Agenda Packets - 1987/03/16 - Laserfiche WebLink

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DOCKETS UNIT PAGE SEVEN MARCH 24, 1987 On new lines, install remote -control shutoff valves every 20 miles in rural areas; every 4 miles in urban areas. Periodically test these valves. (Minn. Rep., Rec. 5.3) Response: The inEtallation of automatic or remote shutoff valves provide an additional level of safety not currently available on most pipelines. These valves could be activated at the time of a rupture to prevent backflow of product which would exacerbate a spill. The shorter the distance between these valves limits the amount of product being spilled at a rupture location which can be particularly important in urban areas where a greater chance of injury or death exists. Questions: (a) For new pipelines, are automatic or remote -control shut- off valves included in the design, and, if so, where are they installed? Response: The City is unaware of current pipeline design practices. (b) Are automatic or remote -control shutoff valves effective in mitigating the consequences of a pipe- line accident? Response: Had an automatic or remote -control shutoff valve been located where a manual valve currently exists on the WPL No. 2 - 8 inch line at Mile Post 10, the amount of product that spilled and fed the fire in Mounds View would have been greatly reduced. It is possible that an automatic valve would have limited the spill to the extent that the fire and explosions causing injury and death would have been prevented. (c) Do automatic remote -control shutoff valves present any operational difficulties? Response: These valves should only present operational difficulties if they are not properly maintained and clear operational guidelines are not established. (d) What would be the conversion costs for existing pipelines; the installation costs for new pipeline; the operating costs for both?