Evaluating Reactive Barrier Technology to Enhance Microbially -Mediated Denitrification during Managed Aquifer Recharge

EPA Grant Number: SU835995
Title: Evaluating Reactive Barrier Technology to Enhance Microbially -Mediated Denitrification during Managed Aquifer Recharge
Investigators: Fisher, Andrew T
Institution: University of California - Santa Cruz
EPA Project Officer: Sergeant, Anne
Phase: I
Project Period: September 1, 2015 through August 31, 2016
Project Amount: $14,972
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2015) RFA Text |  Recipients Lists
Research Category: P3 Awards , Pollution Prevention/Sustainable Development , Sustainability , P3 Challenge Area - Water

Objective:

We aim to determine how to achieve the contemporaneous improvement to water supply and water quality using managed aquifer recharge (MAR), with an emphasis on conditions leading to denitrification. During MAR, surface water is infiltrated into shallow aquifers and subsequently recovered. MAR is a management strategy that can increase groundwater supply and play an important role in sustainable water management. Under the right conditions, MAR can also improve water quality was water infiltrates through the vadose zone via filtration, dilution, adsorption, and/or denitrification. We will complete a series of field experiments in which hydrologic, biogeochemical, and microbial processes are linked and quantified.
 

Approach:

Novel technologies we propose to adapt include custom-built probes to measure infiltration rate using heat as a tracer, an autonomous percolation testing field system, real-time data recording and reporting through the internet, use of a permeable reactive barrier, and newly developed genomic tools to identify bacterial diversity and metabolic activity. We will establish replicate field plots and apply water containing nitrate to these plots, sampling water at the surface and at multiple subsurface depths, to measure nitrate and carbon concentration. We will also sample soils before and after the infiltration experiments to assess grain size, carbon and nitrogen content, and microbial ecology and activity. We will determine the infiltration rate during each experiment and assess how changes in nitrate concentrations scale with this rate, and with other parameters, including the presence or absence of a permeable reactive barrier.
 

Expected Results:

We expect to generate soil, fluid and microbiological data that will inform efforts to improve both water supply and water quality. In particular, we hope to resolve relations between soil properties, infiltration, denitrification, and microbiological activity that can be used in design and operation of water resource and restoration projects. We are also developing and testing novel field tools and methods that can be applied at other sites being considered for placement of managed recharge projects.
 

Supplemental Keywords:

Groundwater, recharge, infiltration, denitrification, microbiology, water resource management, remediation.