This document discusses the external costs and public health threats of nutrient pollution from agricultural watersheds in Iowa. It notes the persistent problem of high pollutant levels in Iowa's surface waters, especially nutrients from agriculture. While approximately 90% of Iowa's food is imported, drainage systems are increasing water quantity but reducing quality by transporting nitrates and other contaminants. The document outlines the key pollutant concerns for Des Moines' source water and details a lawsuit by Des Moines Water Works in response to escalating nitrate risks. It argues for treating pollution at its source and holding agriculture accountable for environmental protection.

1. External Costs and Public Health Threats
from Nutrient Pollution in
Agriculture Watersheds
Bill Stowe
CEO and General Manager
O
H
H
H O2

2. Iowa: “First in the Nation”

3. Reality of Iowa
A persistent problem of unacceptably high pollutants
in Iowa’s surface waters, especially nutrients

4. Agriculture Myth:
The Family Farm that “Feeds the World”
Approximately 90,000 Iowa farms
Nearly 90% of Iowa’s food is imported

5. Radical
Changes in
Iowa’s
Hydrology –
Drained Soils,
but Polluted
Waters
I
O
W
A
we
ildlife
n Apology

6. Des Moines is Unique

7. Des Moines’ Top Pollutant Concerns in
Source Water
1. Suspended solids
2. Microbial contaminants (bacteria, protozoa, and viruses)
3. Nutrients: nitrate, phosphorus, ammonia
• Spills
• Total Organic Carbon
• Trichloroethylene (TCE)
• Total Trihalomethanes (TTHM)
• Atrazine and Glyphosate (Roundup®)
• Emerging contaminants: pharmaceuticals and personal care
products, and hexavalent chromium

8. Treatment Plant
Recharge Ponds
Drainage Tiling:
Increasing Water
Quantity while
Reducing Water
Quality

9. Iowa Drainage Districts
Hardin County, Iowa
Tragedy of the Commons:
Free use of water resource
to move waste

10. What’s Unique About Central Iowa?
Mark B. David
University of Illinois at Urbana-Champaign

11. Raccoon River January 2016
Nitrate Load
- University of Iowa
IIHR - Hydroscience and
Engineering

12. Nutrient Delivery to the Gulf of Mexico
- USGS

13. Des Moines
Water Works
Lawsuit in
Response to
Escalating
Nitrate
Concentration
Risks

14. Number of Days Source Waters Above the
10 mg/L Nitrate Safe Drinking Water Standard

15. Lawsuit Key Points/Basic Legal Premise
• High nitrate effluent from artificial drainage tile is not
agricultural stormwater discharge but groundwater rapidly
removed from the soil by means of the drainage infrastructure.
• Artificial drainage systems in portions of Sac County transport
concentrations of nitrate greater than 10 mg/L into surface water
streams.
• Subsurface drainage systems that transport nitrate from the
field to a navigable body of water are point sources by
definition but have been erroneously considered exempt from
regulation under the Clean Water Act.
• If successful, this lawsuit would put agricultural drainage
systems on the same regulatory footing as other point sources.

16. Sac County, Iowa
“The costs of impacts are external
to agricultural systems and
markets for products. They are
borne by society at large.”
– “External Costs of Agricultural
Production in the United States”
Michael D. Duffy, 2004

17. Costs to Water Treatment Facilities
At Farm vs. Downstream
Des Moines Denitrification Costs
2015 O&M Costs $1,500,000
Estimated Cost for Denitrification
Facilities Upgrades $80 million
Paid for by ratepayers
$1.50-$22.00 per pound on the farm
$15.00-$47.00 per pound at municipal treatment plant
– NACWA

18. Costs to Quality of Life
(Future Research Topics)
• Increased public health risks
• Recreation – closed beaches, impaired water ways
• Gulf Hypoxia
Agricultural sources have been responsible
for nearly three times more degradation of
lake and reservoir acreage on average than
have municipal sources. – NACWA

19. Costs to Taxpayers
• Billions of dollars in federal ag subsidies with
no greater use of conservation practices
• No tie between federal subsidies and long-term
accountability
“Fooling Ourselves:
Voluntary Programs
Fail to Clean Up Dirty
Water,” Environmental
Working Group,
February 2016

20. Solutions for Water Quality Improvement
1. Treat pollution at the source: in-field or
edge-of-field solutions.
2. Transparent measuring and monitoring of
protection of public health – NPDES compliance.
3. Agricultural accountability for environmental
protection – resources follow accountability,
not vice versa.
4. EPA enforcement of Nutrient Reduction Strategies
for Iowa and other Mississippi River Basin states

21. ____ THINK DOWNSTREAM ____