unless there is a very heavy contaimination, the chemicals shouldn't pose a problem in a short term situation. it's long time exposure to chemicals that causes dangers. but still i wouldn't want to drink it.

But you could improvise a carbon filter. Charcoal is a form of carbon, so you could filter your water through some charcoal to remove the chemical parcially. Wenn you making one of those you might as well add other layer in the filter to clean the water further up. ( see places like these: http://therangerdigest.com/Tips___Tricks...fying_water.htm )