Laserfiche WebLink
Section 4 <br />Polenlia/forRock to be Toxic Forming <br />be adequate to remove this moi., <br />percolation through the pile. As <br />contributing to this water balani <br />ire through evapotranspiration, preventing <br />iscussed previously, the primary ET mechanism <br />assessment is evaporation. <br />Unsaturated Flow Modeling: Unsaturated flow modeling was used to estimate <br />percolation through the rock pile in a more rigorous manner. UNSAT-H (Fayer 2000) <br />is a Fortran-based model that is used to simulate the one-dimensional flow of water, <br />vapor, and heat in soils. The cod addresses the processes of precipitation, <br />evaporation, plant transpiration, storage, and deep drainage. The procedure for this <br />estimation included: <br />¦ Estimate physical and hydrolc <br />specific sampling and laboratc <br />¦ Compile climate data from loc <br />¦ Estimate percolation through <br />The UNSAT-H model was chosE <br />gal characteristics of development rock using site <br />analyses. <br />as close as possible to the site. <br />t rock areas using UNSAT-H. <br />for this evaluation because it simulates both <br />downward movement of water i to the development rock piles during infiltration <br />and upward movement of water from the rock piles caused by evaporation. <br />Consideration of upward unsatu rated flow is critical for accurate simulation of <br />percolation through mine rock piles in semiarid and and environments (Swanson et <br />al. 2000). Application of rigorous unsaturated flow models based on Richard's <br />equation is becoming a widely u. ed approach to simulate unsaturated flow through <br />mine waste piles (e.g. Ford et al, '2000; Swanson et al., 2000, Fala et al., 2005). Benson et <br />al. (2006) provides basic requirements for unsaturated flow models including: <br />¦ The model must simulate <br />Richards equation); <br />¦ The model must include a su <br />interactions (precipitation, in <br />¦ The model must integrate <br />UNSAT-H meets these requiren <br />Landfill Performance model (Hl <br />estimates, HELP does not meet 1 <br />movement of water through the <br />equation (Benson et al. 2006). Ul <br />plant transpiration, although the <br />Additional details of the calcula <br />are presented in Fayer (2000) ar <br />calculation brief, model input fi <br />presented as Attachment 6. The <br />flow in a rigorous manner (i.e. must solve <br />boundary simulating soil-atmosphere <br />evaporation, runoff); and <br />is data into the solution. <br />ts. Although the EPA Hydrological Evaluation of <br />') has been used in the past for these types of <br />criterion of rigorously simulating upward <br />lose zone through application of Richard's <br />kT-H also is capable of simulating heat flow and <br />options were not applied in this estimation. <br />on methods and procedure applied by UNSAT-H <br />are not discussed further in this document. A <br />s, input data tables, and model output files are <br />alculation brief provides a summary of the modeling <br />• <br />n <br />E <br />4-12