Automation 101: What Every Operator Should Know

A Q&A with Craig Correia, Head of Process Automation (U.S.), Festo Corporation

Without a doubt, automation in water/wastewater plant

operations is a growing trend. It makes sense, given the need for

accuracy and reliability in today’s regulatory environment,

coupled with the reduced manpower attributable to short budgets

and a retiring workforce. But many plants have done quite well

with the status quo, so what’s to convince them to change? Even

then, how does one get started, and what are the cost

implications?

For insight on these topics, I spoke to Craig Correia from Festo Corporation, an automation solutions

company active in the water industry for over 80 years, present in more than 180 countries. The

conversation serves as a good primer for operators just wading into the world of automation.

At a high level, what plant processes are candidates for automation?

Any process with a process valve in place can be automated. A feedback from a sensor or input from

the operator can trigger a whole sequence of events. Process valves can opened or closed, or adjusted

to a mid position to meter flow.

What process(es) should be automated first?

The processes that you repeat the most are the best ones to start with first, particularly those with a

high number of process valves. There lies the highest benefit to operating costs; and the timing of the

processes are usually well known, making it easy to program. The simplest example is to start with a

water or air scrub. These events occur at regular intervals and can be set up to run based on feedback

from a sensor or a manual pushbutton. The most common is membrane filtration, combining influent

and effluent control with the scrub processes.

Can you detail how automation works, by way of example?

It starts with a centralized control cabinet, which controls the network of process valves, sensors, and

operator interfaces. Here resides the program that can be responsible for a simple operation, or the

entire plant. The operator interface can be as sophisticated as a color touchscreen, which gives a view

of the entire plant, or as simple as a few pushbuttons on the cabinet door. Automation doesn’t

necessarily replace operator control — Festo has a system in place where the sequence of operations

can be started or interrupted by the operator.

What are some specific benefits of automation?

Automation provides a host of benefits, including:

• Centralized control brings all data and process control to a single location — no more

walking through the plant to manually open a valve.

• Operators free up time to focus on more important topics such as throughput, quality,

and training.

• Diagnostics features embedded in Festo valves, I/O, and controllers can improve plant

uptime. Data such as valve leakage, flow rates, short circuit, and maintaining cycle

counts can be integrated into a preventative maintenance program.

• Data logging is possible. All critical measurements can be easily logged into a database

or spreadsheet for archiving.

• Automating redundant processes can improve effluent quality and consistency because

it can be controlled the same way each time, regardless of the personnel or time of day.

• Automation can improve plant and operator safety by remote-controlling valves or

sensors in hazardous or hard-to-reach places.

With regard to budgets and capital equipment expenses, it’s pretty easy to make the case for

replacing product that is nearing the end of its lifecycle. How do you make the case for implementing

pneumatic controls and automation products?

This is an excellent question. It is often easy to replace equipment and components with the same

solution in place. The common justification for not changing is that it has worked in the past. However,

ongoing and increasing governmental regulations demand plant flexibility. Choosing and implementing

these capital investments has an impact on plant operations for decades into the future.

Regarding the case for pneumatic controls and automation, this relates to cost and ease of

maintenance. Implementing pneumatically actuated process valves requires that compressed air is

available, usually via a compressor, and that the air quality is maintained throughout the year. Air

quality is particularly important in regions with wide climate changes between seasons. This is seen as a

burden for plants without compressed air, but the benefits make it worthwhile.

The short-term benefit of a pneumatic system is capital cost. The capital costs of a pneumatic actuator

can be less than 1/10th of its electrical equivalent. The long-term benefit of pneumatic actuation is

again cost, but also maintenance. An operator or technician can disassemble a pneumatic actuator and

rebuild it at the plant in minutes. It is very simple and does not require any special tools or calibration.

An electrical actuator has to be returned to the supplier for rework, which adds time and increases the

need for expensive spare actuators.

How large a plant is needed to make automation economically viable?

There is no plant size threshold. Specifically with Festo technology, we’ve successfully automated plants

treating 250,000 GPD, most recently in Salinas, CA. An area of high growth in automation has been

smaller-sized municipalities and OEMs building industrial membrane filtration skids. Most of these

OEMs are already using pneumatic control technology.

Many facilities have retiring operators and are nervous about attaining new hires and training them to

the same level of competence. Can automation help fill the knowledge/labor void?

Automation will never replace training and operator experience. It can, however, ensure safe and

consistent plant operation as employees turn over. The processes controlled via automation still require

that the operators understand how they are working. A good system will have a clear visual application

on the touchscreen displaying all the relevant data. Instead of walking to the process valve and making

a manual adjustment, the software or the operator can make the adjustment at the control panel with

all the information available. This ensures consistent water quality as staff changes over.

How does automation change an operational and maintenance staff’s day-to-day responsibilities?

The responsibility for delivering water meeting a certain standard does not change. Automation makes

critical data available to them and allows them to automate certain processes. The net gain is efficiency.

Their roles change because they have more time to focus on the treatment quality.

Craig Correia has worked for Festo for 16 years, the last five years as head of

process automation in the United States. He holds a BS in mechanical

engineering from the University of Massachusetts and an MBA from

Providence College. He has held various technical, management, and

business development roles at Festo, including two years as global industry

segment manager based in Esslingen, Germany.