Using sludge blanket monitors to automate pump cycles reduces hydraulic loading

Problem

The Punta Gorda (Florida) Water Treatment Plant used a manual system to cycle pumps for biosolids in the upflow clarifiers. This led to frequent depletion of the sludge blanket and large amounts of water unnecessarily sent to the solids drying process. 

Solution

An Entech Design EchoSmart Sludge Blanket Monitor from Analytical Technology was installed in the wasting channel in each clarifier. The monitors were tied into the plant’s pump controls and programmed to keep the blanket level within six inches of the ideal operating set point.

Result:

Previously, the solids drying process consisted of a 12-cell drying bed with underdrains, above which sand was placed to act as a filter and protect the drain system from the weight of the front-end loader used to collect the dried material. After installation of the monitors, loading to the beds was reduced to one cell, greatly reducing amount of sand needed and also reducing hydraulic loading, labor and cost. 940-367-7759; www.entechdesign.com

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Pump protection unit saves damage from power imbalance

Problem

The Cherokee County Water and Sewerage Authority in Cartersville, Georgia, had a power imbalance event at its wastewater treatment plant due to a faulty regulator at the electric utility. The event occurred at 3 a.m.; the current asymmetry registered 12.9%, which would quickly destroy any pump.

Solution

The event was detected because the Grundfos MP204 pump protection unit kept influent pumps from starting. Grundfos supplied full system including wastewater pumps, control and monitoring, and the MP204 units. The company’s GO remote monitoring app was used to remotely check the equipment status and see what alarms the MP204s were registering.

Result:

It took only 20 minutes to find the problem; previously troubleshooting could have taken all night and several pieces of equipment could have been damaged. Plant manager Mike Venters says the MP204 saved several large pumps: “The pump was what gave us the answer to an external power problem. “Getting the MP204s was one of the best decisions we’ve made. Just the ability to troubleshoot so quickly is a cost savings. It’s matter of minutes instead of hours to find out what’s wrong in the system.” Since initial incident, MP204 has saved the pumps a number of times. 800-926-6688; www.grundfos.com/us

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Wastewater collection and treatment plant updated with PLCs, SCADA

Problem

The city of Faribault, Minnesota, needed to improve and modernize its wastewater collection system and treatment plant. The project included a major upgrade to all electrical components, including PLCs and SCADA system programming.

Solution

PRIMEX worked with the electrical contractor on engineering and commissioning the upgrades. A thin client architecture provides scalability and management. Critical upgrades included seven PLCs, motor control centers on a DeviceNet bus, 28 separately enclosed VFD controllers, and the Wonderware System Platform deployed inside the plant on virtualized server hardware. Virtualization allows the city to replace hardware rather than upgrading SCADA software licenses, saving money in the long run. As part of complete integration services, PRIMEX handled overall system documentation, including a comprehensive description of operation, application programming. and overall system responsibility.

Result:

PRIMEX deployed the Wonderware System Platform across the entire plant. Redundant communications links ensure that all communications operate as desired. 844-477-4639; www.primexcontrols.com

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Municipality finds analyzer to monitor free chlorine

Problem

A Florida water municipality needed a new analyzer to monitor free chlorine for more than 20 groundwater treatment plants with aims to improve efficiency, reduce maintenance and save money.

Solution

HF scientific supplied a CLX DPD-based chlorine analyzer and JAW reagent, first deploying both at a plant with the greatest potential issues with hardness. Both were monitored for more than months. A new model of the previous analyzer was tested side-by-side. The CLX proved easier to install, required less maintenance and improved reliability.

Result:

The municipality chose the CLX, which also had the lowest capital and operating costs. The system provides cost-efficient, reliable and accurate chlorine monitoring for the groundwater treatment plants. “I’ve provided the CLX in Florida since they were introduced to the market, and I am very pleased to say that not one customer who has tried the CLX has wanted to turn back,” says Bill Lazenby of Lazenby & Associates, which recommended the equipment. 888-203-7248; www.watts.com/our-story/brands/hf-scientific