Why are fracking liquid waste pools harmful to the environment?

can evaporate into the air and contribute to

When fracking liquid waste is left in pools on the surface,

pollution.

Fracking liquid waste - type of waste produced during hydraulic fracturing in oil drilling operation - comprises a large fraction of salts, hydrocarbons, radioactive materials, and carcinogens. Many of these chemicals (e. g. benzene, toluene, etc) are able to vaporize at ambient environmental conditions, thus making the environment polluted. If they are left untreated in the pit lakes or pools, they are a serious threat to the local fauna and flora. This is because of their toxic, mutagenic, and teratogenic properties.