What does 'slope' refer to in the context of septic systems?

In the context of septic systems, 'slope' specifically refers to the gradient of the land where the drain field is situated, which significantly impacts drainage and absorption capabilities. Proper slope is crucial for ensuring that wastewater can flow away from the septic tank and into the drainage field effectively. If the slope is too steep, it can lead to rapid runoff, preventing proper absorption of the effluent. Conversely, insufficient slope can cause pooling or saturation in the drain field, leading to system failure. Therefore, having the correct slope is essential for the effective functioning of a septic system, ensuring that waste is effectively treated and does not contaminate nearby groundwater or surface water.

Other options do not accurately define 'slope' in this context, as they relate to waste movement, tank angles, or water height, which are separate concepts that do not directly address the significance of land gradient in the operation of a septic system.