Which of the following is a method for effluent distribution on sloping terrain?

Serial distribution is a method used for effluent distribution specifically designed to address challenges presented by sloping terrain. In this approach, effluent is distributed in a sequence or series along the slope, ensuring that it spreads evenly across the area. This method helps in achieving effective wastewater treatment by allowing for gradual infiltration of effluent into the soil, which is particularly important on slopes where runoff may occur.

Utilizing serial distribution on sloping ground optimizes absorption and reduces the risk of surface water contamination, which can occur if the effluent is not properly managed. The method can prevent pooling in lower areas of the slope and ensures that all parts of the system receive adequate effluent, making it a suitable choice for sloped landscapes.

In contrast, gravity drainage typically relies on a level surface to facilitate the downward flow of effluent, which may not be as effective on slopes. Sand filtration involves treating effluent through sand media, which is more about purification than distribution. Subsurface irrigation applies effluent directly to the root zone of plants, but it may not adequately address the unique challenges of sloping terrain related to distribution.