VS, sounds like you need to find out more from the people you are working for. You might need some pants that can take a beating, or, as phat mentioned, chainsaw chaps and steel toe boots. If you need tough pants, then look for the Dickies or Carhart brands. They are 100% cotton, but tough as nails. Or, you can go with the ripstop poly-cotton military pants you find at a surplus store. They are really comfortable, tough, and have extra patches of material in high wear areas. Take one pair of tough,heavy pants, and one pair of light nylon pants. Wear the heavy pants for working and the light ones for the rest of the time. A week isn't that long to need to wash them, even if you get them really dirty. Also, if you are lucky, look at a Sportsmans Wearhouse for steel toe boots, if you need them. They have some that aren't too heavy, and are made more for hiking.