Madam, - When a one-off house is being built and a septic tank installed, local authorities insist on a percolation test. This is to check whether the waste water from the septic tank drains into the surrounding soil, as it should, or whether it just runs into the local watercourse. In other words, it tests the site's suitability to sustain a septic tank without damaging local water supplies.
This test normally must be carried out by a suitably qualified professional. Galway County Council, however, allows planning applicants to conduct their own percolation tests and then takes their word for it.
And people wonder where the cryptosporidium is coming from.
- Yours, etc,
GAVIN TOBIN, Managing and Technical Director, Ethos Technology, Greenogue Business Park, Rathcoole, Co Dublin.