Raise your hand if you’re dealing with a wastewater treatment facility that’s more than 25 years old. Or if you worry that old tanks and rotating equipment will fail at any moment. Maybe you’re under pressure to reduce operations and maintenance staff. And how about those newer limits for parameters like nutrients and total dissolved solids? They’re cropping up in permits more frequently as states implement ambitious river basin programs. Any one of these factors is enough to keep facility managers and owners up at night—and these days, many of us face several of these challenges at once.
Step 1: Step Back
Before you rush to dismantle old equipment or commit to a brand new facility, it pays to take a hard look at not only the existing treatment system, but also at the entire context within which the system must operate. This means reviewing the overall plant’s production processes and wastes, use of raw materials and chemicals, and water and energy consumption, as well as sustainability considerations. Adopting this holistic approach to planning and prioritizing facility improvements will improve efficiency, reduce capital and operating costs, and meet the objectives of both regulators and company management.
Step 2: Evaluate
To be sure, every facility is different, but the questions to consider in evaluating wastewater treatment improvements are pretty consistent:
- How can our wastewater management approach support sustainability objectives through reuse; minimizing waste; reducing energy use; and minimizing other resources, such as chemicals, fuel, and staffing?
- What space constraints exist for upgrading or expanding the treatment facility? How will this drive our decision making?
- What are the wastewater sources and wastewater properties from each source? Are the individual wastewater streams different? Would equalization and/or separate treatment of one or more of the streams offer advantages such as cost savings, ability to reuse, or safety?
- What’s the wastewater like? What are its characteristics and volumes?
- What are our permit limits? If the wastewater has problematic constituents, where do they originate?
- What does the facility’s process wastewater flow schematic or mass balance look like? Do we have one? Is it up to date and does it reflect the latest permit requirements?
- What process manufacturing changes might beneficially affect wastewater volume or properties?
- What are the space and budget constraints? What are the sewer collection system constraints?
- How can we reduce operational costs?
- What do my internal customers—the engineering, maintenance, manufacturing, utilities staff— need? How might a teaming approach help engage these customers?
Step 3: Plan
In most cases, it would be extremely rare to retire a complete system. Instead, after answering the questions above, you would conduct an assessment and prepare some conceptual designs that identify components for reuse. For instance, in a complex manufacturing environment characterized by multiple waste streams with different characteristics (e.g., oily, metal-bearing, or high-strength organic waste), you would want further evaluation to look at the various waste streams and optimize wastewater management. You may decide to segregate a single low-volume, high-strength waste for specialized treatment rather than treating it with the bulk of your wastewater flow.
Step 4: Breathe a Sigh of Relief
So, before you start removing and replacing corroded tanks or budgeting for an entirely new system, take a moment to step back and review the big picture, from the production line to final discharge. The resulting treatment strategies, whether they involve an entirely new facility, an upgraded one, or a combination of both, will help achieve your wastewater management goals well into the 21st century.
Visit our industrial water and wastewater pages for more information.