Written by: Rachel Johnsen
Have you read the Wastewater Treatment Fundamentals series published by the Water Environment Federation (WEF; Alexandria, Virginia)? I served as a development editor for the second book in the series. My time researching wastewater operations from a distance eventually compelled me to jump into the trenches. Today, I am an Operator-in-Training (OIT) for Maryland Environmental Services.
Each water resource recovery facility (WRRF) is different. It is a fact you read about in the training manuals, but it really takes working on site for it to sink in. Becoming familiar with the processes, equipment, and treatment trains of your WRRF is crucial, so it is built into the Maryland Environmental Services Operator-in-Training (MES OIT) program schedule.
When I began my training in October 2020, it really struck me how many moving parts there are to keep a WRRF running — and how much I would need to learn to manage the process.
From Theory to Practice
While working on Wastewater Treatment Fundamentals, I remember listening to Ohio-based WEF Member Christen Wood describe her experience as a woman in the water sector on an April 2019 episode of The Empowering Women Podcast. As she spoke, I envisioned myself in this space. Then knew I was interested in becoming a wastewater and drinking water operator, but I was unsure how to start.
As I learned more about the water sector, I quickly realized that I would need to become certified through the state of Maryland. I researched my options online and discovered that MES offers a 3-year OIT apprenticeship program.
I learned that I would report to the Dorsey Run Advanced Treatment Plant. In Maryland, operators require a certain number of hours of experience at an advanced WRRF like Dorsey Run as a requirement of their Maryland Wastewater 5A certification licenses.
This made Dorsey a great fit for gaining the hours I would need. At Dorsey, we treat about 3,800 m3/d (1 mgd) of influent coming from correctional facilities and local businesses. Dorsey also accepts loads from septic tanks delivered by truck.
We are a relatively small WRRF, but a heavy-duty one. As an example, because most of our influent comes from nearby correctional facilities, our headworks is crucial. Our bar screen removes a significant amount of trash from the water before it even gets to the main treatment facility. From there, Dorsey Run provides primary, secondary, and tertiary treatment. The facility removes solids, biochemical oxygen demand, nitrogen, and phosphorus from the water, followed by disinfection. We discharge to the Dorsey Run creek, a tributary of the Little Patuxent River, which ultimately flows through the Patuxent River into the Chesapeake Bay.
Seeing the water that leaves our facility and knowing its ultimate destination to the largest estuary in the world is incredibly satisfying.
Reporting for Duty
While we are learning about the WRRF every day, at our 6-month, 1-year, and 2-year mark in the program, OITs walkthrough the WRRF with mentors and management. At each milestone, we go deeper and more detailed into the process and treatment streams.
During my first several months, my apprenticeship has focused on wastewater treatment, specifically the liquid treatment train. We have an on-site laboratory for testing to help us monitor, optimize, and troubleshoot our liquid-stream process. One of my fellow OITs or I conduct suspended solids, mixed-liquor suspended solids, ammonium, nitrate, total phosphorus, and settleability tests in the lab each day. These variables, when viewed together, reveal a lot about your WRRF.
I gained valuable troubleshooting experience a couple months into the program while working in the laboratory one morning. I noticed that the nitrate levels in one of our second-stage clarifiers had quickly increased over a 3-day period. After bringing this to the attention of my supervisor, he walked me through the problem and solution. We looked at that morning’s MLSS reading and determined that there was insufficient biomass — or “bugs” — in the anoxic basin to denitrify nitrate to nitrogen gas. We corrected the issue by moving settled sludge from the other clarifier with a sufficiently healthy blanket over to the anoxic basin. We saw a decrease in nitrate levels at the next test, without having to add any chemicals.
This is one example of numerous opportunities I’ve had to apply operator training on the job. Every day brings its own set of challenges, and it’s a great feeling to work with colleagues to find solutions. Being an OIT is a rewarding experience. I would recommend anyone considering a career in wastewater to give it a try.
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