Septic Tank Treatment System (SepTTS) Model for Cleaning Product Chemicals
Overview
ACI is proud to make available to environmental professionals an online copy of the Septic Tank Treatment System (SepTTS) computer program and user manual. This computer program was referenced in the article "Modeling the Fate and Transport of Household Chemicals in Septic Systems."1
The SepTSS model is the result of extensive research by ACI. This model was developed as a screening level tool for assessing the fate and transport of household chemicals in septic systems. Because the model is simple and easy to use, it is possible that the model could be misused and its results misinterpreted. In particular, this model has only been calibrated for detergent builders and validated on surfactants.2 While there is no reason to suggest that this model would not give suitable predictions for other classes of compounds, they have not been tested to date. As with any model, this model should be used with caution.
We hope that you find the computer program useful and instructive. Please do not hesitate to send us your comments on the computer program at info@cleaninginstitute.org.
1. Lee S, McAvoy DC, Szydlik J, Schnoor JL. 1998. Modeling the fate and transport of household chemicals in septic systems. Ground Water 36:123-132.
2. McAvoy DC, DeCarvalho AJ, Nielsen AM, Cano ML. 2002. Investigation of an onsite wastewater treatment system (OWTS) in sandy soil: Modeling the fate of surfactants. Environ Toxicol Chem, in press.
Additional References
Investigation of an Onsite Wastewater Treatment System (OWTS) in Sandy Soil: Part 1: Site Characterization and Fate of Anionic and Nonionic Surfactants (Environmental Toxicology and Chemistry, 21(12): 2606-2616, 2002)
Describes research indicating that commonly used surfactants linear alkylbenzene sulfonate (LAS), alcohol ethoxylate (AE), and alcohol ether sulfate (AES) are readily removed via biodegradation in septic system or sorption onto soils, even under worst-case conditions.
Investigation of an Onsite Wastewater Treatment System (OWTS) in a Sandy Soil: Part 2: Adsorption and Biodegradation of LAS (Environmental Toxicology and Chemistry, 21(12): 2617-2622, 2002)
Describes how laboratory tests confirm the ability of soils receiving septic tank discharges to biodegrade and sorb surfactants. Further, tests on soils not previously exposed to these compounds showed that even they could quickly biodegrade and sorb these materials, indicating that soils possess the ability to acclimate quickly to septic system discharges.
Investigation of an Onsite Wastewater Treatment System (OWTS) in a Sandy Soil: Part 3: Predictive Model for Cleaning Product Ingredients (Environmental Toxicology and Chemistry, 21(12): 2623-2630, 2002)
Describes the validation of a mathematical model previously developed which serves as a screening level tool for assessing the fate and transport of down-the-drain household chemicals in septic systems with field and laboratory data
Click here for the Septic Tank Treatment System (SepTTS) program
Click here to view the user manual in PDF format.