Waste water capture and re-use

[stephanh]

I have installed a Matrix STP. With current enviroment conditions I wonder whether the out flow from the STP could be reused for irrigation purposes. I have been advised that the answer to that is NO.

Has anyone gone down this route successfully?

[Nickfromwales]

On 14/08/2026 at 10:07, stephanh said:

I have installed a Matrix STP. With current enviroment conditions I wonder whether the out flow from the STP could be reused for irrigation purposes. I have been advised that the answer to that is NO.

Has anyone gone down this route successfully?

Irrigation requires a LOT of volume of water, nowhere near enough would come from this type of plant.

 

The person advising you is kosher, it's a "no".  .

 

Irrigation from dedicated RWH systems for these types of current circumstances would, for context, need to be 15,000-20,000L capacity to be anywhere close to being considered 'effective', as the amount of stored water needed to get from 'drought to drought' is huge.

[saveasteading]

On 14/08/2026 at 10:07, stephanh said:

 wonder whether the out flow from the STP could be reused for irrigation purposes. I have been advised that the answer to that is NO.

Volume? Of course it depends on the garden needs, but it's a decent amount of water. But it would be quite low in the ground and might need pumping.

 

Health and safety wise? Everyone will say no, and probably rightly so. But what comes out generally looks clear and I know it hasn't killed trees I've had drains near to.

 

My hunch is probably no harm with decorative plants or trees but should not be used for vegetables.

 

[Conor]

Worked on various projects in the middle east where TSE (treated sewage effulant) is used for municipal irrigation. It's common and perfectly safe for non-crop irrigation. But it all depends on your treatment system and what standard of effulant comes out. Storage, distribution and handling needs to be thought out and designed. 

 

To be honest, I'd just get a couple large rainwater storage tanks (e.g IBCs) instead. Two IBCs will irrigate a medium sized garden for a minimum 20 days with no top-up. Tanks, connectors, pump etc will come in at less than £300.