LONDON — Prince Charles got down and dirty Wednesday, donning a hard hat and protective glasses to visit a sewer tunnel 250 feet under east London.

The heir to the British throne was marking the 150th anniversary of the city’s sewers, created by engineer Joseph Bazalgette to erase the “Great Stink” caused by sewage and effluent that was being dumped into the River Thames.

The 19th-century stench was so bad it overwhelmed lawmakers in the Houses of Parliament, who hired Bazalgette to find a solution. His sewers, a wonder of Victorian engineering, were designed for use by 2 million people but now struggle to serve an additional 6.6 million people.

The prince visited the ornate Abbey Mills Pumping Station, wearing a high-visibility jacket to inspect a new tunnel designed to reduce the 43 million tons of untreated sewage that is still released into the river each year.

Tony Brown, one of two young apprentices who showed Charles around the 23-foot-wide concrete tunnel, declared the prince “down to earth and a real nice guy.”

The 4.4-mile Lee Tunnel, the deepest ever built under London, is due to go into use in December as part of efforts to deal with the flow of waste from London’s 8.6 million inhabitants. Their sewage not only taints the Thames but often creates “fatbergs,” – blobs of congealed fat, baby wipes and other waste that can weigh tons and clog sewers.

Charles’ great-great-grandfather, King Edward VII, opened the sewer network in 1865.

—From news services reports