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Water is a large concern mentioned by citizens when discussing potential data centers in MN. Is this concern founded or fearful? How do we know?
To start, I pose several questions that have driven my research. How much water do we have in the aquifers below us? How much water do our communities currently use? How much water do these potential data centers intend to use? In the large scheme of things, are these numbers significant or insignificant to the total water available?
The major aquifer that Dakota County and Goodhue County pull from is named the Prairie Du Chien- Jordan aquifer. As John Gleason, the DNR South District Hydrologist Supervisor to our area, explained to me in emails (reference link from above web address), “the Prairie Du Chien Group and Jordan Sandstone are distinct geologic formations, but they are hydraulically connected so together they are sometimes considered as a single aquifer” [emphasis mine]. While similar in name and proximity, it is important to denote if the source that a person is reading is referencing these aquifers separately or jointly because when speaking about numbers, while similar, they are not always identical.
In general, the Prairie Du Chien-Jordan aquifer extends beyond the St. Cloud, MN area, and far south into Iowa and east/southeast past La Crosse. Within this area the aquifer ranges in thickness, on average between 250’ – 450’ thick. The depth, or starting point below ground, varies due to topography and geography. For oversimplification and averaging, not factoring rock space and porosity, below the 1 square foot space you are standing on is an aquifer space 250’ thick, and within this 250 square foot vertical column lies roughly 1800 gallons of water. Under the average 5000 sq foot home lot size there lies roughly 9,000,000 gallons of water. Factor that out past your neighbor’s house, the road, the park, and nearby field, the space and quantity of water below us is substantial.
So, how do we ascertain if the aquifers can accommodate the potential water use that these data centers wish to use? Numbers vary between different data center proposals, but it is common to see possible water numbers range between 50,000-300,000 gallons per day, and sometimes peak numbers upwards of 1 million gallons per day on hot days between the months of April to October. To consider if these numbers are significant, we can utilize some MN DNR and US hydrology reports.
As mentioned, the aquifers range in average thickness of 250-450’ in Minnesota. We can look at monitored wells in the Prairie Du Chien – Jordan aquifer in a DNR report found at the above link. It shows a general average of around a 10’ drop during the summer months when water usage is high. Then the aquifer typically recharges during the cooler months as precipitation from the summer starts its descent, percolating through the ground leading to the aquifers recharging. In the historical view, some seasons are drier than others and less recharging of the aquifers occur, but on average, the aquifers around Dakota County remain steady.
So, how much water does the metro already pump from the Prairie Du Chien – Jordan aquifer? A Metropolitan Council report indicates that a small section in Dakota County sustains average pumping of 500 million gallons per month, with seasonal peaks in excess of 1.5 billion gallons of water per month. The current data center proposal in Hampton indicates possible industrial water use of 12.5 million gallons per year, or about 2 gallons per month April through October. Certainly, different developments will utilize different amounts of water, and this should be considered when looking at our water availability in the Prairie Du Chien – Jordan aquifer. I am trying to ascertain the proposed water use that each of these nearby data centers desire, but as of this writing, my information is incomplete.
So, what about some other common concerns, will these data centers to affect water availability to domestic and agricultural water users? Will the data centers affect the water level of our streams and rivers? And is there potential for water contamination? I think an excerpt from an email from John Gleason, MN DNR South District Hydrologist Supervisor, summarizes the state’s position on the first question:
“[The] DNR examines the potential for increases in pumping to adversely affect water availability or water quality for other nearby well owners and may limit a permit if such a potential exists. [… The] DNR must allocate water use in accordance with priorities listed in state statute. These priorities place domestic water usage first, followed by smaller volume use, agricultural use, power production, [then] other commercial and industrial uses, and non-essential uses such as car washes or lawn irrigation […] In this case, the proposed data centers would constitute a commercial and industrial use, 5th on the priority list. […] When a high-volume water appropriation causes another well to run out of water, it is referred to as a well interference. Domestic water use is the highest priority water use under Minnesota law and private domestic water uses must be protected in any permit decision. This is not, however, a “zero impact” standard. Rather, it means that adverse impacts affecting the usability of a private domestic well must be remedied by the large volume water user if their use is causing the adverse impacts.”
In short, Minnesota has a hierarchy for water usage with domestic users being the first priority and agricultural being third. Minnesota law also says, based on this hierarchy, that if a large volume water user makes your well run dry, there are legal ramifications available to those harmed by well interference.
Now, what about surface waters and streams? MN DNR John Gleason says, “[The] DNR considers how the aquifer may be connected to surface waters to make sure the additional use [such as from data centers] will not negatively affect surface waters and the ecosystems that rely upon them […] Minnesota law outlines DNR’s authorities for managing the quantity of surface and groundwater throughout the state […]” The DNR factors into account the surface waters when approving new water use applications.
Some people have expressed hazardous pollution concerns in the belief that the industrial water will be contaminated. The purpose of this industrial use water is for cooling, a medium for transferring heat. It seems that it will be drawn out of the ground and used as non-potable water, thus it won’t need to be treated by a city. Then it will pass through lead-free pipes, such as galvanized steel, plastic pvc, or copper, just like the pipes in your house. Then, after being used to draw away heat from the servers, the water will cool through means of some evaporation before the remaining water goes to a holding tank to be used again at another time on site. Minnesota state law does not allow “one time water use” in industries using more than 5MGY. Industries must re-use water multiple times, as stipulated in MN statute 103G.271. Depending on the data center design, this relatively clean water, straight from the ground, which has touched only internal pipes, seems to be disposed of by letting it percolate back into the ground through rapid infiltration basins, naturally cleaning the water again through rock and sediment on its way back to the aquifer, just like the water that accumulates in your ditch after a rain.
The concern over water resources is certainly a valid question, and through my ongoing research, I have found water is a replenishing resource and it seems our aquifers have a great deal of it in store. The world is going to change significantly in the coming years. AI and data storage is going to be an integral part of the world we move into and as we technologically advance, we will also unlock the ability to utilize our resources more efficiently for the betterment of society.
With these data centers, let us not be driven by a sense of fear, but rather by a pursuit of genuine knowledge, for in seeking to understand, we can have rational discussions with one another with the aim of doing what is best for our communities.
I welcome any input from those concerned or interested. I am not infallible in my research, but this is where the facts I have found are leading me this far. I can be reached at StayfreeMN@gmail.com. All of my source documents can be found at: https://sites.google.com/view/water-energy-noise/home
~Erik Porten
