$1.$ Consider the following cases. Would they need to model their air emissions. Assume that each case is located in a class II region that is currently in attainment, with no nearby class I regions.

a$)$ A new coal$-$fired boiler, burning $0\mathrm{.}5$ tons$/$hr of coal with an $8\%$ ash content. Assume the only emission is PM

b$)$ A power generator burns $5000$ gal$/$hr of No$.2$ fuel oil in an existing facility, and undergoes an expansion that doubles its use of fuel oil. Assume the only emission is PM

c$)$ A new coal fired boiler which burns $20$ ton$/$hr of bituminous coal with $3\%$ sulfir, and with equipment that will remove $80\%$ of SOx. Assume SOx is the only emission.

d$)$ A medical waste incinerator burns $/$ ton$/$hr and removes $97\%$ of the PM generated. Assume the only emission is PM$.$