Please fix consistency issues in this text.
It was not until the early 20th century that the city had the resources to construct sewerage and sewage treatment plants. Environmental progress was slow, and Buffalo Bayou was still heavily polluted through the late 1940s.
It was not until the early 20th century that the city had the resources to construct sewerage and sewage treatment plants. However, environmental progress was slow, and Buffalo Bayou was still heavily polluted through the late 1940s.