Install utility sink at outdoor kitchen cleanout

In many places the plumbing code requires an outdoor clean-out near the kitchen sink.  It took me many years to find out what it is.  Also in these places, most likely it is frowned upon to discharge waste water outside, or even wash your car.

Our kitchen sink clog often, or drain very slowly, like once a month.  I used fine metal mesh filters at the twin sinks.  I even installed a mesh filter down at the trap.  It didn't matter.  I suspected my wife bypass the filters.  But it must be grease and other stuff like rice, but mostly grease.  We don't fry and so we don't have grease that we pour into the sink.  But we stir fry a lot and the residue oil cannot be poured elsewhere.

I thought of installing a grease trap as in the restaurants but it is too expensive.  The undersink is already reserved for a 4 gal reverse osmosis system.  And you have to maintain it like washing the filters.

I have everything to clear clogs and I'm well trained at all those.  Once I snaked until the entire length of the snake is in.  An online plumber told me in that case my snake would have traversed the whole house and reached the sidewalk in front of the house.  That wasn't a real solution.  I hate snaking.  You can't leave the dirty snake inside the garage.  If you clean it you have to add oil.  I don't have an outdoor drain to clean anything.  When it's not too late I can pour a gal of drain cleaner into the kitchen sink.  That would work overnight, but not less than a gal.  The other thing is at least 8 oz of sulphuric acid that work every time, but I am afraid I would damage the pipes if I apply once a month.  And I have to pour at the clean-out.  Anyway, chemicals are too expensive and environmental unfriendly.  It's like pouring a $10 note down the drain every time.

For years I pour the dirty bucket of mob water into the toilet after my wife did the cleaning.  When we have to wash anything bigger and dirty we have to do it in the bathtub.  And after some oil change or repair, I hate to bring myself, tools, and anything toxic into the house for cleaning.  I don't want anything to accumulate at the yard too.

The more I look at it, the more I am convinced that I cannot install a sink outdoors.  I have to find the right section of pipe near the wall, beak the wall, install a tee and seal the wall.

But I have added pipes at the cleanout to make it easier to add chemicals, friendlier chemicals that you have to add more often.  I even thought of adding a small sink for RV's to enlarge the end of pipe.

But now I found the solution.  Big laundry / utility sinks that have stands on it's own, to be installed at the cleanout.

I didn't want it to be big.  But they all come in that size suitable for the laundry.  Big has it's advantages.  When the pipes down the kitchen sink clogs, you have a big reservoir to allow water backup, before dirt water backup into the kitchen sink.  Or, depending on the height of the sink, dirt water will overflow outside and never backup into the kitchen sink.  Both have it's merits and disadvantages.

You need a p-trap under the utility sink, just as you need one under the kitchen sink.  That would prevent sewage gas (bad smell) from escaping.  Why I didn't think of that?

The joints are screw at the cleanout, and slip-joints with compression screws elsewhere, the most common types.  Typically, the slip-joints can be unscrewed and taken out rapidly by hand.  But you should design the cleanout joint section so that it's simple to unscrew.  You can add a permanent section while still be able to put in a snake.  But it would be difficult to put in a pressure bladder without direct access to the cleanout.  The bladder is the most convenient equipment and effective that I love.

It helps a lot if the sink is light weight.  The weight of the sinks surprised me.  At the hardware store, the sinks weight like huge stone.  For the cheapest one I got online, I can lift it with one hand, with the steel legs included!  So if you prepare to access the cleanout often, you should get a light weight one so you can lift the whole thing away.

And since the sink is moving, I should have got a p-trap with a flexible pipe section.  I can joint the parts together perfectly with addition slip jointed pieces and ABS glue.  But when the sink moves, perfect alignment cannot be maintained all the time.  The legs rest on a flower bed.

You might be able to get all the parts without the need for glue.  But for my case I already have a PVC (white) piece and ABS (pipe).  So I adapt them to the PVC p-trap.  If you really have to glue different materials together, do not use any super dupper glues for boats.  Different materials will expand and contract in different rates.  There are transition glues designed for gluing PVC to ABS.  But I saved money.  Someone reported experiments with all the combinations of glues and mismatch.  He reported anything goes without problem.  Another found out too late and have to dig out the yard to correct the mistake just in case.  He reported that PVC glue did nothing much to the ABS.  So I used the ABS glue I have to save money.  The pipes are never under pressure and are outside over the flower bed.

Now I can clean stuff contaminated with pet waste outside.  I can clean my car with the two bucket method without pouring the dirty water into the flower bed or into the toilet after bringing it all the way into the house.  I may use mob again that do not need to be cleaned using the washing machine.  Life is good, until the kitchen clogs.

ps The most good that came out of it.  You know water will backup before water backup into the sink.  When the tap is on, water will flow normally for a few minutes before slowing down or backup into the sink.  The outdoor sink, usually on a lower level, will give you early warning.  And if the next day you see some food residue in the sink, you know water was there when the dishwasher drains overnight.