Everything you need to know about wash bays

Cleanawater on 20 August 2021

What is a wash bay?

A wash bay is a structure designed to wash cars, heavy vehicles, containers, or equipment. It can be permanent or temporary, small or large, covered or uncovered. However every wash bay must contain the used water for treatment before discharging it to a sewer network. This requirement is set by regulators and enforced by local councils.

Most wash bays use degreasers and detergents to remove stubborn dirt or oil from vehicles and equipment. Unfortunately these products also have some negative properties. They form an emulsion with oil, making it difficult to remove the oil from the wastewater before it discharges to a sewer. Quick break detergents overcome this challenge by releasing oil from the emulsion rapidly.

Guidelines and regulations for wash bays

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Regulations applying to wash bays have the primary focus of protecting the environment from contaminated water. This could include oil, chemicals or disease causing bacteria. The most stringent regulations cover the quarantine of imported goods.

The regulations cover items such as whether a wash bay should be roofed or not, what type of water treatment should be applied and what the specific limits are for wastewater quality. Local water authorities enter into trade waste agreements with each wash bay operator before accepting their wastewater into the sewer network. They require wash bay operators to have effective risk management systems in place, to keep records of the wastewater quality and to comply with their trade waste agreement. Failure to do so could result in fines or even shutdown of the facility.

Different areas in Australia have slightly different requirements for wastewater quality. This is due to differing capacity and technology in their water treatment plants. It is important to verify the exact requirement of your local authority when installing a new wash bay. All these criteria will form part of the trade waste agreement and could prevent a wash bay from coming online if the conditions are not met.

Types of wash bays

There are several types wash bay, and choosing the best solution depends on the application. Some specialised applications require specific features for compliance, like the quarantine wash bay, but other applications are more flexible. The following list gives an indication of different types of wash bay and their uses.

Portable wash bays

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Portable wash bays do not require any excavation or site modification. They can easily be moved from one location to another and are ideally suited to a business on rented premises or one which will soon outgrow its current location.

Permanent wash bays

Permanent wash bays provide all-encompassing and permanent solutions for washing vehicles or equipment. These units are built into the property through civil construction and are best suited to stable businesses with a long term presence on their site. Permanent wash bays are custom designed and engineered for the site.

Car wash wash bays

Car wash bays are designed for commercial car washes that provide an environmentally friendly way to clean vehicles. These businesses are required by law to treat wastewater before discharging due to the potential of oil and other contaminants. Many cash wash bays integrate with other environmentally focussed solutions like wastewater recycling and rainwater harvesting.

Construction wash bays

Construction equipment gets caked in dirt during normal operation. However, this dirt has the potential to get into moving parts causing damage and wear. Regular washing of construction equipment and heavy vehicle is an essential part of any construction site or mine. Wastewater from construction wash bays could contain chemicals, oils and greases and a large amount of silt. Portable wash bays are often used for these applications due to the temporary nature of a construction site and the need to move from one area to another.

Truck wash bays

Truck wash bays are normally large structures with a heavy duty construction to handle the weight of large trucks with several axles. These wash bays must have the capacity for high water use, silt collection and wastewater processing.

Heavy equipment wash bays

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Heavy equipment wash bays are designed for industrial or mining applications using heavy vehicles and equipment. Critical features of these wash bays are their design and construction for heavy loads. Even access covers must be re-enforced to prevent water pits from cracking and leaking untreated wastewater into the ground.

Another feature of heavy equipment wash bays for mines is the high volume of water handling. Wastewater sewers may not have the capacity for this injection of water, in which case the mine may have settling ponds to store the water and spread out the flow to the sewer.

Quarantine wash bays

Quarantine wash bays must comply with Australian Quarantine Inspection Services (AQIS) standards. They are used in import/export yards, container handling depots, docks and shipping facilities and other similar applications. The requirements for quarantine wash bays are more stringent than other models and may include the use of filters to capture any contaminants from the wastewater.

Any wash bay associated with imported plant or animal products must also meet the biological criteria of AQIS. These requirements are aimed at preventing alien species from entering the Australian ecosystem.

Choosing the right wash bay

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Any business washing vehicles and equipment produces wastewater and therefore requires a wash bay to comply with regulations. Allowing this wastewater to enter the stormwater system or to discharge directly to the environment is not lawful. However, there are several types of wash bay available.

Some helpful factors to bear in mind when choosing a wash bay are:

  • Portable wash bays are for temporary or moveable applications while permanent wash bays are for long term installation.
  • Wash bays for heavy vehicles and equipment must have a heavy duty construction.
  • Water recycling options and rainwater harvesting can be applied to a variety of different wash bays.
  • Larger wash bays require a roof or a first flush diversion system. This helps to prevent a large volume of clean water from entering the wastewater sewer network during a rainstorm.

How do you build a wash bay?

Wash bays have several key features for compliance with regulations and effective management of wastewater. The base of a wash bay prevents wastewater from seeping into the ground. Water must be collected in a collection pit or troughs built into the structure. Silt traps prevent the build up of solids in the wastewater and treatment solutions like oil water separators remove contaminants. Larger wash bays require a roof or rain water diversion system to prevent excess rainwater from overloading downstream water treatment plants.

When building a new wash bay, it is advisable to work with an experienced partner who understands the industry and the regulations. They can help you navigate decisions about whether to install a temporary or permanent structure, the trade waste licence application as well as wastewater treatment options.

Well known applications like car washes could use an off the shelf solution. But other applications may require some customisation. A typical project will include defining the wash bay specifications by reviewing the current and medium term needs of the business. It is important to identify what contaminants may be present as this will dictate the wastewater treatment requirements. Once the specifications are defined, a wash bay can be designed and built by a professional contractor.

How much does it cost to build a wash bay?

Wash bay prices range from $5,000 to $175,000 depending on the application, size and specific requirements. In general, portable wash bays are cheaper to build than permanent structure. Roofed wash bays cost more than unroofed, but they offer the potential for rainwater harvesting. Each extra component, like rainwater harvesting, wastewater recycling, or AQIS requirements, adds to the cost of a wash bay.

While installing a wash bay is a significant investment, the consequences of not complying with regulations are even more severe. Fines and enforced shutdowns can cost a business far in excess of the price of a compliant wash bay.

Wash bay problems and solutions

Some of the main problems associate with wash bays come from misunderstanding the regulations and the impact of wastewater on the environment. Expert wash bay builders and suppliers can help you navigate your wash bay installation and avoid these pitfalls. For example, even after silt and oil removal, wastewater is not as clean as stormwater. It may not be discharged into the environment or the stormwater sewer.

Wash bay design should take into account future growth. Taking the lowest cost solution up front is sometimes costly in the longterm due to modifications needed for expansion. Sizing a wash bay correctly is a critical step to avoid problems later.

Wash bay operation also has some challenges. Degreasers and detergents cause oil to form an emulsion which will not separate from wastewater in an oil water separator. This will result in wastewater discharge that does not comply with the regulatory limits. Only quick break detergents and degreasers should be used to avoid this operational problem.

Wash bay servicing and maintenance

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Routine servicing and maintenance tasks can keep a wash bay working smoothly. Even more important, these tasks help to ensure the wastewater management system remains effective to remove contaminants. Common tasks include:

  • Removing solids from the silt trap prevents particles from overflowing into the downstream wastewater treatment systems.
  • Disposing of oil and sludge from the oil water separator regularly, which keeps the separator working effectively.

Other regular checks could include looking for leaks in the wash bay floor, checking the operation of the first flush diversion system and servicing oil water separators. All these tasks are critical to maintain the compliance of your wash bay.

Wash bay benefits

The primary benefit of a wash bay is its compliance to regulations and its protection of the environment. These benefits allow businesses to focus on their core activities with a sense of confidence that they have fulfilled their duty of care under the law. This means that they have taken all reasonable and practical steps to avoid causing environmental harm.

There are also several practical benefits of wash bays. A well-designed wash bay meets the needs of a business by making it easy to wash vehicles or equipment. Water supply points deliver high pressure water all around the vehicle and detergent is applied automatically. The quality of cleaning from a well-designed wash bay is far superior to a manual operation which is inadequate in design and equipment.

Talk to Cleanawater for expert wash bay advice

Contact Cleanawater for expert advice about your wash bay application. We have more than 20 years experience in the Australian market with experts than advise you each step of the way. Cleanawater offers off the shelf wash bays, custom designs, and service and maintenance contracts.

Contact Cleanawater to find out more about our wash bay solutions.