Flowcharts

This area chart sample was redesigned from the picture "Outstanding trends of wastewater treatment plants" from the Washington State Department of Ecology website.
[ecy.wa.gov/ programs/ wq/ wastewater/ op_ cert/ kudos.html]
"Sewage treatment is the process of removing contaminants from wastewater and household sewage, both runoff (effluents), domestic, commercial and institutional. It includes physical, chemical, and biological processes to remove physical, chemical and biological contaminants. Its objective is to produce an environmentally safe fluid waste stream (or treated effluent) and a solid waste (or treated sludge) suitable for disposal or reuse (usually as farm fertilizer). Using advanced technology it is now possible to re-use sewage effluent for drinking water, although Singapore is the only country to implement such technology on a production scale in its production of NEWater." [Sewage treatment. Wikipedia]
The area graph example "Outstanding trends of wastewater treatment plants" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Area Charts solution from the Graphs and Charts area of ConceptDraw Solution Park.