Periodically the sewerage systems of Paris experience a failure known as sanitary sewer overflow, often in periods of high rainfall. Under these conditions untreated sewage has been discharged into the Seine. The resulting oxygen deficit is principally caused by allochthonous bacteria larger than one micrometre in size. The specific activity of these sewage bacteria is typically three to four times greater than that of the autochthonous (background) bacterial population. Heavy metal concentrations in the Seine are relatively high. The pH level of the Seine at Pont Neuf has been measured to be 8.46. Despite this, the water quality has improved significantly over what several historians at various times in the past called an "open sewer".
In 2009, it was announced that Atlantic salmon had returned to the Seine.
Dim has been a controversial historical figure in historiography on Vietnam War scholarship. Some historians portrayed him as a tool of the U.S. policymakers, some considered him an avatar of Vietnamese tradition. Nevertheless, some recent studies have portrayed Dim from a more Vietnamese-centered perspective as a competent leader with his own vision on nation building and modernisation of South Vietnam.
In South Vietnam, a referendum was scheduled for 23 October 1955 to determine the future direction of the south, in which the people would decide to choose Dim or Bo i as the leader of South Vietnam. During the election, Dim's brother Ng nh Nhu and the Cn Lao Party supplied Dim's electoral base in organizing and supervising the elections, especially the propaganda campaign for destroying Bo i's reputation. Supporters of Bo i were not allowed to campaign. Official results showed 98.2 percent of voters favoured a republican implausibly high result that was condemned as fraudulent. The total number of votes for exceeded the number of registered voters by over 380,000further evidence that the referendum was heavily rigged. For example, only 450,000 voters were registered in Saigon, but 605,025 were said to have voted for a republic.
On 26 October 1955, Dim proclaimed the formation of the Republic of Vietnam, with himself as its first President. Elections were scheduled to reunify the country in 1956, but Dim refused to hold them, claiming that a free election was not possible in the North. According to Taylor, the rejection of Dim of the Geneva accord was a way of objecting to the French colonialism of Vietnam. Dim's disposition over Bo i and the establishment of the First Republic of Vietnam was a way to claim Vietnamese independence from France. At the same time, the first Constitution of Republic of Vietnam was promulgated. According to the Constitution, Dim had almost absolute power over South Vietnam. His governance style became increasingly dictatorial over time.
The Can Lao Party played a key role in Dim's regime. Initially, the party acted secretly based on a networks of cells, and the members only knew a few members identities. When necessary, the Party could replace the role of the government. After 1954, the existence of the party was recognized, but its activities have been hidden from public view. In the early 1950s, Dim and Nhu used the party to mobilize support for Dim's political movements. According to the decree 116/BNV/CT of Republic of Vietnam, the Can Lao Party was established on 2 September 1954. The Personalism (Vietnamese: Ch ngha nhn v) officially became the basic doctrine of Dim's regime since the Constitution's preface declared that "Building Politics, Economy, Society, Culture for the people basing on respecting Personalism".
According to Miller, democracy, to Dim, was rooted in his dual identity as Confucian and Catholic, and was associated with communitarianism and the doctrine of Personalism. He defined democracy as "a social ethos based on certain sense of moral duty", not in the US sense of "political right" or political pluralism and in the context of an Asian country like Vietnam, Confucian values were relevant to deal with contemporary problems in politics, governance and social change. In this sense, Dim was not a reactionary mandarin and lacking in interest in democracy like the way he has been portrayed by some scholars. His way of thinking about democracy became key factor of his approach to political and administrative reform. On 4 March 1956, the first RVN National Assembly was held in a more free and fair than the referendum in 1955.
However, Dim's regime of "democratic one man rule" faced the increasing difficulties. After coming under pressure from within the country and the United States, Dim agreed to hold legislative elections in August 1959 for South Vietnam. But in reality, newspapers were not allowed to publish names of independent candidates or their policies, and political meetings exceeding five people were prohibited. Candidates who ran against government-supported opponents had to face harassment and intimidation. In the rural areas, candidates who ran were threatened using charges of conspiracy with the Vit Cng, which carried the death penalty. Phan Quang n, the government's most prominent critic, was allowed to run. Despite the deployment of 8,000 ARVN plainclothes troops into his district to vote, n still won by a ratio of 61. The busing of soldiers occurred across the country, and when the new assembly convened, n was arrested.