On Wednesday, a milk tanker crashed into the River Dulais in Carmarthenshire, Wales, spilling its contents and turning the water white. According to officials, 28,000 liters of milk leaked, causing significant discoloration.

Although milk may appear a benign substance that some people drink every day, once it gets into the water, it can affect hundreds of kilometers and become the equivalent of napalming a forest. Milk is seven times more polluting than cattle slurry, and it can affect the complex web of life that includes zooplankton which fish eat, plant life which rodents are reliant on, and the fish that birds feed on.

The river began to clear two days after the incident; however, authorities continued to closely monitor the situation, the insects and animals along the waterway, and they asked people to report any dead fish that they spotted.

Difficult words: benign (not harmful), napalm (to attack with bomb containing napalm, which is a sticky substance that contains petrol and it burns strongly), slurry (a semi-liquid mixture of water and animal waste).