Groundwater Contamination Due to Nitrate

Groundwater Contamination Due to Nitrate

in a Coastal Aquifer: Conjecture and Identification

Along the West Coast from Katana to Negombo,

Sri Lanka

Higher amount of nitrate in drinking water can cause severe methaemoglobinaemia and cancer in infants and adults. Land-uses and anthropogenic activities accompanied by hydrogeological conditions cause nitrate contamination in groundwater. This study aimed at estimating and identifying using box-plot, empirical approach and nitrate:chloride ratio (1:1 8:1) as feasible methods to prove the possible sources in the western coastal area in Sri Lanka from Katana to Negombo. The outputs show that a high nitrate in groundwater of the area is originated mainly from on-site sanitations (i.e. soakage, pit latrine, septic tank) under denser populated settlements, while agriculture plays as a secondary source. Current groundwater nitrate levels from analyzed water wells indicated that about 30% of the water samples exceed the Maximum allowable value of 10 mg/L NO3 , however, samples with nitrate greater than 50 mg/L were not found. Denitrification processes may also contribute regulate nitrate levels in the area. Although nitrate concentration at present is not alarmingly high in the area, an increasing trend of contamination is expected with population, settlements and agriculture growth. Therefore, appropriate management and special care from relevant parties should be set up to rectify the problems and to use precious groundwater resource sustainably.

KeywordsNitrate contamination, coastal aquifers, Sri Lanka, methaemoglobinaemia, nitrate:chloride ratio, on-site sanitations

https://www.ijert.org/groundwater-contamination-due-to-nitrate-in-a-coastal-aquifer-conjecture-and-identification-along-the-west-coast-from-katana-to-negombo-sri-lanka

https://www.semanticscholar.org/paper/Groundwater-Contamination-Due-to-Nitrate-in-a-and-Ratha-Nandalal/8521bbd40f53730ef044751bb942ab1c4d1a545d