The Tanzanian government is encouraging local communities that live near the Indian Ocean to move further inland where water sources are less contaminated by sea water, according to a report in AllAfrica.
Fresh water in the coastal town of Pangani in Northeast Tanzania is becoming increasingly contaminated as salt water seeps in from the Indian Ocean, the report said.
Scientists have linked the growing problem of saltwater intrusion worldwide partially to climate change. As sea levels rise, sea water will inundate wetlands and other low-lying lands, intensify flooding and increasing the salinity of rivers and groundwater tables, according to the U.S. Environmental Protection Agency.
In Tanzania, changing weather patterns will make coastal communities more vulnerable to rising sea levels, according to a 2011 study, “Economics of climate change in Tanzania,” published by the Tanzania government in collaboration with the U.K.’s Department for International Development.
Tanzania’s 310-mile Pangani River and underground aquifers are the main sources of drinking water for thousands of Pangani residents, located about 250 miles north of the capital, Dar es Salaam. Over the last few decades, the rising ocean has been leaking salt water into aquifers and wells.
Dwindling rainfall exacerbated the problem, and Pangani residents said underground wells previously resilient to salt water have been contaminated.
Most water sources have been contaminated, leaving people with no other option but to drink salty water, said Hamza Sadiki, a researcher with Pangani Basin Water Board. “The rate at which dissolved salt is leaking into freshwater sources is quite alarming,” he said.
“Most people drink salty water whose salinity exceeds acceptable standards, but we simply can’t tell them don’t drink it,” said Mohamed Hamis, a water engineer with the Pangani Town district authority.
Salt water is a huge problem in the town, but locals drink it anyway since fresh water has become scarce. “We need help,” said Amran Shamte, a 65-year-old local resident.
The acceptable level of dissolved salts in fresh water lakes, rivers and ground water is 20 to 800 milligrams per liter, according to the World Health Organisation.
Samples taken by researchers from the Pangani Basin Water Board show that the total soluble salt levels downstream of the Pangani River are far beyond acceptable standards at 2,000 milligrams per liter.
“It is for this reason that the government decided to set its own standards of salt water to enable people in coastal communities to drink this water,” Arafa Maggid, an engineer from Pangani Basin Water Board.
Drinking salt water over a long period could be hazardous since salt dehydrates the body, said Sabas Kimboka, a nutritionist from the Tanzania Food and Nutrition Centre.
“There is no safe amount of seawater to drink,” he said. “Salt makes you more dehydrated and requires you to drink more fresh water (that) you probably don’t have.”
The saltwater intrusion has gone six miles upstream, making it difficult for the authority to supply fresh water, especially during high tide, Hamis said. The town authority now pumps water only during low tide and plans to move the pump further upstream.
It has not conducted a census to establish how many people are affected.
The government is considering hiring experts to drill salt water barrier wells to protect underground aquifers from contamination, but this project will depend on availability of funds.
Residents have been forced to travel longer distances to find fresh water. Many say they cannot afford to move.
Hamis said the government has raised the acceptable standards of water salinity beyond international norms.