Andrew Henderson

Anne Asselin

Martin Heller

Olivier Jolliet

The Rime of the Modern Dairy-er, or, Water, water, here and there; how much can we drink?

From feed → state milk → national milk

Corn grain

Corn silage

Alfalfa hay

Alfalfa silage

Soybean

S. meal

Grass hay

Grass silage

DDGS

(wet & dry)

Pasture

On-farm

activities

kg milk

produced

in state i

rations in

state i

kg

“national”

milk

kg feed

produced

in states j

How do we address large systems?

• Borrowing from yesterday’s plenary…

www.waterfootprint.org

Dairy’s life cycle

feed production cows (housing, milking)

transport,

processing,

packaging,

distribution

retail consumption

disposal

impacts

Total U.S. Carbon Footprint for Fluid Milk Consumed

Primary Sources of Greenhouse

Gas Emissions for U.S. Fluid Milk

Carbon footprint = 17.6 lbs. CO2e per gallon of fluid milk consumed

Thoma et al. (2013) “Greenhouse Gas Emissions from Milk Production and Consumption in the

United States: A Cradle-to-Grave Life Cycle Assessment circa 2008.” Int. Dairy J.

GHG survey: feed practices

LCA survey dairy farm demographics

Extending the LCA

Build on GHGs to include

• land use

• human health

• ecotox

• water

• nutrients

USDA & other

data sources

Helmes, Henderson, et al., 2012

P res.

time:

0.01 to

30 (yr)

Water – modeling choices

Blue

Green

Grey

Irrigation for corn grain (FRIS)

0

200

400

600

800

1000

1200U

T

AZ

AK

WA

OR

CA

MT

WY

NV

NM CO AR TX ID KS

OK

NE

GA

WV FL

L co

nsu

med

/ k

g D

M C

orn

gra

in (s

tate

)

Major feeds

WSI represents competition for water,

as a function of use and availability

water consumed (blue water) /

water availability

Water stress index (WSI)

Pfister et al, 2009, ES&T, WSI

Boulay et al., 2011, ES&T, Human health impacts

Dealing with spatial data – matrix approach

CF (water stress /

L water consumed)

B (L water consumed /

kg corn produced)

FP (kg corn produced /

kg corn consumed)

R (kg corn consumed /

kg milk produced)

CFxB (water stress /

kg corn produced)

CFxBxFP (water stress/

kg corn consumed)

CFxBxFPxR (water stress/

kg milk produced)

X

water in competition

due to corn

water consumed /kg corn Water Stress Index ( WSI)

Water in competition = water consumed x WSI

Water in competition

L_eq in competition / kg state corn grain

Weight by US corn grain

production:

mainly in the corn belt!

National average of corn grain water footprint:

Water consumed 53 Leq. consumed /kgcorn

Water stress 37 Leq. in competition /kgcorn

Water in competition at the national level

Contribution to

national corn grain

impact

NETXCO

CA

KSAR

NM

AZ

WY

UT

IL IA SDMO MN 35 Others

0 20 40 60 80 100

0.0E+0

1.0E+2

2.0E+2

3.0E+2

4.0E+2

5.0E+2

6.0E+2

7.0E+2

8.0E+2

9.0E+2

1.0E+3

L eq

. in

co

mp

etit

ion

/ k

g D

M C

orn

gr

ain

(c)

(sta

te)

Corn grain Production %

Water stress from corn at the national level

Water impact

contribution to

national corn

grain average

22 Leq. in competition in NE out of 37 Leq. in competition national

From feed → state milk → national milk

Corn grain

Corn silage

Alfalfa hay

Alfalfa silage

Soybean

S. meal

Grass hay

Grass silage

DDGS

(wet & dry)

Pasture

On-farm

activities

kg milk

produced

in state i

rations in

state i

kg

“national”

milk

kg feed

produced

in states j

Milk-level results

CA

AZ

NM

IDTX

WA

CO

UT

ORKS

NV

NE

OK

SD

NYFL

PA

ND

WY

MT

MOMD WI VAAR

25 Others

0 20 40 60 80 100

0

100

200

300

400

500

600

700

L eq

. in

co

mp

etit

ion

(as

Blu

e w

ater

) /

kg

FPC

M (

stat

e)

Milk Production %

Milk-level results – by feed

CA

AZ

NM

IDTXWA

CO

UT

ORKS

NV

NEOKSD

NYFL

PA

ND

WY

MTMOMD WI VA

AR25 Others

0 20 40 60 80 100

0

100

200

300

400

500

600

700

L eq

. in

co

mp

etit

ion

(as

Blu

e w

ater

) /

kg

FPC

M (

stat

e)

Milk Production %

Corn grain Corn silage Alfalfa hay Alfalfa silage

Crop - other Grass hay Grass silage Soybean meal

Cow Drink Cow Wash

Inducer (milk producer) vs. Receiver (feed producer)

Feed is where the action is

0.0E+0

2.0E+1

4.0E+1

6.0E+1

8.0E+1

1.0E+2

1.2E+2

1.4E+2

1.6E+2

L eq

. in

com

p. /

kg

FPC

M

Water, lake to Raw

Water, well, in ground to Raw

Water, unspecified natural origin/m3 to Raw

Water, river to Raw

Water, turbine use, unspecified natural origin to Raw

Water, cooling, unspecified natural origin/m3 to Raw

Field and dairy farm: Blue water

Beware averages

• using averages:

62 L in competition / kg milk

• Using spatial model + inventory

uncertainty:

91-151 L in competition / kg milk

Water quality: impacts vs. dilution

• LCA attempts to model impacts

– Can compare (carefully) impacts from P, N, and

pesticides

– Any grey water dilution volume would also have these

impacts embedded

• Ongoing work to improve

– UNEP/SETAC LCIA Global Guidance

National Nutrient Loss and Soil Carbon (NNLSC) & EPIC models

Potter 2006, The National Nutrient Loss and Soil Carbon Database Reference Guide

P loss over all pathways

NNLSC: corn grain P state averages

P (kg to water

/ kg corn)

1x10-4 to

2x10-3

P inventory emissions – milk production

P fate factor for emissions to water

Helmes et al., 2012

Fate factor

(yr)

0.01 to

30

Milk: Freshwater eutrophication

inventory

Looking at different resolutions

28

Conclusions & discussion

• Climate, farm practices, topography, soil

→ yield

→ water & nutrients (use and loss)

• Spatial models can help address, but

outside of LCA

Conclusions & discussion

• Inventory & impact: resolution may be important

– national / regional / watershed / state / county

• Uncertainty (data, model) vs. spatial variability

• Inducer, emitter, receiver: may not be same

Corn grain

Corn silage

Alfalfa hay

Alfalfa silage

Soybean

S. meal

Grass hay

Grass silage

DDGS

(wet & dry)

Pasture

On-farm

activities

kg milk

produced

in state i

rations in

state i

kg

“national”

milk

kg feed

produced

in states j

CA

AZ

NM

IDTXWA

CO

UT

ORKS

NV

NEOKSD

NYFL

PA

ND

WY

MTMOMD WI VA

AR25 Others

0 20 40 60 80 100

0

100

200

300

400

500

600

700

L eq

. in

co

mp

etit

ion

(as

Blu

e w

ater

) /

kg

FPC

M (

stat

e)

Milk Production %

Corn grain Corn silage Alfalfa hay Alfalfa silage

Crop - other Grass hay Grass silage Soybean meal

Cow Drink Cow Wash

Appendices

NNLSC: corn grain NH3 state averages

Effect & characterization factors

• Effect factor (EF)

– relates P conc. to species effect

– EF for P-limited rivers & lakes (Payet 2006)

– depends on existing P conc. (EPA 2010)

• EF: PDF * m3 / kgin water

– PDF = potentially disappeared fraction of species

– limited variation: 280/680 (river); 2400/3000 (lake)

• Characterization factor (CF)

– CF = EF * FF = PAF * m3 / (kgemit/yr)

Milk: Freshwater eutrophication

WI

NY

CA

PAMI

MNOH

FL

TX

ID

VA

IA38 Others

0 20 40 60 80 100

0.0E+0

2.0E-2

4.0E-2

6.0E-2

8.0E-2

1.0E-1

1.2E-1

1.4E-1

1.6E-1

PD

F.m

2.y

r (A

ll so

urc

es)

(All

flo

ws)

/ k

g FP

CM

Milk Production %

P: 0-10 µg/L P: 10-100 µg/L P: 100+ µg/L

EPIC models →National Nutrient Loss and Soil Carbon (NNLSC) database

• National Resource Inventory (1997)

– Crop extent, land management, conservation

– ~180 k sample points, ~80% US cropland

• Cropping Practice Surveys (2000)

• Soil data

• Monthly climate

Potter 2006, The National Nutrient Loss and Soil Carbon Database Reference Guide

% of cropland included (yellow → green)

Environ. Policy Impact Calculator (EPIC)

Management effects on:

• crop yield

• soil erosion

• water, pesticide, & nutrient transport

• Inputs: Weather, surface runoff, return flow, percolation, ET, lateral subsurface flow

and snow melt. Water erosion; Wind erosion; N & P loss in runoff , nitrogen leaching;

Organic N & P transport by sediment; N & P mineralization, immobilization and uptake;

Denitrification; Mineral P cycling; N fixation; Pesticide fate and transport; Soil temperature;

Crop growth and yield for over 80 crops; Crop rotations; Tillage, Plant environment control

(drainage, irrigation, fertilization, furrow diking, liming); Economic accounting; Waste

management (feed yards dairies with or without lagoons).

NNLSC: corn grain NO3 state averages

Eutrophication assessment framework

EPIC model:

kg Pemit / kgcrop

P fate model: fate factor (Helmes et al. 2012)

kg P in water / (kg Pemit / time)

Effect factor (Payet 2006)

PDF m2 / kg P in water

P concentration in US

watersheds (EPA, 2010)

Freshwater eutrophication impact

PDF m2 yr/ kg P or FU

Dairy feed rations:

kgcrop / kgmilk

• emissions to main water system

Grid Cell

P fate model: 0.5° x 0.5° grid cell

Small (sub-grid)

rivers

Main water system Downstream

grid cell

Upstream

grid cell(s)

Soil

Hydrological grid: Vorosmarty et al. (2000); Processes: Mayorga et al. (2010),

Wollheim et al. (2008), Alexander et al. (2004)

advection advection

retention

(physical settling, bio. uptake & settling)

runoff

human water

use &

irrigation

Dominant P removal processes

Effect factors

• Effect factor (EF, PDF.m2 / kgin water)

– P conc. → species effect (potentially disappeared fract.)

– EF for P-limited rivers & lakes (Payet 2006)

• limited variation:

280/680 (river);

2400/3000 (lake)

– depends on

existing P conc.

(EPA 2010)

Corn grain: Freshwater eutrophication

40 Others

0 20 40 60 80

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

PD

F.m

2.y

r (

fro

m C

orn

gra

in) /

kg

DM

C

orn

gra

in (s

tate

)

Corn grain Production %

Phosphorus

40 Others

0 20 40 60 80

0.0E+0

5.0E-4

1.0E-3

1.5E-3

2.0E-3

2.5E-3

3.0E-3

kg P

(Ph

osp

ho

rus)

/ k

g D

M (

stat

e)

Corn grain Production %

inventory

Initial GHG Survey and US milk supply

NASS Dairy farm demographics

LCA survey dairy farm demographics

FP: Feed production & transport mix

R: Rations kgcorn consumed i/kgmilk i

Impact/kgcorn produced j CFxB

Impact/kgcorn consumed i CFxBxFP

B: Emission kgemitted/kgcorn produced

CF: Impact/kgemitted

kgcorn prod j

kgcorn cons i

Impact/kgmilk i I=CFxBxFPxR

Irrigation (mm/yr)

state-based

reported irrigation (USDA FRIS)

vs.

modeled

evapotranspirated

irrigation (Siebert and Döll, 2010)

Crops and water: is irrigated water ‘used’?

corn grain

soybean

Evapotrans. modeled 5 yr. avg.

US

DA

su

rve

y (

12

yr

avg

.)

US

DA

su

rve

y (

12

yr

avg

.)

Evapotrans. modeled 5 yr. avg.

1:1

1:1

0.0E+0

1.0E-4

2.0E-4

3.0E-4

4.0E-4

5.0E-4

6.0E-4

7.0E-4

kg s

ub

stan

ce e

mit

ted

/ k

g D

MP emissions per feed type (national average)

kg

P t

o f

res

hw

ate

r / k

g D

M

Characterization, PDF.m2.yr/kg for P emission

Char. Factor

(PDF.m2.yr)

0.1

to

5x104

Characterization, PDF.m2.yr/kg for P emission

Char. Factor

(PDF.m2.yr)

2

to

4x103

Spatial differences matter

Scopus: spatial LCA

Characterizing water

1.0E-2

1.0E-1

1.0E+0

AZ

NE RI

WY

VA

OK

MT ID

WA

ME IL AK

MS

L eq

. in

co

mp

etit

ion

/ L

con

sum

ed

Receiving location

Pfister et al, 2009, ES&T, WSI

Boulay et al., 2011, ES&T, Human health impacts