Prior to commencement of works, Contractors are required to prepare a Construction Environmental Management Plan (CEMP) detailing the environmental control measures required to mitigate environmental impacts during the construction stage of the project.

The CEMP is just a plan, but implementation of the plan is the most important aspect of any environmental management on construction projects. This aspect is where the majority of contractors fail.

The focus of implementing the plan is to prevent adverse environmental impacts rather than controlling, treating or remediating as a result of a harmful incident.

Construction sites are constantly changing and systems must be in place to review and modify control measures to maintain their effectiveness. Therefore, frequent inspection, verification, monitoring and auditing are required to maintain and improve the effectiveness of on-site environmental management plans.

In a typical construction project the following tasks are required for a sound environmental practices to safeguard the potential impacts to the environment during the construction stage:

Before project starts

The 1^st step is to prepare an Environmental Management Plan (EMP); the plan must be a site specific based on the environmental impact assessment  (EIA) or the Review of Environmental Factors (REF) for the development of the site.  Other factors to consider for the development of the EMP are the conditions of approval, any licenses/permits required and applicable environmental legislation.

The 2^nd step is to induct the project delivery team on the requirements of the EMP and the responsibilities of team players at each stage of the project. Any additional environmental training required for the team must be planned and provided in a timely manner.

During works

During the delivery of the works the requirements of the EMP must be implemented and regularly monitored; the following tasks are required during construction:

• Install Erosion and sedimentation controls (ESC) on the site.
• Conduct regular inspections and after heavy rain to the ESC to ascertain they are working effectively.
• Implement any other environmental safeguards required by the EMP, such as:

• Conduct regular workplace environmental inspections to monitor the effectiveness of environmental safeguards
• Other important factor on each construction project is the management of waste; which requires the establishment of waste register to capture waste generated, recyclable waste and waste disposal to approved disposal site, some types of waste may also require tracking.
• If disposing waste on private land, an approval is required from the owner and in some instances an approval from local council is also required.

• During works any environmental incident requires be notified to client or the Environmental Protection Authority (EPA). The EPA will be notified of pollution incidents on or around the site, which have occurred in the course of the works, only on certain circumstances defined on State Government legislation.
• A register to capture members of the public complaints must be established, complaints may be because of dust, noise, driveway access; complaint should be addressed immediately.

• If applying herbicides or pesticides an Application record must be completed and kept on project records.

On completion of the project

All disturbed areas must be restored to a standard at least similar to their original condition or landscaped according to contract requirements.

If you’ve got questions about anything in this article or anything related to Ensafe or the construction industry, you can contact us via phone or email or leave your question in the comments below.

Introduction

The construction industry is one of the major waste producers in Australia. The construction waste is generally defined as waste emanating from construction, demolition and renovation activities.

Similarly, it may include surplus or damaged products and materials and concrete waste water resulting from construction work. The traditional disposal method of construction waste was landfill.

Now, due to stringent waste disposal laws and dwindling number of landfills available in the country, the construction companies are forced to explore alternative ways of managing construction waste.

In essence, prudent and proper management of waste streams have been the priority. Thus, many construction contractors are looking for various practices and ways to reduce construction waste such as “concrete waste water” at the source itself.

This article is only looking at how to manage concrete waste water during construction.

Why is it important to Manage Concrete Waste Water?

• Concrete waste water or fresh concrete or cement based mortar are highly toxic to marine and plant life.
• Concrete waste water is highly alkaline and has very high pH value around 12. Due to high alkalinity it can burn fish and plants in natural streams. A small quantity of concrete waste water cans hundreds of aquatic life including plants.
• Australian Water Quality Guidelines recommend that fresh water pH should not be kept between 6.5 and 9.0. Any changes beyond 0.5pH value either from lower or upper limit should be probed.
• Higher penalties (>Aus$1500) are imposed on pollution from concrete construction.

Site Preparation

The management should ensure that all construction workers are fully aware of the compliance requirements and procedures under Environmental Management System/Plan including waste disposal methods available.

Provide Separate Wash-down Area

• Make it compulsory that all concrete mixer trucks should return to Ready Mix Plant (RMP) premises for washing.
• Ensure that the concrete wash area (at RMP) is located at least 20m from storm water drains, pits and inlets.
• Remove or scrape concrete from the equipment and trucks before washing.
• It is essential that the washing area is fully secured with plastic lining to capture cement slurry run-offs. Alternatively, provide temporary lined pits or removable containers.

Waste Water Management and Disposal Procedures

• Regular inspections and controls should be carried out to check whether correct procedures (as per the Environmental Management Plan) are adhered during construction. If any equipment or mixer has the vulnerability to leakages, those must be repaired or replaced immediately.
• Concrete waste water emanating from the wash-down areas must be carefully transported to RMP for either treatment or disposal at an authorised landfill or recycled.
• Prevent any spills during truck mixers transfer of concrete to concrete pumps for placement. Use suitable plastic sheets to capture any concrete spills on to bare soils. Dispose the collected spills (as described before) once the trucks leave the site.
• When cleaning the concrete pump lines, always ensure that the concrete will not splatter at the end of the pump line.

In the absence of Designated Wash-down Areas

Use drums (with sufficient capacity) to collect concrete waste water or slurry run-off. Similarly, use suction pumps or wet industrial vacuum cleaners to filter the concrete waste run-off.

Recycle the filtered water whenever possible. If it is not practical, dispose the waste water using approved disposal method.

Concrete Saw Cutting

• Ensure dust and sediment controls are introduced. For example, sandbags or sponges should be placed around storm water drains or collection pits or manholes to prevent toxic concrete waste water entering into storm-water drains.
• Divert concrete slurry or concrete waste water run-off into a pool located close to the working area as appropriate.
• Immediately remove any concrete dust or residue from the work area including wash-down area. It’s better to use appropriate tools and equipment such as shovels, sweepers and vacuum systems.
• Warning: You should avoid hosing any residue into the storm-water drain
• Use very little water when wet cutting of concrete
• Always try to locate cutting equipment away from storm water drains. Also, the work area must be adequately big enough to control concrete waste water or slurry or residues.

If you’ve got questions about anything in this article or anything related to Ensafe or the construction industry, you can contact us via phone or email or leave your question in the comments below.