This document summarizes research on a rain garden monitoring project in Connecticut from 2002-2005. Three key findings are:
1) The rain garden retained 99% of inflowing water and significantly reduced nitrogen, with 67% reduction in nitrate and 82% reduction in ammonia.
2) Modifications to add a saturated zone improved nitrate removal from 19% to 56% of outflow samples below detection limits.
3) The rain garden continued to effectively treat stormwater over winter, with frost depths not impacting annual performance.
Research Inventy : International Journal of Engineering and Scienceresearchinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Carbon dioxide, methane and nitrous oxide emissions from an oil palm plantati...CIFOR-ICRAF
Although nitrous oxide only makes up 8% of global greenhouse gas emissions, it has nearly 300 times the global warming potential of carbon dioxide. In this presentation, CIFOR scientist Kristell Hergoualc’h explains results from collaborative research between CIFOR, ICRAF, CIRAD and PT Bakrie, which show that nitrogen fertiliser can exacerbate the production of soil nitrous oxide greenhouse gases when applied to oil palms grown on deep peat. She gave this presentation on 23 February 2012 at the International Conference on Oil Palm & Environment (ICOPE) held in Bali, Indonesia. The conference had the theme ‘Conserving forest, expanding sustainable palm oil production’.
Research Inventy : International Journal of Engineering and Scienceresearchinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Carbon dioxide, methane and nitrous oxide emissions from an oil palm plantati...CIFOR-ICRAF
Although nitrous oxide only makes up 8% of global greenhouse gas emissions, it has nearly 300 times the global warming potential of carbon dioxide. In this presentation, CIFOR scientist Kristell Hergoualc’h explains results from collaborative research between CIFOR, ICRAF, CIRAD and PT Bakrie, which show that nitrogen fertiliser can exacerbate the production of soil nitrous oxide greenhouse gases when applied to oil palms grown on deep peat. She gave this presentation on 23 February 2012 at the International Conference on Oil Palm & Environment (ICOPE) held in Bali, Indonesia. The conference had the theme ‘Conserving forest, expanding sustainable palm oil production’.
1. Rain Garden Research and
Current Issues
Michael Dietz, Ph.D.
CT NEMO | Cooperative Extension
Univ. of Connecticut
Managing Stormwater from Impervious Surfaces: Green Infrastructure
Solutions for New Jersey
The Heldrich | New Brunswick, NJ
January 27, 2011
7. Methods
•Lab analysis of water samples for:
•Nitrate‐N, ammonia‐N, total Kjeldahl‐N, total
phosphorus, copper, lead, zinc
•Water level in each garden measured
•Temperature measured at inlet and outlet
(underdrains)
•Weekly measurements of soil moisture,
redox potential (Eh), and frost depth
8. Flow balance
cm % of Inflow
Inflow
Roof Runoff 1202 79.7
Precipitation 306 20.3
Total 1507
Outflow
Underdrain 1438 95.4
Overflow 13 0.8
Total 1451
Residual 56 3.7
99% of inflow
retained!
9. Percent retention
NO3-N NH3-N TKN TP TN ON
g
Total In 388 30 250 9 647 211
Total Out 128 5 186 20 316 181
% Retention 67 82 26 -108 51 14
-Two years of results (year 1 much less)
-Remember: 99% of inflow was retained
10. Total Phosphorus
0.25
Roof runoff
Underdrain average
Exponential (Underdrain average)
0.2 Linear (Roof runoff)
Total Phosphorus (mg/L)
0.15
0.1
0.05 R2 = 0.47
R2 = 0.06
0
Sep-02 Dec-02 Mar-03 Jun-03 Oct-03 Jan-04 Apr-04 Aug-04 Nov-04 Feb-05
Date
11. Comparison with other research
• Consistent with North Carolina
– Hunt et al., 2006. Evaluating bioretention hydrology and nutrient removal at three field
sites in North Carolina. Journal of Irrigation and Drainage Engineering, Vol. 132(6), pp.
600‐608.
• Consistent (N) & inconsistent (P) with
Maryland
– Davis et al., 2006. Water quality improvement through bioretention media: nitrogen and
phosphorus removal. Water Environment Research, Vol. 78(3), pp. 284‐293.
• Consistent with New Hampshire
– Roseen, et al., 2009. Seasonal performance variations for storm‐water management
systems in cold climate conditions. Journal of Environmental Engineering, Vol. 135 (3),
pp. 128‐137.
• Lots of variability in results!
19. Winter performance
• Measured frost depth
• Did not impact annual performance
• http://www.youtube.com/watch?v=cq6WB6VKeac
• Similar findings at UNH Stormwater Center
– Roseen, et al., 2009. Seasonal performance variations for storm‐water management
systems in cold climate conditions. Journal of Environmental Engineering, Vol. 135 (3),
pp. 128‐137.
22. Two year ANOVA/mean separation
Bulk Underdrain Overflow1
Variable n Unit Deposition Roof Runoff Treatment Control Treatment Control
*** -1
NO3-N 73 mg L 0.7 bcd 0.9 abc 0.2 d 0.4 cd 2.0 ab 2.1 a
-1
NH3-N*** 78 mg L 0.04 a 0.04 a 0.01 b 0.01 b 0.08 a 0.04 a
TKNns 79 mg L
-1
0.5 a 0.6 a 0.4 a 0.5 a 0.6 a 0.3 a
TN*** 72 mg L
-1
1.3 abc 1.6 ab 0.7 c 0.9 bc 2.7 a 2.4 a
ONns 77 mg L
-1
0.4 a 0.5 a 0.4 a 0.5 a 0.5 a 0.2 a
TP*** 80 mg L
-1
0.009 b 0.015 b 0.039 a 0.043 a 0.009 b 0.016 b
-1
Cutotal ns 26 µg L 3a 5a 3a 4a 3a -
-1
Pbtotal ns 26 µg L 3a 3a 3a 3a 3a -
-1
Zntotal ns 26 µg L 11 a 9a 10 a 5a 8a -
*** p=0.001
ns=ANOVA comparison non significant
1
n=4 for overflow samples
Means followed by the same letter are not significantly different at p=0.05