2012 Annual Report 1a.Objectives (from AD-416): To develop a filter treatment system (containing modified iron) to remove nutrients and pesticides from agricultural drainage waters. 1b.Approach (from AD-416): Laboratory contaminant batch tests, saturated hydraulic conductivity tests, and saturated solute transport tests, followed by field pilot tests, will be used to develop filter treatment systems (containing modified iron) capable of removing nutrient and pesticide contaminants from drainage waters. 3.Progress Report: Research related to this project directly supports achieving the overall goal of Sub-Objective 1d for parent project, which is to "develop effective and efficient filter treatment systems capable of removing nutrients and pesticides from waters discharged by small- and large-scale subsurface drainage systems". This past year, a laboratory investigation (hydraulic conductivity, batch, and column tests) was carried out to evaluate the capability of a porous iron composite filter material to remove phosphate from drainage water. Results indicate that the porous iron composite filter material works well for phosphate water treatment as indicated by near 100% phosphate removal during a column test even though initial influent phosphate levels were very high (1 and 10 ppm phosphate-phosphorous). Furthermore, a laboratory evaluation (batch and column tests) of four iron-based filter materials showed that porous iron composite worked best for water treatment of the pesticides 2, 4-D, alachlor, and atrazine. Close to 100% of 2, 4-D, alachlor, and atrazine were removed during a porous iron composite column test, even though initial influent pesticide concentrations were extremely high (500 ppb).