Is Poland's tap water really protected by clams?

Summary by Krater

Tom Scott investigates whether Warsaw's tap water supply is genuinely monitored by live clams in the Vistula River. He visits the water treatment facility and confirms that the bio-monitoring system using freshwater mussels is real and active.

From the video

Answers: Does Warsaw really use clams to monitor its water supply?

• Biomonitoring water quality with freshwater mussels
• Warsaw tap water treatment and safety
• Early warning systems for water contamination
• Vistula River water supply

What it concludes

• Warsaw's tap water quality is monitored by freshwater mussels as part of an early warning system.
• Eight clams are placed in an aquarium with sensors attached to their shells to detect water contamination.
• If six out of eight clams close their shells for more than four minutes and the average closing percentage rises above 25%, an alarm is triggered.
• Clams spend about two weeks acclimatizing and are returned to their natural habitat after three months.