Concrete drainage contaminates urban water

Concrete infrastructure in urban environments appears to be altering the chemistry of rainwater flowing into our urban streams.

Researchers analysed the pH (acidity) of water from urban and non-urban streams and found that urban streams tended toward neutral pH while non-urban streams tended to be more acidic (low pH).

Researchers found that the chemistry of the rainwater changed as it passed through concrete drainage, increasing in bicarbonate and calcium levels. Both of these additives served to raise the pH of the water, making it more chemically neutral.