9 replies to this topic

[MtceMgrFood]

I am very confused about the wording on 11.3.5.6 (Edition 10)
 

"Sanitary drainage shall not be connected to any other drains within the premises and shall be directed to a septic tank or a sewerage system in accordance with regulations." - Emphasis mine

I found some previous threads on this forum about the topic:
-https://www.ifsqn.co...ar-on-drainage/
-https://www.ifsqn.co...combined-sewer/


This situation where the toilet does not connect to the same sewer pipe as the floor drains within the building is very uncommon in the USA. In the dozen or so facilities I have been in only one facility did this, and only because they had to manage process wastewater pH prior to the municipality. 

Unless you have a purpose built facility you likely don't comply with this rule as written. Is the intention of this rule something other then it is clearly written? Or is it poorly written?

 

Reading between the lines I would expect the real goal of this rule to be to "keep the dirty, stinky, biologically contaminated water and air out of the gowning, storage, and food prep area (the building as a whole)"   ... Right?

I would expect something more reasonable like "Process drainage and sanitary sewer gasses shall be blocked from the interior of the building by P-traps, one way air admittance valves and other standard plumbing practices in accordance with regulations"
 

Am I missing the point because I only have experience in facilities in the USA?

All the other rules I am seeing are reasonable and logical, this one is the exception. Any advice, perspective, or auditor experience with this would be helpful. 



 

Edited by MtceMgrColorado, 06 May 2026 - 07:02 PM.

[TimG]

I am in the USA, and I absolutely make sure floor drains to my process area are not connected to sanitary sewer drains. They have been separate in all 5 of the food manufacturing facilities I've worked in.

 

For one thing, discharge of washdown water into the sewer is a no-go as far as state rules go, at least in every state I've worked in (without pre-treatment/permits). Are you in an industrial/manufacturing facility?

Edited by TimG, 06 May 2026 - 07:47 PM.

[MtceMgrFood]

Light industrial zoning, multi tenant building. We have all the units in this building. I have an underground plumbing drawing which shows it all connected. 

I have only been in one facility that had wash down water processed, otherwise it all went to the sanitary sewer. All of the <100,000sq/ft food manufacturing buildings I have been in have done it this way.

 

Edited by MtceMgrColorado, 06 May 2026 - 07:59 PM.

[GMO]

Never seen them connected in the UK for obvious reasons.

[MtceMgrFood]

USDA food code does have something similar in 5-202.13 of the food code. Process water drains need an "air gap"
And 9 CFR Section 416.2(b)(2)
"Sewage must be disposed into a sewage system separate from all other drainage lines or disposed of through other means sufficient to prevent backup of sewage into areas where product is processed, handled, or stored."
 

That terminology makes sense. Process drains are not directly connected to the sanitary sewer, but are given an air gap. Floor drains are trapped (P-trap) and vented (vent stack through the roof) but downstream are directly connected with sanitary sewer lines. 

I keep seeing reference to "back flow" preventers, those are extremely common on water supplies, but I have never seen them in reference to sewer lines. 

That has been my experience in the food manufacturing world here. However most of my experience is in smaller facilities. 
 

This issue may be all my ignorance, so please correct me if I am wrong. 

[MtceMgrFood]

Here is another relevant post from this forum. It's topic is in relation to vent stacks in food manufacturing drains. 

https://www.ifsqn.co...a-food-factory/

In post number 6 FurFarmandFork shares:
"A lot of small facilities share drain systems where pre-tretment of your industrial waste does not need to occur (think very small establishments or restaurants).

 

In that case you want the air vents to be sealed and located downstream of any exposed trench drain, no one is cleaning the inside of their entire wastewater drain system, just the exposed areas and potentially foaming the outflow points to keep biofilms from reentering the trenches."


Even in the >100,000 sqft facility that I got to see get built from the (below)ground up, which had a sump pit collecting all the process water had P-traps in each floor drain, with vents to the roof for each branch. However we had a "permit" from the local waste water facility with pH restrictions which drove that decision. That has been my only experience with separate sanitary (toilet) waste and process waste. We flowed something like 400,000 gal/day down the drain though. 

[Tony-C]

Hi MtceMgrColorado,

 

 

Welcome to the IFSQN forums

 

As per previous posts, sewage systems should be separate to other drainage on site.

 

Perhaps drainage all ends up in the same place but they shouldn’t be connected on site.

 

Kind regards,

 

Tony

[Scampi]

my facility is roughly 90 000 sq feet, we have 15 backflow preventers       and the toilet drains DO NOT connect to the drains in production 

 

CFIA and GFSI both require as much

[MDaleDDF]

Ours our separate too...   isn't this just standard practice in commercial construction?   They all meet at the main in the street, but that's it.

 

You say yours connect downstream.   How far?   Do they connect to each other or meet a larger pipe downstream?   Because maybe they're fine?

Edited by MDaleDDF, 07 May 2026 - 01:44 PM.

[GMO]

Do a what if. If there was a blockage or back up on the sewage system, what would happen and how quickly would it impact your site? If there was air flow from the sewage system, could that link to your system? Is there anything to stop it?