Modeling Land Application of Food Processing WastewaterFood-Processing Wastewater

in the Central Valley, CAy,

G Miller1 Y Rubin1 P Benito1 J McLaughlin1G. Miller1, Y. Rubin1, P. Benito1, J. McLaughlin1, Z. Hou2, S. Hermanowicz1, K.U. Mayer3

1Civil and Environmental Engineering University of California-BerkeleyCivil and Environmental Engineering, University of California Berkeley2Geology, State University of New York-Buffalo

3Earth and Ocean Sciences, University of British Columbia

http://hilmarsep.com

Food Processing Wastewater in the Central Valley

• Over 600 facilities• >$62 billion in revenue• Water use: 80 million m3 yr-1

• High in salinity (FDS), organic g y ( ), gcarbon, and nitrogen

• Typical disposal method: land application for irrigation

• Discharged to alluvial fan and fl d l i d itfloodplain deposits

An Environmental Threat?An Environmental Threat?Metric Municipal Waste Tomato Canner

BOD (mg-O2 L-1) 450 820

FDS (mg L-1) 720 1680FDS (mg L-1) 720 1680

pH 6.7 5.4

Nitrogen (mg-N L-1) 25 51

Flow Rate (gal d-1) 2.6 x 107 1.5 x 106Flow Rate (gal d ) 2.6 x 10 1.5 x 10

Pathogens present? Virtually certain Very unlikely

Sources: food, disinfectants, processing chemicals

Groundwater Degradation?

Winery Exampley p1300 acres

Fixed Dissolved SolidsFixed Dissolved Solids(mg/L)

Nitrate(mg/L)

Regulating Food Processing Waste

• Study itself product of legal settlementP t t C lif i ’ i t b th?• Protect California’s environment, economy, or both?– Regulators vs. industry?

– Water resources vs. economy? (Porter-Cologne Act)

• All agree on need for regulations based on science– What is the natural attenuation capacity of the soil?

– Is there a safe agronomic rate for salinity application?g y pp

– What discharge management processes are effective?

– How do the economic costs of land application compare toHow do the economic costs of land application compare to those of the alternatives?

Modeling Challenges• Very Large Scale

– 600+ producers with a diversity of wastewater600 producers with a diversity of wastewater characteristics and application site hydrogeology

• Attenuation Processes– Condition specific rates, strong

potential for interaction

• Data Deficiency– Few measurements in vadose

zone, none long-term

• Disparate systems– Required complexity different for

vadose and saturated zones

Modeling StrategyDevelop and implement

model of waste attenuationAddress diversity of sites

and waste streamsLand application

i it ti i i tiNitrogen, organic carbon,

d lt f t tLand application

i it ti i i tiNitrogen, organic carbon,

d lt f t t

30

40

ncy

Root zone

UnsaturatedZone

(MIN3P)

Vadose zone flow

Root water uptake

+ precipitation + irrigation

Ion exchange

Mineral dissolution/precipitation

Degradation of organic matter

Nitrification/denitrification

Plant nutrient uptake

and salts from waste waterSoil gas

exchange with

atmosphere O2, CO2, N2

Effective soil properties

Root zone

UnsaturatedZone

(MIN3P)

Vadose zone flow

Root water uptake

+ precipitation + irrigation

Ion exchange

Mineral dissolution/precipitation

Degradation of organic matter

Nitrification/denitrification

Plant nutrient uptake

and salts from waste waterSoil gas

exchange with

atmosphere O2, CO2, N2

Soil gas exchange

with atmosphere O2, CO2, N2

Soil gas exchange

with atmosphere O2, CO2, N2

Effective soil properties

0

10

20

10 20 30 40 50 60 70Ksat, m/d (after Burows, 2004)

Freq

uen

SaturatedZone

(GMS)Groundwater flow

Mass loading to water table

SaturatedZone

(GMS)Groundwater flow

Mass loading to water table

Use “transfer functions” to describe UZ/SZ connection

, ( , )

Run groundwater model to determine extent of degradation describe UZ/SZ connection

1500200025003000

(mg

L-1

) Case 1Case 2Case 3

determine extent of degradation

0500

1000

0 5 10 15 20 25 30Time (yr)

FDS

Land Application Conceptual Model

Land application+ precipitation + irrigation

Nitrogen, organic carbon, and salts from waste water

Root zone Root water uptake

+ precipitation + irrigation

Plant nutrient uptake

and salts from waste waterSoil gas

exchange with

atmosphere

UnsaturatedZ

Vadose zone flow

Ion exchange

Mineral dissolution/precipitation

O2, CO2, N2

Zone(MIN3P)

p p

Degradation of organic matter

Nitrification/denitrificationEffective soil

properties

SaturatedZone Groundwater flow

Mass loading to water tableZone

(GMS)Groundwater flow water table

Vadose Zone Model Scenarios

• 12 scenarios – 4 industries, 3 casesB t/ t f it t ti d d t• Best/worst case for nitrogen, saturation dependent

• Simulations implemented in MIN3P numerical code

Case Soil Saturation Waste water composition Best/worst?

Hi h f bi Hi h NH + CH O FDS1 High for anaerobic(0.9 – 0.99)

High: NH4+, CH2O, FDS

Low: NO3Worst for NH4

+

2 Low for aerobic High: NO3+NH4+, FDS W t f NO2 Low for aerobic

(0.4 – 0.5)High: NO3 NH4 , FDSLow: CH2O

Worst for NO3-

3 Moderate for mixed (0 8 0 9)

Low: CH2O, FDS, NH4+, and

NO l l ti t CH O Best for both3 (0.8 – 0.9) NO3 low relative to CH2OBest for both

Applied Waste ConcentrationsWaste Components

Calcium (Ca2+)

Winery Waste Water Footprint

Magnesium (Mg2+)Potassium (K+)Sodium (Na+)

A i (NH +)Ammonium (NH4+)

Manganese (Mn2+)Zinc (Zn2+)

Copper (Cu2+)Copper (Cu )Iron (Fe2+)

Carbonate (CO32-)

Phosphate (PO43-)p ( 4 )

Sulfate (SO42-)

Chloride (Cl-)Nitrate (NO3

-)pH

Labile organic carbon(CH2O)

Example Transfer Functions

10001500200025003000

S (m

g L

-1) Case 1

Case 2Case 3

15

20

L-1

) 0500

1000

0 5 10 15 20 25 30Time (yr)

FDS

10

15

mg-

N L

Case 1Case 2 0.20

0.30

0.40

(mg-

N L

-1)

Case 1Case 2Case 3

0

5

NO

3 (m Case 2

Case 3 0.00

0.10

0 5 10 15 20 25 30Time (yr)

NH

3 (

00 5 10 15 20 25 30

Time (yr) 4000

6000

8000

O (m

g L-1

) Case 1Case 2Case 3

(y )0

2000

0 5 10 15 20 25 30Time (yr)

CH

2O

Comparison to Groundwater Data

Degradation of Groundwater

Layer 2Layer 2

Layer 3y

Conclusions• Attenuation condition dependent, not

necessarily sustainablenecessarily sustainable• Attenuation processes contributing most

d d t th t i twere dependant on the contaminant• “Safe agronomic rate” questionable for FDS• Lateral migration in groundwater limited

Need for increased vadose zone monitoring• Need for increased vadose zone monitoring and characterizationModeling can provide tool for policy makers• Modeling can provide tool for policy makers, but does not offer definitive solution