Wt. of ${\text{CaCO}}_3$ aqueous solution $=1000\text{ g}$

$\text{ppm}=\frac{\text{no}\text{.of parts of one component}}{\text{Total no}\text{.of parts of all components}}\times {\text{10}}^{\text{6}}$

$\text{Concentration}\text{in ppm}=\frac{10}{1000}\times {10}^6=10000\text{ppm}$ .