State Government of Victoria

Environment Protection Authority

Business, industry and planning guidance

Drilling mud classification


Drilling mud classification in more detail + Expand all Collapse all

  • Documented assessment (Clause 5.1)

    The documented assessment needs to be a clear record of research and observation for the site where the drilling mud will be produced.

    Producers must provide a copy of the documented assessment to the waste receiver.

    All Producers and waste receivers must keep a copy of the documented assessment for two years.

    At a minimum it will include the following:

    • Investigation of past and current use of the site – was the site previously an industrial facility, drycleaner, service station etc? What materials were handled there?
    • Investigation of past and current use of surrounding sites – as above
    • Observations indicating contamination – for example, hydrocarbon or chemical odours, oil sheen on surface waters or soil discolouration.

    A useful reference to assess the risk from site use is the Planning practice note: Potentially contaminated land (PDF 74KB, Department of Transport, Planning and Local Infrastructure)

    Sites with potential acid sulfate soils must be managed as per the Industrial Waste Management Policy (Waste Acid Sulfate Soil) (publication S125)

    The documented assessment does not need to be completed by an environmental auditor or consultant. However, where potential soil contamination is identified you may need to engage an environmental auditor or consultant for further investigation or to help manage your site.

    If the documented assessment indicates potential site contamination, test results must be attached to confirm there is no contamination in accordance with Soil hazard categorisation and management (publication IWRG 621).
  • Appropriate transport (Clauses 5.4 and 5.5)

    Transport must be safe, secure and leak-free. To meet this requirement please refer to Vehicle guidance: Tanker/tanker trailer (publication IWRG 816)

    In addition, tankers should be clean and not contain PIW residues. Waste transporters should develop and use up-to-date procedures to ensure drilling mud is not contaminated with tanker PIW residues.
  • Records (Clause 5.6)

    Records must include:

    • name and address of waste producer
    • location from which waste was received
    • transport date, quantity and vehicle registration
    • date and quantity received.

    Records must be kept for a minimum of two years.

    Receivers of drilling mud should obtain this information from the producer and/or transporter.
  • Dewatering options (Clauses 5.8 and 5.9)

    Natural dewatering or air drying is only acceptable when you are confident that drilling mud comes from an uncontaminated site and is free from industrial contamination such as bricks and concrete.

    Natural or airdrying site Dewatering facilities
    Use only for drilling mud that meets the classification and when the documented assessment indicates no industrial waste or PIW contamination. Use is appropriate for managing drilling mud contaminated with industrial waste (bricks, concrete etc). However, the drilling mud must meet the classification requirements above, including having a documented low risk of PIW contamination.
    Site must ensure the protection of surface, groundwater and land through appropriate siting and management, such as construction of a barrier or bunding.
    Placement of the drilling mud on site should allow evaporation of liquid and prevent liquid and mud from leaving the site or entering waterways, stormwater systems or groundwater.    		 Site must have bunding per Bunding guidelines (publication 347) and management processes.
    Liquid generated must be directed to a wastewater treatment plant or managed in accordance with Industrial water reuse (publication IWRG632)

    Regardless of the type of dewatering option the site must meet all requirements under the Act, and any relevant state environment protection policies (SEPPs) including, for example, SEPPs for water, groundwater and land.
  • Spill management plan (Clause 5.10)

    Printed copies of your site-specific spill management plan must be kept on hand for quick reference during an incident. You must be able to provide the spill management plan to EPA on request.

    In addition, EPA must be immediately notified of any incident or spill that is likely to have an offsite impact.
  • Testing requirements (Clauses 5.1, 5.8 and 5.9)

    The table below summarises when testing is required, how it must be conducted, and what it means. Results must be kept for two years.

    When testing is required Testing requirements and management Consequence
    Soil testing at the drilling site

    Before drilling where:

    • the site has potential contamination
    • the drilling mud will be transported off site for dewatering.

    Manage as per Soil hazard categorisation and management (publication IWRG621).

    You should engage a consultant to help investigate contamination of the site.

    		 Testing must meet fill material criteria; otherwise, the drilling mud is category A PIW and the classification does not apply.
    Drilling mud dryness testing Before drilling mud residues are transported off the dewatering site. Test as per method 9095B Paint filter liquid test (US EPA 2004) Drilling mud that does not meet the test requires further dewatering.
    Residual soil testing Before any solid drilling mud residues are transported off the dewatering site.

    Sample soil as per Soil sampling (publication IWRG702).

    Manage soil as per Soil hazard categorisation and management (publication IWRG621).

    		 Test results will inform the appropriate disposal and reuse options for the soil.
    Liquids from drilling and mud testing Before determining water reuse options – required for all liquids from drilling mud not sent to a wastewater treatment plant. Manage liquid as per Industrial water reuse (publication IWRG632). Test results will inform the appropriate reuse or disposal options for the liquid.

Page last updated on 31 Jul 2020