Environmental Engineering

Everything Environmental (CPESC, ADD MORE)

Explain RUSLE?

Revised Universal Soil Loss Equation

A = R × K × L S × C × P

Where:

A: Average annual soil loss (tons per acre per year)

R: Rainfall erosivity factor, which reflects the amount and intensity of rainfall. This factor varies by location and is crucial for understanding potential erosion risk.

K: Soil erodibility factor, which indicates how susceptible a particular soil type is to erosion. This factor is influenced by soil texture, structure, and organic matter content.

LS: Slope length and steepness factor, which accounts for the effect of topography on erosion. It is determined by measuring the length and steepness of the slope.

C: Cover management factor, which represents the effect of vegetation and land cover on soil erosion. Different crops and land management practices can significantly alter this factor.

P: Support practice factor, which accounts for the effects of practices like contour farming or terracing that help reduce soil erosion.

Is there a Notification form required to be submitted to the Queensland Government whenever there is planning to clear vegatation under the "‘Clearing for infrastructure accepted development code”? If so, what Act enforces this law? What is also required?

Yes.

Vegetation Management Act 1999

A Property Report is also required

What is the contact number required to call for Vegetation Property Reports to the DoR?

135 VEG

135 834

Explain a Type A, Type B, Type C and Type D Basin

Type A: Continuous Flow

Type B: Continuous Flow

Type C:

Type D: Batch Type Basins

Characteristics of a Type A Basin? (IECA)

1. Clayey Soils - Type A basins are considered the most effective sediment traps for clayey soils.

2. Pond size - Pond size is governed by both minimum volume and minimum surface area requirements.

3. Automatic Chemical Dosing - Operation of the sediment basin relies on the installation of an automatic chemical dosing system.

4. Floating Decant System - A floating decant system collects water from the top of the water column during the storm event.

5. Dewatering - In most circumstances, the settling pond is required to be de-watered to the nominated static level prior to a rain event that is likely to produce runoff.

6. 63% AEP - Temporary basins are typically sized for the 1 EY (63% AEP), 24-hour storm event.

Characteristics of a Type B Basin?

• Pond size is primarily governed by a minimum required surface area.

• These basins are typically larger in volume and surface area than Type A basins.

• Operation of the sediment basin relies on the installation of an automatic chemical dosing system.

• Ideally the settling pond should be de-watered prior to a rain event that is likely to produce runoff; however, during dry conditions water may be retained in the pond as a source of water for usage on the construction site.

• Temporary basins are typically sized for a discharge of 0.5 times the peak 1 EY (63% AEP) critical duration storm.

Characteristics of a Type C Basin? (IECA)

• Type C basins are limited to works within non-dispersive, low-clay, sandy soils.

• Pond size is governed by a minimum required surface area.

• These basins are free-draining, which means they are normally ‘empty’ at the start of rainfall; however, under certain conditions water may be retained in the pond as supply a source of water for usage on the site.

• Temporary basins are typically sized for a discharge of 0.5 times the peak 1 EY (63% AEP) critical duration storm.

Characteristics of a Type D Basin? (IECA)

• Pond size is governed by a minimum required volume.

• Operation of the sediment basin normally relies on chemical dosing, using either an automatic or manual chemical dosing system.

• The settling pond is required to be de-watered to the bottom of the settling zone prior to a rain event that is likely to produce runoff.

• Temporary basins are typically sized for an 80%ile, 5-day rainfall depth, depending on catchment conditions and risk.

What is the C-factor in Sediment and Erosion Control?

It is the ground cover factor. This stems from the RUSLE calculation.

Maximum of 0.10 Groundcover for stockpiles after 10 working days

How do you calculate the Tree Protection Zone?

Diameter at Breadth Height (DBH) x 12

What are the documents that are to be used to refer to when developing an ESCP/CPESC?

International Erosion Control Association (Australasia) (IECA) Best Practice Erosion and Sediment Control

TSS? (IECA)

Total Suspended Soils