Erosion Control Techniques: Construction & Operational Sites

  • Long-Term Dust Solution for Tailings Storage Facility in Orange, NSW

    Erizon's Low Bearing Capacity HydroRig towed by a tracked tractor applying FibreLoc onto the delicate surface of the tailings storage facility in Orange, NSW

    In early 2020, Erizon won a major contract to develop a dust management solution for a 700ha tailings storage facility (TSF) at Australia’s largest gold mine, located in Orange, NSW. Erizon carefully tailored an innovative, new solution resulting from multiple scientific trials and testing of our own accord.

  • EcoArmour In Action on Railway Cuttings

    When a V/Line railway cutting in Merbein, Victoria fell into disrepair, Erizon were called out to undertake a site visit […]

Erosion Control Techniques for Construction and Operational Sites

Soils are routinely disturbed by water, wind, ice, and gravity. These erosive procedures take away soil particles from A horizons (the uppermost soil layer) and expose subsurface horizons, resulting in significant soil losses. These losses can wreak havoc on agriculture and forestry. In addition, soil losses cause substantial economic consequences by impacting aquatic and marine flora and fauna and man-made structures (such as buildings, bridges, culverts etc.).

All of this can lead to significant issues on construction and operational sites, so let’s discuss some source control techniques that can be employed to minimise this erosion.

Raindrop Protection

Erosion is dependent on the likelihood and intensity of predicted/expected rainfall. Site activities should be managed while being cognisant of predicted rainfall. The twenty-eight day and five-day rainfall forecasts must be monitored regularly (minimum of once a week). Erosion control measures that we’ll outline here should be deployed to reduce the likelihood of soil erosion occurring on-site and to protect any exposed areas from raindrop impact erosion if there is a greater than 50% chance of rainfall equal to or greater than 10 mm.

Disturbance Minimisation

Where practicable, the soil erosion hazard on the site should be kept as low as possible. Clearly visible barrier fencing should be installed to assist traffic control and prohibit unnecessary site disturbance while also clearly defining limits of any “No-Go” zones. Vehicular access to the site should be limited to relevant people who should enter the site through access points stabilised through gravel or heavy mulching.

Existing vegetation strips should be maintained to minimise soil disturbance. Erosion control on the embankment crests, downstream batters and any other exposed areas should be provided by utilising effective polymer-based, spray-on erosion control emulsion (much like Erizon’s EcoArmour), which forms a durable crust, provides protection for up to six months, is non-toxic, is suitable for all types of stockpiles, withstands heavy rainfall events and is cost-effective.

No-go Zones

Any areas outside of the work limits should be designated as “No Go” zones to minimise or prevent access by personnel or vehicles. Temporary fencing or barricading such as Para webbing or barrier tape is to be utilised on the cleared perimeter with accompanying signage. Site inductions and toolbox meetings should include the importance of observing “No Go” zones, particularly in areas near to any identified sensitive area.

Stabilisation

Short-term protection of areas such as stockpiles and other disturbed surfaces should be provided by utilising effective erosion control emulsions (such as Erizon’s SuppressX) to decrease pollutant loading on end-of-line sediment control measures. All temporary earth banks, flow diversion systems, and embankments where runoff should flow uncontrolled off site are to be stabilised with rock/gravel over geo-textile, or vegetation. A success criterion for ground cover is a minimum of 75% cover.

Erosion prevention

Site activities should be undertaken in a manner that minimises erosion from the site, including waterborne, wind-blown, and traffic-generated particulate matter. All activities on the site should be undertaken with the objective of preventing visible emissions of dust from the site. Water carts and/or erosion control emulsions should be used as appropriate to minimise dust emissions. Where dust emissions are visible, site activities should be temporarily stopped and re-assessed to minimise those emissions. Where required, dust screens should be constructed to minimise dust emissions.

Access Track Management

Site access tracks can be a major contributor to the overall sediment and pollutant loads and therefore, require careful management. To minimise sediment contribution from access tracks, polymer-based heavy-duty erosion control emulsion (such as Erizon’s RoadBond) should be applied. Polymer-based emulsion enables the creation of a trafficable layer on the surface of the access track and can provide protection for up to six months. It also improves road stability, reduces tyre wear and is cost-effective.

Stockpile Management

Stockpiles on sites should be located in elevated areas to minimise the risk of inundation. In addition, all stockpiles should ideally:

  • Be separated into soil and use types
  • Be located further than 40 meters from drainage pathways
  • Be located at least one metre away from site boundary fencing
  • Not be located against the base of significant trees
  • Be protected through effective spray-on erosion control emulsions as required to minimise erosion and dust emissions

Erosion and Sediment Control Training for Site Personnel

Preferably, site operators should consider several training methods, including an on-site, site-specific ESC (Erosion & Sediment Control) induction workshop. The workshop should be conducted by an appropriately qualified professional (such as a CPESC, or Certified Professional in Erosion & Sediment Control).

Toolbox meetings should also be conducted regularly (at least fortnightly), to address any issues related to operations, safety, environment and more. All issues relevant to the land disturbance activity are to be highlighted during these meetings, in order to ensure that all staff on-site are aware of changes or restrictions.

TOP