KATHMANDU, April 22 (Xinhua) -- Water pollution in the south side of Mt. Qomolangma, also known as Mt. Everest, has worsened in recent years because of the influx of visitors and the increase inhuman waste, according to a survey conducted in Nepal.

    The survey, sponsored by the Hindukush Karakoram Himalaya Partnership Project and the Nepal Academy of Science and Technology, was carried out in Sagarmatha National Park and its Buffer Zone (SNPBZ) of Nepal, some 130 km east of Nepali capital Kathmandu, in 2007 and 2008.

    The survey on "Impacts of Tourism in the SNPBZ" was carried out by Professor PK Jha, in cooperation with researchers NP Ghimire and BB Shrestha of the Central Department of Botany, Tribhuvan University of Nepal, according to local newspaper The Himalayan Times on Wednesday.

    According to the research, bacterial contamination was recorded in 13 percent water samples and one sample of mineral water.

    "E coli and Streptococcus faecolies were found in the waters ofKhumbu Valley," Dr. Jha said.

    Dudhkoshi, Bhotekoshi, Imja Khola and Gokyo lake are the major water bodies in the south side of Mt. Qomolangma.

    Besides local visitors, the total population of the area is 5,869. Unsafe toilet and use of manures are the major causes of water contamination, the report said.

    According to the report, litter toilet is common among farming population and the waste is later used as fertilizer in potato fields. There are three types of toilet tanks, simple pit, stone-wall septic tack and cement-wall septic tanks. Only 4.66 percent of the people have cement-wall septic tanks.

    A total of 2,197 tons of manure is produced in the region annually and eight tons of manure is used in a hectare of arable land. The excessive use of manure contaminates the water bodies badly, Jha added.

    Six water samples collected in the area had iron content of 1.2 mg/liter in Dudhkoshi at Jorsalle and 0.64 mg/liter in Bhotekoshi near Thame. The iron content in drinking water should be less than 0.3 mg/liter, according to the World Health Organization.

    "Water pollution prevention program should be implemented to control this hazard," Jha said.

    The samples collected in the region were tested under standard methods at Environmental Assessment Material Testing Division, in Kathmandu.