Environmental hygiene and sanitation in the fishing communities of Trivandrum district

Open defecation poses a health threat for the fishing communities in Trivandrum district, Kerala, India. This paper proposes four alternative sanitation options for these communities. These are: the (1) "Tidal Cleansed Pit Latrine", the (2) "Beach Composting Toilet with Shelter Belt", (3) aquatic plant lagoons, and (4) a composting toilet linked to evaporative reedbeds. (1) The first option is a water-seal latrine atop a pit of which the part passing through the freshwater layer is water- proof, and the part below the lowest seasonal freshwater table is perforated. By using seawater, which is heavier than freshwater, for flushing, the tidal rise and fall is expected to empty the pit. (2) The beach composting toilet is a combination of sanitation and erosion prevention. Urine and washwater are led separately via a pipe to the roots of nearby shelter bed vegetation. (3). The lagoon system, which is already in operation, replaces the blocked soakaways of an existing block of ten pour-flush latrines. Effluent from the latrines and sullage from a women's bathing well, first pass through an aerobic decanter-digester, then a series of aquatic plant lagoons, and finally a slow sand filter. Part of the treated effluent is recycled for toilet flushing. (4) The last option is a composting toilet feeding urine and flush water into a pair of alternating reedbeds. Harvested reeds can be used both as a source of organic carbon for the composting toilet and as domestic fuel.