When Fargo-Moorhead residents think of water, they’re likely to have floods or fishing in mind. West of the Red River, that overlooks one major reason to treasure the flow that defines by far its biggest value: the community’s supply of drinking water.
Here in Moorhead, faucets also bring its flow into some 12,000 homes and businesses. But that precious liquid – judged the best-tasting in Minnesota in three recent years – doesn’t depend on the Red alone. Unlike its larger sibling to the west, MPS has a priceless resource deep, deep underground.
Kristofer Knutson, who manages Moorhead Public Service’s water division, took MPS commission members, city council members and staff on a hunt for its hidden assets last week. Traveling by bus, they visited the sites where about 40 percent of Moorhead’s current water supply is pumped from underground, then piped to MPS’ 20-year-old water treatment plant on North Highway 75.
Two major aquifers keep the taps running in Moorhead and its neighbor Dilworth. The Buffalo Aquifer stretches from south of Wolverton to north of Dilworth. From half a mile to six miles wide, the underground “river” contains some 200 billion gallons of clean, pure water. It dates back 8,000 to 10,000 years, when retreating glaciers left the surrounding sand and gravel in the bed of what became, for a time, ancient Lake Agassiz.
The second, smaller and somewhat mysterious source lies directly below the water treatment plant. Known only as the Moorhead Aquifer, its waters rest much deeper and farther back in time – hundreds of millions of years. Wells drew on it in the early days of Moorhead, when Fargoans and other outlanders traveled to the well at 11th Street and First Avenue North for its pure, typhoid free supply. Major pumping dates back to the 1940s. Today it’s a dependable secondary source backing up the major supply of the Red River and Buffalo Aquifer.
Kris guided the group through the city’s original south Buffalo well east on Highway 10. The wellfield has been in service since 1955, and is often pumped in the summertime as demand for water grows due to seasonal lawn watering. The wellfield is able to deliver 1,800 gallons per minute as seasonal demand requires it.
Another, newer wellfield three miles north can deliver similar flow to the Water Treatment Plant when it’s required. The Public Service Commission is planning a third deep well near Sabin at 60th Avenue and 70th Street South, projected sometime in the next five years. The third wellfield would provide additional flow from the Buffalo Aquifer during a drought, when MPS would rely solely on groundwater for water supply.
MPS drew much of its daily water supply from the Buffalo Aquifer from the 1940s through 1994, when the water treatment plant was completed. Since then, about 80 percent of MPS’ supply generally comes from the Red River intakes north of the city, with the deep wells supplying the balance.
MPS, along with Clay County, guards the Buffalo Aquifer from the modern pollution that could threaten this key regional asset. Most of it flows safely enough through clay and gravel from 20 to 120 feet below the surface. It emerges, though, in several places, including the enormous Benedict gravel mining operation north of Sabin. MPS negotiated a settlement with the pit operator, Northern Improvement, some ten years ago. A dike around the 100-foot-deep pit helps prevent surface water overflow from carrying impurities and contaminants into the source.
A little farther north, the aquifer flows clean today roughly beneath the route of Minnesota Highway 336, which connects Interstate 94 and U.S. Highway 10. The area around the I-94 interchange presented a major challenge to its integrity in the 1990s, when two large truck stops leaked petrochemical pollution into the soil. The Superfund cleanup of the site was mostly complete by 2010.
Water supply is critical not only to the city’s quality of life but its future development. The region’s long-range wet and dry cycles complicate planning and management, Kris points out. The Red River ran dry for 80 days in the summer of 1936, while record floods were recorded in 1897, 1950, 1997 and other years, including the all-time record in 2009.
Deep ground-water wells saved the city during the 1930s and for more than 50 more years. Dependence on the deep aquifers, though, was reducing their volume to a worrying level by the 1990s, when MPS invested in the treatment plant that now also draws surface water from the Red — currently about 80 percent of its daily supply. Meanwhile, the decade-long wet cycle allowed the Buffalo aquifer to be naturally replenished.
Today, says Kris, “the aquifer is as full as it’s ever been.” Hydrologists estimate that about 10 years’ worth of water rests underground for use during a drought– a reassuring point, since the Palmer Index of meteorological data suggests the cycle turned dry about two years ago.
Gathered from sites in Clay County, the water is gathered at the MPS water treatment plant. Then the powerful High Service Pumping Station – completed in 2015 – utilizes water from nearby reservoirs and sends clean water into the distribution system. From there, the powerful pumping system distributes it to homes and businesses in Moorhead, Dilworth and the surrounding area. A year-old 1.3 megawatt natural gas-powered generator ensures that the water will keep running even when electrical power halts.
“We’re vigilant – both here in Moorhead and in Fargo – to monitor and protect the water supply,” Kris emphasized, speaking of both the shared surface water of the river and Moorhead’s ace in the hole, its deep and steady aquifers. “It’s critical. If the electrical supply is interrupted, we can still figure out ways to survive. But if our water is gone, life as we know it ends.”
Moorhead Public Service is hosting an open house at the water treatment plant on Tuesday, Oct. 4, when residents will be invited to learn more about how the best-tasting water in Minnesota is purified, stored and pumped.
