Removing Dissolved Pollutants from Stormwater Runoff. Andy Erickson, Research Fellow St. Anthony Falls Laboratory October 3, 2012

Transcription

1 Removing Dissolved Pollutants from Stormwater Runoff Andy Erickson, Research Fellow St. Anthony Falls Laboratory October 3, 2012

2 Removing Dissolved Pollutants Dissolved pollutants Current treatment methods New treatment technologies Field applications and results Questions

3 What s IN Urban Stormwater? Solids (inorganic, organic) Nutrients (nitrogen, phosphorus, etc.) Metals (copper, cadmium, zinc, etc.) Chloride Hydrocarbons Bacteria/Pathogens Others

4 A Quick Poll On Average, what percentage of the total concentration does the dissolved fraction represent? a) 0% b) 25% c) 50% d) 75% e) 100%

5 &'()*+, -./0+10-2'30+10 Dissolved Pollutants are a -344)' 5)./ 6+,7)8 Significant Fraction 93:.8;<=+((38>)/;?;@.':+,18.:)A =+((38>)/! " #! #" $! $" %!!"#$%&'()**+,%&,'-)&."&,/%,$)&! "! #!! #"! $!! $"! %!! Dissolved Fraction 45.5% 50.0% 29.7% 50.0% 18.9% B+*, 44.4% 45.5% Source (adapted from): Pitt, R., Maestre, A., Morquecho, R., Brown, T., Schueler, T., Cappiella, K., and Sturm, P. (2005). "Evaluation of NPDES Phase 1 Municipal Stormwater Monitoring Data." University of Alabama and the Center for Watershed Protection.

6 '3+835#&"<& ;$#$&/=6!"#$%&'(")*("+,)& 7"5835#+$#9"5&/:12-6 Dissolved Fraction is Variable!$ ($ #!$ #($ %!$ #!!! #!! #! #!"# -./01/23425./ 6.47 #!!!!"!#!"!#!$ #!$ %!$ &!$ '!$ (!$ )!$ *!$ +!$,!$ #!!$ ;9))"%43.&'3+835#&/"<&#"#$%&*(")*("+,)6 Source (adapted from): Brezonik, P. L., and Stadelmann, T. H. (2002). Analysis and predictive models of storm water runoff volumes, loads, and pollutant concentration from watersheds in the twin cities metropolitan area, Minnesota, USA. Water Res., 36, #!! #! #!"#!"#$%&'(")*("+,)&-"$.& / #6

7 Dissolved Pollutants Negatively Impact Water Quality More Bioavailable Nutrients! eutrophication Metals! bioaccumulation, toxicity Petroleum hydrocarbons! toxicity Pictures source: Sources: Sharpley, A.N., Smith, S.J., Jones, O.R., Berg, W.A. and Coleman, G.A. (1992) The Transport of Bioavailable Phosphorus in Agricultural Runoff. Journal of Environmental Quality 21(1), U.S. EPA. (1999) Preliminary data summary of urban storm water best management practices, U.S. Environmental Protection Agency, Washington, D.C.

8 A Quick Poll Do current treatment methods (e.g., sand filters, wet ponds, filter strips, swales, etc.) remove dissolved pollutants from stormwater? a) Yes b) No

9 Current Treatment Practices Are Not Good Enough ()*+,-./0 123+,-./ )5632/ /0 98./+:;732) :;732)+93);<0=>)8002/+9?8720!" #!" $!" %!" &!" '!!"!"#$"%&'(")*+,- Source (adapted from): P.T. Weiss, A.J. Erickson and J.S. Gulliver Cost and pollutant removal of storm-water treatment practices, Journal of Water Resources Planning and Management,133(3), , 2007.

10 Dissolved Pollutant Removal Processes Vegetative processes: plant uptake and rhizospheric activity (microbes, etc.) that use and convert dissolved pollutants Sorption: surface sorption or complexation, ion exchange, etc. to capture dissolved pollutants Biodegradation: bacteria conversion of nitrates to nitrogen gas or petroleum hydrocarbons to carbon dioxide

11 Phosphorus Sorption with Iron Sand Filtration Particulate capture > 80% Photo Courtesy: A. Erickson Enhanced Sand Filtration Steel wool increases dissolved phosphorus capture via surface sorption to iron oxide Source: Erickson, A.J., Gulliver, J.S. and Weiss, P.T. (2007) Enhanced sand filtration for storm water phosphorus removal. Journal of Environmental Engineering- ASCE 133(5),

12 !"##$%&'()*+$#,+$-.#) /$01'02-32"$0) )#$ )#( )#* )#! Experimental Results (Iron Enhanced Sand Filtration, SAFL) n = 112 n = 336 n = 336 n = 336 n = 112!"#$% &"#'% ""#(% ) +,-./0,1!))%234,5 )#(%2678, *%2678, 9%2678,!"#"$%&'()*+*#(

13 A Quick Poll When compared to laboratory experiments, field applications of the Minnesota Filter work remove phosphorus: a) Much better b) A little better c) About the same d) A little worse e) A lot worse

14 MN (Iron Enhanced) Filter (5% iron filings, Maplewood, MN) Photo Courtesy: A. Erickson

15 01*231*452&6*78(794,9:*7& ;)<=>?!"'$!"'#!"'!"!&!"!%!"!$!"!#! Field Monitoring Results (MN Filter Basin, Maplewood)!"#$%& '()*+,-./#.%& '()*+,- ()*+,-./)01/) ),678-./)01/)230 9:;,37:* <;;,37:*!"#"$%&'()*+*#(

16 MN Filter Trenches wet detention ponds (Prior Lake, MN) Photos Courtesy: A. Erickson

17 MN Filter Trenches around wet detention ponds (Prior Lake, MN) Volume Treated by Trenches (Filter Volume) Overflow Grate Normal Water Surface Elevation Water Level Control Weir Drain tile Iron Enhanced Filter Drain tile

18 !"##$%&'()*+$#,+$-.#) /$01'02-32"$0) #$.#.2.#.1.#.0.#./. Field Testing Results (MN Filter Trenches, Prior Lake)!"#$%& '()*+, (47!%&38*4&9:-:4;<!"#"$%&'()*+*#(

19 MN Filter Trenches (Prior Lake MN) MN Filter Bioretention (Carver County, MN) Photo Courtesy: A. Erickson Photo Courtesy: W. Forbord MN Filter Bioretention (Maplewood Mall, MN) MN Filter Weir (Vadnais Heights, MN) Photo Courtesy: A. Erickson Photo Courtesy: VLAWMO and EOR

20 The Capacity for Phosphate Capture is Significant Maplewood Sand Filter (5% Iron) SAFL Experiments (5% Iron) Time Equivalent Volume 18.4 ft 3 /ft 2 -yr 566 ft 3 /ft years Phosphate Concentration Load 16 µg/l 340 µg/l lb/ft 2 -yr (8.3 mg/ft 2 -yr) lb/ft 2 (5451 mg/ft 2 ) 656 years

21 Designing for Phosphorus Capture with Iron As iron rusts, sorption sites for phosphorus are created, therefore: System must be oxygenated to ensure iron oxides remain aerobic Design Iron Enhanced Filter systems for watersheds with significant dissolved phosphorus fraction Design systems with 8% or less iron by weight to prevent clogging

22 A Quick Poll Which of the following applications of the Minnesota Filter would work for you, your clients, or someone you know? a) Minnesota Filter Basin b) Minnesota Filter Trenches c) Minnesota Filter Bioretention/Rain Garden d) All of the above e) None of the above f) I m thinking of a new application

23 Compost Can Capture Metals Source: Morgan, J. G., Paus, K. A., Hozalski, R. M., and Gulliver, J. S. (2011). "Sorption and Release of Dissolved Pollutants Via Bioretention Media." Project Report 559. St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN.

24 Biodegradation of petroleum hydrocarbons Petroleum Hydrocarbons are captured in rain gardens through sorption Biodegradation prevents accumulation of petroleum hydrocarbons Rain gardens are an effective option for sustainably treating petroleum hydrocarbons in stormwater Source: LeFevre, G.H., Hozalski, R.M., and Novak, P.J. (2012, in press). "The Role of Biodegradation in Limiting the Accumulation of Petroleum Hydrocarbons in Raingarden Soils." Water Research.

25 Compost Can Export (i.e., leach) Phosphorus Source: Morgan, J. G., Paus, K. A., Hozalski, R. M., and Gulliver, J. S. (2011). "Sorption and Release of Dissolved Pollutants Via Bioretention Media." Project Report 559. St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN.

26 Designing for Metals and Petroleum Hydrocarbon capture with Rain Gardens Compost can capture metals and petroleum hydrocarbons but can release phosphorus, therefore: Incorporate compost in treatment practices to capture metals and hydrocarbons Ensure aerobic conditions to promote biodegradation Incorporate another process to capture any phosphorus that passes through or is leached from the compost

27 Conclusions Dissolved Stormwater Pollutants are important Approx. 45% of total concentration is dissolved Physical methods are not enough Chemical and biological mechanisms can be used to capture dissolved fractions There are field-tested solutions! Minnesota Filter (iron-enhanced sand)! phosphorus

28 Acknowledgements Collaborators: John S. Gulliver (U of MN) Peter T. Weiss (Valparaiso University) Multidisciplinary Technical Advisory Committee Funding Partners: LRRB, EPA/MPCA, RWMWD, City of Prior Lake, PLSLWD, Scott WMO, Carver County, VLAWMO

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30 For more information, contact: Andy Erickson Photo Courtesy: A. Erickson