Tag: groundwater

Groundwater – Invisible but Precious

Bob Otwell, FLOW Board of Directors
December 2016

Most of us in northern Michigan drink groundwater and use it to bathe. Outside of metro Detroit, the majority of Michigan’s public water supplies along with water in rural homes comes from groundwater. Groundwater also is used to water golf courses and supply the growing thirst of irrigated farm land. We would not have trout in our northern streams if they were not nourished during the heat of the summer by cold groundwater. This is our invisible resource.

This blog is the first in a two-part series examining groundwater; this article will provide the reader a better understanding of the physics, and the second one will examine current groundwater regulations.

Understanding Groundwater

Groundwater is simply rainfall and snowmelt that has percolated into the ground. In northern Michigan, about one third of our annual 33 inches of precipitation ends up as groundwater. The remainder runs off on the surface to lakes and streams, or is taken up by plants and is lost through evapotranspiration. In the Great Lakes Basin, abundant groundwater is stored in the layers of sand and gravel left behind by the glaciers, and in sandstone and limestone bedrock. The temperature of groundwater is generally the average annual air temperature above the ground. In northern Michigan, this means 50 degrees Fahrenheit all year round. This temperature cools trout streams and provides a nice cool drink in the summer, and it also helps keep small streams from freezing in the winter.

Groundwater flows naturally by gravity through permeable sands and other porous materials, and continues moving downhill until it seeps into wetlands, springs, streams, rivers or lakes. We’ve all seen groundwater percolating into a spring, or felt the cool currents on our feet while swimming in one of our clear lakes. But groundwater discharge to surface water bodies is in fact continuous throughout the bottom of the stream, lake, etc., even though we can’t see it. They are connected, and if you care about a certain babbling brook, you in fact care deeply about the groundwater that makes it what it is. Rivers and streams flow at a velocity measured in feet per second, whereas groundwater flows at a rate of feet per day. This sure and steady seepage provides the base flow that makes a perennial stream flow all year round.

Groundwater also flows unnaturally where the “downhill” direction is altered through the installation of wells and pumps. This pumping creates a “drawdown cone” around the well. If a small well is installed, there is a small blip in the groundwater table. By contrast, if a large well is placed with a large capacity pump, the groundwater table can be altered dramatically. Where there are many large wells, serious regional impacts can take place. The High Plains (Ogallala) aquifer that extends from South Dakota to Texas has been over-pumped for decades, resulting in a lowering of the groundwater table in some areas of over 150 feet. This significant drawdown forces other groundwater users to deepen their wells, increasing their costs and energy requirements. This “mining” of water has created a net loss of groundwater in the High Plains of 340 km³. What would be the effect if this volume of water was taken from Lake Michigan? If spread out over the surface area, this would reduce the lake level by 20 feet.

Large wells can also dry up springs and streams. The most vulnerable springs and streams are those near the headwaters, where flowing tributary groundwater is limited. Ironically, due to FDA requirements, this area is where bottled water companies must install their wells if they want to label the bottle “Spring Water.” Pump a gallon out of the ground in these areas and you lose a gallon in the stream.

Groundwater, springs, wetlands, rivers and lakes are all interconnected. To care about one, is to care about all. Are we taking care of our groundwater in Michigan?

To be continued next time.

Note: I have simplified the discussion above to aid in understanding. Hydrogeology is complicated by a combination of confined, unconfined and perched aquifers, separated by discontinuous layers of less permeable soils (silt, clay and glacial till). In addition, we only know for sure what we find in a soil boring at a specific location, and we must then interpolate between the borings. Our knowledge is dependent on the funds available to install multiple borings.

Fracking: It’s All About the Water

Hydraulic fracturing (“fracking”) for oil and gas in Michigan is the subject of scrutiny in the recent Integrated Assessment report series from the University of Michigan’s Graham Sustainability Institute.  The report confirms that the future development of tight shale formations appears to be massive and intensive in size and scope and will require unprecedented quantities of water to explore and produce these reserves.

How are oil and natural gas wells are being developed in fracking?
First a large pad is cleared, then as many as 6 or more wells are drilled on this one pad known as a “resource hub,” Then, several of these “resource hubs” are developed within close proximity to each other. Clusters of these hubs are then widely developed across townships and counties. Over the next several years, just one oil and gas company, Encana, plans to develop as many as 500 hundred wells in Kalkaska County, Michigan. Each resource hub can consume 90 to 180 millions of gallons of fresh water or more. The most recent numbers in Kalkaska County, Michigan—where fracking operations of this intense nature are underway—show that a group of these hubs in close proximity are presently using or plan to use more than 618 million gallons of water. As fracking expands in Kalkaska, reports indicate that number will be in the billions.

How will these unprecedented water withdrawals impact the groundwater and the streams and lakes within the watershed where the fracking is occurring?
The answer is no one knows. Current Michigan DNR and DEQ procedures do not measure the cumulative impact of these numerous wells and resource hubs on a local watershed and the impact on the nearby streams and lakes in that watershed. Each well permit which includes the amount of water withdrawn is approved independent of each other and does not take into account the amount of water withdrawn by the other wells on the pad and nearby hubs. It’s as if the other wells did not exist.

This is deeply concerning when put in the broader context of Michigan groundwater withdrawals. Bridge Magazine recently reported that 12 Michigan counties are already facing groundwater shortages. In light of present groundwater availability concerns, the increased consumption of groundwater for fracking operations will likely exacerbate the situation. Under current DEQ procedures for oil and gas drilling permits, there is no assurance our government can or will adequately protect our groundwater, lakes, and streams from these current and future massive water withdrawals.

What happens to all this water?
To frack the shale gas or oil reserves deep underground, these massive quantities of water are mixed with a cocktail of chemicals, many hazardous and/or known carcinogens, and sand. In Michigan, after a well is fracked, the contaminated water (“flowback”) is not treated, but is transported and disposed of in deep injection wells. What this means is that such massive quantities of water will never return to to the water cycle. We consider this a “consumptive” use of water. Other major concerns include the handling of the contaminated water. And, fracking is exempt from key federal and state regulation, including the Clean Water Act, the Safe Drinking Water Act, and the Resource Conservation and Recovery Act. In short, these massive quantities of water are gone forever after used in the fracking process.

What can be done?
FLOW’s Chairperson, Jim Olson, and Executive Director, Liz Kirkwood, submitted comments to the Graham Institute. To strengthen water resource protections, FLOW recommends that the State of Michigan:

  • Require development plan(s) and generic or cumulative environmental impacts and alternatives as required under the Michigan Environmental Protection Act (MEPA) before a lease or leases and permit or permits are finally approved or denied;
  • Refine and strengthen all aspects of the Michigan Water Withdrawal Assessment Tool (WWAT) and require baseline hydrogeological studies and pump aquifer yield tests; and
  • Encourage cooperation between state regulations and appropriate local regulation of land use, water use, and related activities to address potential local impacts.

To learn more about FLOW’s research and recommendations, please read our Executive Summary or our Full Recommendations submitted by Olson and Kirkwood to the Graham Institute.

For more about FLOW’s work on fracking, visit flowforwater.org/fracking