Water Quality Issues from Dairy
Farms in the Northeast
Peter Wright, State Conservation Engineer
Natural Resources Conservation Service
Syracuse NY
Curt Gooch, PRO-DAIRY Environmental
Specialist Cornell University
Dairy Farm Polluted Water
Sources
Concentrated Sources:
Waste Wash water
Barnyard runoff
Silage Leachate
Manure
Storage
Spreading
Estimated BOD LB/yr
M
ilk
in
g
Ce
nt
er
W
as
te
Si
la
ge
Le
ac
ha
Ba
te
rn
ya
rd
R
un
Do
of
f
m
es
t ic
W
as
te
50000
45000
40000
35000
30000
25000
20000
15000
10000
5000
0
M
Ce
nt
er
W
as
te
Si
la
ge
Le
ac
ha
Ba
te
rn
ya
rd
R
un
Do
of
f
m
es
t ic
W
as
te
ilk
in
g
Estimated N LB/yr
4500
4000
3500
3000
2500
2000
1500
1000
500
0
M
Ce
nt
er
W
as
te
Si
la
ge
Le
ac
ha
Ba
te
rn
ya
rd
R
un
Do
of
f
m
es
t ic
W
as
te
ilk
in
g
Estimated P LB/yr
500
450
400
350
300
250
200
150
100
50
0
Concentrated Sources
Amounts and concentrations vary
daily
seasonally
from farm to farm
They can be Managed
When Rain Driven the impact is less
diluted
not observed
Concentrations
Milking Center
Silage Leachate
Barnyard
Manure
Domestic Waste
N
400 ppm
4,400
1,000
P
60 ppm
500
200
5,600
900
30
7
Annual Load from
Concentrated Sources
Milking Center
Silage Leachate
Barnyard
Manure
Domestic Waste
N
3,000 lb
3,900
700
P
30 lb
440
150
31,600
5,000
70
22
Conclusions
Concentrated sources need to be controlled
Prevention is key
Look for low cost alternatives to treatment
Prevention
Eliminate
Reduce
Reuse
Wash Water Reduction
Eliminate Leaks and Spills
Manually rinse or scrape first
Reuse gray water
Design system for easy cleaning
Quantities
Range
1-40 gal/cow/day
Typical
2-5 gal/cow/day
Reduce at the Source
Feed Milk
First flush
Colostrum, treated milk
Scrape Manure
Parlor and holding area floors
Correct Soap Amounts
No Precooler Water
Treatment
Aerobic – with oxygen
Low odors
Fast rate
By products
- Carbon dioxide and water
Treatment
Anaerobic – without oxygen
Odors produced
Slow rate
By products
- plug soil pores
Liquid Manure System
Advantages
Easy
Low pollution potential
Helps manure flow
Disadvantages
More to haul
Larger storage needed
Liquid Manure System
1,000 gal. of milkhouse wastes may contain:
1.67 lbs. Nitrogen
0.83 lbs. Phosphorus
2.50 lbs. Potassium
5.00 lbs. of nutrients @ $0.25/lb. = $1.25
Spreading costs:
1,000 gallons @ $0.005 per gal. = $5.00
Grass Filter
Advantages
Lower cost
Efficient treatment
Small space
Disadvantages
Needs O&M
Extreme cold weather problems
Settling Tank and Pump
Milking Center Waste
Estimated Nitrogen Fate
Immobilized Soil OM
Denitrified
Crop Uptake
Leaching
Total
21%
30%
32%
17%
100%
Milking Center Waste
Estimated Nitrogen Fate
Immobilized Soil OM
Denitrified
Crop Uptake
Leaching
Total
1.3 Lbs N/cow /year
68 Lbs.
98 Lbs.
104 Lbs.
55 Lbs.
325 Lbs.N/Acre
250 Cows
Barnyards
Eliminate
Reduce the size
Reduce the runoff
Exclude outside water
Pavement increases runoff
Vital to control runoff flow
NRCS Standard
Source Control
Scrape, time in barnyard, waterers
Solid removal
15 minutes of 2 yr 24 hr rainfall
Cleaned out
Filter area larger of:
15 min. flow time for 25 yr 24 hr storm
0.5 inches deep OR
500Lbs N per acre per year
Abuse Areas
Purpose?
Increased loading
Fences can be moved
Image
Barnyards
Sized correctly
Clean surface water diverted
Paved and curbed
Runoff controlled
Vegetated filter strip to treat BOTH: barnyard
runoff and milkhouse wastewater
VFS has Two
Discharge Points
Milkhouse wastewater P concentrations
Avg - 16 mg/L, Range from 10 to 21 mg/L
Screens and Collector Drop Box
Dissolve
P Removal
in a Grassas
VFS
on Lackawanna
sl
Grass VFS
Performance
Percent
P Removal
Phosphorus Removal, %
100
75
50
Average
25
Wet Period Average
Dry Period Average
0
0
50
100
150
200
250
Distance from Loading Source, feet
300
Barnyard Runoff
Estimated Nitrogen Fate
Immobilized Soil OM
Denitrified
Volatilization
Crop Uptake
Leaching
Total
20%
20%
20%
30%
10%
100%
Barnyard Runoff
Estimated Nitrogen Fate
Immobilized Soil OM
Denitrified
Volatilization
Crop Uptake
Leaching
Total
100 Lbs.
100 Lbs.
100 Lbs.
150 Lbs.
50 Lbs.
500 Lbs. N/Acre
Barnyard Runoff
Assumptions:
20 gallons manure /cow per day
32 Lbs. N/1000 gallons of manure
230 Lbs. N / cow per year
Time in barnyard proportional to manure left
Daily cleaning leaves 10% available to flow
Settling removes 25% of N
Barnyard Runoff
230 Lbs. N / cow per year
10% Time in barnyard
23 Lbs. N/cow/yr.
Daily cleaning leaves 10% available to flow
2.3 Lbs. N/cow/yr.
Settling removes 25% of N
1.7 Lbs. N/cow/yr.
Pollution Prevention
Eliminate
Reduce
Recycle
Barnyard
Purpose?
Holding
Feeding or water
Resting
Exercise
Heat detection
Eliminate!!
Bunk Silos
Storage of:
Silage juice
Runoff
Drainage water
25 year 24 hour storm
Silage leachate is very high in BOD, N and P
Solutions
•Catch and store it all
– Then spread according to a NMP
•Roof the Storage
•Collect only the concentrated low flow
– Treat dilute high flows in a grass filter
Effluent Varies
Silage juice
Dry matter
Runoff from rainfall
Outside water
Amount of empty bunk area
Evaporation
Other commodities
Conclusions:
Concentrated Sources Need to be Controlled
Prevention is Key
Look for Low Cost Alternatives to Treatment
Why Do We Store Manure?
To reduce the need for frequent hauling
and land spreading
To allow land spreading at a time when
soil and climatic conditions are suitable
To allow nutrient application at or near the
crop’s growing season
6
200000
Fecal Coliforms (Wet)
4
Fecal Coliforms (Dry)
0
140
<- Irrigation stopped
100000
<- Irrigation started
Cumulative Fecal Coliforms/m
2
300000
Discharge (Wet)
2
Discharge (Dry)
145
Time after Manure Application, hours
0
150
Cumulative Tile Discharge, mm
Cumulative Fecal Coliforms and Tileflow 6 Days
after Surface Manure Application and No Incorporation
Spreading Costs, dollars per cow per year
Spreading
Costs
$350.00
$300.00
$250.00
$200.00
$150.00
$100.00
$50.00
$0.00
0
2
4
6
8
10
Manure Storage Capacity Months of Production
12
14
16
Capital Costs
Spreading Cost
Net Cost of Storage Systems
Basics of Separation
Solid Effluent
Influent
Solid-Liquid
Separator
1-15% dry matter
(20-30% dry matter)
Liquid Effluent
(1-8% dry matter)
Energy
Potential Goals of Separation
Remove a portion of solids for pumping ease
Reclaim separated solids for bedding
Partition nutrients for application to far off fields or export
Reduce the size or extend the use of a long term storage
Needed Information
The impact of separation on Comprehensive Nutrient Management Plan
(CNMP)
The quantity and quality of reclaimed manure solids so accurate economic
projections can be made with respect to their end use
Nutrient partitioning between separated solid and liquid effluents to
determine the potential for nutrient export
Example Test Methods for Nutrients and Solids
Sampling / Monitoring Parameter
Test Method
Total Solids (TS)
EPA 160.3
Total Volatile Solids (TVS)
EPA 160.4
Total Phosphorous (Total P)
EPA 365.3
Ortho Phosphorous (Ortho P)
EPA 365.3
Total Kjeldahl Nitrogen (TKN)
EPA 351.4
Ammonia-Nitrogen (NH3-N)
Organic Nitrogen (ON)
Total Potassium (Total K)
SM18 4500F
By subtraction
EPA SW 846 6010
Anaerobic Digestion Systems
Biological
Manure and Effluent Handling
Separation
Gas Collection
Conditioning
Engine
Electric
Heat
Management
Table 3. Digestion comparisons of five different manure digestion systems.
Farm
No. of Milking Cows
AA
500
DDI
850
NH
1,100
ML
740
Digester Type
Plug flow, soft top,
manure infeed
Plug flow, soft top,
manure infeed
2 parallel Plug flow,
hardtop,
Manure infeed
Mixed, soft top,
manure and food
waste infeed
85
41
64
*
% CO2 / % Methane
38% / 62%
32% 68%
38% / 62%
30% / 70%
Hydraulic Retention
Time
40 days
21 days
25 days
21 days*
Gas Use
Caterpillar engine
generator 130 kW
Capstone
microturbines
Caterpillar engine &
Marathon generator
130 kW
Waukesha engine
& Marathon
generator
145 kW
Smith cast iron
boilers
3
gasProductionft /cowday
Fecal Coliform
Reduction (%)
60 kW*
3
1
FA
100
Fixed Film,
concrete tank
separated liquids
infeed
*2
24
1
33% / 67%*
4 days*
99%
99%
98%
94%
98%*
ffluent Volatile Acids
mg/kg
496
1,413
Digester 1 = 520
Digester 2 = 590
386
929*
otal Solids Reduction
4
%*
27
23
24
62
22*
32
23
31
67
26*
37
27
37
11*
17
13
3
15*
atile Solids Reduction
(%)
ncrease in Ammonia
(%)
crease in Otho-P (%)
Digester
Digester
Digester
Digester
1
2
1
2
= 36
= 30
= 60
= 45
1
* 250,400 ft3/day of biogas was calculated as the average daily production. Since most of the biogas is from food waste,
per cow figure is not appropriate.
2
* For the period 6/2/02 to 4/25/03 when the digester was performing as a fixed film digester. Separated manure liquids
only.
3
* Problems with biogas pre-treatment have resulted in poor performance of the microturbines.
4
* Reduction in solids from the influent to the effluent of the digester.
2
2
2
2
2
2
2
2
Fecal Coliform cfu/gram manure (log scale)
Fecal Coliform data for digested and non-digested dairy manure
10,000,000
1,000,000
100,000
10,000
1,000
100
10
1
Raw
Manure
Farm P
Non
Non
Digested Digested
Separated Separated
Liquid
Solids
Non
Digested
Storage
Raw
Manure
Farm A
Digester
Effluent
Digested Digested Digested
Separated Separated Storage
Liquid
Solids
Johnes Disease Organism
Table 4. Estimated net income or loss for the five digester systems.
Farm
AA
DDI
NH
Number of Cows
Capital Costs
Digester Set
Separator Set
Gas Utilization Equipment
500
850
$192,000
$50,000
$61,000
Total Capital Cost
Total Capital Cost Per Cow
FA
740
100
$442,200*4
$89,000
$138,200
$339,400 $298,149
$61,000 $61,689
$287,300 $130,431
$80,183
$44,013
$13,135
$303,000
$606
$669,400
$788
$687,700 $490,269
$625
$663
$137,331
$1,373
Annual Projected Capital Cost
Annual Projected Capital Cost Per Cow
$25,468
$51
$52,978
$62
$63,274
$58
$49,016
$66
$13,396
$134
Total Estimated Annual Cost*1
1
Total Estimated Annual Cost Per Cow*
$37,540
$75
$79,317
$93
$103,960
$95
$70,880
$96
$21,497
$215
Total Estimated Annual Revenues
Total Estimated Annual Revenues Per Cow
$56,445
$113
$60,400*3
3
$71*
$77,680 $287,685
$71
$389
$10,900
$109
Total Estimated Annual Cost or Benefit*1 *2
Total Estimated Annual Benefit Per Cow*1 *2
$18,906
$38
-$18,917 *2 *3
-$22*2 *3
-$26,280*2 $216,805
-$24*2
$293
-$10,597*2
-$106*2
1
1,100
ML
* Does not include system electrical use.
2
* Negative numbers mean the farm incurs a net loss from the digester system.
3
* The electrical savings for DDI assumes the price of electricity is 10 cents/ Kw. This farm actually incurs a lower cost
due to a specific business initiative. Since this is not typical of most dairy farms, the higher price is used.
*4 This cost assumes the microturbines were purchased new.
Centralized Digestion
Advantages
Economics of sale
Equipment
Management
Disadvantages
Manure transportation
Electric utilization
CNMP/CAFO - biosecurity
Anaerobic Digestion Systems
Biological
Manure and Effluent Handling
Separation
Gas Collection
Conditioning
Engine
Electric
Heat
Management
Summary
Producers generally do not know the annual cost for handling manure on
their farm.
The projected annual economic cost for the analyzed system is $427,000
or $127 per cow.
A complete analysis should include cost of conveying manure to the SMS
and the cost of applying processed effluent to crop land.
A complete analysis also needs to include the nutrient value cost/benefit
for the cropping enterprise.