on Thursday, March 9, 2017
Take Heed. It's Your Water AND Your Health
Thanks to IEC member Tim Wagner, who contributed this blog post for Groundwater Awareness Week. March 5-11. The Iowa Groundwater Association spring conference, March 30 in Newton, will include educational sessions on karst and livestock management. Register and view the agenda here.
As a resident of northeast Iowa, the reactions I hear from first-time visitors to this region of the state are usually centered on one main theme. “This is stunningly beautiful country.”
It is true. Northeast Iowa’s geography is like no other in the entire state. With its many rivers, creeks, timbered bluffs, abundant wildlife, and a myriad of outdoor recreation experiences, it is this unique geography and the water that draws so many people and ultimately keeps them here.
But there is an underlying threat to this beauty and to the health of the local residents, with increasing incidents of pollution from agricultural animal waste impacting the region’s shallow groundwater aquifers and springs. It is these very systems that provide public drinking water and also supply the areas popular cold water trout streams.
In 2016, Iowa produced more than 22 million hogs, nearly all them raised in concentrated animal feeding operations (CAFOs), making it the top state in the U.S. for pork production. These industrial operations house anywhere from 1,200 hogs to many times that amount. Northeast Iowa’s two most northeastern counties, Allamakee and Winneshiek, have more than 60 large, industrial-scale pork facilities.
These high numbers represent tremendous amounts of manure, usually collected in deep, concrete pits directly under the slatted floors of hog facilities. Studies estimate that an average- size hog produces many times the amount of liquid and solid waste as an average adult human. But unlike human waste, which is required to be processed through municipal waste water systems or rural septic systems, waste from livestock is allowed to be broadcast or “knifed” across Iowa fields with limited restrictions.
Nearly all of Iowa’s agricultural lands are used for row crop production, which means that they are often void of cover or deep-rooted plants that can utilize nutrients in manure or reduce leaching of waste applied to fields. This makes it easier for pollution from nitrate and phosphorus, antibiotics and other compounds in animal wastes to reach ground water, including major aquifers that provide drinking water for thousands of Iowans.
This problem is especially acute in northeast Iowa, which is dominated by karst geology. Karst is typified by highly fractured and easily dissolved bedrock of limestone and dolomite that allows the formation of caves, sinkholes and disappearing creeks. Because of these characteristics, karst areas have many more direct conduits to underground aquifers from soil surface activities, such as large-scale applications of animal wastes. The region’s thin soils also have limited filtering capacity to reduce pollution before it reaches the groundwater.
Karst geology dominates large portions of Winneshiek and Allamakee counties. It is also found in portions of Howard, Fayette, Clayton, Delaware, Dubuque and Jackson counties, and more limited areas of karst extend into Mitchell, Floyd, Chickasaw, Bremer, Butler, and eastern Cerro Gordo counties. According the Iowa Geological Survey, the karst region is the source of drinking water for approximately 15% of Iowa’s municipal water systems and countless private wells.
To illustrate the risks, a series of private water well tests conducted in northeast Iowa in 2016 showed that out of 365 wells in Allamakee County, about 39% showed unsafe bacteria levels (either total or fecal coliform). The ratio of bacteria-contaminated wells jumped up to 52% in Winneshiek County, which has seen a larger increase in CAFO numbers in recent years. It is certainly worth noting that not all bacteria contamination can be blamed on livestock operations. But the trend still shows a pattern which demands attention.
The bottom line is that this all points to a looming public health crisis unless Iowans take a more proactive stand. Safe drinking water is critically important to all Iowans, including those who live in towns with public water supplies and rural residents who depend on private wells. We need better measures for local control by counties concerned with their residents’ health and welfare. This is why numerous counties in the karst region and throughout the state are now passing or considering resolutions calling for stronger state laws to guide siting of CAFOs and related manure management practices that can be tailored appropriately for local issues. If you are concerned, contact your county commissioners and state legislators to voice support for measures to allow more local control over CAFO siting and management to protect Iowans’ drinking water and health.
We must protect our beautiful landscape and our natural resources if we want healthful, clean water -- for all of us and for our grandkids. These treasures are at risk: We dare not take them for granted.
Tim Wagner is a returning Iowan and resident of Decorah. He has a long history in environmental and public health advocacy that includes serving as Executive Director for Utah Physicians for a Healthy Environment.
- land stewardship
- nitrate pollution
- phosphorus pollution
- water quality