Around the same time , the city of San Francisco began using raw sewage for irrigation of Golden Gate Park , an area which was just sand dunes at the time .
Is now a lush garden - of - eden - esqe meadow .
Around the same time , the city of San Francisco began using raw sewage for irrigation of Golden Gate Park , an area which was just sand dunes at the time , and is now a lush garden - of - eden - esqe meadow .