A septic tank is a crucial component of an underground wastewater treatment system. It is designed to hold wastewater long enough for solid waste to settle down to the bottom, forming sludge, while oil and grease float to the top, forming scum. The liquid wastewater, called effluent, then exits the tank.

Septic Tank Capacity Range

The capacity of a septic tank refers to the volume of wastewater it can hold. This capacity is typically determined based on the estimated daily flow of wastewater, which in turn depends on factors like the number of residents in a household.

For residential purposes, there are standard guidelines for determining the minimum required septic tank capacity. While the exact required size varies based on location codes and specific usage, a common range considered typical or minimum capacity per person served is important to understand.

Considering typical design standards and requirements for residential septic systems, the capacity per user is often specified. A widely accepted range for the required capacity per person is from 0.07 m³ to 0.13 m³.

This range accounts for the necessary volume for sedimentation, sludge storage, and scum accumulation between pumping cycles.

Analyzing the Options

Let's look at the given options and compare them with the typical range for septic tank capacity:

• Option 1: 0.07 m³ to 0.1 m³
• Option 2: 0.13 m³ to 0.15 m³
• Option 3: 0.1 m³ to 0.13 m³
• Option 4: 0.07 m³ to 0.13 m³

Comparing these options to the standard typical capacity range of \(0.07 \text{ m}^3\) to \(0.13 \text{ m}^3\) per person, we find that Option 4 matches this range exactly.

Therefore, the capacity of a septic tank, often considered per person served, is typically taken within the range of \(0.07 \text{ m}^3\) to \(0.13 \text{ m}^3\).