Our Effluent is crap, settleability by the numbers is "ok" but there are floating puffballs of solids, we are seeing low DO/F:M filaments...

WWTP Stats:
~ Average of 1.5 MGD entering the plant
~ Extended aeration, 1.1 MG capacity in aeration basin B, .64 in aeration basin A.  Three clarifiers of capacities .154, .178 & .224 MG.  ~ Influent TSS 350-450 mg/L, COD 550 mg/L
~ MLSS from both basins are hovering around 2000 mg/L.
~ 5 min settling is around 400, 30 min is 200, 60 min is 160.
~ SVI 82-100, WCR 550-700
~ Effluent TSS 25 mg/L, COD 65 mg/L
~ MCRT is currently at 14 Days
~ thick foam on both basins, ranging from dark brown to whitish brown.
~ Seeing white foam constantly from one main line entering the WWTP
~ Still working with the cycling of our new aeration system (3 turbo blowers, two aeration basins, ONE air line...)

Microscope Info:
~ can see oil in the whitish foam samples from one of the basins
~ Maybe possible start of problem with Nocardia, but will check the scope again tomorrow...

There are those that say we cannot find the source of the "white foam" entering the facility, though I think it's more accurate to say, we don't know what and how to TEST for whatever may be the cause of the problem (foam or not)...

Is it possible to see a high COD or TPH or visual foam at the plant but not see the same results closer to the source because of other "additives" to the contaminant? I'm not a chemist so I really don't know   ?

Ideas? Comments?

Oh goodie... surfactants...  

Although we're waiting for other process configurations to stabilize, we will probably increase our MCRT, in the past heavier LBS in the plant has greatly reduced the negative effects of surfactants.

Has anyone been able to track down the culprit (assuming there is ONE or TWO...) via what tests? Visually we do NOT see any foam or oil sheen above our location.

The foam we see is from one specific line, this line comes down to our plant by a sharp grade downhill and is churned up quite a bit just as it reaches us.  The manhole before the drop, we never see anything like foam or an oil sheen...

Oh, and I've started a similar thread in the Treatment forum  

Filamentous growth isn't a problem now, they're present, but not to levels that are alarming...yet...

We've tested for surfactants in the past and get highly mixed results... I've also heard that wastewater isn't easy to test because of the nature of the waste... and frankly my boss is sick of hearing about "surfactants"... makes it difficult to propose more testing... but will relay the message!

We've increased our MCRT to 17 days, trying to increase our mass to handle the surf. loading... for now... and also checking for filaments daily.

So how would your sampling plan look? Grabs, Composite? There's not a lot of industry around here (on that line)... making us think it's possibly homeowners?  

Wastewater is a pain to test for surfactants.  Oftentimes there is some sort of interphase layer that appears during the extraction that is diffucult to properly decide where it goes.  I would guess that you have someone who has plumbed there dishwasher or clotheswasher drain to where it goes straight into the stream.  I think surfactants have to be done on a grab.  The holding time for them is only 48 hours.