keeping such a system in operation was quite a special job. The flow rate extracted decreased significantly and with it the effectiveness of the control measure.

In 2014, it was really time to intervene, and TAUW and Verhoeve were asked to install and maintain a new system. Since that time, groundwater has been extracted from 8 deepwells, with the water being taken through individual pipes to the plant's water treatment plant.

High iron concentration

The high iron concentration in the groundwater is literally and figuratively an ongoing concern. Every 5 weeks the pumps are cleaned and the pipes are cleaned 2x a year. The wells themselves are regenerated once a year.

But the result is pleasing. At about 300 m3/day, the groundwater contamination is well controlled. This is considerably less than the previously anticipated more than 400 m3/day. Therefore, the flow rate to be extracted was "ex officio" changed from 413 to 300 m3/day in 2020. The graph gives a nice picture of the decreasing flow rate until 2013, and then the average stable picture of the flow rate despite the difficult conditions.

Substantial removal of Zn

It is also important to mention that significant removal of Zn occurs with the management measure. On average about 7.5 mg/l. For the year 2024, that meant a removal of 800 kg of zinc! This makes the system unintentional but certainly welcome actually a hybrid form of an active remediation measure and a management measure.

Unfortunately, the source of the problem cannot be reached in the coming years; the management measure will have to remain in place for the time being.

This article was written is collaboration with Bert Scheffer of TAUW. For more information, please contact Jeroen Schoovers of Verhoeve Netherlands at 06-22 55 20 57.