SINGAPORE — The National Environment Agency (NEA) has started monitoring levels of Escherichia coli (E. coli) at Sentosa's beaches, following news that swimming events at the World Aquatics Championships were twice delayed due to elevated levels of the bacteria in the waters.NEA does not usually assess marine water quality based on E. coli levels.Instead, it follows World Health Organisation (WHO) guidelines to determine the suitability of a recreational beach for primary contact activities, by measuring the levels of another group of bacteria, Enterococcus.In response to queries from The Straits Times, NEA said that WHO recommends using only Enterococcus for assessing marine water quality. Epidemiological studies have shown a strong correlation between Enterococcus levels in marine waters and public health risks. Read more