Four-point plan to combat Bangkok’s salty tap water

The problem is caused by seawater intrusion at the Samlae Raw Water Pumping Station in Pathum Thani, where salinity was measured at 0.25 grams per litre on Tuesday. The World Health Organisation has set the daily intake of salt at 2 grams and recommends people do not consume tap water with sodium exceeding 0.2 grams.

Drought conditions had reduced the amount of water released from Chao Phraya dams to flush out the seawater, explained MWA director of Water Resources and Environment Development Somsak Passananon.

As a result, people living on the Chao Phraya River’s eastern bank in Lak Si, Don Mueang, Lat Krabang, Bang Phli, Bang Na and Samrong districts are suffering brackish tap water. Residents of western Bangkok receive their water from the Mae Klong River Basin and are not affected.

Salty tap water in east Bangkok is expected to persist throughout February, said MWA deputy governor Raksak Suriyaharn.

The MWA said it has a four-pronged plan to combat the crisis.

First, it is monitoring water at the Samlae pumping station, though it says it can only prevent high saline levels for four hours per day given Bangkok’s high tap water consumption.

Second, it has launched two water-hammer operations to flush seawater, on January 13-16 and January 28-31.

Third, it is providing clean water points for the public at 18 WMA offices.

Fourth, it is updating the public with reports and forecasts of water salinity on social media platforms.