They will spend weeks acclimatising around the four camps set up between the base camp at 5300m and the 8850m summit. The camps have tents and some essential equipment and supplies, but not toilets.
Tshering said: "Climbers usually dig holes in the snow for their toilet use and leave the human waste there."
He added that waste has been "piling up" for years around the camps.
At the lowest base camp, where there are more porters, cooks and support staff, toilet tents have drums to store the waste.
Once filled, these are carried to a lower area, where the waste is properly disposed of.
Dawa Steven Sherpa, who has been leading Everest clean-up expeditions since 2008, said some climbers carry disposable travel toilet bags to use at higher levels.
"It is a health hazard and the issue needs to be addressed," he said.
Nepal's Government has not yet come up with a plan to tackle the matter of the waste but officials stationed at the base camp will strictly monitor the condition of the mountain from now on, said Puspa Raj Katuwal, the head of Nepal's Mountaineering Department.
The Government imposed new rules last year that required each climber bring back 8kg of rubbish to base camp - the amount it estimates a climber discards along the route.
More than 4000 adventurers have scaled Mt Everest since 1953, when it was first conquered by New Zealander climber Edmund Hillary and his Sherpa guide, Tenzing Norgay. Hundreds of others have died in the attempt, and many have succeeded only with help from oxygen tanks, porters and guides.
— Independent