What about Pur packets?

Apparently its use flocculants can remove a lot of pollutants, how much exactly I'm not sure.

If I were in a situation where the only available water was highly contaminated with industrial or farm waste, an HTI filter would be my top choice. According to this FAQ it has shown 95% plus rejection of herbicides and pesticides and 85-90% plus rejection of heavy metals.

No affiliation with either of these and no firsthand experience.