The correct option is (a).
Explanation
Composting pits are a method of waste disposal and management where organic matter is decomposed biologically. In the context of sanitation, they function as onsite systems designed to treat human excreta and organic waste locally, converting it into manure without the need for water transport.
Statement-wise Analysis:
- Statement 1 is Correct: Composting pits are classified as onsite sewage disposal systems. They manage and treat waste at the point of generation (e.g., a household or community unit) rather than transporting it to a distant treatment facility. Other examples of onsite systems include septic tanks and pit latrines.
- Statement 2 is Incorrect: Composting pits are generally considered a low-cost sanitation solution. They require minimal infrastructure compared to centralized sewage treatment plants and sewer networks. They are often promoted in rural or developing areas as an affordable and sustainable alternative to expensive sanitation systems.
- Statement 3 is Incorrect: Onsite systems like composting pits are primarily utilized in areas without a centralized sewerage system. They are independent units designed to function where connecting to a main sewer line is geographically difficult or economically unfeasible.
Key Takeaway:
Composting pits are low-cost, onsite sanitation systems used for the biological decomposition of organic waste, typically deployed in areas lacking centralized sewerage infrastructure.