Question: when was the sewage system built in the city that Claire Clairmont's sister is from?

<P0-S0> philadelphia has dedicated landmarks to its sister cities. <P0-S1> dedicated in june 1976, the sister cities plaza, a site of 0.5 acres (2,000 m2) located at 18th and benjamin franklin parkway, honors philadelphia's relationships with tel aviv and florence which were its first sister cities. <P0-S2> another landmark, the toruń triangle, honoring the sister city relationship with toruń, poland, was constructed in 1976, west of the united way building at 18th street and the benjamin franklin parkway. <P0-S3> in addition, the triangle contains the copernicus monument. <P0-S4> renovations were made to sister cities park in mid-2011 and on may 10, 2012, scp was reopened and currently features an interactive fountain honoring philadelphia's ten sister and friendship cities, a café and visitor's center, children's play area, outdoor garden, and boat pond, as well as pavilion built to environmentally friendly standards. <SEP> <P1-S0> the dnipro metro (; ) is a single-line rapid transit system that serves the city of dnipro, the fourth largest city in ukraine by population. <P1-S1> the metro was the third system constructed in ukraine, after the kiev and kharkiv metro systems, respectively, when it opened on december 29, 1995. the metro was the fourteenth built in the former soviet union region, and the first to open after the collapse of the soviet union in 1991. <SEP> <P2-S0> Mary Shelley was born Mary Wollstonecraft Godwin in Somers Town, London, in 1797. <P2-S1> She was the second child of the feminist philosopher, educator, and writer Mary Wollstonecraft, and the first child of the philosopher, novelist, and journalist William Godwin. <P2-S2> Wollstonecraft died of puerperal fever shortly after Mary was born. <P2-S3> Godwin was left to bring up Mary, along with her older half-sister, Fanny Imlay, Wollstonecraft's child by the American speculator Gilbert Imlay. <P2-S4> A year after Wollstonecraft's death, Godwin published his "Memoirs of the Author of A Vindication of the Rights of Woman" (1798), which he intended as a sincere and compassionate tribute. <P2-S5> However, because the "Memoirs" revealed Wollstonecraft's affairs and her illegitimate child, they were seen as shocking. <P2-S6> Mary Godwin read these memoirs and her mother's books, and was brought up to cherish her mother's memory. <SEP> <P3-S0> Joseph Bazalgette, a civil engineer and Chief Engineer of the Metropolitan Board of Works, was given responsibility for the work. <P3-S1> He designed an extensive underground sewerage system that diverted waste to the Thames Estuary, downstream of the main centre of population. <P3-S2> Six main interceptor sewers, totalling almost 160 km (100 miles) in length, were constructed, some incorporating stretches of London's ``lost ''rivers. <P3-S3> Three of these sewers were north of the river, the southernmost, low - level one being incorporated in the Thames Embankment. <P3-S4> The Embankment also allowed new roads, new public gardens, and the Circle line of the London Underground. <P3-S5> Victoria Embankment was finally officially opened on 13 July 1870. <SEP> <P4-S0> Clara Mary Jane Clairmont (27 April 1798 – 19 March 1879), or Claire Clairmont as she was commonly known, was the stepsister of writer Mary Shelley and the mother of Lord Byron's daughter Allegra. <P4-S1> She is thought to be the subject of a poem by Percy Bysshe Shelley.