Municipal wastewater plants handle typical residential waste, but food manufacturing wastewater is… well, not typical. It’s often heavier on organic materials, solids, and grease, which means it takes extra work (and extra money) for municipalities to treat. A surcharge is essentially the city asking you to pitch in for the added effort.
Here’s what the main terms on your notice mean:
- BOD (Biological Oxidative Demand): A measure of how much oxygen it takes for microorganisms to break down organic materials in your wastewater. High BOD = a lot of organic waste, like sugars, oils, and proteins.
- TSS (Total Suspended Solids): Tiny solid particles like food scraps, grains, or undissolved materials that don’t settle out easily. Too much TSS can clog treatment systems.
- FOG (Fats, Oils, and Grease): The fatty stuff left behind from frying, baking, or cleaning greasy equipment. FOG can solidify in pipes, cause blockages, and disrupt treatment processes.
When any of these exceed the limits set by your municipality, you’re likely to see a surcharge on your bill.
Why Did You Get a Surcharge Notice?
Municipal wastewater treatment plants are designed to handle typical domestic waste, but food manufacturing processes can create highly concentrated wastewater that exceeds the plant’s capacity for efficient treatment. When this happens, municipalities impose surcharges to cover the additional costs of treating your wastewater.
Surcharge notices often specify the excess levels of certain contaminants in your discharged water, such as:
- BOD (Biological Oxidative Demand): This measures the amount of oxygen microorganisms need to break down organic matter in your wastewater. High BOD levels indicate a significant amount of biodegradable material, such as fats, sugars, or proteins.
- TSS (Total Suspended Solids): This measures the concentration of solid particles suspended in the water, such as food scraps, grains, or other undissolved materials. High TSS can clog municipal systems and increase the cost and complexity of treatment.
These metrics are crucial because wastewater treatment plants rely on finely balanced systems to clean water. Excessive BOD or TSS can overwhelm these systems, requiring municipalities to invest more effort and resources to treat the water.
How Does Food Manufacturing Generate Wastewater?
Food and beverage production processes inherently use large amounts of water, whether for cleaning equipment, rinsing raw materials, or incorporating water directly into products. As a result, wastewater from these operations can contain:
- Organic Matter: Ingredients such as sugars, oils, and proteins from spills or product loss.
- Solids: Particulates like flour, grains, or vegetable scraps.
- Fats, Oils, and Grease (FOG): Byproducts from frying, baking, or processing certain foods.
- Cleaning Agents: Residues from soaps and sanitizers used during equipment cleaning.
The specific composition of your wastewater depends on your manufacturing processes, but it’s common for food manufacturers to generate high-BOD and high-TSS wastewater.
Solutions for Managing Wastewater
There are a wide variety of solutions to mitigate wastewater surcharges, ranging from simple and only slightly helpful to expensive, complicated, but extremely effective. Here’s an expanded look at some of the most common approaches:
1. Grease Traps
Grease traps are simple devices that separate fats, oils, and grease (FOG) from wastewater before it enters the municipal system.
- Why It Matters: By capturing FOG, grease traps reduce clogs, protect downstream equipment, and lower TSS. They’re especially useful for food manufacturers with high levels of grease, such as bakeries or frying operations.
- Implementation Tips: Regular maintenance is key—neglected grease traps can become a source of odors and blockages. Work with a service provider to set up a cleaning schedule.
2. Screening
Screening involves physically removing large solids and debris from your wastewater before it flows into the municipal system.
- Why It Matters: Capturing solids early reduces TSS levels and prevents clogs in downstream treatment processes. This simple step can significantly lower your surcharge costs.
- Implementation Tips: Use appropriately sized screens for your operation, and routinely clean and maintain them to ensure efficiency.
3. Dissolved Air Flotation (DAF)
DAF systems use microbubbles to float suspended particles, fats, oils, and grease to the surface of a tank, where they can be skimmed off.
- Why It Matters: Highly effective for reducing both TSS and FOG, DAF systems improve the efficiency of downstream biological treatment processes.
- Implementation Tips: DAF systems require proper setup and calibration. Consulting with a wastewater expert can help you optimize the system for your specific needs.
4. Moving Bed Biofilm Reactors (MBBRs)
MBBRs are biological treatment systems that use floating plastic carriers to support colonies of microorganisms. These microorganisms break down organic material in the wastewater, reducing BOD.
- Why It Matters: MBBRs are compact and efficient, making them a good choice for manufacturers with limited space. They’re also effective for handling fluctuating loads of wastewater.
- Implementation Tips: While relatively low-maintenance, MBBRs require a balance of oxygen, nutrients, and temperature to maintain healthy microbial activity. Monitoring and occasional adjustments are necessary.
5. Anaerobic Digesters
Anaerobic digesters break down organic matter in the absence of oxygen, converting it into methane-rich biogas and nutrient-rich sludge.
- Why It Matters: Digesters are excellent for reducing BOD while generating biogas, which can offset energy costs. They are especially beneficial for larger operations.
- Implementation Tips: Anaerobic digesters require a higher upfront investment but can deliver significant long-term savings. Evaluate the volume and consistency of your organic waste before committing.
What’s the Payoff?
Investing in wastewater treatment isn’t just about avoiding surcharges (though that’s a big plus). It’s about building a more efficient, sustainable operation. You’ll reduce your environmental footprint, strengthen community relationships, and position your company as an industry leader.
Wastewater management might not be the most glamorous part of food manufacturing, but it’s one of the most impactful. A little effort goes a long way—both for your bottom line and the planet.
Let’s Make It Happen!
Ready to tackle your wastewater challenges? Whether you’re just starting out or looking to optimize your existing systems, we’re here to help. Reach out for tailored solutions that fit your business and budget.
