In terms of gross overall costs, on the basis of 100 samples: CONSULTANT CASSIAR Samples $20000 $3000 Labour $ 6000 $2000 Equipment N.A. $ 10000 Transport & Accomodation $ 1500 N.A. Misc. ยง 2600 $2000 -$30,100_ $17,000 It is therefore not considered economic to perform our own emission stack sampling unless a sufficient number of samples are required. If the sampling is to be of a continuing nature, and require say perhaps 30 to 50 samples, it is rec- ommended Cassiar purchase equipment required and perform the analysis. AMBIENT AIR Ambient air quality monitoring is used at Cassiar to measure such parameters as suspended particulate matter (amount of solids not settling to the ground but which remain suspended due to their small size), dustfall (particulate matter which does settle out of the atmosphere), and sul- phation rate (relative quantities of sulphur dioxide in the air.) Other parameters such as soiling index and nitrous oxides are not measured since the former three provide the most needed current information.