Dental plaque in transport pipes

Doing nothing means cavities.

There I was, on a draughty terrain with a view over a lot of transport pipes. It was cold and windy, but it didn't bother me, because the impressive view of the pipes dominated. A transport pipeline is in fact a great invention! No trucks, train carriages or ships, but pipelines that transport products from A to B. In the Netherlands, we have no less than 300,000 kilometres of underground transport pipelines. You hear nothing, smell nothing and with underground pipelines you see nothing either, so it's a win-win-win situation. Fascinating...

The fact that you see nothing does not mean that nothing is happening. On the contrary, a lot is happening underground. And that's why I was out here. Accelerated corrosion was found on the inside of one of the pipelines. This is undesirable because it means the pipeline has to be decommissioned prematurely, repaired or even replaced. An expensive affair. The corrosion was so rapid that there was a strong suspicion of microbiological corrosion (MIC). In MIC, bacteria predominate. You can compare it to dental plaque. The bacteria attach themselves to the surface and subsequently produce acids. If you do nothing, you end up with holes. So we had to clean the pipe wall thoroughly to get rid of the bacteria and prevent further corrosion. Just like your teeth: cleaning with a brush (pig) and rinsing with a bactericide (biocide).

In this case, the biocide turned out not to produce the expected effect at all. The bacteria remained unabated and active. What was going on here? It was up to us to solve this microbiological puzzle. In our laboratory we simulated the situation on a small scale and we started testing which biocide kills the most bacteria in this specific pipe and in what concentration and contact time. Based on this, we determined the most effective treatment. Then comes the most exciting part: the field test. After applying the biocide, I took a sample from the pipe to verify that the agent had done its job. The result was perfect: no more bacterial growth to be seen. That's what gives me a kick!

Specific situations like this require specific solutions, proven solutions that are verified and monitored and where nothing is left to chance. If we rely on underground pipelines, we must also be able to trust that these pipelines are safe and the processes manageable.