Rodding eye / rectangular hopper

[barto22]

Hello. 

 

I'm removing a concrete pathway around the perimeter of a house and replacing with porcelain paving. Pipework from inside the house (dishwasher, washing machine, sink waste etc) are all in different locations but have all been fitted in a similar fashion. Currently it looks like they have been plumbed into the shallow side of rectangular hoppers where the other square side, where there is normally a grid, has just a solid blank lid. Around the pipes themselves and across the top of the shallow end of the hopper have been covered in concrete. The pots themselves seem to be clay rather than plastic. I can't honestly say that I've seen this before, but it is what it is.

 

My question is; Is there anything out there that I can buy to replace these? Preferably in plastic. The concrete excavation is certainly going to break them. Originally I assumed they were regular rodding eyes, but turns out not to be the case. 

 

In hindsight I should have taken a photo - perhaps I'll get one tomorrow so that I can post here.

 

Any help would be much appreciated. Many thanks!