Grease Traps

Your fear vote is founded on outdated and ill informed and innacurate information.

Large tanks are not more efficient than modern HGI's(Hydromechanical Graese Interceptors) to give them their correct title, in fact a good HGI is between 93% and 99% efficient where the large in ground tank is typically more like 80% to 85% at best.

HGI's are designed to separate FOG from transitional flow using design features such as flow control, air entrainment baffle design and modern materials to outperform their oversized and expensive in ground counterparts.

Large tanks with extended service periods are equally if not more an environmental risk than the HGI. FOG and food debris/solids if left without attention for more than 3 months at most, will generate hydrogen sulfide gas which is not only dangerous it also accelerates decay of concrete and metallic materials leading to failure of the tank itself and the downstream piping in as little as 5-7 years.

This has been seen increasingly by those local municipalities that enforced this ill informed stance only to find that they have created a different monster to which the current response is enforcing more regular cleaning on the food service operator. This is typically being based on monthly cleaning or 'the 25% rule' which dictates that no more than 25% of the rated capacity can be filled with FOG. So not so large capacity afetr all!

My "fear vote" is not with the manufacturers of good HGI's. According to Plumbing Engineeer, a publication that bills itself as "The Authoritative Source for Plumbing, Hydronics, Fire Protection and PVF", "Regular maintenance of grease interceptors is critical to their long-term performance. Unfortunately, most restaurant owners do not even know what the purpose of their grease interceptor is. Therefore, within a relatively short period of time (sometimes within two weeks), especially for devices that are located in "greasy spoon" restaurants, interceptors will be filled to capacity with FOGs. This often results in the FOGs passing through the grease interceptor into the sanitary sewer system, followed, in many areas, by monetary fines from the water authorities."

Firstly my apologies - The 'Fear Vote' thing was a typo - This was meant to read "My fear is that your vote is..."

Generally I do not disagree with your response, but putting this discharge as the article favors into a large external tank alone, is not the answer for the reasons highlighted.

It was largely a knee-jerk reaction to the very situation you describe above where municipalities were/are being increasingly pressured by EPA (rightly so)to address what has been a lack of clear grease ordinance.

The challenge is to educate these municipal ordinance committees and decision makers with the factual information about the proven alternatives that exist.

The large tank route has in the main only created a different set of issues which take a longer time frame to appear but when they do are far more of a challenge and more costly to correct -all at the expense of the Food Service Operator.

It is like most things - the preference will develop over time until someone comes up with a giant-killer. The is a bit of a cyclical thing here too.

First was the traditional grease trap which over time proved to be problematic to pretty much all stakeholders - but due to perceived cost benefit they continue to be used today! This has been followed by large tank products (where again plastic solutions are without doubt beneficial) and more recently the migration to AGRU/GRD's and/or a return to modern HGI's is being seen.

HGI monitoring and alarm dveices are beginning to make their way into the market, that as well as monitoring FOG build up and indicating when maintenance is required, some also provide traceability for municpal officers/departments. These systems are a positive step forward and allied with the modern HGI give an operationally effective solution that will not break the bank of the FSO.

The Plumbing and Drainage Institute (PDI) with the recently published PDI-G102 standard provides performance criteia for these products which unlike early attempts seem to be becoming more reliable and effective. Might be worth another blog?

hi, would like to ask you about hydrogen sulfide gas. I work for a company cleaning grease traps and interceptors, wondering if this gas (HSG) OR ANY OTHER gases could affect my health and the health of my peers. WE DONT use any mask "cause is not provide from our employer and some traps and manhole get service passing over 2 months and i have noticed strong odour that make my eyes and face react to an allergic reaction that i am not aware.....please let me know if this gases have any affect to human health just by cleaning grease traps interceptors, atc

Julio,

H2S is a very nasty and toxic gas. It can produced symptoms similar to and as dangerous as Cyanide gas. Please review the link below.


http://emedicine.medscape.com/article/815139-overview

You will note that the symptoms you report in your post are covered and that there is a relatively fine line between that and very serious health risk.

On small traps this is rarely if ever going to be an issue but with large tanks the risk is certainly increased.

If the tanks are being cleaned regularly then the build up of gas will be lower but it will still likely be present. If you are attending a 'new location' that you have no history on then be particularly careful.

If I were you I would at the very least go to your local hardware store and pick up an off the shelf paint respirator. It will probably run you about $30-$40 and you will usually find them in the paint aisle or close by.

You are however (my personal opinion) justified to take this up with your employer again and should at least have a gas rated (or whatever is appropriate) respirator mask on the truck

Good luck

Grease Traps or HGI or GRD removes 93-99% of what? PDI calls for 90% removal and 90% of 12000 ppm is 1200ppm, this is not meeting the 100 ppm needed to help POTW's. Plus, traps can be manipulated in the restaurant. The baffles get removed, the GRD's get unplugged and neither on will work then. Daily maintenance is required on the trap devices. A seperate container is required to store the grease after it is removed from a GRD. Sorry! I disagree that trap are not the best solution.

So AntiTrap, Negativity is all very well but what would you offer up as an alternate solution?