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Vietnam - Groundwater levels in the Mekong Delta falling

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  • Vietnam - Groundwater levels in the Mekong Delta falling

    Nation?s groundwater drained dry by out-of-control well drilling

    Unquenchable thirst: A farmer pumps water from his Chu Se District well in the Central Highlands province of Gia Lai.
    Underground water levels have decreased remarkably over the last decade due to the reckless drilling of wells for agricultural, household and industrial use, experts warn.

    A recent report by the Center for Water Resources Technology and Assessment, under the Ministry of Natural Resources and Environment, says groundwater levels are 10 meters lower in Ho Chi Minh City, and six meters lower in Hanoi than they were 10 years ago.

    Professor Ngo Dinh Tuan from Hanoi Water Resources University warned that groundwater levels in the Central Highlands were sinking due to the over-irrigation of crops, mainly coffee.

    A study done at the university also found that groundwater levels in the Mekong Delta had fallen to 10 meters over the last decade and could run completely dry over the next five years.

    ?Without proper planning, Ho Chi Minh City?s groundwater could be all used up in only 30 years,? said Huynh Le Khoa from city?s Department of Natural Resources and Environment.

    Can Tho University professor Le Anh Tuan added that pollution could ruin the groundwater even before it dries out as local authorities have not kept a vigilant eye on open abandoned wells, which act as open veins through which pollution flows into groundwater.

    Drill everywhere, all the time

    Farmer Tran Thanh Hien from the Mekong Delta province of Soc Trang?s Vinh Chau District said his old well, 106 meters deep and 49 millimeters in diameter, used to irrigate his vegetables while another well provided for family use.

    However, he had to drill a third well, deeper and larger, when the farming well ran dry after two years of use.

    An estimated 2,000 wells are being used by residents living on Nam Song Hau Road in Vinh Chau District alone.

    Wells are also a common sight in the fields of nearby Bac Lieu Province, where they are used to irrigate vegetables and shrimp farms.

    ?The groundwater is nearly exhausted and shrimp farmers are drilling larger wells and installing stronger water pumps,? said Pham Van Chu of Vinh Trach Dong Commune in the province?s eponymous capital town.

    He also said many farmers had two wells, each with a capacity to draw 1.9 million liters a day.

    In HCMC, many families still use wells even though they have tap water supplies.

    A recent survey found the city has 200,000 wells in outlying districts and 90,000 others in central districts, in addition to 100,000 more for industrial use.

    Nguyen Huu Hiep, deputy director of Trung An Water Supply Company, said at least 150 households had been caught using well water even though they had tap water, a clear violation of local regulations.

    Besides family use, residents in HCMC also use underground water for crop irrigation in districts 12, Thu Duc, Hoc Mon, Binh Chanh and Cu Chi.

    Drying out

    The HCMC Environment Protection Agency said water in the Pleistocene plate lowered by 0.25-0.6 a meter year-on-year in 2008 and by up to three meters year-on-year so far in 2009.

    Water levels in the Pliocene plate at a monitor station in Binh Chanh District have lowered by 2.03 meters since 2007, leading to a total reduction of over 13 meters in the past 13 years, according to the agency.

    Nguyen Thanh Tam, who has drilled HCMC wells for 30 years, said he used to make wells 16 meters deep in Go Vap District. But now he has to drill to 24 meters to withdraw usable water.

    He also said the usable groundwater is as low as 160 meters from the surface in districts 6, 8 and Binh Chanh.

    Hanoi, known for its rich groundwater supply, has also seen a reduction in its supply after years of using up to 800 million liters of the valuable resource per day.

    Nguyen Van Dan of the Ministry of Natural Resources and Environment said a shortage of groundwater has occurred in central Hanoi, including the areas of Phap Van, Ha Dinh, Ngoc Ha and Mai Dich.

    Many residents in Dong Anh and Hoang Mai districts said they had to drill deeper wells every four or five years to reach lower water.

    Nguyen Thi Ha, who is in charge of the Center for Water Resources Technology and Assessment, said the well at Ha Dinh Water Plant was 29 meters deep in 1997. However, the level lowered to 32 meters in 2002 and 35.2 meters in 2007.

    Scientists have also warned that groundwater levels in the Mekong Delta have fallen by 10 meters over the past decade.

    Murky water

    A 2008 study conducted in HCMC found most water samples from 16 stations monitoring the Pleistocene plate failed to meet safety standards, with high levels of harmful chemicals like nitrate and ammoniac as well as coliform and fecal coli bacteria.

    The nitrate concentration increased by 3.5-4.1 times year on year in 2008, with a remarkable increase in the first quarter this year, the city?s Environmental Protection Agency has reported.

    At the Phu Tho station, nitrate concentration is 69.6 mg/l, far exceeding the 15mg/l level deemed safe.

    The Saigon Water Supply Corporation has shut down some 10 groundwater plants since 2005 because of ammoniac pollution.

    In Ca Mau Province, underground water in several places has been infected with bacteria, according to the provincial Department of Natural Resources and Environment.

    Ly Nhan, the department?s deputy director, said coliform bacteria have tainted water supplies in several districts at concentrations five times higher than the level deemed safe.

    Concerned authorities also warned that out-of-control drilling by private companies had polluted groundwater with saline water, bacteria and chemicals because many firms have left abandoned wells, often drilled in areas without a sufficient water supply, uncovered.

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