Exterior Mop Sink 1

[mkred]

I am doing the site design for a gas station. The Owner has requested that the mop sink for the building be just outside the back door. The Architect is trying to push the design/detailing of the mop sink off on me since it is outside the building. The Architect described it as a two-foot square area surrounded by a concrete curb with a drain in the center. A standard hose bib on the side of the building would be the water source. I will have to connect it to the sanitary lateral since it will have wash water and cleaning chemicals drained into it.

Has anyone ever designed something like this or seen details for one? Do I need a trap on the drain? Would the plumbing code apply to this situation?

 

[PEDARRIN2]

I would push back hard to get the thing inside.

There are all sorts of problems that can/will happen with an outdoor fixture like this.

It will drain whatever rainwater that falls into it. It will likely be used to wash down oily items which will introduce oil into the sanitary.

It is likely this would be required to go to an oil interceptor because of this. But sizing it will be a mess due to the outside nature of the drain - i.e. excess water going to it.

Then it will need to be winterized or the trap and piping will freeze and possibly break.

Since it will be within the "normal" 3'-5' of the building, it will likely need to follow the plumbing code.

If you want to look at what one looks like, you can look at Stern Williams' website. Mustee also makes them.

 

[bimr]

The only person who is capable of answering your question is the local plumbing code official.

The attached link below shows that in some areas of the country, such an outdoor installation as you described it is acceptable. However, a roof over the drain will probably be required.

http://www.sonoma-county.org/PRMD/docs/techbulletin/p-8x.pdf