UPSS Groundwater monitoring bores at sensitive sites
sourced form www.epa.vic.gov.au 14/11/2013
Owners/occupiers of UPSSs need to take all practicable measures to achieve the nominated level of performance for leak detection set out in section 4.
At sensitive sites30 (for both new and existing UPSS) it is also practicable and therefore necessary to install groundwater monitoring bores as an additional precaution.
For existing UPSSs at sensitive sites, groundwater monitoring bores should be installed within two years of the date of publication of these guidelines.
For new UPSSs at sensitive sites groundwater monitoring bores need to be installed and developed before operation of the UPSS.
The number of groundwater monitoring bores installed needs to be sufficient to reasonably detect a leak from the UPSS (including all associated pipe work), as well as determine the local groundwater flow direction.
Prior to installation of a groundwater monitoring bore, a licence is required to construct works in accordance with section 67 of the Water Act 1989 (Vic). If specified as a condition of the licence issued under section 67, the work must be carried out by, or under the direction of, a licensed driller, in accordance with section 316 of the Water Act 1989.
The method of design, construction and installation (including drilling method) of groundwater monitoring bores, and the location of sampling points, can affect the ability to collect a representative groundwater quality sample. It is important that a competent and experienced hydrogeologist assesses the site to determine the number and location of groundwater monitoring bores required.
The design, construction and installation of groundwater monitoring bores should be carried out in accordance with:
- ARMCANZ (1997) Minimum construction requirements for water bores in Australia
- the relevant sections of EPA publication 669, Groundwater sampling guidelines.
Groundwater quality monitoring at a sensitive site should include monthly observation for separate phase hydrocarbons.
Where the occupier has reason to suspect significant groundwater contamination, sampling and analysis for dissolved contaminants should be undertaken31.
Any sampling needs to be carried out in accordance with EPA publication 669, Groundwater Sampling Guidelines.
Where groundwater monitoring indicates the presence of hydrocarbons in groundwater, occupiers need to follow the leak and spill response procedures outlined in section 5.