The three basic requirements for life are Energy and Water so that the necessary biochemistry can take place to create Biomass.
Water serves three main purposes for Man
- a primary input for drinking
- ablutions and sanitation and thus maintaining public health
- a primary input for Biomass (food) production.
Prior to modern urban development all fecal waste produced by Heterotrophs was dumped on the land and through the action of the weather and biochemical decomposition, it was broken down, dissipated and re-assimilated into the soil where it could become nutrients for plant Biomass formation.
Virtually none of this waste was dumped directly into water so the impact on nutrients in the Water Cycle was negligible.
Water quality in the Water Cycle was maintained because the Nutrient Cycle in the aquatic environment was not distorted or overloaded and by the cleansing effect of the Primary Water Cycle; evaporation, transportation in clouds and precipitation.
The impact of the Anthropocene on Water has probably been greater than the impact of greenhouse gases on the atmosphere, and arguably poses a greater and more imminent threat.
We have been forced to distort natural water courses to supply urban centers and the effect has been to concentrate downstream wastewater flows. The residual contaminants/nutrients in these flows is overloading nutrient levels in bulk water resources and driving the process of eutrophication.