I know this is very specific, but I'm hoping someone has done a similar solution or knows someone who has and can give me some input. We've recently installed a whole home RO system for a new home build. We're located on red clay, so foundation movement is likely to be a problem. The RO product to waste ratio is close to 1:1, so we're going to have around 2-300 gallons of wastewater everyday. It was suggested to us that we pipe that water into a buried drainage system around the perimeter of the house. The system would consist of corrugated, perforated drain pipe enclosed in a filter sock, installed on graded gravel and then covered with gravel. The water would dump into the highest point, and make its way through the drain before exiting at a lower elevation. I'd likely also include a bypass in case too much water is being deposited around the foundation. The thinking is that we could make good use out of that wastewater. Any thoughts on the value or efficiency of this proposed system?

Yikes lot to unpack here. Too tired to
Respond now I will revisit sometime tomorrow

That's a great use of water that is otherwise wasted. However, before you spend the expense, you may want to find out if you need it. Our house that we recently sold was about 5,000 sq feet and on top of red clay. However, there were 38 bell bottom piers under the slab as designed. The house didn't move an inch in the 20 years of it's life we were a part of. If yours is similar, then you may just be wasting money, even if is it is a beautiful way upcycle otherwise wasted water.

Assuming you aren't on piers and this is necessary, I don't think your system is the best way to do this. It is low maintenance, but I feel like you are going to 'run out' of water. If it were me, and I am no engineer, I would figure out how to store up that waste water and then utilize a pump on a timer to feed it into 1/2" poly pipe with built in pressure compensating drippers situated every 12". You can run that along the foundation, or even partialy bury it and it will allow the water to reach the far ends. These usually only need 7psi to operate. I think you have to store up a buffer amount of water before giving it the go. Even if you water it once a week, that's going to be more than adequate since you are doing it so regularly.

This is my opinion, and it's probably not idea. I'm just worried about your system being able to work everywhere if its water that is 'as available'.

Thanks for the reply.

It is an engineered foundation (by Dudley) but it's pretty basic, no piers.

I have considered what you're suggesting. It would require a holding tank for the wastewater, and a treatment system for the wastewater as well, since that untreated water, when exposed to the atmosphere would grow microbes. As you mentioned, it would also require a repressurization pump and I would have to incorporate an overflow system to reroute wastewater when the holding tank becomes full. It's a lot of moving parts, but I wouldn't have to bury the drip line so it could be monitored more closely and the watering would be more consistent. I may have to incorporate a pressure tank because I'm not sure how the repressurization pump would react to the back pressure created by the drip line tubing if the overall flow rate didn't closely match what the pump is putting out.

AND this is a lot of work, space and money put into a solution that I'm not even sure makes a difference. I can't find any good research online about whether or not watering your foundation actually makes a difference, even though intuitively, it makes sense.

Agreed. It is a lot of moving parts. I think your idea will work if your RO system will generate enough water quickly enough to get even distribution. I don't know if it will. If it will, I think you are in business. If it wont, then you might end up soaking the nearest areas a lot and the furthest areas never, that is what I was concerned with. 300 gallons a day is a lot of water, so if you can harness it evenly, it will work fine I think.

It could work with corrugated pipe however as mentioned above, the area nearest the inlet will take all of the water, hence the evenly spaced 1/2" suggestion. You could also do this with the 1/2" or 1" poly or PVC with no pressure compensated drippers and instead manually drill holes (0 psi required) with less holes near the inlet and more at the end to try to distribute the volume more evenly. Then you would leave the end open/partially open and tie the overflow to where it's going now or a pasture.

We have made a) soaker systems & b) DIY trenches work on CHEAP slabs on clay in Aggieland, even those w/2in dropped corners BUT
A Dudley slab is NOT cheap, it is well designed and substantial. Ergo, any advice should come solely from Dudley, who stands on-call to help with any problems future with their education, license & experience.

For those with slab-on-piers, it's best NOT to employ soaker systems, et al. in case there's a breach in the buried bulkhead that keeps invading waters away from pier footings = bad effects to the whole system and 18month dry-out expected for all solutions to this invasion. That said, slab-on-piers usually have the designing engineer as the best advisor.