Lab testing in clean-water plants is critical to permit compliance and the process controls that enable it.

An essential part of testing is taking samples in correct amounts and at the right intervals and handling them properly to ensure accurate and reliable test results. Manual sampling can be a time-consuming job and one that can introduce variability in results.

Now Emerald Coast Mfg. has introduced an automated sample collection technology that allows for composite sampling with high accuracy. The WAVE sampler is a heavy-duty, electronically controlled vacuum-based unit.

It enables users to specify the volumes of wastewater to be collected and to program times or flow intervals for sample collection. It is an all-climate unit designed to suit indoor as well as harsh outdoor environments. Ronnie Jones, company president, talked about the device in an interview with Treatment Plant Operator.

What advantage does this technology have over other sampling solutions?

Jones: This is a vacuum-style sampler, which means that customers don’t have the maintenance that is required on peristaltic-style samplers. We use a vacuum pump to bring the sample into a chamber where it is measured. The sample accuracy and velocity are sustained over time.

Where in the process are samples taken with this device?

Jones: It is typically placed in the headworks area, and many time also at the outfall. They bring in composite samples for measuring parameters such as BOD, COD and TSS. If they sample at the front end and the back end, then if they know what their BODs and TSS were coming in, they know how much they are removing.

How are the samples regulated?

Jones: The operators can set this unit up to pull samples based on flow pacing, or time, or a combination of flow and time. For example, if they want to sample every 50,000 gallons, but they don’t want to sample at an interval less than 30 minutes, they can program for that. So in slow-flow periods like the wee hours of the morning, they can sample every 30 minutes, but at midmorning when the flow is are high, they can sample at every 50,000 gallons.

How do operators program the sampler?

Jones: It has a color touch-screen user interface that makes programming very simple. They can program for the sample size, the amount of purge time, to the amount of vacuum time needed to draw the sample into the unit, and how many times to rinse the line before it actually pulls the samples. All that can be programmed with the user interface.

How easy is the system for the operators to learn?

Jones: I would say that if operators can use a smartphone, they can program this unit. It’s very user-friendly. For example, if they want to change the sample size, they go into the sample tab, choose sample size, and enter whatever size they want, from 20 mL to 500 mL. The unit has a removable refrigeration module so that if there is a problem with it, they can pull it out and send it in for a factory repair. And they could have a spare sitting on the shelf to slide in for an immediate replacement.

How would you characterize the accuracy of the sampler?

Jones: It has 1% repeatability and 3% accuracy on sample size. So a 250 mL sample will be within 1% of that volume every time, whether it be the first 10 samples or 250 or more samples down the road.

Is this unit permanently mounted?

Jones: Yes. Installation involved taking it to the level area where they’re going to mount it, having 120-volt AC power available, having any remote signal available, such as from a flowmeter, and connecting suction tubing with a strainer on it to the stream of water they will be sampling. The unit can perform vertical lifts of nearly 30 feet, such as to pull samples up from a wet well. It can also pull long lengths and still maintain the U.S. EPA’s required velocity.

Is the unit temperature-controlled?

Jones: The unit is designed to operate in all climates, from 125 degrees F and high humidity to 32 degrees or colder. It maintains 4 degrees C inside the cabinet, which is the U.S. EPA requirement.

How is the unit hardened against tough environments?

Jones: The enclosure is made of acrylic ABS plastic that is designed to handle outdoor environments. The material is similar to the center console of a boat; it’s designed to be out in the weather all the time. We reinforce that with fiberglass on the inside to give it strength. Then we have sealed compartments that exclude anything from the outside. All openings except where the refrigeration module is located have rubber seals to keep external air and rain from affecting the electronics and the samples.

How do operators get access to remove the samples?

Jones: There is a single latch on the compartment where the sample container is sitting. The sample containers are optional items. Customers have a choice of a 2.5- or 5-gallon container. They can also choose the length of suction tubing and whether they want a PVC or stainless steel strainer.

What installations do you have so far?

Jones: We have units in different places in northern U.S., in the panhandle of Florida, and in Alabama. We installed a unit for one of our customers on a Tuesday and did a text follow-up on Thursday. Their response was, “The sampler is awesome … some may even say it’s life-changing.”

Is any particular size of facility a sweet spot for this technology?

Jones: The state regulatory agency probably would dictate the need to have an automatic sampler. Another group would be wastewater treatment plants that just want to automate their process. For example, if they are required to pull a sample every hour, that’s hard to do late at night if you don’t have a 24-hour staff. An automatic sampler is the way to do that.