At that time the plant was built to treat sewage from a population of 650,000, but by 1943 the population grew to 1.5 million people, contributing much more sewage, and upgrades to the plant were necessary.
The plant was built to treat sewage from a population of 650,000. This was at that time. The population grew to 1.5 million people. This was by 1943. The population was contributing much more sewage. This was by 1943. Upgrades to the plant were necessary.