Evaluation and remediation of irrigation water and soil at Scissortail Park

This project addresses the significant water and soil quality issues at Scissortail Park, a reclaimed brownfield site in Oklahoma City. The park’s current irrigation source, a high-salinity, high-bicarbonate lake, leads to hardened soil with limited permeability, affecting plant health and root growth. Objectives focus on reducing the irrigation water’s pH, salt, and bicarbonate levels, and improving soil texture to enhance water absorption and root penetration. Primary recommendations involve conducting trials to evaluate potential solutions for both water and soil issues, given the park’s unique circumstances. Water trials aim to assess the viability of three alternative irrigation sources along with a control. These include lake water, lake water with SeacureCal, lake water with sulfuric acid, and Oklahoma City water. Testing included plant growth trials using two plant species that are expected to survive well in the current conditions. The trials will be conducted at the park from March 27, 2025, to April 17, 2025, with visual monitoring of plant health and survival. For soil remediation, trials tested six treatment combinations, including surface-applied organic matter, subsurface organic matter with tilling, gypsum addition alone, and combinations of these methods. Plots in the park were monitored from February 10, 2025, to April 17, 2025, to evaluate changes in soil structure and texture, with initial and follow-up testing to measure improvements. Baseline water and soil quality data will guide these assessments. From our results, we saw that the best method to lower pH, bicarbonate, and salt was gypsum combined with organic matter and tilled. The second best option was organic matter surface. Because it would be very time consuming and disturbing to the park to till it, add organic matter and gypsum, the simple recommendation was to add organic matter to the surface. For water testing, the best water option was the OKC water. Since it would take an entire change of the park’s water infrastructure, we recommend that they use SeaureCal with the lake water to act as a buffer to the pH and improve the irrigation water quality. By addressing water and soil issues simultaneously, the project identified scalable, site-specific solutions to improve soil health, enhance water absorption, and support vegetation resilience, ultimately fostering long-term sustainability at Scissortail Park.