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City of Arden Hills <br />Technical Memorandum – SCADA System Recommendations <br />Page 2 of 8 <br /> <br /> <br />1. INTRODUCTION <br />HR Green was contracted by the City of Arden Hills to assess their current SCADA system versus the <br />needed improvements to convert 3G cellular to 4G, replace cellular units (if needed) or develop a pathway <br />towards implementing a private radio network. <br /> <br />1.1. Background of Existing Facilities <br />Arden Hills currently has fourteen (14) lift stations, two (2) water towers and one (1) booster station. There <br />are plans to add one (1) lift station, one (1) water tower and one (1) booster station. Refer to Appendix A <br />for locations of the infrastructure through the City. At an Arden Hills operations meeting, the City indicated <br />that they had no desire for any remote control, just monitoring only. <br /> <br />The Engineer has visited all existing sites and the proposed location for the new lift station. As the previous <br />report indicates, as a whole, all sites are well maintained and in good condition. Important key factors were <br />identified as: <br />1. All lift stations, whether new or older, are using the same cellular modem -- the OmniSite Crystal <br />Ball, which is a fully functional RTU, instead of the lowest cost OmniSite RTU. <br />2. The North Tower, and South Booster Station utilize the HighTide Cellular RTUs; The South Tower <br />utilizes an OmniSite XR50 RTU. <br />3. The Booster Station at the South Tower utilizes an out of date PLC for controls and has an <br />additional RTU belonging to Roseville for their monitoring purposes. <br />The Owner has provided GPS locations for all lift station sites, basic drawings of the two water towers and <br />the most recent cellular billings. <br />1.2 Purpose for Improvements <br />The primary purpose of this technical memorandum is to provide recommendations for improvements to <br />the City’s SCADA system that: <br /> Provides a pathway to eliminate vulnerability to the discontinuation of 3G service. <br /> Improve operations of the potable water monitoring and control. <br /> Provide recommendations for SCADA system improvements such that new locations will easily <br />be added to the existing system, when the time comes. <br /> Provide cost comparisons for each possible theme and variation for the SCADA system going <br />forward. <br /> <br /> <br />2. RECOMMENDATIONS <br /> <br />2.1. Existing Cellular Systems <br />The existing OmniSite cellular system is in good condition, relatively new, operates reliably and is <br />standardized for all lift station sites. On simply economic and pragmatic basis it is difficult to justify replacing <br />all of this equipment. <br /> The Engineer investigated the methods and costs to upgrade the Crystal Ball RTUs. Since these are <br />the more expensive and more functional units, OmniSite has an installation kit that replaces the 3G <br />cellular modem with a 4G by simple replacement of a circuit board that is easily disconnected and the <br />new modem is the exact same physical size and mounting. This allows for a very simplified update <br />procedure, which the city could do on their own, if they so choose. A You Tube video is available that