Mark the correct answer $($s$)$ for a typical untreated domestic wastewater

$($If necessary, you may mark more than one answer$)$

a$.$ Raw sewage contains significant amount of fecal coliform

b$.$ Raw sewage total nitrogen concentration $($as N$)$ ranges between $150-250m\frac{g}{l}$

c$.$ Chloride in raw sewage is a significant contaminant that has to be removed in treatment plants

d$.$ Raw sewage COD concentration ranges between $400-800m\frac{g}{l}$