Concrete wastes

Please note that this section of the manual may contain out-of-date information. It has been retained to provide general information until a revised version is available. For further up-to-date information on this topic please contact the EPA.

AIM OF THIS DOCUMENT

This document has been prepared to guide councils, local sewerage authorities, architects, town planners, builders, developers, concrete pumpers and concrete delivery truck drivers towards a common code of practice for collecting, treating and disposing of concrete wastes. It also gives authorised officers some practical examples of the types of development consent and building approval conditions they may need to impose.

The overall aim is to minimise the impact on the environment caused by concrete wastes discharged from cleaning activites, pumps, truck agitator chutes, pipes and other equipment.

This is very much a 'living document' that will need to be changed from time to time as our technology and experience change.

DEFINITIONS

Developer

Includes the person or company doing the development or construction works on the site (that is, the builder) or some other legal entity such as the owner or the occupier of the site (or a combination of these).

Development consent

Means approval to develop under the Environmental Planning and Assessment Act 1979. Development includes such activities as building on the land, working on the land, using the land or building, or subdividing the land. Building approval is given under the Local Government Act 1993.

Concrete wastes

Includes concrete washings, concrete effluent, concrete delivered to a site but not used for the development and any other waste material containing concrete.

Concrete waste facility

Means a concrete waste collection, treatment and disposal facility that is designed to adjust pH and non-filtrable residues in concrete waste and complies with the design criterion given later in this guideline.

Large development

Means a development that uses a total of more than 200 cubic metres of concrete.

Small development

Means a development that uses a total of less than 200 cubic metres of concrete.

pH

pH is defined as -log₁₀ [H⁺], where H⁺ is the hydrogen ion concentration in moles per litre. A solution of pH 0 to 7 is acidic, pH 7 is neutral, and pH 7 to 14 is alkaline. (See Standard Methods for the Examination of Water and Wastewater published jointly by the American Public Health Association and the Water Pollution Control Federation.)

Non-filtrable residue (NFR)

The material retained on a standard, weighed glass fibre filter disc after filtration of a well mixed sample of wastewater. The residue is heated at a constant weight at 103 to 105ÂºC. The increase in weight of the filter paper represents the total non-filtrable residues. (See Standard Methods for the Examination of Water and Wastewater.)

GENERAL REQUIREMENTS

Regardless of the size of the development, the developer must make sure that concrete wastes are effectively collected, stored and treated. In the Building Application (BA) and/or the Development Application (DA), the applicant must indicate:

how the concrete wastes are going to be stored on- or off-site
how the concrete wastes will be collected from these storage points, and
where the wastes will be taken to and how they will be treated.

It would be feasible to include a condition stating that if waste is not stored and treated (on- or off-site) in accordance with the BA or DA, then the BA or DA will lapse.

Sometimes other ways of removing and treating concrete wastes may be appropriate. Such measures will have to be looked at carefully in terms of their likely impact on the environment. Developers must note details of these alternative measures in the BA or DA.

If concrete wastes will be both stored and treated on site, the developer will have to build a concrete waste facility on site. The details of this facility must be included in the BA or DA.

One method of treating concrete waste (particularly with larger developments and where an adequate area of land is available) is to irrigate or recycle the treated wastewater on-site. To irrigate treated wastewater the pH must be between 6.5 and 8.5. If the pH level is not between these levels, using the water may damage or kill the vegetation. Loss of vegetation could lead to soil erosion and possible pollution of the environment in the surrounding area. The wastewater must be applied to the irrigation area in a manner that stops surface runoff occurring.

REQUIREMENTS FOR LARGE DEVELOPMENTS

Obligations of the developer or architect

For large developments, the developer must make sure that a concrete waste facility is installed on the development site because a large volume of concrete waste is likely to be generated.

In the early planning stages the developer or the architect should decide where to put the facility for receiving concrete waste so it can be integrated into the development as it is being built. Treated wastewater from the concrete waste facility should be either transported to the local batching plant for treatment, or treated on-site. On-site treatment may include:

discharge to the sewer. The local sewerage authority may require the developer to apply for a trade waste agreement to discharge the treated wastewater to the sewer. The facility for treating the concrete waste must be designed to adjust the pH and remove non-filtrable residues to meet local sewerage authority standards.
if no sewer is available, irrigation or recycling on the development site. The developer should consult with the council before installing the concrete waste facility. Pollution Control Approval might be required for major developments, and the developer may also have to hold a licence from the EPA for any discharge to the environment.

The developer or architect should put enough detail in the development application and/or the building application to enable the council to satisfy itself that the treatment of concrete wastes from the development is acceptable. This information must include:

details of the estimated amount of concrete needed to complete the development
details of the estimated volume of wastewater to be generated
scaled drawings of the proposed location of the concrete waste facility
details of how the treated wastewater from the concrete waste facility is going to be disposed of or recycled,whether it is taken off-site to a local batching plant or treated on-site
details of the point of discharge to the sewer (if applicable)
details of how the wastewater is going to be irrigated or recycled (if applicable)
and
a report outlining how the concrete waste facility will effectively adjust pH and remove NFR.

Obligations of council

When it assesses the DA (if required), council should satisfy itself that the developer will install a concrete waste facility that will adequately collect, treat and dispose of concrete waste. Suggested conditions for councils to impose on development consents for large developments are listed later in this guideline.

When it assesses the BA, council should satisfy itself that the developer has scientifically demonstrated that the treatment facility will adjust pH and remove NFR. If the council is satisfied that the treatment facility will meet the local sewerage facility's standards, then relevant operating conditions should be attached to the BA (see later). (This suggested requirement may be appropriate only for councils that are also local sewerage authorities.)

The routine building inspections done by council officers should include inspecting the concrete waste facility. This is to ensure that the facility is being used in accordance with council's conditions of approval. (See later.)

Obligations of concrete pump operators and concrete agitator truck drivers

The concrete deliverer and the concrete pumper should at all times use the concrete waste disposal facility provided on-site.

The concrete agitator truck driver should return all concrete waste, including that from the agitator,to the local batching plant for treatment and re-use.

REQUIREMENTS FOR SMALL DEVELOPMENTS

Obligations of developers and architects

For this type of development there are various ways that can be used to collect, treat and dispose of concrete waste. The method chosen will depend upon the amount of concrete waste, the pumping requirements and the site area. Sometimes site restrictions will mean that a concrete waste facility will be needed regardless of the volume of concrete waste generated.

If the developer is not required to install an on-site concrete waste facility, he or she may store or dispose of the waste in either:

a disposable waste bin
a pit (if there is enough land on the site).

The waste bin

A waste bin installed in accordance with this guide must be leakproof, removable, have a lid, and be lined with a vapour barrier membrane. The vapour barrier membrane should be taped to the bin with pressure-sensitive tape. The tape ensures that the membrane does not collapse while concrete wastes are being loaded into the bin.

The waste bin should be placed on the development site. If it is placed on the footpath or part of a public road, the developer must get permission from the local council and make sure there is no discharge to waters.

Before lodging the BA, the developer must determine:

the amount of concrete needed to finish the development
the pumping requirements (in order to find out whether the concrete wastes can be re-used or recycled on the development site)
the number of bins and the amount of membrane required.

The developer should give this information to the local council with the DA (or BA if no DA is required).

Concrete waste stored in the waste bin must be either transported to a local batching plant for treatment and re-use, disposed of at an approved landfill, collected by a waste concrete recycler, or recycled on-site.

The pit

The volume of the pit must be 120 per cent of the estimated volume of concrete waste. The pit must be lined with a vapour membrane to ensure that concrete does not get into the ground. The pit must be covered while it is not being used to stop rainwater getting in. The edge of the pit must be raised to stop surface water runoff getting in.

The concrete waste stored in the pit must be either transported to a local batching plant, disposed of at an approved landfill or by a waste concrete recycler, or recycled on-site.

Regardless of whether a bin or a pit is to be used, when the developer submits the BA the applicant must determine the location of the local batching plant, approved landfill, or waste recycling plant.

Obligations of council

When council receives the BA it should determine whether the applicant's proposal to provide either a leakproof, lined, removable bin(s) with a lid, an excavated pit, recycling, off-site re-use at a local batching plant, or on-site re-use, is going to be an effective way to collect and treat concrete wastes. To do this council will need full knowledge of the proposal, the site, the pumping requirements and the amount of concrete to be used. Council should also be satisfied that the developer has provided for the removal of concrete wastes as needed.

Once council has determined the application it should attach the relevant operational conditions to the BA. Listed later in this document are some suggested conditions of development consents and BAs.

During their routine inspections the council officers should inspect the concrete waste facility or pit or bin or other facility approved for the collection, storage or treatment of concrete waste. This is to ensure that the facility is being operated in accordance with the approval conditions.

Obligations of concrete pump operators and concrete agitator truck drivers

Concrete agitator truck drivers and the concrete pumpers should at all times use the concrete waste facility or pit or bin or other facility approved for the collection, storage or treatment of concrete waste.

Before the concrete pumper starts the job, he or she should make sure that a concrete waste facility is available on the development site. If it is not, the concrete pumper should carry an appropriate container (such as the 210 L plastic container currently used by the Concrete Pumpers' Association) to hold all pump and equipment washout water and solids. The concrete pumper must make sure all the waste in the container is delivered to either a local batching plant, an approved landfill, or a waste concrete recycler (see later).

The concrete pumper should also carry a vapour barrier (minimum size 2 m x 4 m). This should be put on places like nature strips, lawns and gutters to collect solids and high pH wastewater that fall beneath the chute of the concrete agitator. These solids should be disposed of in the facilities provided on-site by the developer. Alternatively, the concrete waste should be put in the container provided by the concrete pumper.

The concrete agitator truck driver should return all the concrete waste (including that in the agitator) to the local batching plant.

GUIDE FOR LOCAL SEWERAGE AUTHORITIES

Below is an example of the types of standards and operational guides used by one sewerage authority for controlling effluent discharges to the sewer. This guide may not apply to other local sewerage authorities; developers and architects should contact their own local sewerage authorities for advice.

Sample development consent conditions for large developments

(1) The applicant must install on the development site a facility for collecting, treating and disposing of concrete wastes generated in the construction of the development (the 'concrete waste facility'). The installation of the concrete waste facility must comply with the Concrete Wastes guide (EPA, 1995).

(2) With the BA, the applicant must submit the following details relating to the concrete waste facility:

the estimated amount of concrete to be used to complete the development
details of the estimated volume of wastewater to be generated
how the concrete wastes are going to be collected, treated and disposed of
how the concrete waste facility is expected to perform in adjusting the pH and removing NFR
how the treated wastewater from the concrete waste facility is going to be disposed of, including how it is going to be transported to the local batching plant or to the point of discharge from the concrete waste facility to the sewer, or how it is going to be irrigated or recycled
scaled drawings of the location of the concrete waste facility
and
a technical report outlining how the concrete waste facility will effectively adjust pH and remove NFRs.

Sample building approval conditions for large developments

(2) If treated wastewater from the concrete waste facility is to be discharged to the sewer, the applicant must provide evidence to the council that he or she has approval from the local sewerage authority to dispose of the treated wastewater to the sewer, before any concrete is poured on-site.

(3) The treated wastewater from the concrete waste facility may be discharged to the sewer only in accordance with the requirements of the local sewerage authority.

Sample development consent conditions for small developments

(2) With the BA, the applicant must submit the following details relating to the collection, treatment and disposal of concrete wastes:

how much concrete will be needed to complete the development
how the concrete wastes are to be collected, treated and disposed of, including whether a waste bin or excavated pit will be provided on the site and whether the concrete wastes will be re-used or recycled on or off the site.

Sample building approval conditions for small developments

(1) The applicant must comply with the Concrete Wastes guide (EPA, 1995) in relation to the collection, storage and treatment of concrete wastes.

(2) Without limiting the generality of condition (1), before any concrete is poured the applicant must install on the site leakproof removable waste bin(s) with lid(s), lined with a vapour barrier membrane. The vapour barrier membrane must be joined with pressure-sensitive tape. The bins must be installed and operated in accordance with the guide.

(3) Without limiting the generality of condition (1), the applicant must install a pit excavated and sized according to the estimated volume of waste concrete. The pit must be lined with a vapour barrier membrane. The pit must be covered when not in use to stop rainwater getting into the pit. The pit must be installed and operated in accordance with the guide.

Note: For safety reasons, councils may consider it necessary to apply condition(s) relating to appropriate covers, fencing and signposting of pits or bins or concrete waste facilities.

Design requirements for collection, treatment and disposal facilities

(1) It is important that the facility is conveniently located for washing out equipment and also so that it can be integrated into the construction-site.

(2) The design aim of this facility is to reduce pH and remove NFRs effectively and in accordance with the requirements of the local sewerage authority.

(3) If a sewer is not available, treated concrete effluent may be either disposed of on-site, recycled as washdown water for concrete pumpers' equipment, or used to prepare mortar. Any recycled washdown water must not be discharged to the stormwater drainage system.

The collection and treatment facility and the method of disposal must be approved before they are installed and must have a licence to operate. The EPA's general requirements for the irrigation of treated concrete effluent are:

pH: not less that 6.5 and not greater than 8.5

NFR: not greater than 50 mg/L.

(4) Accompanying an application for approval should be a comprehensive report that demonstrates scientifically the method of treatment and disposal of concrete wastes.

CHECKLIST FOR COUNCIL OFFICERS

What is the quantity of concrete wastes?
What are the pumping requirements?
What are the site conditions?
Will the whole site be developed?
Is the quantity of concrete wastes such that a concrete waste facility is required?
Are the pumping requirements such that a concrete waste facility is required for concrete wastes?
If not, are leakproof bins appropriate?
Is a pit appropriate?
Can bins and a pit be used together?
If a collection treatment disposal facility is proposed, has the developer or architect provided enough details of the proposal? Will it remove NFR and adjust pH according to local authority standards?
Is the sewer available?
Is EPA approval required?
Does the applicant have a trade waste agreement with the local sewerage authority?
Can the treated concrete wastes be recycled or re-used off-site, for example, at a local batching plant?
Can the treated concrete wastes be recycled or re-used on-site?

SUMMARY

Concrete waste from both large and small developments can contribute to environmental pollution and erosion.

Authorised officers should be aware of the recommended methods of collecting, storing and disposing of concrete wastes on and off site. They can then encourage developers to use these methods by making them conditions of the development consent.

FURTHER INFORMATION

If you need to know more about EPA policy on dealing with concrete wastes, contact your local office of the EPA. Offices are listed in the front of this manual.

In this manual:

Effluent Re-use by Irrigation.

IMPORTANT NOTE

The EPA has prepared this document for the manual in good faith, exercising all due care and attention. No representation or warranty, expressed or implied, is made as to the accuracy, completeness or fitness for purpose of this document in respect of any user's circumstances. Users of this document should carry out their own investigations and where necessary seek appropriate expert advice in relation to their situations. This document should be read in conjunction with other documents in this manual, and any other legislation and/or policies within which authorised officers operate; for example, Local Government officers should also refer to such legislation as the Environmental Planning & Assessment Act 1979, the Local Government Act 1993 and Occupational Health & Safety legislation, as well as specific Occupational Health & Safety policies developed by Local Government for its employees.

Updated 14 July 2021