Grantee Research Project Results
2018 Progress Report: Evaluating Biofiltration in Small Urban Areas: Chico, California Case Study
EPA Grant Number: SV836930Title: Evaluating Biofiltration in Small Urban Areas: Chico, California Case Study
Investigators: Matiasek, Sandrine , Copson, Bryn , Faulk, Chad , Dearden, Eric , Nguyen, Quoc , Libby, Rachel , Vitamanti, Richard , Gruenberg, Robert
Institution: California State University - Chico
EPA Project Officer: Callan, Richard
Phase: II
Project Period: October 1, 2016 through September 30, 2018 (Extended to September 30, 2019)
Project Period Covered by this Report: October 1, 2017 through September 30,2018
Project Amount: $74,971
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2016) Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources , Sustainable and Healthy Communities
Objective:
The project objectives are to fill in a knowledge gap in biofiltration systems in small urban areas by 1) identifying key design parameters to achieve biofilter resiliency and 2) carrying out detailed long- term performance monitoring of existing biofilters. The innovative aspect of this project lies in its focus on testing pollutant removal efficiency in biofilters because the monitoring of current systems is mainly limited to hydrologic performance. Phase II research is conducted both in the laboratory and in the field. Long-term (18-month) laboratory experiments extend investigations from Phase I in order to identify optimal plant-media combinations and design configurations to achieve resilient biofilters. In-depth monitoring of biofiltration systems on college campuses in the Chico area (CSU Chico and Butte College) assess long-term hydrologic and pollutant removal performance of existing biofilters. In addition, a life cycle analysis (LCA) of biofiltration designs was initiated during year 2 of Phase II and will be continued during year 3. Increased public awareness about urban green water infrastructure is achieved through regular education outreach events in the local community.
Progress Summary:
This project has, to date, characterized the typical composition of urban storm runoff and evaluated the performance of three biofiltration systems in Chico, CA (Goal 2). Preliminary findings highlighted the importance of biofilter design for optimal water treatment: greater hydrologic residence times enhance heavy metal and total petroleum hydrocarbons removal, while vegetated systems need additional management strategies to efficiently remove nutrients and fecal coliforms. At the Butte College bioswale, water treatment varied over the course of the rainy season, with optimal contaminant removal during the first storms and a leaching of nutrients and some trace metals in the spring. We also investigated the role of native plants and media additives in a greenhouse setting to identify key design parameters contributing to biofilter performance and resiliency (Goal 1). Metal phytoaccumulation was documented in all plants tested and trace metals were found to accumulate in the root zone rather than in above-ground plant tissues. This contrasts with findings from the previous reporting period and indicates that further research is needed to identify factors controlling metal phytoaccumulation in biofiltration systems. Various media additives are being tested to assess their contribution to biofilter performance and resiliency (Goal 1). Preliminary results demonstrated that additives generally enhanced nutrient removal from stormwater, particularly zerovalent iron and water treatment residuals.
Future Activities:
These findings are relevant to the EPA’s mission to protect human health and the environment by providing a critical assessment of design criteria in biofiltration systems to improve water quality in urban storm runoff. The third year of the project will prioritize the monitoring of biofiltration systems during the 2018-19 rainy season and the assessment of the long-term performance of media additives in column experiments. The hydrology of the bioswale at Butte College will be characterized in-depth using flow measuring devices (flumes and weirs) and pressure transducers. This equipment will enable the continuous measurement of inflows and outflows in the system and the calculation of a water balance during storms, which will allow for the calculation of contaminant loads, leading to a greater understanding of the system. Due to its lack of performance (attributed to its design), the CSU Chico rain garden will not be further monitored. Media additives will be tested over 18 months to improve long-term nutrient removal, particularly nitrate. Additional undergraduate students in civil engineering will be recruited to complete the life cycle analysis of the project.
Journal Articles:
No journal articles submitted with this report: View all 23 publications for this projectSupplemental Keywords:
storm water management; urban water planning; low impact development; best management practices; green infrastructure; water treatment technology; pollutant removal; bioretention; water cycle; cost benefit analysis; environmental education.Relevant Websites:
Environmental Chemistry Laboratory at CSU Chico
Progress and Final Reports:
Original AbstractP3 Phase I:
Evaluating Biofiltration in Small Urban Areas: Chico, California Case Study | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.