ABSTRACT: Climate regimes and gradients strongly influence both spatial and temporal opportunities and constraints for disposal of wastewater by land application. Availability of long-term digitized daily weather data allows analysis of the design of such systems by modelling multiple years of daily operations at different locations with computer simulation. A 30 yr simulation of a 3800 m³ d^-1 disposal plant in 5 locations in the southeastern United States demonstrates that the best design requires disposal field sizes ranging from 256 ha in the coastal and eastern parts of the region to 160 ha in western and inland locations. Results further indicate that a recommended-size system with a 24 ha storage pond 3.7 m deep should fail (overflow on at least 1 day of a month) no more than 3% of the time, a 20 ha pond no more than 17% of the time, and a 16 ha pond no more often than 20% of the time in all months and at all locations in the region. Conversely, these specifications should provide success (no overflow on any day of any month) in 97, 83, and 80% of the time, respectively.

KEY WORDS: Wastewater . Climate . Computer simulation . Design criteria

Published in CR Vol. 6, No. 1 (1996) on January 30
ISSN: 0936-577X. Copyright © Inter-Research, Oldendorf/Luhe, 1996