Foam in Wastewater


Biological Products:



Bioaugmentation products for Wastewater applications in Papermills, Refineries, Chemical, Tanneries, Municipalities, Textiles, Steel, Agriculture, Animal feedlot,  Gun Powder plant, Food and Beverage- Dairy Products, Orange Juice factory, Wineries, Cookie factory, Vegetable processing plant, Meat packing, Barbecue Restaurant, Aquaculture, Ornamental Ponds for algae control, CAFO, Nursing homes, Military, Campgrounds, Universities, Regulatory agencies



Lab Services:



Filamentous Identification Lab Service. One reason to identify filaments is to determine the filaments characteristics and then determine the type present.  If the type is found out, a root cause can usually be associated with a particular filament.  If the cause is known, then a correction can be made to alleviate problems. Chlorination is only a quick fix.  Without process changes, filaments will grow back after chlorination.

Wastewater Biomass Analyses and Cooling Tower Analyses also available


Training Materials:



Training is an integral part of any job. Not everyone is at the same level of training. Many people want beginning concepts and basics. Some need technical information or troubleshooting. Some want equipment, technology or process information.

We have developed a full set of Basic training, Advanced training, Filamentous Identification the Easy Way as well as custom training CD's Manuals. We also provide hands-on training classes and soon will have an Online "E-University".


Audits and Consulting:


At Environmental Leverage® Inc., we have a team of experienced individuals who come into your plant with a fresh pair of eyes.  The system is checked from influent to effluent.  System optimization, equipment efficiency and operational excellence are key components explored. Key Benefits Equipment efficiency Total Cost of Operation reductions Reliability and safety

An onsite audit is conducted to examine system parameters, process controls, and current monitor and control procedures. A physical walk-through is conducted, process flow diagrams are examined, previous design criteria are examined and current standard operating procedures are evaluated along with data logs.




All wastewater foam is not alike

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What's New!

We have just added "Virtual Audits" to our capabilities. Check out our new Services.  We are in the process of developing new courses for our ""Online E-University" in order to meet the needs of our global customers that cannot travel to our public classes.Visit our new website


wastewater aeration basin foam and Wastewater Training and waste water eLearning trainingThe common misconception is that if you have foam on the surface of your aeration basin, you must have Nocardia. Not all wastewater treatment plants or systems have foam due to Nocardia- Some have Microthrix- Some just have too many solids and some low D.O.. . . . . .. . Some have zoogleal bulking. Sometimes foaming can be due to Zooglea and other times due to Septicity. Do not just assume what your foam cause is. Use your Microscope and let the bacteria present tell you how to fix your plant.


Are you having problems with Grease? Low nutrients and high loading due to industry can also cause foaming as well as septicity?


This is a picture of foam from a wastewater treatment plant that everyone said had to have problems with Nocardia or Microthrix. No one had ever looked under the microscope at the actual filaments or did a Gram or Neisser stain. In reality, this plant had too many solids in one of three basins and was also holding solids too long in the clarifier. The biomass had N. Limicola as the dominant filament. The plant needed to make a number of process changes as opposed to just " adding bacterial product" as a quick fix.


Process monitor and control were big wastewater training recommendations to this plant. All three basins were "not alike" in reality. Flows to each were changed over the years as old pipes became clogged. MLSS was not measured in each basin. Too many solids in one of the basins that only had the foaming problem were detected. Changes to step feed were also recommended since the final basin was also low on F/M. D.O. levels were not checked in each basin. Small changes in that also helped create conditions that literally caused the filamentous bacteria to thrive when they finally reached the last basin in the process.


Always do a walk through on your plant, look for trouble areas. Are you creating dead spots in the primary that can cause problems? In the secondary, in the clarifier, in the sludge holding tank, digestors or in the dewatering and returned supernatant?


Not all foam is bad -but it usually indicates a condition that is going on in your basin- learn what the colors mean. . . .

These are the typical troubleshooting foaming charts- be careful though and use your microscope or you may make the wrong interpretation as to what is causing the foam and how to fix it.


Troubleshooting Secondary Wastewater Treatment Systems:

 Foaming Problems Wastewater Training



     PROBABLE                  CAUSE


White, stiff, billowing or sudsy foam covering a large part of or the entire  aeration basin.

 a) Start-up or high            BOD shock load                  condition resulting in         high F/M and low               MCRT.


 b) Excessive wasting or         hydraulic washout.


 c) Toxic wastes or                    temperature shock.


 d) RAS flow too low or         off.


 e) Excessive dairy fats,          detergents or other             foaming materials or          surfactants.

 a) Increase RAS or decrease WAS, do not waste until MLSS level comes up to proper F/M range.  Maintain adequate DO levels (1 to 3 mg/l).

 b) Reduce wasting and adjust RAS until  normal conditions are reached.

      Segregate stormwater lines from process   water collection system.

      Divert excessive flows to collection basin if   possible for later treatment.

     Add hydraulic equalization basin.

 c) Re-establish activated sludge organisms.             Waste sludge from plant if possible.  Re-seed       if possible (bioaugmentation).  Re-establish normal temperature if possible or adjust MCRT if situation is to continue.

 d) Re-establish adequate RAS rate.

 e) Pre-treat with anti-foam or DAF.  Improve primary oils and grease removal. Consider            bioaugmentation to more aggressively                 degrade waste substrate.

Shiny, thin, dark tan foam  on much of aeration basin surface.

Aeration basin approaching under loaded (low F/M) condition due   to insufficient sludge wasting (too many solids in   the system).

 * Increase WAS rate (not more than 10% per         day) until process approaches normal control       parameters and only a modest  amount of l         light tan foam remains on aeration basin              surface.


   Check MLVSS, F/M and MCRT to optimize.

Thick, greasy dark-   tan foam covering  most of the aeration basin surface.

Aeration basin is critically under loaded (excessive solids due to insufficient    wasting)

Increase WAS rate (not more than 10% per day) until the excess solids are removed from the system and normal balance is restored.  Check MLVSS, MCRT and F/M ratio to optimize process parameters.


clarifier grease foam on aeration basin clarifier weirs foam


Plants with foaming in the clarifier





Thick, greasy dark-   tan foam covering    most of the aeration basin surface, and carries over to the    clarifier (and sometimes over the basin sidewalls).

Filamentous organisms     (Nocardia, M. parvicella)

Increase WAS rate (not more than 10% per day) to reduce MCRT.  Normal filamentous control with chlorine or peroxide must include   treatment (in water spray) and removal of surface scum (foam) in addition to RASS/MLSS as these organisms tend to concentrate in the foam.  Check MLVSS and F/M ratio to optimize process parameters.


Dark brown, almost   black sudsy foam     with detectable septic or sour odor.  Mixed liquor is also very dark brown to black     in color.

a) Anaerobic conditions        within the aeration              basin.


b) Industrial waste               containing dyes or inks.

 a) Check DO levels in basin, and increase                 aeration / mixing.   Reduce organic loading          if possible.


b) Investigate pre-treatment strategies.

Modest amount of   fresh, light tan foam.

Not a problem!   Usually a sign of a well operated       process.

 "If it ain't broke, don't fix it!"




The problem with traditional troubhleshooting charts, is they do not look under the microscope and account for the microbiology.

Use your microscope. All dark brown foam may not be due to grease and oils.

If you have zoogleal bulking due to overload of recent high BOD addition of nutrients and adjusting your MLSS

are completely different process changes than if you had high grease and need to look at primaries or lift stations upstream.


We also have seen plants with high septicity and holding solids too long wind up with filamentous bulking.

Nocardia Foam Nocardia foam Nocardia

Nocardia Foam


M parvicella foamM parvicella FoamM parvicella

M parvicella foam

Stable dark brown greasy foam that can get thick enough to have a crust- plant with Microthrix problems due to grease problems in the lift station.

Adding bio block (MicroBlock™) bioaugmentation can help reduce grease upstream that causes problems in the plant.


 zoogleal bulking zoogleal bulking at a municipalityzoogleal bulking

Zoolgeal bulking due to high BOD loading from industry pretreatment at a municipality


septicity foaming septicity foamingwastewater filamentous bulking and Wastewater Training and waste water eLearning training

Foaming due to septicity at a municipality and resulting in heavy filaments. When heavy filaments are present

we can help with a microscopic biomass analysis with filamentous Identification. Click here for filamentous information


wastewater young sludge foam and Wastewater Training and waste water eLearning training high foaming at chemical plant high foaming at chemical plant


High foaming - white crisp foam- due to young sludge or high recent BOD loading


aeration basin aeration basin wastewater aeration basin and Wastewater Training and waste water eLearning training

Normal aeration basin foaming due to diffused aerators


Keeping track in a daily log sheet, using photographs, correlating data to MLSS and to settlometer data as well as using the microscope are simple wastewater training suggestions and are all ways to help you understand what is going on in your wastewater treatment system.

Remember - it is in reality a "bug factory - you are growing bacteria to make clean water! Start thinking like a bug. . .


Click on the links if you need more information on our Filamentous Identification the Easy WayTraining CD or on Internet wastewater training on Filamentous bacteria, causes and controls


How are your bugs doing?


Contact us today to set up a Filamentous Identification of your MLSS and start saving money at your plant as well as producing a better final effluent~  Did you know some plants save 40-60% on solids handling just by reducing filaments and creating  healthier floc formations in their MLSS. Call Enivronmental Leverage at 630-906-9791 or

email at

Wastewater Training Classes

Wastewater Training CD's

waterfallsWastewater Biomass Analyses with Filamentous Identification


I do not have filaments at my plant


Click on the product pictures below for more information on bioaugmentation in your system


Wastewater Training and waste water eLearning training            Wastewater Training and waste water eLearning training, Wastewater bioaugmentation and wastewater training