Neither do you, apparently. Perhaps if you were more than a cut and paste jockey and really cared about people other than Trump, you would have come across this:
https://www.theguardian.com/us-news...-county-alabama-water-waste-treatment-poverty
Typically, property improvements such as sewer are paid for by homeowners through assessments levied by the Government providing the improvements. In some cases, such as high water tables or frequent flood zones, there are no easy or low cost solutions. The general contractor that created the subdivision on cheap, low land may be gone or financially unable to address the issue. The Government entity that approved the original plans may point out that building standards have changed and deny responsibility.
It also would seem unfair to condemn the subdivision because of homeowner property right's issues. How would they be compensated? I'm sure property values in the affected subdivision are in the toilet due to the stigma of the hookworm issue. However, there are well established precedents in protecting children and the community from infectious diseases such as hookworm. The overriding imperative should be the protection of children and the health of the community.
In my opinion, although homeowners have a responsibility to keep up the maintenance of their homes at to the point of meeting current health codes, they may have been let down by city planning decades ago because residents had no idea of the long term issues a high water table could cause.
It may take a court case to allocate responsibility, but the county appears to be on the hook for a significant amount of it.