Insights / October 25th, 2016

Plan Before You Pump: Proposed Changes To The EPA Guidelines For The Environmental Management Of Dewatering During Construction Could Affect Your Site

The South Australian EPA has recently released for public consultation draft guidelines relating to the environmental management of dewatering during construction activities.

If the dewatering guidelines are issued without revision, it is easy to imagine that planning authorities will, in reliance on the guidelines, take a conservative approach in imposing conditions of development approval relating to dewatering.

This will add further layers to the development approval process for construction projects and has the potential to result in considerable cost increases and project delays for developers.

Submissions on the draft guidelines must be made by 31 October 2016. Not much time is left!

If you would like assistance with considering the guidelines or preparing a submission please contact one of our team.

What activities do the dewatering guidelines propose to cover?

The guidelines deal with the removal of water which accumulates in earthwork excavations or below ground structures as a result of intersecting aquifers, seepage of soil water/groundwater or stormwater events. The guidelines focus on dewatering in the course of construction activities. They do not apply to mining dewatering.

What are the EPA’s current powers to regulate dewatering?

Whilst the EPA has enforcement powers under the Environment Protection Act 1993 (EP Act) and Environment Protection (Water Quality Policy) 2015 (WQEPP) – including to enforce a person’s general environmental duty not to cause environmental harm in the course of undertaking an activity that might pollute waters – the EPA’s ability to regulate dewatering activities prior to those activities occurring is limited to:

  • making recommendations or issuing directions in circumstances where it has been referred a development application under the Development Act 1993 and Development Regulations 2008; and
  • licensing large earthworks drainage activities involving the discharge to marine or inland waters of wastewater containing suspended solids exceeding relevant thresholds under the EP Act.

Outside of these specific circumstances, the EPA’s ability to regulate dewatering during construction is limited.

What is the aim and effect of the proposed new dewatering guidelines?

The aim of the dewatering guidelines is to ensure that the potential for dewatering to occur as part of a construction project is considered and assessed upfront, and potentially prior to submission of a development application.

The guidelines are not clear on the process which the EPA is proposing. It appears that a two-pronged assessment process is contemplated:

  • a desktop risk assessment; and
  • a hydro-geotechnical assessment.

What is of particular concern is that the guidelines state that “…prior to any construction or dewatering activities, a desktop risk assessment should be carried out to highlight potential environmental risks” (our emphasis added).

If interpreted literally, the practical implication of this would be that every single project involving construction work could be required to undertake a desktop assessment as a prerequisite to, or as a condition of, obtaining development approval.

Further, it is unclear what triggers the need for a hydro-geotechnical assessment. Is the process of undertaking these two assessments intended to be staged or concurrent? The guidelines do not state that if a desktop risk assessment does not identify any potential for environmental harm to the environment, then a hydro-geotechnical assessment is not required.

In addition to the assessments described above, the guidelines place particular emphasis on the use of dewatering management plans (DMPs), forming part of or in addition to a Construction Environment Management Plan, as a tool for managing dewatering activities. It is also not clear what circumstances will trigger the need for a DMP. Given that DMPs will be expected to be prepared by a qualified hydrogeologist, there should be a risk-based mechanism for determining when a DMP may be required.

It is not yet clear if the intended reforms in this area will, in effect, amount to an informal EPA referral process, outside of the statutory referral process under the Development Act. Even if it does not have this outcome, the guidelines are still a means by which the EPA can influence the management of dewatering beyond its existing statutory powers.

Ensuring that the guidelines are clear will be instrumental to ensuring that development approval conditions relating to dewatering are proportionate to the level of risk presented by a proposed development. Otherwise, there could be unwarranted and potentially significant cost and delay implications for developers.