Environmental Impacts of Compost Application on Construction Sites

Transcription

1 Environmental Impacts of Compost Application on Construction Sites Tom Glanville Agricultural & Biosystems Engineering Department by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University t

2 Acknowledgements Tom Richard Russell Persyn Sponsors Iowa Dept. of Natural Resources Iowa Dept. of Transportation Dr. John Laflen Compost Suppliers Davenport, Ia. Bluestem Solid Waste Des Moines Metro by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 2

3 Project Mission Iowa Dept. of Natural Resources Charged with implementing Waste Reduction and Recycling Act of 1989 Mandated 50% reduction in solid waste buried in landfills Banned yard and garden wastes from landfills 70 new composting facilities in past decade Process > 320,000 metric tons of organics per year Seeking new markets for compost Iowa Dept. of Transportation Faced with increasing stringent storm water control regulations for construction sites Seeking new runoff & erosion control alternatives by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 3

4 Project Objectives Compare compost-treated & conventionally-treated roadway embankments. Quantity & Chemical Quality of Runoff Erosion Vegetation by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 4

5 Conventional Roadway Embankment Erosion Control Embankment soils with good vegetation growth potential seed* existing compacted embankment soils Embankment soils not anticipated to produce good vegetative add 6-inches imported topsoil seed topsoil layer * seed mixture - oats, annual rye, timothy, red clover by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 5

6 Test Plot Layout Media vegetated unvegetated A - Biosolids Compost A - Biosolids Compost B - Yardwaste Compost C - Bio-industrial Compost T - Topsoil 0 - Compacted Embankment Soil Depth 5-5 cm cm cm by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 6

7 Test Plot Layout by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 7

8 Soils / Composts Applied topsoil yard waste bio-industrial bio-solids by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 8

9 Rainfall Simulation by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 9

10 Rainfall Intensity-Duration-Frequency Chart Central Iowa 300 Precipitation Intensity (mm/hr) yr 5-yr 10-yr 25-yr 50-yr 100-yr Typical Compost Runoff Period Typical Soil Runoff Test Period Typical Compost Runoff Period Duration (min) by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 10

11 Time to Initiate Runoff Un-Vegetated Treatment No. Time (min) Standard Deviation Vegetated Time (min) Standard Deviation Biosolids (A) b b Yard Waste (B) a a Bio-industrial (C) a,b a,b Control (P) c c 4.91 Topsoil (T) d c 2.86 s within the same column with different letter designations are significantly different (p<0.05). Longest Middle Shortest by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 11

12 Total Runoff Volume Un-vegetated plots 30-minute storm Runoff (mm) N Biosolids Geo. Yard Waste Geo. Bioindustrial Geo. Control Geo. Topsoil Geo b <0.01 a 0.08 a,b c c Lowest Middle Highest by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 12

13 Total Mass Interrill Erosion Un-vegetated plots 30-minute storm Eroded Solids (mg) N Biosolids Geo. Yard Waste Geo. Bioindustrial Geo. Control Geo. Topsoil Geo b 0.02 a 2.52 b 42,714 c 40,046 c Lowest Middle Highest by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 13

14 Interrill Erodibility Factors Treatment No. Un-Vegetated Interrill Erodibility Factor x 10-6 (kg-sec/m 4 ) Standard Deviation Interrill Erodibility Factor x 10-6 (kg-sec/m 4 ) Vegetated Standard Deviation Biosolids (A) b b,c 0.04 Yard Waste (B) a a 0.01 Bio-industrial (C) b a,b 0.11 Control (P) c c 0.03 Topsoil (T) d d 0.38 s within the same column with different letter designations are significantly different (p<0.05). Lowest Middle Highest by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 14

15 Rill Erosion Concentration of eroded solids Un-Vegetated Vegetated Treatment N Rill Solids Conc. (g/g) Std Dev N Rill Solids Conc. (g/g) Std Dev Biosolids (A) b b Yard Waste (B) a a Bio-industrial (C) b b Control (P) a,b a Topsoil (T) c c s within the same row with different letter designations are significantly different (p<0.05). Lowest Middle Highest by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 15

16 Chemical Concentrations in Composts & Soils Element N Biosolids (A) (mg/kg) σ Yard Waste (B) (mg/kg) σ Bioindustrial (C) (mg/kg) Control (P) Topsoil (T) by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 16 σ (mg/kg) σ (mg/kg) As 6 <1.20 a c b c c 1.37 Cd b 0.18 <1.20a 0.00 <1.20 a 0.00 <1.20 a 0.00 <1.20 a 0.00 Cr d b c a,b a 0.63 Cu d b c a a 3.43 Hg b a,b 0.84 <1.20 a 0.00 <1.20 a 0.00 <1.20 a 0.00 Mo b a a 1.34 <1.20 a 0.00 <1.20 a 0.00 Ni c a b a,b a 1.60 Pb d b c a,b a 1.87 Se 6 <1.20 a 0.00 <1.20 a 0.00 <1.20 a 0.00 <1.20 a 0.00 <1.20 a 0.00 Zn 6 1,033.5 d b c a a N 6 25,560 d 3, ,962 c 1, ,758 b ,070.1 a ,391.3 a P 6 15,702 d 1, ,582.3 b ,887.6 c a a K 6 5,951.8 c 1, ,906 d 1, ,269.1 b a a s within the same row with different letter designations are significantly different (p<0.05). Lowest Middle Highest σ

17 Soluble Mass of Chemicals in Runoff 30-Minute Storm Un-vegetated Plots Biosolids Yard Waste Bio-industrial Control Topsoil Parameter N Geo. 1 Geo. Geo. Geo. Geo. (mg) (mg) (mg) (mg) (mg) Zn 12 <0.01 a <0.01 a <0.01 a 0.15 b 0.16 b P b,c <0.01 a 0.01 a,b 1.38 c 0.76 c K a 0.09 a 0.29 a b b s within the same row with different letter designations are significantly different (p<0.05). 1 Geometric (Geo.) Lowest Middle Highest by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 17

18 Adsorbed Mass of Chemicals in Runoff 30-Minute Storm Un-vegetated Plots Biosolids Yard Waste Bio-industrial Control Topsoil Parameter N Geo. 1 Geo. Geo. Geo. Geo. (mg) (mg) (mg) (mg) (mg) Cr b <0.01 a <0.01 b 0.92 c 0.76 c Cu b <0.01 a 0.01 b 1.03 c 0.66 c Ni 12 <0.01 b <0.01 a <0.01 b 0.96 c 0.67 c Pb b <0.01 a <0.01 b 1.82 c 0.95 c Zn b <0.01 a 0.03 b 6.55 c 3.99 c N b <0.01 a 0.09 a,b c c P b <0.01 a 0.09 a,b c c K b <0.01 a 0.09 a,b c c s within the same row with different letter designations are significantly different (p<0.05). 1 Geometric (Geo.) Lowest Middle Highest by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 18

19 Planted Vegetation & Weeds by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 19

20 Vegetation Mass Planted Species Treatment No. Mass of Planted Species (g/m 2 ) Standard Deviation Biosolids (A) a Yard Waste (B) a Bio-industrial (C) a Control (P) a Topsoil (T) a s within the same column with different letter designations are significantly different (p<0.05). Lowest Middle Highest by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 20

21 Vegetation Mass Weed Species Treatment No. Weed Mass (g/m 2 ) Standard Deviation Biosolids (A) a Yard Waste (B) a Bio-industrial (C) a Control (P) b Topsoil (T) b s within the same column with different letter designations are significantly different (p<0.05). Lowest Middle Highest by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 21

22 Conclusions Compost Blankets vs Conventional Soil Treatments Runoff Response Compost require significantly greater rainfall to produce runoff Composts produce significantly less runoff Erosion Composts show significantly less interrill erosion Compost show significantly less rill erosion than topsoil, but are no better than compacted embankment soil by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 22

23 Conclusions Compost Blankets vs Conventional Soil Treatments Chemical Quality Significantly greater concentrations of some nutrients and metals in some composts Total mass of nutrients and metals in compost runoff significantly lower than in soil runoff Due to significantly lower runoff and interrill erosion by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 23

24 Conclusions Composts Blankets vs Conventional Soil Treatments Vegetation Planted Species No difference between composts and soils Weed Growth Composts significantly less weed biomass Depth of Compost Application 5- vs. 10-cm Blankets Little difference between depths Compost Type Yard waste generally better at reducing runoff and erosion by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 24

25 Compost Application Recommendations For erosion control - blanket applications preferred reduces application costs reduces weed competition Compost particularly useful for difficult construction situations Timing end of season too late for vegetation growth Extreme climatic conditions too wet or dry for vegetation growth Poor quality soils Difficult access for heavy equipment apply with blower truck Rilling considerations Avoid blanket placement in areas of concentrated water flow Aesthetics Highway officials reluctant to use composts containing visually undesirable components Environmental concerns Potential to reduce herbicide applications in environmentally sensitive areas by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 25

26 Questions Project Website: by Dr. Tom Glanville, Agricultural & Biosystems Engineering, Iowa State University 26