Adaptation of Hydroponics to Remove Excess Phosphorus from Urban Lakes

EPA Grant Number: SU835725
Title: Adaptation of Hydroponics to Remove Excess Phosphorus from Urban Lakes
Investigators: Small IV, Gaston Elvin
Current Investigators: Small IV, Gaston Elvin , Brundrett, Ashley , Adamich, Ben , Sisombath, Brendan , Spangenberg, Claire , Thoresen, Douglas , Kellner, Jack , Griffith, Joseph , Hunt, Kirsten , Foster, Malia , Dahmus, Maria , Sciamanda, Marianne , Lauzon, Megan , Rivard, Tyler
Institution: University of St Thomas
EPA Project Officer: Hahn, Intaek
Phase: I
Project Period: August 15, 2014 through August 14, 2015
Project Amount: $15,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2014) RFA Text |  Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Sustainable and Healthy Communities , P3 Challenge Area - Safe and Sustainable Water Resources , P3 Awards , Sustainable and Healthy Communities


In many urban lakes, water quality is degraded due to phosphorus (P) pollution. Despite efforts to reduce P inputs to lakes in many urban areas, achieving improvements in water quality is hampered due to continued P release from lake sediments. Our proposal explores the potential to use hydroponic vegetable production to remove excess P from Como Lake in Saint Paul, MN, while generating an economically viable product and providing a unique product for public outreach. Hydroponics has been used successfully to remove nutrients from aquaculture effluent; the focus of our project is to adapt this technology to urban lakes. Our preliminary trials in lake water mesocosms have shown that it is possible to simultaneously produce nutritious vegetables with no accumulation of heavy metals, while achieving measurable reductions in dissolved P levels.


An interdisciplinary team of undergraduate students will conduct a series of experiments to assess the feasibility of large-scale implementation of hydroponic farming on urban lakes to remove excess P. In a series of greenhouse experiments, they will measure potential P uptake rates by different vegetables grown in lake water, and assess nutrient limitation through supplemental fertilization experiments. They will measure plant nutrition (chlorophyll, carbon, nitrogen, and phosphorus content) for plants grown in thus study. Informed by these experiments, the team will construct a prototype hydroponic garden alongside Como Lake during the summer of 2015 to test the capacity of the system to sequester P from lake water, and also to serve as an outreach tool. Based on results from the study, the team will conduct a const-benefit analysis of a scaled-up implementation of this system, and write a business plan for a community supported agriculture model of distribution of these vegetables to residents within the watershed.

Expected Results:

The output from this project is an innovative application of hydroponic plant production used to remove nutrient pollution from an urban lake. Project outcomes include: improved lake water quality; production of nutritious, locally-grown vegetables; creation of educational opportunities for the public related to urban water quality; and training a team of students to be leaders in environmental problem-solving.

Publications and Presentations:

Publications have been submitted on this project: View all 1 publications for this project

Supplemental Keywords:

remediation, urban agriculture, water quality, TMDL

Progress and Final Reports:

  • Final Report