# Clogging Effect on Hydraulic Conductivity Soil clogging decreases porosity in the biozone with inert and biological materials. With the reduced soil porosity, the hydraulic conductivity of soil decreases with time (USEPA, 1980). A field-scale experiment suggests the reduction in hydraulic conductivity in the biozone is primarily influenced by STE loading rate and the type of infiltrative surface (Bumgarner and McCray, 2007). Weintraub et al. (2002) proposed a relationship between the biozone hydraulic conductivity and soil moisture contents. $$K\_{bz}=K\_{sat}\frac{\theta -\theta\_f}{\theta\_s-\theta\_f}$$ (7) where $$K\_{bz}$$ is biozone hydraulic conductivity (mm/hr), $$K\_{sat}$$ is saturated hydraulic conductivity of soil (mm/hr), and $$\theta$$ is moisture content of biozone (mm). An advantage of this model is that, $$K\_b$$ is directly related to $$K\_s$$ and the soil moisture content. The theoretical basis on the formulation of the equation is not presented in the literature; instead, the formula is indirectly validated by comparing percolation to the subsoil layer as a function of time. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://swatplus.gitbook.io/io-docs/theoretical-documentation/section-6-management-practices/septic-systems/biozone-algorithm/clogging-effect-on-hydraulic-conductivity.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.