Laserfiche WebLink
The jury-rigged system we have working now has a sensor on the water line in the booster <br />station. We have determined that we are about 5 feet off from sensing the correct water tower <br />level in the morning and up to two feet off in the afternoon. Based on this and a search for a <br />different sensor we have determined that there are no sensor controls that can be installed in the <br />water lines at the booster station that can sense the water levels in the tower accurately enough to <br />meet our needs. <br />We tested and determined that a 900 Mhz radio system between the water tower and the booster <br />station can provide the needed reliable communications needed. A 900 Mhz radio system does <br />not require a license and also, does not require a clear line of site (no trees in the way) between <br />the antennas to function properly. <br />Based on the above, staff requested proposals from two contractors who know our control <br />system. The proposals are for both a (one-way) unidirectional system that will enable the water <br />tower to send signals to the booster station and a (two-way) bi-directional system that will enable <br />city crews to view tank level, alarms, and set-point controls at either location. The advantage of <br />the bi-directional system is that City crews can respond to problems at either site, instead of have <br />to go to the booster station first and if needed to the water tower as required with the <br />unidirectional system. Both proposals also include needed unintemrptible power supplies. They <br />are: <br />Company Unidirectional Bi-directional <br />Duane Nielsen Co. $7,600.00 $10,700.00 <br />Connelly Industrial Electronics $8,099.19 $9,656.06 <br />Staff would have to purchase and install a tower at the booster station to support the <br />antenna at an estimated additional cost of $800. <br />This project is listed in the 2004 Water and Sewer Capital Budget for $8,000, however, we were <br />not pursue this project until we determined if the City of Little Canada was to keep the water <br />system or the communication system failed. <br />Based on the total annual cost of $1,944 per year for our existing unreliable system we could pay <br />off of the unidirectional radio system in just over 4 years and a bi-directional radio system in just <br />over 5 years. Due to the potential savings in staff response times to either the water tower or <br />booster station sites based on their location; and the potential to resolve the problem more <br />quickly with the same information at either site; staff recommends the bi-direction system. <br />To accomplish the installation of a radio system staff will need to install a 40 foot high triangle <br />leg design antenna tower (similar to those used to support a TV antenna or amateur radio antemia <br />at a residential house) at the booster station to enable us to receive the signal from the transmitter <br />at the water tower. According to City Ordinance 903.140 Antennas and Towers, we need to <br />obtain a conditional use permit for this tower. As shown by the attached sketches, this tower is <br />to be mounted in the ground next to the booster station building. The tower will be 60 feet from <br />the property to the east and 50 feet from our property line to the south (all within the "fall zone" <br />k[:\GregS\Water\Boosier SCation Antenna Tower.doc <br />