Where should percolation tests be performed?

The correct answer highlights that percolation tests must be conducted specifically in designated primary and reserve septic areas. This is crucial because these areas are selected based on their suitability for septic systems. The percolation test evaluates the soil's ability to absorb water, which is essential for the proper functioning of a septic system. By conducting the test in the primary and reserve areas, it ensures that the septic system will function effectively without risking contamination of the nearby environment or ground water.

The primary septic area is where the primary system will be installed, while the reserve area acts as a backup in case the primary system fails. Testing in these areas ensures compliance with local regulations and proper planning for waste management.

In contrast, the other options do not align with the guidelines for conducting percolation tests. Performing tests in any remote area or only in urban areas disregards the necessity of location relevance to septic system effectiveness. Testing near water sources could risk contamination and is not in line with best practices for septic system installation.