The Greater Wenatchee Irrigation District’s New Pump Unit

The Greater Wenatchee Irrigation District’s New Pump Unit

Jerry Larossa with the GWID’s new Watertronics pump.

The Greater Wenatchee Irrigation District (GWID) services 10,000 acres in north-central Washington State. Its fully piped and pressurized system provides water for farmers who grow apples, cherries, pears, and other crops, mainly using drip and microsprinkler irrigation. The GWID recently replaced one of its pumps with a new Watertronics pump unit that includes a motor, a variable-frequency drive (VFD), and a meter in an easy-to-install format. In this interview, GWID Manager Mike Miller tells Irrigation Leader about the advantages of the new pump.

Irrigation Leader: How long have you been with the GWID, and how long have you been the manager?

Mike Miller: I’ve been here for 29 years and have been the manager for the past 11 years.

Irrigation Leader: Please tell us about your recent pump upgrade.

Mike Miller: We had a pump that served a single farmer and that never quite did what it was supposed to do. A few years back, we went on a tour of the Watertronics facilities. I was impressed with the way the company put its pumps together as a single pack. When this pump went bad and we needed to replace it, I wanted to try one of the Watertronics pumps.

Irrigation Leader: What about this situation required a specialized pump?

Mike Miller: This is the highest delivery in the area, and it typically has low pressure. We have a VFD that feeds that area of our system, and we were turning up the pressure in the whole zone to try to get this customer water and breaking other people’s pipelines in the process. The new Watertronics pump was oversized and came with a VFD, so we could actually boost the pressure on the other side of the pump. The pressure was 40 pounds per square inch (psi) at his meter, but at the high spot, it was only 20 psi or so. The Watertronics pump takes the 40 psi pressure and boosts it to 60 psi, bringing the pressure at the high spot up to 40 psi. That allowed us to dial our pressure in that zone down so that we weren’t blowing other people’s pipes up.

Irrigation Leader: Your system is entirely piped, correct?

Mike Miller: Yes; it is entirely piped and pressurized. Typically, we try to keep the pressure in our system at 80 psi, but in some cases, we increase it to 105 or 110. We noticed that other farmers were having failures in their systems because of our changes in pressure. That told us that we needed to figure out a different plan. We operate at a minimum of 35 psi.

Irrigation Leader: Tell us about this pump. How big is it and what are the specifications?

Mike Miller: It’s only a 7½ horsepower pump. It’s a 240‐volt, single-phase pump, because we didn’t have three phases at the location. What is distinctive about it is that it comes in a case that also includes the motor, the VFD, psi sensors, computer controls, and a meter. We meter everything and have been replacing old propeller meters with mag meters from Badger. The new meters have an antenna that reads to a Trimble unit and reports readings to our office. Our remote-read antennas should connect to the meter installed in the pump cabinet. Another nice feature is its built-in bypass. To make installation even simpler, the electrical disconnect box is prewired into the unit, so all we had to do was make the connections from the local power company electrical meter.

The installation of this pump was simple. We had to pour a concrete pad. The pipe came out of the ground and went over to the pump, so I just had to make some measurements to decide where to place the base of the pumps. We bolted the pump on the pad and bolted on the discharge. It was slick and easy. The electrical control box with the disconnect is outside the pump enclosure, and it is prewired. The state inspector who looked at it was thoroughly impressed with the pump and the way it was put together.

When we did the initial start, we discovered that one of the pressure sensors was dysfunctional and had come that way from the factory. This was an opportunity to see how fast Watertronics could get us repair parts. It was quick—the Watertronics staff said they could have done it the next day if it had been necessary. I was really impressed with that. We were able to operate the pump without the sensor with little loss of control. The part arrived quickly, and we were able to replace it and get it working without a hitch.

Irrigation Leader: So it’s not just a pump—it’s a pump, a meter, and everything else, all packaged together, and all you needed to do was pour a concrete pad and bolt it down?

Mike Miller: Yes. I’m a licensed electrician, and I did the installation with two of my crew members. We poured the concrete pad one day, did the installation the next day, did the electrical work, had the electrical inspector out to see it, and then it was finished. Had we not had to have the electrical inspector out, it would have been a 2‐day turnaround. We spent about 29 man-hours on it in total. It attaches to the district’s and farmer’s systems with Victaulic connections. Everything necessary was included.

Irrigation Leader: Normally, would you have had to buy all the items individually and put them together yourself?

Mike Miller: Yes. We would have had to find a VFD that fit with the pump motor and put in a meter, bypass, computer, flow switch, psi sensors, and an electrical panel. Then we would have had to wire and plumb all those components together. In this case, everything was included. We connected three wires—the ground wire and two hot wires—and we were operating. It was really simple.

Irrigation Leader: That certainly saves a lot of time.

Mike Miller: When we’re subdividing, we’ve had problems with individual pumps that go out to individual zones like the one I mentioned. There is one area that is subdivided into hundreds of small parcels, but where there are not yet any homes. We’re going to recommend to the contractor that rather than putting in a remote-read meter and a separate pump—in which case the meter alone costs $6,000–$8,000 by the time it is installed—they replace the existing pump with one of these packages. The VFD will prevent fluctuations in pressure. It will shut off when nobody is running water and turn back on when water pressure drops. This is good, especially in a residential area where people will want their yards to be watered automatically. We won’t have to figure out a way to make that work; it is all built into the pump.

Irrigation Leader: What kind of meter is built into the pump?

Mike Miller: It’s a Data Industrial insert meter.

Irrigation Leader: Are all the components inside a sealed compartment?

Mike Miller: Yes. You just open the lid and everything is inside. If you need more access, you can remove the front panel. One of the other advantages is that all the components come from a single vendor. If something goes wrong, we can call Watertronics, which is the source of all the pieces. The components are guaranteed for 1 year from the date of installation.

Irrigation Leader: Did you order the pump directly from Watertronics?

Mike Miller: They have a salesperson in Pasco named Jerry Larossa who came to the district to inspect and help get information to build the pump. He also inspected everything on the day we did the wiring and performed the initial startup. He’s the person who discovered that the pressure switch was bad and ordered a new one for us. He’s supposed to be here next week to check on things. He wanted to make sure that the pressure sensor was installed correctly so that we’re ready for next season.

A view inside the Watertronics pump unit.

Mr. Larossa is a nice and knowledgeable gentleman. He knew exactly what he was doing. We had bonded the neutral inside, and the inspector didn’t like it. Mr. Larossa looked at it and said that the inspector was exactly right. He took the bond off and did it the right way.

Irrigation Leader: Do you have a pump-replacement program right now, or does the GWID just replace pumps as needed?

Mike Miller: We typically don’t replace unless we can’t repair, but the situation in areas that are getting subdivided is different. This is why: In an area that has farmland on one meter and pump, the farmers go down and start their pumps, run their water sets, and then turn their water and pumps off. We’ve burned up four or five pumps trying to get water users to quit leaving the pumps running when no water is flowing. Using one of these Watertronics pumps avoids that problem because it just cycles on and off.

With the Watertronics pump that we installed in Howard Flats, when I turned the water in the orchard off, the pump turned off within about 10 seconds. When I turned on a different section, it was back on and running within about 3 seconds. It got the pressure back up when we had the zone set. It was perfect. It came from the factory programmed to do that based on what we told them.

Irrigation Leader: When you burn up one of your standard pumps, what does it cost you to replace it?

Mike Miller: Typically, we spend about $6,000–$7,000 to replace a small pump. We only need to replace the motor and the pump. The Watertronics pumps are a bit more expensive to put in, but you get a better-functioning pump that will probably have a longer life. We spent around $20,000 to install our new pump, including install time and labor.

Irrigation Leader: What do you think the expected life is?

Mike Miller: I would guess we’ll get 25–30 years out of it. The Watertronics pump at Howard Flats is near our board president’s house, and he’s meticulous about everything. The ones that will be the real storytellers are the ones in these residential areas. Mr. Larossa is supposed to be out there next week. He’ll look at the two areas in which we want to replace the existing pumps with similar Watertronics pumps. One of them is being replaced on the contractor’s dime.

I bet I’ve gotten at least 10 miles of pipeline replaced for free this year, but that’s a story for a different day. I never thought I would see orchards coming out at a breakneck pace and homes going in in their place just as exuberantly.

Mike Miller is manager of the Greater Wenatchee Irrigation District in East Wenatchee, Washington. He can be contacted at mikem@gwid.org.