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Monroe County Pure Waters
Saves $500,000 with Flo-Dar Flow Meter
Known for their abundance of water resources including Lake Ontario to the north and the Genesee River, is Monroe County, New York. The County’s Dept of Environmental Services-Division of Pure Waters was established in 1967 to reduce pollution in County waters and establish master plans to carry the county through to the year 2020. The Division currently operates two wastewater treatment plants, VanLare and Northwest, as well as several miles of interceptor tunnel, pump stations, and sewer collection system for the Rochester and Gates-Chili-Ogden districts.
Two permanent flow monitoring sites, a 120” bypass line at the VanLare plant and a 66” influent line located in the collection system at St. Paul Boulevard had remained unmonitored due to high velocities and large line sizes. The VanLare Wastewater Treatment Plant has a total treatment capacity of 600 mgd, and is permitted for 135 mgd, with a current daily average of 100 mgd. The plant also contains a deep-rock tunnel system designed to convey and control sewage and stormwater during large wet weather events. The tunnels were placed beneath portions of the sewer system that were overloaded due to an aging and undersized system. A decision to build the tunnels was based on the fact that they would cost half of what it would cost to dig up the old system and would also be much less disruptive.
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According to Jeff Helfer, Instrument Technician for Pure Waters, “We use the 120” bypass line at VanLare when flows get up over 200 mgd in the plant. We go to what’s called a 120 event type situation where they are bypassing some of the flow.” Due to the size of the line, submerged style flow meters were not an option. An engineering study was performed that came back with a recommendation for the installation of a flume and some other equipment. Helfer adds, “Some of the quotes were $500,000-$750,000. Our local Hach flow meter rep Mark Boswell of Total Control System Services recommended a Marsh-McBirney Flo-Dar non-contact flow meter. The flow meter’s uniqueness lies in its ability to remotely monitor flow from above the fluid eliminating fouling and maintenance associated with submerged sensors. Flo-Dar combines digital Doppler radar velocity sensing technology with ultrasonic pulse echo level sensing to accurately monitor flow in a wide variety of applications. The meter is virtually maintenance free and can be installed and removed from street level without the need for confined space entry costs and constraints.
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Pure Waters decision to purchase the Flo-Dar meter for the VanLare plant has really paid off. For just the cost of one Flo-Dar meter the County was able to save between $500,000-$750,000. Helfer adds, “The savings were huge with Flo-Dar. Along with the savings the meter is non-contact and we will save additional money because you don’t have to do manhole entry with gas detectors and the whole nine yards.” When a 50-year storm event happened in Monroe County in July 2006 Helfer stated that the Flo-Dar meter kept right on monitoring. He adds, “The water was so high that it actually took the bracket that the Flo-Dar was mounted on and bent it so it was pointing 90 degrees in the other direction. When the event was over I went down on a tripod, bent it back to where it was in position. The Flo-Dar sensor was covered with rags but it never left the mount. I bent the mount back into position and it’s been there ever since working perfectly.” Everyone was amazed that the Flo-Dar sensor could hang in there under such extreme conditions when manholes were reported to have been jumping 4 to 6 feet in the air. He adds, “It was quite an event for us. To have that much flow and the Flo-Dar was never taken out is unbelievable. I thought for sure it would end up in Lake Ontario.” To date the meter has been installed for 3 years and according to Helfer has been working great and they’ve had no problems with it.
The other Pure Waters flow monitoring application was located on a 66” influent line that had high velocities ranging from 11-13 feet per second. Helfer states, “Attempts were made in the beginning to use one of the band type meters with a submerged sensor but the velocity is so strong that everything got scoured away. This application has been sitting there for years with no one making an attempt to try to meter it because nothing seemed to work in the past. We just had nothing due to the high velocities and the way the meter would have to be situated in the manhole.” On one of Boswell’s visits to Pure Waters, Helfer took him to the site and pulled up the manhole cover. Boswell looked down the manhole and was confident that the Flo-Dar meter could do the job. “Sure enough, we got a unit and put it in there. We tested it and it worked perfect. We were thrilled with the meter’s performance and it was a big deal for us. When I gave the plant personnel the Flo-Dar readings they were ecstatic.” The meter has now been in operation for 1.5 years.
Enjoying the many benefits of Flo-Dar, Helfer is especially pleased with the accuracy and the non-contact nature of the sensor. He especially appreciates not having to do confined space entry with all of the required gear any longer. He adds, “I really enjoy that we can feed this data into a SCADA system. I’m currently reading the meter all of the time so it’s 24/7. We have our own front-end graphics package that we store all of the data in but with the internal data logging, I like that I can write some really easy and nice reports with Flo-Ware. When I was first getting the meters going and trying to get them on board with everything I was feeding plant personnel the Flo-Ware reports from the meters themselves. I’d print out the reports and when they had a 120 event and I could tell them exactly when the event started, stopped, and the entire progression of how it took place and they were using those numbers to report to the state. If for some reason our SCADA system goes down and they lose the event they know that they can get the data just by me taking my laptop out and downloading the information. That’s a really nice feature to have. Even when the SCADA system is not down I am asked to provide Flo-Ware reports anyway because it gives us such a nice printout and has everything that they need.”
Delighted with the successful application and cost savings of Flo-Dar, additional meter purchases are planned by Pure Waters. Helfer adds, “There are some new applications that we’ve been scoping out including one for a line coming out of the plant as well as flirting with the idea of putting one on the pipe that goes out in to Lake Ontario.”
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