Action item 7.11
Progress
Complete.
Approved by decision makers.
Recommendation implemented.
That prior to the grant of any further exploration approvals, in order to minimise the risk of groundwater contamination from leaky gas wells:
- all wells subject to hydraulic fracturing must be constructed to at least Category 9 (or equivalent) and tested to ensure well integrity before and after hydraulic fracturing, with the integrity test results certified by the regulator and publicly disclosed online;
- a minimum offset distance of at least 1km between water supply bores and well pads must be adopted unless site-specific information of the kind described in Recommendation 7.8 is available to the contrary;
- where a well is hydraulically fractured, monitoring of groundwater be undertaken around each well pad to detect any groundwater contamination using multilevel observation bores to ensure full coverage of the horizon, of any aquifer(s) containing water of sufficient quality to be of value for environmental or consumptive use;
- all existing well pads are to be equipped with multilevel observation bores (as above);
- as a minimum, electrical conductivity data from each level of the monitor bore array should be measured and results electronically transmitted from the well pad site to the regulator as soon as they are available. The utility of continuous monitoring for other parameters should be reviewed every five years or as soon as advances in monitoring technology become commercially available; and
- other water quality indicators, as determined by the regulator, should be measured quarterly, with the results publicly disclosed online as soon as reasonably practical from the date of sampling. This monitoring regime should continue for three years and be reviewed for suitability by the regulator.
Completed.
Action item update
Implementation
The Northern Territory Government worked with independent scientific experts to develop the Code of Practice for Onshore Petroleum Activities in the Northern Territory (the Code) to implement Inquiry recommendation. The Code is legally enforceable because compliance with the Code is a statutory requirement on a petroleum title (see s 58(ab) of the Petroleum Act 1984). Further, the Petroleum (Environment) Regulations 2016 require that all environment management plans must demonstrate compliance with the Code. The finalised Code was published on 12 June 2019 and is on the DEPWS website.
The Code requires proponents to comply with the Preliminary Guideline for groundwater monitoring bores for exploration petroleum wells in the Beetaloo Sub-basin. The Guideline stablishes monitoring requirements to address the risk of groundwater contamination from leaky wells. It was finalised on 29 November 2018 and is available on the DEPWS website.
The Guideline does not require 3 sensors to be placed in the top, middle and bottom of a monitoring bore. Evidence to date has indicated that sensors are subject to fouling, which makes the electrical conductivity results from the bore unreliable. This is why the Guideline requires other mechanisms to be in place (for example laboratory testing of in-field samples and pressure testing) to ensure signs of a leaky well are detected early.
The Guideline requires the monitoring bore to be screened (i.e. perforated) to ensure that water from the top, middle and bottom of the aquifer can enter the bore for sampling.
A regulatory statement on electrical conductivity has been published on the DEPWS website outlining difficulties associated with use of sensors and other measures used to rapidly detect contamination of aquifers.
Department of Environment, Parks and Water Security (DEPWS) will facilitate an independent review of the Guideline in late 2022. The outcomes of the review will be included in the publically available Code to ensure all mandatory requirements for groundwater monitoring are in one easy-to-find document. As part of this review, an independent expert will consider the most appropriate early warning monitoring system for the Territory context, taking into account Recommendation 7.11 and experience to date.
DEPWS publishes information from water monitoring bores as soon as the data is made available by industry. The data is not currently electronically transmitted from the well pad site to the regulator.