Seawater intrusion and elevated levels of chemical contaminants are degrading groundwater quality in several coastal areas of Visakhapatnam, with water found to be unfit for drinking in four locations, according to a study by GITAM University researchers.
The study analysed groundwater samples collected from borewells at 15 locations along a 26-km coastal stretch between Kothajalaripeta and Bheemunipatnam. Samples were collected in May, ahead of the monsoon, and again in November for physical and chemical analysis.
The researchers used three indices to assess the samples: the Water Quality Index (WQI) to assess overall water quality, the Revelle Index (RI) to determine the extent of seawater intrusion, and the Langelier Saturation Index (LSI) to assess parameters such as temperature, hardness, alkalinity and total dissolved solids.
Groundwater in Siva Ganesh Nagar, Jodugullapalem, Sagarnagar and the Government Girls’ Gurukulam was found to be unfit for drinking in both sampling periods.
Sagarnagar recorded the highest WQI, at 143 in May, which fell to 134.9 in November. The corresponding figures were 125 and 121 at Siva Ganesh Nagar, 106.6 and 102.9 at the Government Girls’ Gurukulam, and 100.2 and 100.3 at Jodugullapalem.
A WQI value above 100 indicates that water is unsuitable for drinking.
Seawater intrusion detected
The study found elevated RI values at Kothuru, Bheemunipatnam, Ernimamba Temple and Thimmapuram. The RI should ideally remain below 0.5, while Kothuru recorded a value of 2.16.
The researchers attributed the seawater intrusion to excessive groundwater extraction along the coast. Researchers also found that increased industrial activity affected groundwater quality in some areas.
Elevated fluoride levels were detected in Siva Ganesh Nagar, Jodugullapalem, Sagarnagar and the Government Girls’ Gurukulam, while manganese levels were high at Panduranga Swamy Temple, Pedajalaripeta and Jodugullapalem.
The findings are significant as many households and gated communities in Visakhapatnam rely on tanker water to meet their daily needs. Residents in some areas have reported skin irritation and hair loss after using tanker-supplied water.
Budda Ravi Prasad, Kakarla Jagadeeswara Rao, Nanduri Srinivas, and Kolli Suresh Kumar, faculty members at GITAM University, conducted the study. The findings were recently published in the Research Journal of Chemistry and Environment.