Browsing by Subject "Effluents"

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    Assessment and Recommendations for the Operation of Standard Sumps as Best Management Practices for Stormwater Treatment (Volume 2)
    (Minnesota Department of Transportation, 2012-05) McIntire, Kurtis D.; Howard, Adam; Mohseni, Omid; Gulliver, John S.
    In order to improve the performance of standard sumps as a best management practice (BMP) in treating stormwater runoff, a baffle was designed to be installed as a retrofit in standard sumps. The retrofit is a porous baffle called “SAFL Baffle”. The effect of the SAFL Baffle on the performance of standard sumps was assessed by conducting laboratory tests on small scale as well as full scale straight flow-through standard sumps equipped with the baffle. In addition, a number of tests were conducted to determine the performance of standard sumps with the SAFL Baffle when the baffle is clogged with debris like trash and vegetation. Furthermore, the performance of two other configurations of the baffle was studied: (1) the SAFL Baffle in a sump with an outlet pipe 90 degrees to the inlet pipe, and (2) the SAFL Baffle in a sump with some water entering the sump through an overhead inlet grate. Standard sumps equipped with the SAFL Baffle were evaluated using two metrics: (1) How well the system captures sediment during low flow conditions (Removal Efficiency Testing), and (2) how well the system retains the previously captured sediment during high flow conditions (Washout Testing). The results of the tests showed that the SAFL Baffle dissipates the energy of water entering the sump and as a result, at low flow rates, it captures sediment better than a standard sump with no baffle. More importantly, at high flow rates, the washout of the previously captured sediment reduces to near zero.
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    Water Use at Minnesota Rest Areas: Final Report
    (Center for Transportation Studies, University of Minnesota, 2016-01) Nelson, Taylor; Heger, Sara
    The Minnesota Department of Transportation (MnDOT) Statewide Rest Area Program consists of a coordinated system of public rest areas that are intended to help motorists travel safer. In 1979, MnDOT collected data at rest areas to refine assumptions and improve techniques for design of rest area water supply and sewage treatment. They found people used an average of 2.8 gallons with water conserving devices and 4.5 gallons with non-water-conserving devices. This study evaluated the accuracy of the 1979 MnDOT design charts and formulas based on plumbing code fixtures and traffic patterns. A total of six rest areas, Culkin Rest Area (R.A.), Frazee R.A., Fuller Lake R.A., Lake Pepin R.A., Central Minnesota Travel Information Center (TIC), and St. Croix TIC, were included in the study. Average water use estimations were calculated from hourly people counts, hourly traffic counts, and hourly water flow data. Site specific average water use per person ranged from 0.7 gallons to 3.8 gallons, with an overall average water use of 2.3 gallons and a 95% confidence level average of 3.5 gallons. When accounting for variation, error and providing a safety factor, a water use per person design value of 5 gallons per person per day is recommended. The results of this two-week study appear to indicate that the 1979 design values are still valid, but additional data is needed for further conclusions. The University of Minnesota recommended MnDOT conduct similar water use studies for longer time periods prior to designing new rest area septic systems.