Browsing by Author "Kasahara, Sophie M"
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Item 2015 Olmsted County Dye Traces(2019-04-17) Larsen, Martin R; Johnson, Scot B; Green, Jeffrey A; Kasahara, Sophie M; Wheeler, Betty J; Alexander Jr, E CalvinItem 2017 York Blind Valley Dye Trace Fillmore County, MN(2018-10) Larsen, Martin R; Green, Jeffrey A; Barry, John D; Kasahara, Sophie M; Wheeler, Betty J; Alexander Jr., E CalvinItem Crystal Creek Dye Trace Report Fillmore County, Minnesota(2017-05) Kuehner, Kevin J; Green, Jeffrey A; Barry, John D; Rutelonis, J. Wes; Wheeler, Betty J; Kasahara, Sophie M; Luhmann, Andrew J; Alexander Jr., E. CalvinItem Dye Tracing to Camp Coldwater Spring, Minneapolis, MN(Minnesota Ground Water Association Newsletter Volume 20 Number 4: December 2001 Page 4 - 6. Additional results from Sophie Kasahara's Senior Thesis "A Hydrological Study of Coldwater Spring, Minneapolis, MN." - UM Geoengineering Department, 2016., 2017-06) Alexander Jr., E. Calvin; Alexander, Scott C; Barr, Kelton D; Kasahara, Sophie M; Wheeler, Betty JCamp Coldwater Spring is a ~6.3 liter/sec spring that emerges from a Platteville Limestone ledge at the top of the west side of the Mississippi River gorge. It was the original water supply for Ft. Snelling in the early-mid 1800’s and is a registered Minnesota State Landmark. Potential impacts from nearby highway construction led to two successful dye traces to help define the groundwater basin feeding the spring. These traces are the first traces through the Platteville in the Twin Cities. Dye input trenches were dug with a backhoe to the top of the water table. Input B reached the top of the Platteville and the water table was a few inches above the bedrock surface. Eosin dye input into the trench reached Camp Coldwater Spring, 125 meters away in less than 1.5 hours. The minimum flow velocity in the fractured Platteville Limestone was 83 m/hr. Input C reached the water table while still in glaciofluvial sediments and was 305 meters from the spring. Fluorescein dye from Input C reached the spring in 16 days. The slower flow velocity is a combination of flow through the glaciofluvial sediments and through the fractured Platteville Limestone. These two positive traces demonstrate that Inputs B and C are inside the ground-watershed that supplies the Spring and support concerns about the potential impact of dewatering and construction activities on the Spring. The trace is ongoing.Item Fountain Spring Cave Dye Trace Fillmore County, MN 2016 Dye Trace Report(2018-10) Larsen, Martin R; Barry, John D; Kasahara, Sophie M; Wheeler, Betty J; Alexander Jr., E CalvinItem Groundwater Tracing in Orion, Marion and Eyota Townships of Olmsted County, Minnesota(2016) Larsen, Martin R; Green, Jeffrey A; Wheeler, Betty J; Kasahara, Sophie M; Alexander Jr., E. CalvinOrion, Marion, Eyota and Pleasant Grove Townships are located in Olmsted County southeast of Rochester, Minnesota and host a significant number of mapped karst features including the Orion Sinkhole Plain. The area is intensively farmed and is increasingly residential as part of Rochester’s exurbs. The area bedrock is composed of a relatively flat upland underlain by limestone, dolomite, and silty limestone of the Middle Ordovician Stewartville, Prosser and Cummingsville Formations. The carbonates are underlain by the Decorah Shale, which forms a partial aquitard; though the Decorah is truncated by incised stream valleys. Numerous karst springs emerge just above the Decorah and form tributaries which flow to the Zumbro and North Branch Root Rivers. These regional base level rivers are incised into the St. Peter Formation and Prairie du Chien Group. Thin, discontinuous glacial sediments and loess overlie the bedrock. Groundwater is the sole source of potable water in the area. Groundwater tracing research was initiated in the area due to environmental issues related to the presence of confined animal feedlots. Dye tracing has been successfully used to define connections between water running into sinkholes or losing streams and water emerging from springs, wells or along gaining reaches of streams in the karst of southeast Minnesota for 75 years. Dye traces have proven to be singularly effective tools in helping elevate discussions among communities, landowners and farmers about surface water-groundwater interactions. Information gained helps landowners implement strategies to minimize nutrient and bacteria losses into vulnerable karst aquifers. We initiated nine traces between 2014 and 2016. Eight of the traces were positive, in that at least one connection was confirmed between the sinkhole input of the dye and a monitored spring or creek. The positive results are drawn as springshed maps illustrating these connections, and are overlain on a base map of the previous dye tracing work. The base springsheds map will be updated as new traces are completed and the map is available on-line at: http://files.dnr.state.mn.us/waters/groundwater_section/mapping/springshed/springshed_map.pdfItem A Hydrogeological Study of Coldwater Spring, Minneapolis, MN(2016) Kasahara, Sophie MThis project has monitored the water chemistry of Coldwater Spring, Minneapolis, MN to document human impacts on the spring's water quality. Temperature, dissolved oxygen, conductivity, pH and anions were monitored weekly and cations and alkalinity monitored monthly at Coldwater Spring and the adjacent Wetland A from 15 February 2013 through 18 February 2016. Dye was injected into two rain gardens in the Veteran's hospital parking lot, located northwest of Coldwater Spring. Coldwater Spring's water flows through fractures in Platteville Limestone of Ordovician age. The basic chemistry of Coldwater Spring should be the calcium magnesium bicarbonate water typical of carbonate springs. However, on an equivalent basis, Coldwater Spring's water currently contains almost as much sodium as calcium + magnesium and more chloride than bicarbonate.Item Springdale Dye Traces 2016 Olmsted County, MN(2017-03-31) Larsen, Martin R; Green, Jeffrey A; Kasahara, Sophie M; Wheeler, Betty J; Alexander Jr., E. CalvinItem Wiskow Dye Traces 2014 Olmsted County, Minnesota(2014-09-03) Johnson, Scot B; Green, Jeffrey A; Larsen, Martin R; Kasahara, Sophie M; Wheeler, Betty J; Alexander Jr., E. CalvinThe Wiskow dye traces were conducted near Predmore, Minnesota in Eyota, Marion, Orion and Pleasant Grove Townships in Olmsted County from April 9, 2014 to June 12, 2014 (Figures 1 and 2). Dye traces have been completed in this area in the past. This recent effort further refined the delineation of the springsheds in close proximity to Kinney Creek and Mill Creek which are designated trout streams in Minnesota. In addition, there are growing concerns amongst citizens in the area and local units of government regarding the spreading of manure in winter. During snow melt there is a greater potential for contaminated surface water to infiltrate into sinkholes and negatively impact domestic well water quality and groundwater dependent resources such as springs and trout streams.