Evaluation of Feed Storage Runoff Water Quality and Recommendations on Collection System Design
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Transcript of Evaluation of Feed Storage Runoff Water Quality and Recommendations on Collection System Design
Bunker Silage Storage Leachate and
Runoff Management
April 2, 2015
Waste to Worth, Seattle, WA
Becky Larson, Assistant Professor and Extension Specialist,
University of Wisconsin-Madison
Aaron Wunderlin, Discovery Farms
Eric Cooley, Discovery Farms
Mike Holly, Ph.D. Student UW-Madison
Leachate Production Based on
Dry Matter Content
Bastiman (1976) and Bastiman and Altman (1985) (– - - –); Sutter (1957) (– - – -); Zimmer (1974) (– – –); Haigh (1999) (—)
(Haigh, 1999)
Recommended harvest moisture
65 - 70% Corn Silage
60 - 65% Hay Silage
Dry Weather Leachate
Constituent Leachate1
Liq. Dairy Manure2
Dry Matter 2-10% 5%
Total N (mg/L) 1,500-4,400 2,600
P (mg/L) 300-600 1,100
K (mg/L) 3,400-5,200 2,500
pH 3.6-5.5 7.4
BOD (mg/L) 12,000-90,000 5,000-10,000
1Cornell 1994 2Clarke and Stone 1995
Runoff Concentrations
Constituent Leachate1
Liq. Dairy Manure2 Runoff
Dry Matter 5% (2-10%) 5% 0 - 4.6%
Total N (mg/L) 1,500-4,400 2,600 20 - 1,356
P (mg/L) 300-600 1,100 8 - 659
K (mg/L) 3,400-5,200 2,500 n/a
pH 3.6-5.5 7.4 4 - 7
BOD (mg/L) 12,000-90,000 5,000-10,000 500 - 61,210
Management to Minimize Silage Storage
Runoff Constituent Concentrations
• Cover
• Top
• Maintaining face (minimize exposure)
• Cover/wrap side walls
• Cover when filling if rain is forecast (minimize water additions)
• Clean pad (remove litter) particularly if rain event is forecast
• Cover spoilage and litter until removal (removal can include many options, land application, composting, digestion, among others)
Silage Storage Collection System Design
Objectives
• Minimize collection volumes• Reduce hauling requirements
• Reduce environmental impact• Collect high strength waste for storage and land
application
• Send low strength waste to treatment systems
Current System Design
• Capture the initial volume and send to storage as it has the highest concentrations
• This assumed a first flush scenario exists where the first portion of the runoff has higher strength than remaining runoff, unconfirmed
• First flush exists in urban runoff, though it would follow this pattern
Normalized TKN Data – Farm A
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
% e
ven
t lo
ad
% event flow
Event Load:Flow Ratio (5%): TKN - Farm A
Normalized TKN Data – Farm C
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
% e
ven
t lo
ad
% event volume
Event Load:Flow Ratio (5%): Total Kjeldahl Nitrogen - Farm C
TKN - Farm C# % # % # % # % # %
Above 2 7% 6 21% 6 21% 3 10% --- ---
W/in 29 100% 22 76% 22 76% 25 86% 29 100%
Below --- --- 1 3% 1 3% 1 3% 0 0%
Above 8 28% 10 34% 9 31% 8 28% 2 7%
W/in 21 72% 17 59% 16 55% 18 62% 26 90%
Below 0 0% 2 7% 4 14% 3 10% 1 3%
Flow (%)
10 20 50 80 90
10%
5%
Normalized Phosphorus Data – Farm A
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
% e
ven
t lo
ad
% event flow
Event Load:Flow Ratio (5%): TP - Farm A
TP - Farm A# % # % # % # % # %
Above 0 0% 2 4% 0 0% 0 0% --- ---
W/in 51 100% 44 86% 33 65% 36 71% 39 76%
Below --- --- 5 10% 18 35% 15 29% 12 24%
Above 2 4% 3 6% 3 6% 0 0% 0 0%
W/in 46 90% 28 55% 23 45% 26 51% 31 61%
Below 3 6% 20 39% 25 49% 25 49% 20 39%
5%
10%
10 90805020
Flow (%)
Normalized Phosphorus Data – Farm C
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
% e
ven
t lo
ad
% event volume
Event Load:Flow Ratio (5%): Total Phosphorus - Farm C
TP - Farm C# % # % # % # % # %
Above 0 0% 0 0% 2 7% 0 0% --- ---
W/in 28 100% 28 100% 26 93% 28 100% 28 100%
Below --- --- 0 0% 0 0% 0 0% 0 0%
Above 2 4% 5 10% 8 16% 3 6% 0 0%
W/in 26 93% 21 75% 17 61% 23 82% 27 96%
Below 0 0% 2 4% 3 6% 2 4% 1 2%
10%
5%
Flow (%)
10 20 50 80 90
Constituent Correlations
• All constituent data (TKN, TP, TS, COD, BOD) was
statistically correlated EXCEPT pH which was
negatively correlated
Total TKN Loading
0
500
1,000
1,500
2,000
2,500
Load
(lb
s)
2013 Cummulative Total Kjeldahl Nitrogen Loading: Farm A
Collected To VTA
2007 lbs
1359 lbs
Total TKN Loading
0
500
1,000
1,500
2,000
2,500
3,000
3,500
Load
(lb
s)
2014 Cummulative Total Kjeldahl Nitrogen Loading: Farm A
Collected To VTA
2235 lbs
2901 lbs
Total TKN Loading
0
50
100
150
200
250
300
350
Load
(lb
s)
2013 Cummulative Total Kjeldahl Nitrogen Loading: Farm C
Collected To VTA
60 lbs
315 lbs
Total P Loading
0
60
120
180
240
300
360
420
480
540
Load
(lb
s)
2013 Cummulative Total Phosphorus Loading: Farm A
Collected To VTA
470 lbs
317 lbs
Total P Loading
0
100
200
300
400
500
600
700
800
900
Load
(lb
s)
2014 Cummulative Total Phosphorus Loading: Farm A
Collected To VTA
687 lbs
782 lbs
Total P Loading
0
10
20
30
40
50
60
70
80
Load
(lb
s)
2013 Cummulative Total Phosphorus Loading: Farm C
Collected To VTA
10 lbs
58 lbs
Collection Design Recommendation
• First flush does not exist so collecting initial runoff does not target collecting the greatest load per volume collected
• Recommended to collect low flows only (stop collecting during high flows)
• If the system design to shut off during high flows is not practical, collect low flows throughout the storm
• Additional collection of runoff within 2 weeks of filling will increase load collection
• Grade your pad to ensure all flows enter at one central collection point
• Check pad for cracks or other potential issues and repair
• Provide subsurface drainage to collect leachate which permeates through the pad
Low Flow Collection
• Calculations show a greater loading collected when collecting the low flow
• Low flow was calculated using 1% of the peak flowrate from a 2-year 24-hour design storm
• Peak runoff flowrates can be calculated using the Rational Method (although there are many methods which you can use to do this)
• These can be calculated by hand or using software such as HydroCAD
Conductivity Meter to Route High
Strength Runoff to Storage
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
0
100
200
300
400
500
600
700
800
0 4 8 12 16 20 24 28 32
Co
nce
ntr
atio
n (
mg/
l)
Flo
w (
gal/
min
) &
Co
nd
uct
ivit
y ((
us/
cm)/
10
)
Hours
Example Event with Conductivity: COD
Flow ConductivityMid-pt Discrete