THIRUVANANTHAPURAM: Ever wondered where those lorries that empty septic tanks take the waste to? The highest probability for the waste to be dumped is in a water body after spraying it with a microbial cocktail to keep the odour away.
While the state has no methods or plans for treatment of septage, and septic tanks in Urban areas becoming major sources of groundwater pollution, the Centre for Water Resources Development and Management (CWRDM), Kozhikode, supported by Suchitwa Mission is all set to develop a septage management plan for the state.
“The population density is very high in Kerala. So is the case with wells. As per a rough estimation we have as many as 250 to 300 wells in 1 sq km. The water quality of these wells is directly linked with sanitation,” said P S Harikumar, head of the Water Quality Division of CWRDM.
The objective of the study is to generate data on septage load produced in all districts, to characterise the septage to ascertain its quality, developing a concept for septage collection and septage treatment and to carry out a detailed proposal for septage treatment options.
As a preliminary work, the CWRDM team would collect a lot of authentic data, especially related to existing scenario of septage collection and disposal. Samples would be collected from Corporation, municipalities and panchayats. “It is estimated that 500 m3 of septage is collected per day in Greater Kochi area. The operators dump the septage in water bodies and relatively less polluted areas,” said Harikumar.
Septage from hotels and hospitals would be collected separately and characterised. Representative samples from lowland, midland and highland as well as pre-monsoon and post-monsoon samples would also be analysed.
Attempts will be made to collect samples based on ageing.
After analysing the samples for various chemical parameters such as alkalinity, oxygen demand, ammonia, nitrogen, oil, grease and phosphorous, the CWRDM team would explore the various kinds of treating the septage such as land application, co-treatment with sewage treatment plants and stand-alone treatment plants.
“Pathogen free septage may also be explored as a resource for soil amendments or as organic manure. The anaerobic treatment system has the potential of generating energy and the possibility of harnessing energy from the process shall also be explored,” said Harikumar.
As per a projection of the Suchitwa Mission, the generation of septage quantity by 2026 will touch 4250 m3 per day in Kerala. While a management plan is absolutely essential, the present study also aims at a feasible concept that would promote septic tanks along with improvements in the collection as well as adequate sludge treatment.