Affiliations: Deltaic Regional Centre, National Institute of
Hydrology, Kakinada – 533003, Andhra Pradesh, India | Dept. of Civil Engineering, Indian Institute of
Technology Delhi, Hauz Khas, New Delhi – 110016, India
Abstract: The major non-agricultural source of nitrate in groundwater is
septic-soak pit systems and unsewered conditions in the east coastal plains of
India. This paper deals with the assessment of nitrogen loading from septic
tanks in the Kakinada urban east coastal plains of Andhra Pradesh State, India.
The proposed assessment methodology makes use of available databases of
population, number of houses, sanitary information, soil types etc., in each
village or sub-basins which are generally available in India or elsewhere.
Two-dimensional Fuzzy c-Means clustering Technique (2 D FCM) was used to
classify nitrogen load over the Kakinada urban coastal plain into low, medium
and high zones. Further, these zones were validated with the respective average
groundwater quality. The average groundwater nitrate and electrical
conductivity values are following the patterns of nitrogen loading zones.
Therefore, groundwater nitrate contamination is mainly due to the unsewered
conditions and high density of septic systems in the study area. The
methodology adopted in the present paper is useful for the assessment of
nitrogen load from leaky septic systems in the coastal plains and also for
prioritizing the villages or sub-basins for better management of
non-agricultural sources of nitrate in coastal plains.
