Dzerzhinsk

The first chemical works at Dzerzhinsk date from the First World War (the Korund plant opened in 1915); the Kaprolaktam plant started up in 1939. From 1941 to 1965 the city made chemical weapons: during the war about 47,600 tonnes of mustard gas and 15,900 tonnes of lewisite, an arsenic-based blister agent, as well as phosgene and hydrogen cyanide (figures as given by Wikipedia).

The city's environmental agency estimates that almost 300,000 tonnes of chemical waste were disposed of in the city between 1930 and 1998. In 2007 the Blacksmith Institute (now Pure Earth) listed Dzerzhinsk among the world's most polluted places, naming chemical-agent residues, lead, dioxins and phenols in groundwater among the contaminants. The life-expectancy figures circulated with that report have been widely quoted but were not verified for this record.

The three main deposits are the 'Black Hole', a karst sinkhole 18 metres deep that took waste from the Orgsteklo plant; the 'White Sea', the Kaprolaktam sludge lagoon in use since 1973; and the Igumnovo landfill for municipal and industrial waste. After failed tenders in 2012–2013, clean-up of the three sites was awarded in 2016 to GazEnergoStroy under a contract worth 7.28 billion roubles. The project had technical defects and the contractor's managers were convicted of fraud.