INDUSTRY INSIGHTS

Record-breaking rainfall in April 2026 led to widespread flooding, road closures, overwhelmed municipal infrastructure, and state emergency declarations. Many parts of the Midwest shattered long standing rainfall records within the first half of the month, with Wisconsin setting a new 24-hour precipitation record of 14.66 inches.

With headlines focused on flooded streets and overwhelmed treatment plants, it’s natural for food and beverage processors to ask: What does this mean for our wastewater systems?

The Surprising Reality: Limited Direct Impact for Many Industrial Facilities

Over the following weeks, most major Wisconsin waterways slowly receded below official flood stages, although there is still lingering high water and dangerously fast currents being reported as we enter the second half of May. Given the magnitude of rainfall Wisconsin experienced in April, it would be reasonable to expect widespread disruption within industrial wastewater treatment systems. In practice, however, most food and beverage facilities saw minimal direct impact to core treatment performance and the ability to discharge fully-treated, clean water to local waterways.

That outcome isn’t accidental. It’s a result of how industrial wastewater systems are designed, engineered, and operated.

While many facilities did see storm-related inflow during peak rain events - sometimes equating to 10% or more of individual tank volumes - those volumes were introduced gradually over time, rather than as a sudden hydraulic shock. When viewed in the context of continuous production flows, sanitation cycles, and clean‑in‑place (CIP) events, the net effect was often a relatively small deviation from normal operating conditions.

Why Industrial Treatment Systems Remained Stable

Industrial wastewater systems are engineered around predicable, process-driven loading, not short-duration weather events; making them fundamentally different from municipal systems.

Predictable but Variable Industrial Flows
Food and beverage facilities generate wastewater continuously from production, washdown, and CIP operations, resulting in generally predictable hydraulic and organic loading. However, these flows are not steady throughout the day - rates and loads can fluctuate significantly by hour or process. This variability is why many industrial systems rely on high‑strength waste (HSW) diversion and equalization to deliver a consistent, controlled feed to the wastewater treatment plant (WWTP).

In contrast, municipal systems typically see more stable average loading patterns, with daily peaks in the morning and evening, while people are home. These facilities can experience daily hydraulic loading increases up to 250%!
Additionally inflow and infiltration (I&I) introduce large, unintended volumes of clean water – such as storm water and ground water – into sanitary sewers through direction connections and aging infrastructure. During wet-weather, these flows are uncontrolled, variable, and can significantly reduce available treatment capacity for municipal systems.

The wastewater characteristics vary significantly between municipal wastewater and industrial wastewater, which plays a key role in why the design and operation of the facilities varies significantly.

^{MUNICIPAL WASTEWATER TREATMENT SYSTEMS}

^‍·         Primarily domestic  sewage

·         Relatively dilute  organic strength

·         Predictable daily  patterns (morning/evening peaks)

·         Heavily impacted  by inflow & infiltration (stormwater, groundwater)

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^{INDUSTRIAL WASTEWATER TREATMENT SYSTEMS}

‍^‍·         Process-driven  wastewater (production, washdown, CIP)

·         Often  high-strength (elevated BOD/COD, TSS, FOG, nutrients, chlorides)

·         Variable by hour,  product run, and cleaning cycle

·         Designed around  known, controllable sources, not weather events

Equalization and High Strength Waste (HSW) Diversion
Given the anticipated variability and high strength wastewater generated from food and beverage production, many industrial systems include equalization capacity specifically designed to buffer short-term hydraulic and organic variability. Treatment plants with HSW diversion have additional flexibility, allowing for wastewater streams with elevated organic loading – such as first-rinse CIP wastewater, product losses, or concentrated washdowns – to be isolated and routed to the equalization tank. This approach allows high‑strength wastewater to be reintroduced to the treatment process at a controlled rate, protecting biological performance and maintaining efficient WWTP operation. As a result, any rain‑driven inflow was typically managed within this built‑in flexibility, without disrupting any downstream processes.

Resilient Biological Processes
Properly maintained biological treatment systems are more tolerant of small hydraulic changes than they are of abrupt organic changes, temperature fluctuations, or toxicity shocks. Because April’s storms did not materially change the organic loading profiles, biomass health and treatment efficiency remained largely intact.

Putting the Numbers in Perspective

Even where rainfall temporarily increased influent volumes, those increases were small relative to daily operational throughput. A tank that saw 10% of its volume influenced by rainfall over several hours was still treating many multiples of that volume from normal plant operations over the same period. As a result;

• The rain did not overwhelm treatment capacity
• Solids retention times were largely preserved
• Oxygen demand and nutrient loading stayed within expected operating ranges

This allowed most facilities to continue to meet performance expectations without requiring major operational intervention.

Where Impact Was Seen

While most systems held steady, April’s rainfall did create challenges in specific scenarios: 

^{PRODUCTION SLOWDOWNS DRIVEN BY MUNICIPAL CONSTRAINTS
‍}Some food and beverage facilities were forced to slow or halt production, not because of on‑site treatment limitations - But because the municipal systems they discharge to were overwhelmed by stormwater. In several cases, municipalities were forced to bypass or discharge partially treated wastewater into local waterways during peak storm events.

Effects for industrial users tied closely to municipal capacity included:

• Reduced allowable discharge volumes
• Temporary shutdowns
• Increased operational coordination with local utilities

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^{LAGOON BASED TREATMENT SYSTEMS
‍}Facilities relying on lagoon systems or retention ponds offer limited real-time control over the treatment process, with performance depending heavily on factors such as temperature, weather and retention time. As a result, they are much more susceptible to upsets (rain events, seasonal transitions), which directly impact treatment. With a larger surface area than mechanical treatment systems and the potential for additional runoff, lagoon based systems experienced more noticeable effects from the record rainfall, including:.

• Increased hydraulic loading
• Reduced effective retention time
• Created challenges with solids management and treatment performance

^{INFILTRATION & INFLOW (I&I) CONCERNS
‍}Facilities that must treat stormwater coming into contact with ground contaminants saw an uptick in flows driven by:

• Groundwater intrusion
• Surface water infiltration
• Aging infrastructure exposed during high‑water conditions

 While often manageable, these conditions are generally observed in older treatment systems and municipalities with long wastewater gravity mains and can stress hydraulic capacity if left unaddressed.

 Ongoing Impacts to Land Application & Land Spreading

Land spreading allows nutrients like nitrogen and phosphorus to be returned to the environment as a fertilizer or soil conditioner. Careful management benefits the environment, limits the need for landfill disposal, and provides a free or low-cost source of fertilizer for farmers.

However, saturated soil acts like a wet sponge – once saturated, it cannot absorb more liquid or more nutrients. To prevent runoff and protect the environment, land application programs can remain affected long after the rain stops. Some of these effects include:

• Delayed spreading windows, or in many cases the need to halt land spreading entirely
• Increased reliance on interim storage or alternative disposal options

 For many operators, these impacts will extend well beyond the spring.

 The Takeaway 

During periods of heavy rainfall, including the events seen across Wisconsin in April 2026, several municipal systems were pushed beyond capacity, resulting in the discharge of partially treated - and in some instances raw wastewater to local waterways. But, the record‑breaking rainfall doesn’t automatically translate to record‑breaking treatment disruptions for Industrial wastewater treatment systems.
Industrial wastewater treatment systems are designed, engineered, and operated under a fundamentally different model and they are remarkably resilient by design - especially when predictable production flows dwarf short‑term storm impacts.

If you have concerns about how your treatment facility faired the wet weather or are facing land-application challenges, our team of wastewater experts is here to help.
Send Us An Email or call us at (262)264.5665 to Explore Your Best Wastewater Solution.

For food and beverage manufacturers, wastewater challenges rarely arrive with much warning.

One day, everything seems routine. The next, you’re facing unexpected surcharges, stricter discharge limits, a compliance notice, or pressure to plan for an expansion that your current treatment system may not be ready to handle. When that happens, wastewater treatment can quickly feel overwhelming - not because solutions don’t exist, but because it’s not always clear where to start.

The reality is that many wastewater problems aren’t caused by sudden system failure. They’re caused by gaps in understanding — incomplete data, outdated assumptions, or a lack of clarity around what’s actually coming from the production facility.

Common Wastewater Pain Points for Food & Beverage Manufacturers

Wastewater generated by food and beverage manufacturers is highly variable and uniquely complex. Even facilities with similar products can generate dramatically different waste streams depending on production schedules, cleaning practices, seasonal shifts, and raw materials.

Some of the most common parameters that drive challenges include:

• pH – Sudden swings from CIP cycles or ingredient changes can create biological stress or trigger permit violations.

• Chlorides – Increasingly regulated and difficult to remove, especially for facilities discharging to municipal systems.

• Phosphorus – Often tied to cleaning chemicals, additives, or raw materials and subject to tightening limits.

• TSS (Total Suspended Solids) – Can fluctuate with production changes, leading to solids handling and surcharge issues.

• BOD/COD – High-strength organics can overwhelm biological systems or exceed POTW capacity agreements.

When these parameters aren’t well understood — or when they change unexpectedly — facilities often find themselves reacting instead of planning.

Why “Just Fixing the System” Isn’t the First Step

A common response to wastewater issues is to jump straight to a quick-fix: new equipment, add on treatment processes, or chemical programs. While those tools can be effective, they’re rarely successful without one critical foundation:
A clear, accurate understanding of your unique wastewater.

Without that, it’s like driving at night with your headlights off - you may keep moving, but you’re reacting at the last possible moment, and every turn feels risky.

Before evaluating treatment upgrades or compliance strategies, facilities need to answer some fundamental questions:

• Where are problem parameters originating?

• How do flows and loads change over time — hourly, daily, seasonally?

• Which streams drive surcharges, compliance risk, or biological stress?

• How do current conditions compare to municipal limits and future regulatory trends?

Those answers don’t come from a single grab sample or an old study. They come from intentional, well designed sampling efforts.

The Value of Targeted Wastewater Sampling

Effective wastewater sampling is not just about collecting data - it’s about collecting the right data.

Knowing where to sample, how often, and which parameters matter most is critical. Poor sampling plans can create misleading results that either overstate risk or mask real problems entirely.

At The Probst Group, wastewater sampling events are designed to help facilities:

• Identify specific sources of high strength or problematic waste streams

• Understand variability tied to operations, cleaning, and production cycles

• Establish a defensible basis of design for permitting, planning, or system upgrades

• Compare basis of design to current and anticipated future limits

This information becomes the foundation for better decisions, and better solutions - whether that’s negotiating with a municipality, planning an expansion, or evaluating treatment alternatives.

Moving From Reaction to Strategy

When facilities take the time to truly understand their wastewater, the conversation changes.

Not only are we able to address the immediate problems and concerns, but also consider the most effective solutions for the future.  

That shift allows operators and owners to:

• Reduce surprise costs and compliance risk

• Prioritize capital investments more confidently

• Align wastewater strategy with production and growth plans

• Engage regulators and municipalities with better data and clarity

Wastewater challenges don’t stop at sampling and developing a basis of design - they evolve into questions around permitting, alternatives analysis, and treatment options that fit both operational and regulatory realities.

If wastewater uncertainty is creating risk or limiting your ability to plan ahead, it may be time to turn the headlights on. Contact The Probst Group to schedule an initial wastewater evaluation and start building clarity — before the next surprise hits

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In the Upper Midwest, spring is rarely calm. Facilities can move from freezing nights to warm afternoons, from snowmelt to heavy rain in a matter of hours. Add in a couple of feet of fast-falling snow and blizzard conditions just for fun. And, while these conditions are often expected, their effect on wastewater treatment systems is often underestimated.
Spring is not just another season. It’s a transition period, and transitions are where treatment systems are most vulnerable.

Temperature Change and Biological Stability

Biological treatment systems depend on living microbial communities that respond gradually to environmental change. In spring, air and wastewater temperatures often shift faster than biology can adapt. Cold conditions slow microbial metabolism, especially for nitrifying organisms. When temperatures rise quickly, biological activity increases - but not always evenly or predictably. The result can be short term instability: fluctuating ammonia removal, changing oxygen demand, or inconsistent effluent quality.
From an operational stand point, the challenge isn’t simply “cold” or “warm” weather. It’s rapid temperature change, which can push systems out of balance, even when design capacity hasn’t changed.

Mechanical Systems Under Spring Conditions

‍Beyond the potentially warmer outdoor temperatures that make it more appealing to perform general equipment maintenance, mechanical infrastructure often feels spring weather first. Freeze–thaw cycles can affect pumps, seals, valves, air piping, instrumentation, and clarifier mechanisms, making spring the time when minor mechanical vulnerabilities become operational problems.

Why Spring Is Often Harder Than Winter

Winter conditions tend to be cold but stable. Spring removes that stability.
Biology is still operating at winter adjusted performance levels while flows, temperatures, and influent characteristics change rapidly. This combination makes spring one of the most common periods for:

• Ammonia excursions

• Sludge settling changes

• Increased operator intervention

• Short term compliance risk

In our experience, spring performance issues are rarely caused by a single factor - they’re the result of multiple small stressors occurring at the same time.

Planning for Transition, Not Just Extremes

Successful spring operation isn’t about chasing weather events. It’s about planning for variability.
Facilities that navigate spring most effectively typically focus on:

• Monitoring trends rather than isolated data points

• Anticipating biological lag during temperature swings

• Preparing mechanical systems for variable operation

• Adjusting operations proactively as conditions change

Spring serves as a reminder that resilient, flexible treatment systems aren’t just designed for peak loads or extreme temperatures — they’re designed and operated to handle change.

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