According to guidelines, who is responsible for installing the correct sized septic tank?

The contractor is responsible for installing the correctly sized septic tank because they are the professionals trained and qualified to assess, determine, and implement the specific requirements of a septic system installation that complies with local codes and regulations. The contractor conducts soil tests, evaluates site conditions, and determines the appropriate tank size based on factors like the number of bedrooms in a home, anticipated usage, and local health regulations.

Local authorities primarily oversee permitting and compliance with regulations but do not engage in the installation process themselves. The property owner may have a role in deciding on the system's characteristics and providing access but ultimately relies on the contractor's expertise for proper installation. The project manager may coordinate tasks and schedules, but they are not directly responsible for the physical installation of the septic tank, which is squarely in the contractor's domain. This emphasizes the professional responsibility and expertise required for successful installation of critical systems like septic tanks.