Valve positioner provides boost to effluent quality

Problem: An Illinois wastewater treatment plant needed to improve the valve position on each of its three drainage doors and then send the information to its Emerson Process Delta V plant control system for monitoring. Because each drainage door had different opening characteristics, plant personnel needed to modify the analog output signal for each unit. To complicate matters, the valve actuator housings were extremely small and located in extremely challenging environments.

Solution: The plant purchased field-programmable Kinax 2W2 Angular Position Transmitters from Absolute Process Instruments. Each transmitter is 1.95 inches in diameter and 1.10 inches deep, small enough to be installed in the actuator housings. They use relative capacitive sensing technology and create no drag on the valve gearing.

Result: The transmitters give an accurate and repeatable linear 4-20mA signal for the valve position that easily interfaces with the control system. This allows the operators to achieve more accurate flow control and improve effluent quality. 800/942-0315; www.api-usa.com.

---

Electrical signature analysis helps detect faults

Problem: A five-stage vertical turbine pump overheated at a pump station that supplies drinking water to Henderson, Nevada.

Solution: The in-house predictive maintenance team investigated five pump motors, using hand-held ALL-TEST Pro 31 and ALL-TEST IV Pro de-energized motor-testing instruments to reveal potential winding faults and indicate rotor problems. “The extensive rotor testing indicated there were issues with Motors 1 and 5,” says Alex Panattoni, control systems technician. “We asked ALL-TEST Pro to perform on-site electrical signature analysis with their energized testing instrument, and at the same time we had a third party perform vibration analysis. The vibration analysis did not show any rotor problems, but the ESA data taken with the On-Line II indicated several rotor bars could have been broken.”

Result: Motor 5 was pulled, and the repair shop confirmed that 30 percent of the aluminum rotor bars were broken. Motors 1 and 5 were rebuilt with copper rotor bars, and another round of testing was performed after re-installation. The ATPOL II, which is both a motor analyzer and a power quality analyzer, provided the maintenance team with ESA data, which helped them to proactively avoid motor failure. 800/952-8776; www.alltestpro.com.

---

Single direction communication software helps city save time

Problem: Veolia Water Ireland saw substantial value in allowing experienced and knowledgeable select personnel viewing access to a water facility while not on site. Security was paramount.

Solution: The system administrators installed Secure Plant Explorer from Automation ONSPEC Software. A separate computer allows remote viewing of plant floor data. It uses a single direction communication protocol to receive updates in real time from the plant floor SCADA computer. This isolates the plant floor from outside attack.

Result: Key employees were given protected remote access to the PC for receiving plant floor updates, allowing them to more effectively supervise the facility. 888/362-5867; www.automationonspec.com.

---

Network upgrade offers self-healing capabilities

Problem: In 2008, the City of Monroe, North Carolina, needed to add fast, automatic self-healing capabilities to its SCADA fiber network. “Our distribution network spans a 40-mile area, including electric and gas transmission plus water control and monitoring,” says Teresa McBrayer, representative with Energy Services at the city.

Solution: The city upgraded its existing H&L Instruments 561-based FiberLoop II network to the 570-based FiberLoop III network. The 570 system is configured in a loop using two redundant masters 15 miles apart, with four 22-mile spans between masters. There were also 2-mile and 15-mile radials out to water towers/lift stations. The Model 570 offers 126 communication channels, remote master/slave configuration over the network via FiberPanel software, and point-to-point communication support.

Result: “After upgrading the network, we experienced two simultaneous fiber cable dig-ins,” says McBrayer. “The 570s instantaneously switched from single-loop mode to two radial networks. The FiberPanel alarms sounded, and we saw immediately where to dispatch crews to begin repairs. However, due to the fast self-healing, we never lost a beat in monitoring and control of our SCADA network.” 603/964-1818; www.hlinstruments.com.

---

Total suspended solids monitoring helps stabilize process

Problem: Inconsistent secondary clarifier performance limited effluent quality at an advanced wastewater treatment facility in Kansas. The operations engineer sought to achieve the lowest TSS and most consistent effluent quality by controlling the solids retention time. To implement the solution, the plant needed a new monitoring system for continuous online measurement of mixed liquor suspended solids (MLSS) and return activated sludge (RAS).  

Solution: After a two-month comparative demonstration of three monitoring systems in an aeration basin, the plant team chose the IQ SensorNet system from YSI, a xylem brand, for having the highest accuracy and the least maintenance due to a self-cleaning system. TSS sensors were installed at the oxic end of each of the four treatment trains to monitor MLSS. Insertion-mounted ViSolid sensors were installed into RAS pipelines.    

Result: The monitoring system has been operating reliably with minimal maintenance. Two facilities owned by the utility have earned Platinum Awards from the National Association of Clean Water Agencies. 800/765-4974; www.ysi.com.

---

Tool helps department build mobile operation interface

Problem: The Water and Sewer Department in Union Township, Michigan, used remote desktop software to monitor flow rates, tank levels, pump status and other data from wells, pumping stations and water treatment plants. The program eliminated traveling to collect data manually, but it required a PC running HMI software 24/7 at each monitored location. Michael Dearing, superintendent, and Shaun McBride, chief water operator, wanted a reliable and less complicated monitoring solution using mobile devices like smartphones and tablets.

Solution: They selected groov from Opto 22 to help in building mobile operator interfaces and apps for control systems. Running at department headquarters, it securely connects to and exchanges data with control systems and equipment at remote sites, enabling operators to use a Web browser or an app on smartphones, tablets, PCs and smart TVs to connect to control systems and devices without having to write or debug code.

Result: Staff members use groov on their smartphones and tablets from any location to monitor site equipment status, process measurements, tank levels and other information. For wastewater, they monitor flows, power consumption, tank levels and key metrics like dissolved oxygen, pH and turbidity. “Considering the limited time we had between other projects, we were surprised that we were up and running so quickly with a new product,” McBride says. 800/321-6786; www.groov.com.

---

Instrumentation helps city reduce disinfection chemical costs

Problem: With rising disinfection chemical costs, the City of Corvallis, Oregon, sought a solution to monitor various parameters, including E. coli.

Solution: The city chose LiquID Stations from ZAPS Technologies. Using real-time monitoring, plant operators can close the treatment process control loop around the instantaneous E. coli levels to pace chlorine addition on time scales measured in minutes instead of days and stop over-chlorinating. The system uses hybrid multispectral analysis, an optical approach specifically for online monitoring. It uses no chemicals or membranes, requires no calibration, has low maintenance and produces no waste.

Result: Real-time E. coli data allowed the staff to optimize treatment to actual conditions with confidence, while improving oversight. In 2013, the annual chemical savings from the changes totaled $75,000 per year, or 62 percent of the previous annual chemical budget. 866/390-9387; www.zapstechnologies.com.

---

Aquaculture monitoring solution offers Web control

Problem: Cooke Aquaculture is a processor of Atlantic salmon with more than 100 farm sites off the Northeast coast. At the Oak Bay Hatchery in New Brunswick, Cooke hatches eggs and raises brood stock for shipment to other freshwater facilities. The pH and flow of the hatchery water must be tightly controlled to maintain the health of the fry. The hatchery has always used sensors and controllers connected to PLCs, but there was no way to monitor outside the building. The facility needed a controller with a Web interface.

Solution: Mitchell Dickie, project manager, chose the AquaMetrix 2300 from Water Analytics with total Web control, inputs for four analog and three flow sensors, four relays, data logging and email notifications. He set up two in the hatchery. For pH control, he used an AquaMetrix P65C8 probe, and for flow, he used a paddle wheel. He found that configuring the unit was fast. “I’m not a PLC programmer, and being able to configure it by following the wizard made setup easy,” he says.

Result: The hatchery has cut down on chemical use and maintained the pH within the optimal range. “Anytime, I can just go to my phone and check on the tanks. I’m in a comfort zone I’ve never had before,” says Dickie. Data logging allows the staff to troubleshoot problems. Recently they noted pH fluctuations that only became obvious when they looked at data logs. They determined that the pH fluctuated during feed times, and from then on were able to control pH more effectively. 978/749-9949; www.wateranalytics.net.

---

Web platform helps simplify monitoring data

Problem: The City of Richmond, California, was having trouble organizing its environmental monitoring data into a single Web platform. The monitoring network consisted of meters from Isco, Telog and ADS. Inability to house all data in one platform made reporting and graphing tedious.

Solution: The city installed the FlowWorks platform, working with George Elaro and Infrastructure Engineering Corporation (IEC).

Result: FlowWorks helped the city to bring its data into one platform and easily run reports and generate graphs. The engineering and management teams now have access to all the flow monitors in the system along with SCADA data from the wastewater treatment plant. As a result, combined sewer overflows and potential spills are being identified by a system with alarm capabilities. 206/859-6999; www.flowworks.com.

---

Plant relies on thermal flowmeter for gas blending process

Problem: The Rahway Valley (New Jersey) Sewerage Authority embarked on a cogeneration project using large 1.5 MW engines fueled by digester and natural gas to generate power for the facility. The engine control system required independent measurement of both gases.

Solution: RVSA engineers installed Model ST98 thermal mass flowmeters from FCI - Fluid Component International on the digester gas and natural gas lines. The meters can be placed on 4- and 6-inch lines and measure flows up to 500 scfm. Temperature conditions ranged from 50 to 100 degrees F at a pressure of 60 psig.

Result: The meter flow elements have no moving parts and provide direct mass flow measurement with a single process penetration. They are not susceptible to the engines’ vibration and operate with no issues. 800/854-1993; www.fluidcomponents.com.

---

Dosing solution withstands sodium hypochlorite corrosion

Problem: A municipal agency in California needed to disinfect water using sodium hypochlorite. The utility needed a dosing solution that could withstand corrosion.

Solution: The utility installed a gravity-fed system using a Kynar Research Control Valve (RCV) from Badger Meter to control the chemical dosing. Kynar is impervious to corrosion, and the valve can automatically compensate for line pressure changes as the level in the chemical tank falls.

Result: The RCV valve allows the utility to dose accurately, control raw material costs and comply with regulations. Maintenance and downtime are minimal. 877/243-1010; www.badgermeter.com.