Complex sentence: During its operational life up to 1948,2,917,480 tons of sewage sludge was dumped at the site, and following closure, it was sold to the National Coal Board in 1961.
Split into simpler sentences: During its operational life up to 1948,2,917,480 tons of sewage sludge was dumped at the site. It was sold to the National Coal Board in 1961.