More than 80% of wells in the flood-ravaged areas of Varappuzha and Moothakunnam have septic tanks in close proximity to them, it was found.
The proximity of wells to septic tanks in the district is a matter of health concern, cautioned scientists, who surveyed the wells as part of a water quality assessment programme.
A research team, led by scientists of the National Institute of Oceanography (NIO), Kochi, had surveyed over 300 wells in the severely flood-affected panchayats of Alangadu, Varappuzha, Chennamangalam, Moothakunnam, and Chittethukara.
Besides the representatives of the National Health Mission and UNICEF, volunteers from the NIO, Central Marine Fisheries Research Institute, Centre for Marine Living Resource and Ecology, Kerala University of Fisheries and Ocean Science, and Cochin University of Science and Technology, participated in the survey.
The volunteers also looked for the source of safe drinking water, the height of inundation during the flood, cleanliness of surroundings of wells, and the appearance of well water besides its proximity to septic tanks. Wells were also classified into six grades based on the appearance of water and proximity to septic tanks.
Faecal contamination
The faecal contamination of well water depended on the type of septic tank and type of soil in the area.
The chances of faecal contamination in wells dug in laterite or rocky areas and with intact septic tanks were lower when compared to the ones in sandy or clay areas with damaged septic tanks. Appropriate levels of chlorination and boiling of drinking water was suggested in these areas.
The researchers also suggested regular testing of water for faecal contamination and residual chlorine in these areas.
The team, led by T. Pankajakshan, the scientist-in-charge, and Anas Abdulaziz, senior scientist, NIO, advised not to use the water from wells, which were located in close proximity to septic tanks, and that had turbid water in them.
As the possibility of contamination of water in these wells was high and chlorination would not serve any purpose, it was advisable not to use it till appropriate treatment methods were introduced, said the scientists in a report submitted to the district administration.
Around 50% of the wells in Chennamangalam had turbid water, while it was less than 40% in other areas. Turbidity might be due to the suspension of soil particles, mixing of sewage and septic waste with well water, the report said.
The overall surrounding of wells were found to be dirty in Chennamangalam area. Solid waste was found disposed near wells and stagnant water was found in many areas. The stagnant waters may serve as breeding grounds for mosquitoes and trigger the outbreak of vector-borne diseases like dengue, the report said.
