Source Development
Red Rock Rural Water System was looking at the prospect of a costly rate increase from the City of Windom, who is one of their primary water suppliers. In addition to meeting their own water needs and selling water to Red Rock, the City of Windom supplies water to the City of Bingham Lake and the nearby POET ethanol plant. Windom’s water supply was on the decline and they were considering a new water source from a deeper groundwater formation that would require reverse osmosis treatment and a hefty increase in water rates.
DGR Engineering was already working with Red Rock on a constructing a new 1.2 MGD water treatment plant. During the water source exploration phase of that project a potential source was identified in a shallow alluvial aquifer along the Des Moines River. The only problem with the site was that it was within a mile of the County landfill, which could be a major problem from a public perception. However, the bad optics for a drinking water source wasn’t a problem if the source was developed as an industrial water supply.
Looking for a good regional solution to Windom’s water crisis, DGR Engineering and Red Rock Rural Water System teamed up with POET to perform a program of exploratory drilling, test pumping and well field development. DGR designed three production wells capable of supplying 1.4 MGD to the ethanol plant and 9-miles of 10” diameter raw water main to transmit the water from the source to the point of use.
Red Rock’s out-of-the-box approach to a declining water supply and their long-term relationship with DGR Engineering ended up being a win-win-win situation for everyone. POET had a new water source with a lower cost of production while keeping Windom as a back-up supply. POET continues to pay for the debt retirement on their original Windom water source in exchange for an emergency connection. Red Rock avoided a rate increase on their water purchases from Windom, allowing them to continue to utilize a vital water source for their system. Windom was able to reduce their water use by 1/3 and cancelled their plans for a new RO water treatment plant, saving the residents the cost of a rate increase. The entire project was Addition by Subtraction.
As the Little Sioux River winds through the O’Brien County, it passes through a narrow valley with a shallow alluviale aquifer where Osceola County Rural Water has drawn water for years. The depths and quality of sands and gravels is highly variable throughout this valley. OCRWS rapid growth in water demands had pushed their existing wells to the limit, and it was now time to start looking for additional water supply.
The river valley in this area is very narrow, but potential well sites were limited by the size of the floodway and land owners in the valley who were less than cooperative. OCRWS was eventually able to secure an option to purchase on nearly 2 quarter sections of ground, but with so much land to cover, traditional exploration methods using a drilling rig would be expensive and possibly miss highly productive areas.
DGR Engineering partnered with WSP to perform 4 days of surface resistivity testing to give multiple cross section “snap shots” of the aquifer thicknesses in the area. With field results available in the field instantaneously, we were able to quickly dismiss large sections of the exploration areas and focus on areas of high potential. We were even able to access public access state land at the last minute to expand our search. We were able to do this without any permits, due to the non-evasive nature of the testing.
In the end, our team located 2 new well sites in the original search area. We were also able to identify a 70’ deep vein of gravel on State owned ground, nearly double what we found anywhere else in the search. Physical drilling in these locations confirmed the results, and now we are in the final stages of the necessary state permits to drill two new wells on State ground, which will be the most productive wells OCRWS has in the valley.
Lincoln County Rural Water System occupies the margins between Sioux Falls, Tea and Harrisburg, and is positioned to experience substantial growth as these communities grow into the LCRWS service territory. The Board of Directors looked toward the future and wanted to make sure that water supply restrictions were not going to prevent them from serving their customers.
DGR Engineering worked with LCRWS to diversify their water supply options for their future growth. Their growth will be supplied by a combination of 3 different water sources:
- LCRWS currently has 1.5 MGD from Lewis & Clark Rural Water and will be able to expand this supply to 2.5 MGD when Lewis & Clark Rural Water expands their WTP.
- LCRWS has maintained their water right in the Big Sioux Aquifer. DGR Engineering has developed conceptual plans and cost estimates to bring this 1.6 MGD source online, and to match the water quality provided by Lewis & Clark.
- DGR and WSP helped LCRWS to identify an area of high quality and high capacity in the Dakota Sandstone Aquifer. If LCRWS brings this source online, it will add 1.9 MGD to their supply.
In total, LCRWS has water rights and the ability to economically develop 6.0 MGD of water supply, which puts them in a rare position in the Sioux Falls region… having plenty of water to fuel their growth, and an opportunity to become a bulk water provider to the communities near them.
For over 20 years Edgerton has been discussing a connection to Lincoln Pipestone Rural Water (LPRW). The current Council wanted an outside opinion to evaluate all alternatives and to provide a recommendation. These alternatives included expanding their existing well field, connecting to LPRW for 100% of their demand or blending with LPRW. DGR completed a preliminary engineering report that met all the requirements for Rural Development. In fact, this report is being used as an example for other communities to use. This report evaluated the most cost-effective long-term solution for their water system. This included determining the cost of production to compare between the sources. Ultimately, the City decided to connect to LPRW. This was not the most cost-effective solution. However, the non-monetary factors such as the long-term viability of the aquifer and water quality steered the decision to blend the City’s water with LPRW.
The City of Marshall Minnesota (population 13,664) is a thriving community in Southwest Minnesota, who relies on ground water to supply safe drinking water. Their growing water demands were exceeding the long-term capacity of their aquifers, which had the MN Department of Natural Resources placing further restrictions on their limited capacity. They had already gone 8 miles outside of town to find water years before… this time they would have to expand their search.
Marshall Municipal Utilities found a new water source which was 27 miles away from their water treatment plant. DGR Engineering designed a combination of 20” & 24” pipeline to deliver this water to the City. We used our knowledge of cost effective rural construction to save Marshall Municipal Utilities millions of dollars in construction costs. In the end, Marshall Municipal Utilities added over 4 million gallons per day of water to fuel their growth for years to come. And with the economical design and bid prices, they had money left in their project budget to tackle other much needed improvements.