Parts of the Whole

Dewatering landfill gas wells is an important but difficult task for landfill operators, notes Brad Peake, national accounts director, QED Environmental Systems.

If gas wells are not dewatered, negative outcomes can include slope failures, lack of odor control leading to neighbors’ complaints, regulatory compliance violations and potential fines, greenhouse gas violations, elevated temperatures, fugitive emissions, gas leaks, gas blowouts, and liquid seeps, Peake adds.

David B. Kaminski, QED Environmental Systems senior vice president, serves as director of SWANA’s landfill gas and biogas technical division. He notes that the LFG extraction and control committee is currently working on developing guidelines for LFG well dewatering intended to inform members and industry professionals on all aspects of gas well dewatering pump systems, efficiency improvements, typical system costs, and other factors to consider. 

QED Environmental Systems is one of several companies that offer solutions for landfill operators.

“Pneumatic submersible pumps such as the AutoPump system are commonly used at landfills to dewater gas wells,” notes Peake. “The liquid in gas wells is a dynamic mixture of chemicals and solids under varying temperatures and pressures.

“It’s a very challenging application. Pumps tend to plug over time because of the accumulation of solids in the pump. Once the pump becomes plugged with solids, it no longer works and must be pulled and cleaned. This is a difficult and dirty proposition.”

To help landfill operators, QED has developed a new series of pumps that run longer between service events and can handle higher temperatures. The pump series is part of the company’s Ultra AutoPump line.

All QED Ultra pumps feature premium-grade materials, including 316-grade stainless steel to minimize or prevent corrosion.

Ultra pumps are designed with coatings and finishes designed to prevent material from collecting and sticking to internal components as well as for extended run time. When an Ultra pump does need to be cleaned, it cleans up 50% faster than traditional pumps, says Peake.

Pumps in the Ultra offering include the Standard AP4 Ultra, a 3.5-inch diameter rated for 180°F; the High Temp AP4 Ultra, a 3.5-inch diameter rated for 250°F; the High Clearance Ultra, a 4.5-inch diameter, rated for 180°F; and the High Temp High Clearance Ultra, a 4.5-inch diameter rated for 250°F.

“The 4.5-inch Ultra pumps will have the same flow rates (GPM) and air consumption (SCFM per gallon pumped) as the standard Ultra, but only requires half the amount of cycles to achieve the flow,” notes Dave Simpson, liquids product manager. “This means the 4.5-inch pump will have half the wear and tear on internal components to achieve the same flow rates as a standard Ultra model.”

Peake notes that the high clearance Ultra pumps have three times greater clearance between the pump float and the pump casing and between the pump float and the center discharge tube.

“This means it will take much more material buildup before the solids will impede the operation of the pump,” he says. “The Ultra pumps extend run times and lower O & M costs.”

Elevated Temperature (ET) landfills are a big concern for landfill owners, notes Peake.

“Evidence now shows that removing liquids and gases from landfills can prevent them from developing into a runaway reaction referred to as an Elevated Temperature landfill,” he says. “The AutoPump system helps to dewater gas wells, which allows for more efficient gas collection. Good operation and maintenance of an AutoPump system can help prevent a landfill from developing into an ET site.

“When a site becomes an ET, there are many negative consequences. The microorganisms that create methane die off at high temperatures. Hydrogen sulfide concentrations increase, which is a health hazard and an odor problem.”

Mark Wells, owner and operator of Site Maintenance and Remediation in Georgia, works primarily with QED pneumatic pumps in his company’s services of landfill piping, maintenance, and monitoring.

Many times in the gas extraction wells, the liquids come through the garbage where the well is sitting and then start accumulating, Wells’ company will install a pneumatic pump in the well.

“It will de-water the liquids to allow us to be able to keep the liquid level down in that well and therefore allow us to have flow and be able to pull the gas up out of that well,” he says.

Site Maintenance and Remediation works with QED’s older pumps—as well as the newer Ultra pumps.

“They’ve come a long way,” notes Wells, adding that he appreciates that QED staff will do site visits to ascertain how the products are performing.

Wells also favors the use of fiberglass, making the pumps lighter and creating more ease when pulling tubing out.

In landfills, the number of in-well parts exposed to the harsh leachate conditions in the well has been a common issue associated with conventional pumps.

To address this issue, Jeneer Group developed a sensor technology that reads a small float within the pump to cycle the pump, eliminating in-well components. The float position is sensed by the above-grade controller using a microprocessor and a pneumatic circuit that cycles the pump based on the float position. The integrated LED displays accurate cycle counts and converts to the gallons pumped.

The end-user also can observe the float positions, providing insight into liquid conditions and thus improving field troubleshooting capabilities, notes Bob Beyer, principal, Jeneer Group.

The microprocessor can run a diagnosis on pump conditions to identify an issue and stop or restart the pump, he adds.

“This is especially helpful should the pump stall due to high head pressure in the force main,” says Beyer. “The module will turn off the air supply to the pump if it does not empty in the specific time. It will check for compliance every hour and when parameters are met, the pump will automatically be restarted.” 

The company’s current pump only uses one in-well part to cycle the pump, says Beyer, adding that Jeneer Group plans to release a Float-Less pump—currently being field-tested—in the coming months.

“The new Float-Less pump technology float removes all in-well moving parts, making it ideal for applications where high temperature, sediments, or scaling conditions are present,” says Beyer.

“The pump uses three sensor probes to identify liquid within the pump and cycle the pump accordingly. The pump tends not to be influenced by high vacuums in wells, allowing lower liquid level drawdown and therefore exposing more screen to increase gas recovery at a lower vacuum. The pump is driven with the proven NEMA IV control module used on the original Jeneer pump.”

Jeneer Group offers installation kits providing for easy installation of the NEMA IV control module to the well casing. When maintenance is required on the pump, the module provides a simple method to purge the pump, removing the leachate before removing the pump, says Beyer.

“Since the pump and discharge hose are empty, the pump is much lighter, adding to site safety,” he says. “The air and discharge hose fittings on the pump are comparable with other quick-connect fittings commonly used, keeping uniformity on the site.”

With the reduction or elimination of in-well parts, the Jeneer pumps require substantially less maintenance.

“Oftentimes, most sites don’t even stock replacement parts,” says Beyer. “However, the pumps are not maintenance-free. When cleaning is required, the process is much quicker and simpler. Valve adjustments are not required.”

All Jeneer pumps have the option to be upgraded with cellular communication, allowing for remote monitoring of pump operation, says Beyer.

“The technicians can log into the Jeneer website and view pump data, download pump data, and change pump set points,” he adds. “This provides a great tool to monitor critical condensate sumps and wells without dedicating field time driving from well to well.” 

The new technology also enables end-users to remotely access and collect pump data from a smartphone or field tablet, allowing for seamless data transfer to the cloud.

“The technicians can drive within the vicinity of the wellhead and pull up the specific pump and well ID and then view and transmit pump data,” says Beyer, adding that Jeneer Group offers a stand-alone module that can be used with conventional pumps. 

The communication feature greatly reduces field time in collecting pump data and can quickly identify a problem well if issues are occurring with the gas flow at the plant, notes Beyer.

“Without the communication feature, field technicians are forced to drive from condensation sump to condensate pump to identify the problem well,” he adds.

Beyer cites a recent installation of 12 communication units installed on a series of condensate sumps in which before the installation, the field technicians would spend several hours daily driving the well field to check on the sumps.

“Today, they log into the website and can check on the pumps and download the pump data in less than 15 minutes,” says Beyer. 

John Mahony, compliance manager and engineer, Advanced Disposal Services in Zion, IL, works with Jeneer technology in his position maintaining landfill gas systems. The company owns more than 50 landfill systems throughout the Midwest and East Coast.

Mahony’s job is to ensure repairs are made when they need to be made.

Advanced Disposal Services has had 20 of Jeneer’s float pumps in place for four years. Mahony finds them to be efficient.

“They run longer between repairs,” he says. “The liquid level seems to be getting closer to the top of the pump versus standard pumps.”

While Mahony says that he finds both the installation and maintenance to be about the same as a regular pump, Jeneer’s recent sensor redesigns have led to less maintenance time with cleaning and fewer needed repairs.

“A standard pump has valves and exhaust ports; with these, the valve for the air and the exhaust are up in the control panel that’s above grade,” says Mahony. “If something happens to that, all you have to do is fix the control panel.”

Mahony credits Jeneer for a rapid and thorough response when he has encountered a problem.

Blackhawk manufactures top head drive, positive displacement piston pumps. The low-flow pumps with drive motors are designed to power cleanly and safely above the wellhead, notes Mark Bertane, principal of Blackhawk Technology Company.  

“A key advantage of positive-displacement piston pumps is they pump virtually any liquid of virtually any viscosity and chemical composition—including PFAS-infused leachate—in all weather conditions,” says Bertane. “Piston pumps handle the broadest range of flowable materials, including semi-solids.”The pumps accommodate three above-ground power sources, including pneumatic, electric, and solar.

The below-surface downhole pump with reciprocating piston “gently sips liquid that is drawn to surface discharge piping without contacting outside air,” notes Bertane. The pumps are designed to not vent exhaust gases into the atmosphere, he adds.

The company’s new technologies have been reimagined and miniaturized with 21st-century design and materials, says Bertane, adding, “the results are lightweight, low-profile, all-weather pumps for landfill leachate and gas wells, toxic remediation sites, and many other applications.”

For linear-rod Apollo pumps, Blackhawk applied the Scottish Yoke reciprocating motion mechanism, converting the rotational motion of the driver through a slider bar to the up/down linear motion of the downhole piston rod with the added advantage of a few and rugged moving parts, says Bertane.

“The Apollo Solar Piston Pump brings the Scottish Yoke, linear-rod driver, and solar-panel power to gas wells, closed landfills, and remote sites not served by trenched pneumatic or electric power,” says Bertane. “Solar power is free.”

The CleanHead Contained-Pump System is a mechanism designed to return any above-surface fluid from the driver back into the well without contacting air.

V-2 Pneumatic and Anchor Electric ET pumps and products pump fluids to 300°F and beyond, regardless of chemical composition, including PFAS, says Bertane.

In increasing efficiencies, Blackhawk has re-engineered the power sources of the Apollo linear-rod pump to now include AC electric, allowing operators desiring around-the-clock grid electric to use a smaller, lower-cost, highly reliable pump for gas wells and landfill leachate wells, says Bertane.

The Edge Pneumatic Piston Pump is designed as a smaller, highly efficient, lower-cost pneumatic with the same rugged build quality as the V-2 and Atlas pneumatics.

“Efficiencies are particularly notable when replacing older-style submersibles and air-push pumps with Apollo Solar pumps,” notes Bertane.

Ease of maintenance and installation are distinct advantages to piston pumps, says Bertane.

“Because all power and driver mechanics are above the wellhead, all servicing is done above ground—no pump pulling needed,” he says. “Newly-designed Blackhawk seals and cartridges pop out and in and the CleanHead Contained Pump System keeps the stuffing box clean and dry.

“Because the mechanicals are uncomplicated and servicing is above ground, maintenance is significantly faster than with air push and submersible models.”

The below-ground downhole components are designed for reliability and seldom require maintenance, says Bertane.

EPG Companies offer electric and pneumatic pumping systems for leachate and condensate produced at landfills. The company designs and builds custom control panels that are UL listed and tested with the pumps the company manufactures to ensure that the system is operational.

Based on end-user input, EPG Companies has been making changes to its products, including using more robust construction materials that can handle the corrosive environments in which the pumps are being used, high temperature (over 180°F) pumps, and designing ease of cleaning, to reduce the overall costs of the system, says Chris Riddle, applications engineer.

The company’s wheeled sump drainers were designed to make it easier to install its SurePumps in the side slope risers. 

The use of components in the Viridian pneumatic pumps that can stand up to strong acids such as hydrochloric acid is designed to significantly reduce cleaning and maintenance.

That quicker turnaround results in getting the pumps back in service more quickly and requires fewer spare pumps, allowing the field service personnel to spend less time cleaning pumps and more time on the other portions of their jobs, Riddle points out.

Viridian pneumatic and electric pumps are constructed from materials specifically to handle a variety of chemicals and corrosives such as PFAS that are present at landfills, notes Riddle.

“If it is present in the liquid, the pump will remove it from the well/sump for treatment and disposal,” he adds.