H1 annex J4: groundwater risk assessment for treated effluent discharges to infiltration systems

This publication was withdrawn on 1 February 2016

This publication been replaced by infiltration systems: groundwater risk assessments.

How to undertake a groundwater risk assessment to support permit applications for the discharge of treated effluent to subsurface infiltration systems.



This guidance is primarily focused on discharges of treated sewage effluent (domestic and non-domestic) and trade effluent to constructed infiltration systems (drainage fields).

It should be read in conjunction with the Horizontal Guidance Note H1 overview document.