Fat, Oil, and Grease (FOG) Wastewater Treatment Systems for Industrial Compliance
Food processing plants, commercial production lines, and industrial manufacturers generating fat, oil, and grease (FOG) in their effluent face mounting pressure from municipal sewer authorities and environmental regulators. Surcharges, permit violations, and rising hauling costs accumulate quickly when FOG concentrations exceed local discharge thresholds.
As a factory-direct manufacturer of chemical pretreatment programs and dewatering equipment, ALAR engineers FOG wastewater treatment systems that bring pretreatment in-house, helping plant managers and EHS leaders hit permit compliance targets without writing checks to third-party haulers every quarter.
Industry Solutions
FOG Wastewater Needs a Dedicated Treatment Approach
Fats, oils, and greases don't behave like typical industrial contaminants. They emulsify in hot water, congeal in cold pipes, foul downstream biological treatment, and bind with detergents and soaps in ways that make standard separation methods fall short. Food processors, edible oil producers, rendering operations, and personal care manufacturers all run into the same wall: fat, oil, and grease removal requires wastewater treatment, chemistry, and equipment made specifically for the job.
TOG, TPH, and FOG Classifications
Regulatory language matters here, too. Petroleum and oilfield facilities report discharge as Total Oil and Grease (TOG) or Total Petroleum Hydrocarbons (TPH). Food and consumer goods plants report theirs as Fat, Oil, and Grease (FOG).
The classification shapes which permit limits apply, and which treatment chemistries make sense for your stream.
How We Engineer FOG Wastewater Treatment Systems
ALAR's pretreatment systems combine coagulation and flocculation chemistry with mechanical liquid-solids separation and sludge dewatering equipment engineered for industrial flow rates. Configurations available include dissolved air flotation (DAF) units for high-volume processing, rotary vacuum drum precoat filters for DAF sludge dewatering and continuous flow operations, Flex-O-Star® for batch treatment applications, and pH neutralization skids for acid or caustic conditioning.
Each configuration is sized around your actual waste profile, accounting for FOG load, TSS, BOD, COD, metals, and pH variability across production cycles. ALAR's engineering team runs jar testing, bench-scale trials, and on-site pilots to validate chemistry dosing rates and unit operations before fabrication, ensuring the installed system meets permit limits from commissioning forward.
Compliance Benefits Plant Operators Can Measure
In-house fat, oil, and grease removal through wastewater treatment reduces hauling expenses, reduces exposure to sewer surcharges, and protects facilities from enforcement actions for noncompliance. Operators gain real-time visibility into discharge quality, predictable operating costs, and a defensible compliance record during regulatory audits.
Our technical staff supports your team through startup, operator training, and ongoing chemistry optimization as production conditions evolve.
ALAR manufactures industrial wastewater treatment equipment for worldwide distribution.
Industrial wastewater is a moving target; no two waste streams are alike. ALAR understands the difference and uses its chemical, engineering and technological expertise to deliver results that work.
Responsible industrial wastewater management makes the difference between regulatory compliance and non-compliance. ALAR offers a variety of mechanical and chemical pretreatment systems that allow customers to make an educated decision.
ALAR’s Auto-Vac™, Flex-O-Star®, and Dissolved Air Floatation systems effectively remove solid particles from the liquid, producing clean/dischargeable [non-potable] water along with dewatered dry solids. ALAR also designs and builds industrial chemical pretreatment and pH neutralization systems for batch treatment or continuous flow process wastewater applications.
The ALAR® Auto-Vac™ is a rotary vacuum drum precoat filter that effectively removes solid particles from the sludge, producing dewatered dry waste. Typically, this waste is disposed of at a local landfill without further drying. The Auto-Vac® is self-cleaning with every revolution, which prevents blinding or clogging, and provides rapid filtration and extremely high filtrate clarity.
The ALAR® Auto-Vac™ filtering system, available in 16 filter sizes, is skid mounted, pre-piped and pre-wired for easy installation. It is offered in both semi-automatic and automatic modes of operation. This design works with virtually any industrial waste.
The ALAR Flex-O-Star® is an automatic batch or continuous flow chemical pretreatment system, combined with the Auto-Vac™ RVDPF technology.
This system provides comprehensive wastewater treatment for water-based effluents, slurries, and problem wash waters. The design is universal and works with virtually any industrial liquid waste. ALAR’s Flex-O-Star® is engineered to incorporate a two-step filtration process: Chemical & Mechanical.
The first step, chemical treatment, breaks the solids and liquids apart by automatically adding pretreatment chemicals such as pH adjusters, polymers (coagulants and flocculants) or clay.
The second step, mechanical filtration, physically removes the precipitated solid particles from the sludge.
The Flex-O-Star® is a skid-mounted, pre-piped and pre-wired system; available in 12 sizes.
The ALAR DAF / Dissolved Air Flotation System is a wastewater clarification system that incorporates dissolved air to aid in the flotation of fine solids, fats, oils and grease. The concentrated float is skimmed off the surface with a sweeping wiper blade and discharged into a sludge trough. The sludge is disposed of or pumped to a dewatering filter.
The ALAR Chemical Pretreatment and pH Neutralization Equipment is designed to meet effluent discharge compliance via batch treatment and dewatering or simple pH neutralization and disposal. Sometimes, pH adjusting wastewater, without filtration, through a neutralization system meets city sewer discharge requirements.
However, many industrial wastewaters containing emulsified solids, oils, soaps, surfactants, or dissolved metals require pH adjustment in order to precipitate [drop] out of solution prior to filtration or dewatering.
The majority of ALAR wastewater treatment systems are pH driven; oftentimes requiring acid to lower the pH and break the emulsification, followed by caustic to raise the pH and precipitate the contaminants. In most cases, this simple pH adjustment is all the solids, oils and metals require to be captured by a 1-micron precoat filter such as the Auto-Vac™, Flex-O-Star®.
ALAR designs each system to meet the customer's build-to specifications. ALAR begins with stock layouts, and customizes the auxiliary equipment according to the customer's specifications.
These stock layouts are available in PDF format. Contact ALAR for more information.
Frequently Asked Questions About FOG Wastewater
Most Publicly Owned Treatment Works set local FOG discharge limits between 100 and 300 mg/L, though specific thresholds vary by municipality and industrial user category. Facilities exceeding the limit pay surcharges calculated per pound of contaminant above threshold, which can total tens of thousands of dollars annually for high-volume operations.
FOG solubility and viscosity shift significantly with temperature. Warm effluent from cooking, rendering, or CIP cycles keeps FOG dispersed and harder to capture. Cooling the stream through equalization tanks or heat exchangers improves separation efficiency, while chemical programs are tuned to perform across your facility's actual temperature range.
Free oil floats readily and can be removed through gravity separation. Dispersed oil exists as droplets typically larger than 20 microns and responds well to dissolved air flotation. Emulsified FOG, stabilized by surfactants, detergents, or mechanical shear, requires chemical destabilization through coagulants or pH adjustment before any physical separation will work. Identifying which forms dominate your waste stream is critical to selecting the right treatment train.
