Browsing by Author "Deford, Lillian Bell"

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Hydrologic influence of wetland restoration : the Story Mill case study
(Montana State University - Bozeman, College of Engineering, 2016) Deford, Lillian Bell; Chairperson, Graduate Committee: Joel Cahoon
The Story Mill Wetland is a 20 hectare restoration project in Bozeman Montana, intended to help improve the quality of surface water that leaves the city. The streams that border the property, Bozeman Creek and the East Gallatin River, exceed the Montana Department of Environmental Quality's (MTDEQ) water quality standards for nitrogen (0.27 mg/L) and phosphorus (0.08 mg/L). Wetlands in the landscape have become more intriguing in the advent of MTDEQs adoption of Circular DEQ-13, a legal framework for nutrient trading to achieve improved watershed water quality. Earth-work took place in Summer/Fall 2014, including excavating 5,800 m 2 of disconnected floodplain, and filling a surface drain. The research objectives were to quantify the impacts of the restoration so as to make inferences about the short-term changes in groundwater/surface water interaction, wetland volume and area, and the wetland's impact on the water quality in the bordering streams. Measurements of groundwater levels and surface water flow rates, and water chemistry analyses for both water sources, were recorded weekly from 30 shallow wells and 5 stream gauging stations from August 2014 through September 2015. Groundwater velocity and hydraulic residence time were estimated by performing slug tests in several groundwater wells. Spatially normalized wetland area and volume were calculated based on interpolated groundwater surfaces. Throughout the monitoring period, in all surface and groundwater samples, total nitrogen never exceeded 3 mg/L, averaged 0.76 mg/L, and almost always exceeded the target standard for the East Gallatin River. Total phosphorus was below the detection limit in 97% of all samples and never exceeded 0.22 mg/L. Neither average nutrient concentrations nor pH showed significant general temporal trends, while dissolved oxygen decreased over time. Changes in hydrology were generally localized near earth moving activity. Overall, wetland volume decreased slightly and wetland area increased slightly. Hydraulic gradients showed the primary flow of groundwater to be out of the wetland, with an average soil water velocity of 0.11 m/day. The slow moving groundwater in the wetland system appears to limit the extent of groundwater/surface water interaction, and hinders the role of the wetland in enhancing the water quality in the receiving creeks.
Story Mill Hydrology and Water Quality Data [dataset]
(Montana State University ScholarWorks, 2016-08) Deford, Lillian Bell
This dataset includes all of the data collected and used to analyze the Story Mill hydrology and water quality for the thesis: Hydrologic Influence of Wetland Restoration: the Story Mill Case Study. The objective of this project was to use the data to speculate about the impacts of the wetland restoration that took place on the Story Mill property in Bozeman Montana one year after restoration. Raw data was collected from groundwater wells and surface water gauging stations arranged throughout the site, and includes: water levels, total nitrogen, total phosphorus, nitrate, nitrite, orthophosphate, chloride, sulfate, chloride, pH, and dissolved oxygen. Water levels were collected manually as well as continuously with data loggers – both are included. Weather data obtained from the weather station on the Montana State University Campus is included in this dataset, collected and used with permission by Joseph Shaw. Chemical analysis standard data is also provided, developed for the analysis of ionic constituents, total nitrogen, and total phosphorus. Data is arranged in several different spreadsheets but is designed to be linked and correlated – see the dataset illustration. The Primary analysis software used was R, and all code is provided.