Stepping inside Niskayuna’s grout truck reveals a myriad of technology and equipment, which the town is using to repair older sewer pipes.
The grout truck used by Niskayuna’s Water and Sewer Maintenance workers looks plain enough on the outside, but the modern technology inside reveals a mobile command center to address the inflow and infiltration issues the town faces. The New York State Department of Environmental Conservation is currently working with town officials on revisions to the formal plan addressing those issues, and purchasing the grout truck was the town’s solution to the problem, something it found more cost-effective than ripping up and installing new sewer pipes.
The amount of money it would cost to (replace all the pipes), the town couldn’t even afford it, said Matthew Yetto, senior civil engineer for the town. `It is not necessary either because it is structurally sound pipe, it is just leaky joints.`
The truck, which was purchased in 2007 and received in 2008, cost the town approximately $450,000.
How it works
Before the grout tuck even gets into the pipes, a combination vacuum and jetter truck is used to clean and prepare the pipes for repairs. High-pressure water is blasted down the pipe and the vacuum sucks up any debris and deposits removed from the pipe. The truck is also used for regular sewer maintenance, which the older clay pipes require more of compared to the newer plastic pipes.
There is also a monitor on the front of the truck allowing workers to see how the cleaning is going from a camera attached to the equipment inside the pipe.
`For the last three years or so we have had this [monitor] on the front. They just blindly washed before, so you didn’t know how effective you were being with your cleaning or if it was actually necessary,` said Yetto.
The camera also allows workers to see if there are roots growing into the pipe and if the pipe has been damaged in any way. The entire town is inspected once a year with truck.
Pipes throughout the town are all different sizes, ranging from 6 inches to 24 inches, all leading to the waste water treatment plant, said Yetto.
Councilwoman Denise Murphy McGraw said the varying size of pipes was something she wasn’t aware of before she joined the Niskayuna Town Board.
`Throughout the town there is all different size pipes, and it affects the water pressure, the kind of jobs we take on and replacing the pipe,` said McGraw. `I just figured a pipe, is a pipe, is a pipe and so when something happens there is all these different issues that comes up.`
The grout truck has data in a computer onboard that geo-references all the different pipes. If a worker clicks on a section of pipe, they can find out how big the pipe is, the length and what type of material the pipe is made from, along with other information.
To repair the joints of a pipe, which can deteriorate over time, a `packer` is sent into the pipe with a camera attached to it. Newer PVC pipes have rubber joints, which can be more easily repaired and replaced.
Making an old pipe new
The packer has a port where the two chemicals used to seal up joints are injected into it and the bladder inside the packer expands as air is pumped into it. An air test is done to test a joint and if it fails the test by not keeping constant air pressure then the solution seals up the joint.
`These guys went through quite a bit of training over three weeks just to run the truck,` said Yetto. `They are constantly being refreshed with refresher courses.`
The sealant mixture is pumped out of the truck through tubes and takes about 30 seconds to form a solid.
`Sewer (water) can still flow through the packer during work, so service doesn’t get disrupted at all. In fact, this is what makes it so nice ` you don’t have to dig,` said Yetto. `We try to do as little impact as possible to the residents because really we want to avoid digging once you start digging it, it disrupts service and costs a lot more.`
The stretch of pipe the town was repairing on Friday, June 3, was 210-foot long section.
Setting up the truck and equipment is the longest part, said Yetto. To replace a similar section of pipe would take weeks to complete.
The crew also has to be aware of temperature changes, because a 10-degree temperature increase will cut the time in half for the chemical sealer to form a solid.
Kevin Hart, water and sewer maintenance worker for the town, sat at a desk at the front end of a truck with a computer, a screen showing a video feed from the pump and various equipment to seal the pipe joints.
One of the more troubling joints repaired on June 3 took around 3.5 gallons of the solution to fix, which Hart administered several times. Hart uses a joystick to control the packer and several nearby switches controlling air pressure and how much solution is pumped out.
Each time he would add more solution to the joint, wait for it to settle, and then check the pressure of the joints. Since the pressure didn’t remain consistent, the solution was applied several more times.