Hydrology of Spray-Runoff Wastewater Treatment

Liquid measuring procedures used in a 12-month study of the hydrology of the soil treatment system at Campbell Soup Company's Paris, Texas plant accounted for 93% of the total liquid applied to the soil. The rainfall and wastewater applied to the soil system are accounted for as follows: 18% is lost to the atmosphere through evaporative processes; 61% is recovered as runoff; and 21% percolates through the soil. The fraction of the treated wastewater recovered as runoff ranges from a low of 30% to a high of 85%. This range in the percent runoff is influenced by climate, soil textural class, and wastewater spray schedules. Wastewater spray schedules are controlled to partially offset variations in the percent runoff which would normally occur as the result of climatic influences.