We have a dump sink in the basement that uses a pump system, much like a closed sump-pump, to force the water up into our main drain out of the house. Because the pump system holds a bit of water before it activates, I’m wondering if there would be any foreseeable issue with certain things going into the closed-pump system (i.e. last sips of soda, warm & flat beer, soapy water from hand-washing, any other common sink-functions) from the dump sink?
Sewer pumps are designed for specific uses and their ability to handle different liquids and solids varies hugely. Read the documentation for your specific one.
The most common enemies:
- For all drains, not just pumped ones: Fats that harden when slightly cooled. EG, chicken fat, olive oil. If it's solid in the fridge but liquid when you pour it down the drain, the drain will suffer.
- The combination of hair with congealed hair conditioner and soap. This would be a particular problem to a sewer pump that is not designed for it, eg. if you use a bar sink pump for a shower.
- Strong fibrous materials. The most common offenders are dental floss and tampon strings. There are large commercial pumps that can handle these but a lot of residential basement pumps even when designed for solid waste will choke on these. Some cheaper pumps even require you to use cheap toilet paper to avoid the stronger fibers in the more expensive ones.
- Certain strong cleaning agents. Some pumps include instructions to avoid certain cleaning materials or to only use special ones, in order not to harm the pump parts.
As for beer etc, to answer that part of the question: IMO for most residential basement pumps you shouldn't worry about the freshness of the holding tank unless the instructions say you should. Sure you can flush with water but unless the tank is tiny you shouldn't. It's part of the sewage system and should be expected to normally contain sewage.
I would mainly be concerned with hair in a basement dump sink. If anyone using it has long hair I would strongly strongly suggest a basic drain filter. I bought a magnetic one that I thought was a PITA but it was actually so easy to use that I didn't mind dumping stuff out once a week or so into a trash.
That being said you cannot put large items down (chunked mud, pasta, potato). That is just a no and again why a strainer/filter will save you lots of headaches.
1. Get a strainer that works well with your sink. The amount of water and exit size will determine what you get. Don't make your sump pump a strainer... they are very bad at doing this.
2. Flush the sink out after heavy/weird usage. Do not let oils and dirt sit in sump. Run water after each heave usage. The worse kinds of things, the more and the hotter the water. Just doing this could keep the system running 100% with little maintenance. Forget 1-2 times and you will need a new pump.