From John Ray's shorter notes
January 16, 2017
German Greenies turn German water supply brown
Which has been very vexing. When water comes out of your faucet brown, you know something bad has happened. You expect that only in poor countries like India. I have seen it in India. The German authorities do in fact manage to bleach the water before it goes out to households but that's expensive. So why are German streams running brown anyway?
It's because of the German government's hostility to industry. High electricity prices and other policies have chased a lot of German industry to saner countries and the remaining industries are heaviliy regulated in order to reduce pollution of all sorts.
And one effect of that has been a reduction in the industrial emissions of nitrogen compounds into the air. But such componds do not stay in in the air forever. They gradfually fall out into the soil. And in the soil they react with a lot of other stuff, binding it so that it stays put. So in the absence of all those nitrates various other compounds are set free and get washed into the rivers. And among those are brown plant wastes, "dissolved organic carbon".
So where to now? Nowhere to go. They just have to spend more money on treating the water before it is reticulated. Extensive chemical treatment of the water supply before people drink it doesn't seem very Green, though, does it? Maybe brown drinking water is the way ahead for Germans! LOL
The abstract below puts what I have just said into more precise scientific terms
An interesting sidelight. Andreas Musolff has written a book on Hitler which dodges the fact that Hitler's policies were socialist. How did he get from history into hydrology?
Unexpected release of phosphate and organic carbon to streams linked to declining nitrogen depositions
Andreas Musolff et al.
Reductions in emissions have successfully led to a regional decline in atmospheric nitrogen depositions over the past 20 years. By analyzing long-term data from 110 mountainous streams draining into German drinking water reservoirs, nitrate concentrations indeed declined in the majority of catchments. Furthermore, our meta-analysis indicates that the declining nitrate levels are linked to the release of dissolved iron to streams likely due to a reductive dissolution of iron(III) minerals in riparian wetland soils. This dissolution process mobilized adsorbed compounds, such as phosphate, dissolved organic carbon and arsenic, resulting in concentration increases in the streams and higher inputs to receiving drinking water reservoirs. Reductive mobilization was most significant in catchments with stream nitrate concentrations less than 6 mg L−1. Here, nitrate, as a competing electron acceptor, was too low in concentration to inhibit microbial iron(III) reduction. Consequently, observed trends were strongest in forested catchments, where nitrate concentrations were unaffected by agricultural and urban sources and which were therefore sensitive to reductions of atmospheric nitrogen depositions. We conclude that there is strong evidence that the decline in nitrogen deposition toward pre-industrial conditions lowers the redox buffer in riparian soils, destabilizing formerly fixed problematic compounds, and results in serious implications for water quality.
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