Rebuilding an ineffective pump station, a series:

Article Six, by Douglas Muscott CID, Lad Irrigation Co

Today we poured the concrete pump pad and are opening up the ditch for the power conduit from the transformers to the meter base. We are putting a broom finish so the pad will be non-skid. All conduits and pipes are in and ready to set the pumps and discharge manifold.



Here you can see the three 16” well casing wet wells for the turbine pumps to set in. The 4” pipe is for a level control transducer that will connect to the VFD and prevent the pumps from over pumping the concrete water control structure. There are three small conduits, two for transducer conductors and one for area lighting for night operation.



Here is an overall view looking west of the waterbox, electrical control center and newly finished pump pad. After proper curing of the concrete we will set the prefabricated discharge manifold on the pad and support with tie-downs to weld plates poured into the concrete. The two outside wet wills will be cut off and flanged for turbine pump mounting and support.



This photo shows the water inlet from the weir blade of the water company to the waterbox supply pipe which is 14” well casing. The concrete crew formed new walls around the inlet structure and we will cut the pipe flush with the floor and weld on a rebar trash rack to keep large trash out of the waterbox. 4

Rebuilding an ineffective pump station, a series:

Article Five, by Douglas Muscott CID, Lad Irrigation Co

The pipelines for the water inlet and return flow are now connected and we are ready to backfill the entire pump structure and compact the lifts of fill in preparation for concrete. This was a complex operation involving trucking the saved fill material back to the site and placing it where needed with the 590 excavator seen in the photos below. We also used the vibratory compactor attached to the excavator to make sure we have no dangerous settling after concrete is poured and water is turned on.


We have loaded the dump truck with clean fill material we saved from our original demolition. Our operator is placing it carefully into the bottom of the original excavation so we can compact it properly. We are taking extreme care not to come in contact with the existing steel pump structure and cause damage to our newly poured concrete box. Jack is shoveling fresh fill into places we will pack with our hand compactor.  



With the vibratory compactor attached to the excavator, we can now pack the lifts of soil we have placed into the original excavation. This is a multi-step operation and we change between the three foot bucket and the “Hoe Pack” several times as we prepare the site for our concrete pump pad and electrical control center. The closest vertical pipe will house a 75 HP turbine pump and the far pipe will house a 50 HP turbine pump. The 4” black one will house a level control transducer. The bucket covers the return flow air vent.


Here we see the Hoe-pack compacting the pad site while Jack uses the hand compactor to pack between the vertical pump chamber pipes. The center vertical pipe will be a spare for now, providing a home for a backup pump if the customer chooses to add one at a later date. The concrete pad will be 18 feet wide and 22 feet long so he Hoe-pack is compacting the entire site which was measured out and corner pinned to define the needed work area.


The day turned very foggy with the temperature never above 32 degrees. Here Jack is holding the Lazerplane target, giving Mark a tone signal so he can level the pad site exactly to the sub grade needed for the concrete pad to set on. The excess compacted soil will be placed on the north side of the pumping structure and compacted around the inlet and return flow pipes and give Jack a firm footing to pour the concrete structures required there.

Below we see the overall view of construction standing on the east side of the site looking to the west. The pump pad sub grade is accurately set with our Lazerplane and the perimeter forms are set with four inches of pad fall from the waterbox to the south edge of the pad. Rick is running our hand compactor on the west side of the site which is where the return flow water will go to its appropriate pipeline. As will show in future articles, some of these pipelines are two way which complicates construction of the pipefitting down the road.


The electrical controls are prefabricated in our shop and pre wired by our licensed electricians. Looking from left to right we see the 200 amp meter base with 3” conduit incoming. Next to the meter base is our 5 KVA transformer to give 110V single phase power for convenience and lighting. Then is an empty space for a future pump controller if the customer decides to add the spare pump at a later date. Then there is the NEMA #3 pump control panel for the 50 HP Turbine pump which will be controlled by the white box which is a 75 HP VFD that will operate on a pressure transducer to maintain the customer defined set point for the hydraulic system.

Rebuilding an Ineffective Pump Station, a series:

Article Four, by Douglas Muscott CID, Lad Irrigation Co

Pump station design/build requires a blueprint of what you are trying to accomplish. This segment deals with how we develop our construction plans and our procedures for building a project. Following is a set of CAD drawings that outline our vision for this pump station. Articles two and three were carried out with these plans in hand as they were developed after taking survey shots and logging them and a pre-construction meeting with the builders and the project owners. Following is our vision of this project.


This page shows the plan view of our vision of what the new pump station will look like. We do our design work on CAD and this allows us to accurately scale the components and make sure our ideas can come true in the real world.


Page two shows the elevation view of our proposed pump station and allows us to make sure the water will enter and exit the pump structure as we plan. This is very critical and a lot of math is involved in this phase to verify the flow and quantity of water we need for our system.


Page three shows the pump pad layout for the electrical conduits and other items to be built into the concrete poured pump support structure. All this type of construction must be seen in the mind’s eye of the engineer designing the pump station as remodeling corrections into concrete is time consuming and expensive.


Page four shows the exact construction of the electrical controls and how they are to be built and wired into the system. This pump station will be fully automated when complete allowing the operator to simply change valves with the pumps automatically adapting to the requirement with a pressure transducer and a VFD.

Rebuilding an ineffective pump station, a series:

Article Three, by Douglas Muscott CID, Lad Irrigation Co

The concrete pumping structure in now poured and the steel fabricated turbine pump structure is installed and we are now ready for pump pad site preparation. Before we can backfill the structure and prepare the pad sub grade we must connect the pipelines that we cannot access once the backfilling and concrete are poured. The electrical controls will be all assembled and pre wired and set into position before the concrete pad is poured and all conduits must be in place.


Boom and Weilding Trucks

This view shows our boom truck and welding truck on the jobsite. The three pump chambers are the red primer vertical pipes in front of the concrete box. The black pipe between the two left verticals is the level transducer sensing pipe. In the background the ditch from the water company can be seen and water delivery takes place from the far side of the photo. In the foreground you can see the pressurized pipes that will connect to the discharge manifold.


Water Delivery of Pump Box

This view shows the water delivery side of the pump box. The far pipe is the inlet pipe from the supply ditch and is 14” heavy wall steel pipe. If you look closely you can see a knockout for another pipe to supply the box. This will be part of the two way pipeline system and connect to other pipes. The near pipe is 8” heavy wall pipe and it returns water not pumped, to be captured and re-used at another pump site. All our field fabrication is welded with the wire feed welder seen at the far left of the photo.


Delivery Side Looking Towards the Pump

This view is from the delivery side of the box looking toward the pump chambers and the incoming power line. The pipelines that will connect to the pressurized clean water manifold can be seen in the mid-background. The black vertical pipe at the far right is an air vent for the return flow pipeline. The electrical controls will be placed at the far right of the photo as the finished pump pad will extend four feet to the right of the concrete water box.



This project is now ready for backfill on the pump pad side of the structure. We will bring our excavator in with a vibratory hoe-pack and replace the soil removed and trucked out. The finish grade will be established and prepared for the setting of the electrical controls and in-pad electrical conduits. We will then pour and finish the pad with appropriate pour-in plates to support the discharge filters and manifold.

Rebuilding an ineffective pump station, a series:

Article Two, by Douglas Muscott CID, Lad Irrigation Co

Following the decision by the customer to replace the existing pumping plant with a new state of the art installation, we began the site preparation by demolishing the existing installation. We have new construction plans in place and after calling for a power disconnect from the power provider we prepared the site for the first concrete pour, the new concrete pumping structure.


Mechanical and Electrical Demolition

With the mechanical and electrical demolition done, we begin to prepare the site with our excavator. Note the old meter pole in the foreground. It is going away as the new electrical service will be underground to the new electric meter. We have the lazerplane all set up as the grades have all been determined by the cad drawings generated from our preconstruction meeting. We are leaving the existing pressure pipelines pending completion of the new pump pad at which time they will be excavated and re-plumbed to the new discharge manifold.


Removal of Old Pipe

All pipe previously connected to the old pump station is removed to give us a “clean floor” for the new construction. The right tool for the job, in this case a new excavator with a lot of power makes short work of this part of the site preparation. The existing concrete box shown here is removed as well to make way for the nine foot deep hole that the new concrete waterbox will be built in.


Trucking the Spoil from the Excavation

The site has very tight working clearances so we have to truck all the spoil from the excavation away from the site to allow access for the trades following to build the different phases of the project. Here we are loading the truck with dirt removed from our nine foot deep hole and moving it away so it does not impede access to the next phase of construction.



We are now ready to move to the next step of construction which is the pouring on the monolithic concrete pump structure and the setting of the fabricated steel wet well pump structure. After the concrete is poured, the pipefitters and crane operators will deliver and set the structure and install the inlet and outlet of the pump station.

Rebuilding an ineffective pump station, a series:

Article One, by Douglas Muscott CID, Lad Irrigation Co

This is the first entry in a series showing how Lad Irrigation uses the latest construction methods and technology to modernize an existing orchard pumping plant and bring it up to current user friendly standards.

The task here is to keep all the existing functions of the current installation and add the latest pumping and control technology for ease of automatic operation. This installation carries the challenge of having three distinct functions as well as three two-way pipelines. Being an orchard installation, it provides frost protection, irrigation and cooling for the growers many varieties of fruit trees. Here we are going to show the beginning of the project which we have been studying for about four years to provide the best solution for the grower.

Pump Station


To the side you see the view looking at the overall site showing four centrifugal irrigation pumps and the electrical controls which will be updated and changed. The distribution pipelines which have been extensively modified over a period of several decades and will be updated and integrated into a unified system.




Pump Station

To the side you can see an overall view of the pump station. The water is delivered to a concrete box where two lift pumps lift it about six feet and drop it over stainless steel filter screens where the filtered water is made available to the four centrifugal pumps. Management is a huge issue here as the pumps must be operated in conjunction with the orchard blocks being irrigated and valved to the proper pressure. Counting the two lift pumps there are a total of six pumps to manage along with the three two-way pipelines. The completed project will have two pumps utilizing a VFD and level controls to operate the new pump station in full automatic mode.


Pump Station


To the side is another view of this pump station. Notice the water delivery from the canal and the tow lift pumps lifting it up into the screening box. Then there are the myriad of other pipelines running into and out of the pump plant. We are going to change all of this as future articles and photos will show.



The finished project will consist of a concrete screening box that is gravity fed and gravity to the return flow. The electrical will be converted from 230 Volt three phase to 460 volt three phase and the overhead electrical service will be converted to underground feed to the new electrical control center. A VFD controlling two short set turbine pumps operating on a pressure transducer and level control transducer will allow complete automatic operation of the system.