Browsing by Subject "Retrofitting"
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Item 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.Item Use of Mussel Spat Rope for Fish Passage in Culverts(Minnesota Department of Transportation, 2018-03) Kozarek, Jessica; Hernick, MatthewCulverts can act as barriers to fish and aquatic organism passage by a number of mechanisms including insufficient water depth or excess velocity, perched culvert outlets, excess turbulence or behavioral barriers. In Minnesota, maintaining unimpeded fish passage is a concern due to our high-quality fisheries; however, much of the fish passage research in the United States has been conducted on the coasts with anadromous species. Many different methods have been used in Minnesota and nationally to facilitate passage including retrofitting existing culverts. In larger culverts, methods such as baffles or weirs have been installed to create resting areas for fish in culverts with high velocities, but these can be costly, difficult to install in tight culverts, can create maintenance issues, and may only be applicable to larger fish species. Recent research from New Zealand demonstrated the effectiveness of mussel spat rope in facilitating fish passage in steep, perched, or high-velocity culverts. The installation of these ropes in Minnesota box culverts was investigated as a low-cost, low-maintenance method to facilitate fish passage, specifically focusing on 1) the hydrodynamic performance of the ropes, 2) the use of these ropes by Minnesota fish species, and 3) evaluation of field installations in typical box culverts. This project used a combination of physical laboratory measurements on rope hydrodynamics, fish laboratory experiments on use of ropes, and two field demonstration sites. Ropes created low-velocity areas and cover that were utilized by small fish to navigate shallow flows over smooth boundaries.