Storm overflows explained

Why combined sewers discharge to rivers at all, why recorded spills rose so sharply, and what would actually fix it.

How sewage is treated

Wastewater treatment is mostly a controlled biological process: micro-organisms are fed the pollution and then removed.

Water reuse and potable reuse

Treated wastewater is already a major water source, mostly without anyone noticing. Planned potable reuse just makes it explicit.