Q1: In areas where rainy season is limited to a few months, the type of sewerage system recommended is

ANS:C - separate system

In areas where the rainy season is limited to a few months, the recommended type of sewerage system is typically a partially separate system. A partially separate sewerage system is designed to handle both sanitary sewage (wastewater from toilets, sinks, showers, etc.) and stormwater runoff. However, during periods of heavy rainfall, such as the rainy season, the system can become overwhelmed, leading to combined sewer overflows (CSOs) where both sanitary sewage and stormwater are discharged directly into receiving waters without treatment. This can result in water pollution and environmental degradation. In regions with limited rainy seasons, a fully separate sewerage system might be considered excessive because the frequency and intensity of storm events do not justify the cost of separate infrastructure for stormwater management. On the other hand, a combined sewerage system might lead to more frequent CSOs during the rainy season, causing environmental concerns. A partially separate system provides a compromise between the two extremes. It involves separate collection and conveyance of sanitary sewage and stormwater for most of the year, but during periods of heavy rainfall, excess stormwater may be temporarily diverted into the sanitary sewers to prevent flooding of streets and basements. While this may result in diluted sewage entering the treatment plant, it can help alleviate the risk of sewer backups and overflows during intense rainfall events. Therefore, in areas where the rainy season is limited to a few months, a partially separate sewerage system is often recommended as the most practical and cost-effective solution for managing wastewater and stormwater.