They often overflow into rivers and streams during storms.

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When storms hit, these systems can overflow, sending untreated sewage into rivers, lakes, beaches, and drinking water supplies.

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The charity said that overflow pipes which prevent sewage backing up into drains and houses in times of heavy rain are necessary in an emergency.

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Unfortunately, these systems frequently overflow, and so untreated sewage and storm water runoff are expelled into surrounding water bodies.

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The Linux "zombie" machines were compromised when hackers broke into them by exploiting a default setting for the network file system through an RFC buffer overflow, Rouland explains.

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