Natural Grass vs Synthetic Turf Decision Making Guide

A decision making guide when determining whether to use natural grass or synthetic turf.

The use of synthetic turf playing surfaces is becoming more widespread in Australia and Internationally.

An organisation’s (sport club, association, local or state government) decision whether to have a natural grass or synthetic turf sports ground comes down to their specific objectives for environmental, social, health and financial outcomes.

The purpose of this decision making guide (the guide) is to help organisations make an informed choice on surface type - natural grass v synthetic turf for sports grounds specifically football, cricket, lawn bowls, hockey, soccer, rugby, tennis, and other relevant multi-purpose facilities.

The guide will step through a range of considerations including:

  • Demand and capacity
  • Local climatic and environmental factors
  • Sport specific requirements
  • Broader environmental issues
  • Social impacts
  • Health impacts and
  • Asset management and lifecycle costing

The intention of the guide is not to recommend natural grass or synthetic turf, but to provide the known evidence and facts relating to each surface type to allow your organisation to make an informed decision. The diagram to the right outlines the steps you need to follow in determining the most suitable surface for your situation.

This guide provides an outline of the considerations that need to be taken. A detailed report ‘Natural Grass v Synthetic Turf Study’ accompanies this guide and provides extensive information on each of the key considerations. This report should be referred to as you work through this guide, with links to the relevant sections provided at each step.

Natural Grass refers to any natural turf species used for sports ground construction i.e. Kikuyu, Couch and Rye grass.

Synthetic Turf refers to any artificial turf surface used in sports ground construction including unfilled, filled and water-based surfaces.

Traditionally sport has been played on natural grass surfaces. Natural grass sports surfaces were developed on open space sites set aside for recreation as towns and cities evolved. The nature of the sporting activity determined the requirements for the sports ground in relation to size and surface characteristics.

Synthetic turf was first invented in the mid 1960’s in the United States of America; it originally came into existence in the market place to replace natural grass that had difficulty growing in indoor stadiums. The Houston Astrodome was the world’s first fully enclosed stadium with a synthetic turf field

Since the development of first generation synthetic turf sporting surfaces ongoing research and consequent improvements in synthetic turf technology, have overcome some initial issues experienced in the early days and have made synthetic turf more acceptable for a number of sports.

Disclaimer

The information in this guide was published in 2011 and cannot be relied upon as professional advice concerning the decision as to natural grass v synthetic turf. No assurance is given as to the accuracy of any information contained in this guide and readers should seek more up to date information prior to making a decision. Readers should obtain their own independent and professional advice in relation to their project.

Step 1 Trends and capacity

Have you determined the trends in your sport/s and the capacity of your existing playing courts, grounds and greens?

 A key component of determining whether to use natural grass or synthetic turf is the demand for the use of the surface. Sporting participation trends fluctuate and are often cyclical in nature. A number of 
sports such as soccer and lawn bowls have experienced significant growth in the last five years.

In addition to statewide trends local factors need to be considered, such as:

  • Facility provision
  • Club management
  • Availability of volunteer resources
  • Competing sports and their fixturing
  • Local demographics and
  • Marketing techniques

These all impact on participation rates and need to be considered when determining the demand for your sport.

The capacity of a sports ground is the maximum level of traffic/usage that the site can sustain without resulting in a major decline in the turf and surface condition that renders the site unfit for use.

When assessing the capacity of a sports field, two principle considerations are asset management and player safety.

  • Asset management refers to the condition of the asset or the sports field, and in particular the condition of the turf and surface in relation to the desired condition and intended us.
  • Player safety refers to the standard or quality of the turf and surface that is required to safely undertake a specific activity on the site.

Given sports fields are used for diverse activities and levels of sport, the asset management and player safety standards will vary depending on the activity. It is not appropriate for elite sports standards to also apply to local level sports fields. However, all sports fields should be maintained to a ‘fit for use’ condition to minimise the risk to users.

The factors that directly impact on the capacity of a sports ground include:

Sports ground condition

  • Grass species and quality
  • Surface quality
  • Drainage

Weather conditions

  • Temperature
  • Rainfall

Type of usage/sporting code

  • High impact on surface (e.g football, rugby)
  • Low impact on surface (e.g cricket)

Level of usage

  • No of registered teams
  • Competition games
  • Training schedules

Work has been done in developing benchmarks for sports ground usage using the IPOS – Sports Ground Usage Model. Using data in relation to the number of competition games and training schedules, usage rates are determined on the basis of “person hours per week”.

Step 2 Local environment

Have you determined the local climatic and environmental conditions in your area?

A key component of the decision making process is the local climatic and environmental factors which affect the local region. In particular the water supply, rainfall events and other weather conditions.

Western Australia has been experiencing a period of drought conditions and in some areas access to a reliable water supply for irrigating sports grounds has been limited.

Key questions regarding water supply that need to be answered when determining your surface type include:

  • What will be your primary and back up water source for the surface?
  • What will be the cost of this source?
  • Is it sufficient to meet the irrigation requirements to maintain the surface to the minimum standards for use (taking into account rainfall and irrigation requirements)?
  • Is the source's availability likely to change within the short-medium term?

Another key consideration is the average temperature of your local environment, particularly during anticipated playing times. Synthetic surface's can be up to 40% hotter than a natural field, although this can be affected by other environmental considerations such as wind and humidity.

Step 3 Sport specific requirements

Have you considered the sports specific requirements for your playing surface?

Different sports have different requirements when it comes to installing a synthetic option. Synthetic turf surface types vary significantly from sport to sport in terms of factors such as pile height, playability, construction methods and material use (infill, shock pads etc.).

The study has included analysis of seven sports:

  • Australian Rules Football
  • Cricket
  • Hockey
  • Lawn Bowls
  • Rugby Union
  • Soccer
  • Tennis

A number of these sports can use the same type of surface, for example Australian Rules Football and Cricket often use the same oval.

In Western Australia natural grass playing grounds are still extensively used for all the sports. A number of the sports such as Hockey and Tennis have been using synthetic turf surfaces since the 1970’s.

There are currently no synthetic turf sports grounds for Australian Rules Football, Cricket (outfield only), Rugby Union, and Soccer in Western Australia. The first official Australian Football League and Cricket Australia endorsed synthetic turf ground is due to open at Point Cook in Victoria in late 2011.

Hockey is played on both synthetic turf and natural grass fields with nearly all higher level competitions in WA being played on synthetic turf.

Lawn Bowls over the last decade has seen a number of associations shift to synthetic due to factors such as the lack of skilled groundskeepers, water shortages and the desire to play all year round.

Tennis has some unique factors compared with the other sports as there are four types of surfaces that can be used they are:

  • Natural grass (lawn)
  • Hard court (acrylic)
  • En-tout-cas (clay)
  • Synthetic turf

Historically the majority of tennis courts in WA have been natural grass (lawn) and there has been a transition in recent years to hard and synthetic surfaces for a variety of reasons.

Depending on the surface type a number of sports can use the same surface. Multi-use should be encouraged wherever possible to ensure facilities are being well used and the provision of facilities is being done so in an efficient manner.

Step 4 Broader environment

Have you considered the broader environmental impacts of the playing surface?

There are many environmental issues that need to be considered when making a decision on a suitable surface. Rather than provide advice on which is the more environmentally sustainable choice, the information below is provided as a initial starting point and to help initiate thinking and discussion.

With many states of Australia including WA experiencing extreme drought and water shortages over the past decade, the heavy irrigation needs of maintaining natural grass playing fields has been questioned and alternatives have been sought. These include better management and use of water by harvesting rainwater for re-use, or using recycled waste water for irrigation. Another alternative is to install a synthetic turf surface, which, from a water perspective has a major advantage over natural grass for most sports (excludes wet-dressed synthetic surfaces).

Synthetic turf is often promoted as being a ‘green’ alternative to natural grass. The main ecological benefits of synthetic turf that are promoted are:

  • Conserves water (research in the US has shown that each full-sized rectangular field saves between 1.8 million to 3.7 million litres of water each year).
  • No mowing (mowing , especially large areas of natural grass, use fossil fuels and contribute carbon dioxide into the atmosphere).
  • No pesticides or herbicides for pest and disease management are required (reducing harmful chemical inputs).
  • Recycled materials are often used (rubber granules are often used in the base of synthetic turf as infill, these rubber granules are usually made from recycled tyres, keeping them out of landfill and reused sandshoe cushioning can be used for the shock pad).

However, there are other environmental considerations such as:

  • water issues (i.e. stormwater runoff and leaching)
  • carbon footprint
  • emissions from materials manufacture and transportation
  • end of life disposal
  • the impact on local micro environments
  • soil regeneration and dust stabilisation
  • heat dissipation
  • noise
  • glare
  • effects on local biodiversity and habit.

These issues need to be taken into account when considering the full environmental impact of each surface.

It is not the intention of this guide to rule one surface type more environmentally friendly than the other but to present the findings of research into the benefits and impacts of each surface.

The table below provides a summary of the environmental impacts of Natural Grass and Synthetic Turf.

Area

Natural grass

Synthetic turf

Water

Usage

Requires significant amounts of irrigation for growth.

Does not require irrigation for growth, some watering required for maintenance of specific types of synthetic turf i.e. water based hockey pitches.

Stormwater capture

Provides for natural infiltration of water through the soil profile reducing runoff.

Inhibits natural infiltration of water increasing runoff (synthetic turf can include drainage systems to compensate for their inability to take in water and capture and storage systems that can harvest rainwater for re-use).

Runoff Water Quality

Potential for nutrient/chemical leaching from pesticide and fertilisers into waterways if not managed carefully.

Potential for leaching of heavy metals and other residues from synthetic material and/or rubber infill (depending on type of surface and materials used).

Carbon

Carbon footprint

Carbon emissions generally come from the installation and maintenance stage (fertiliser production, mowing and lawn management). Tends to have lower carbon footprint over entire lifecycle.

Carbon emissions come from the processing, production, transportation, installation, maintenance and disposal stages. These material impacts over the entire lifecycle significantly increase the carbon footprint

Carbon sink

Helps remove carbon dioxide from the atmosphere through photosynthesis and stores it as organic carbon in soil, making it an important carbon sink.

Does not have the ability to remove carbon dioxide from the atmosphere

Material

Manufacture

 

Natural product grown from seed. Requires water and chemical inputs in the form of fertiliser and pesticides for growth and quality.

Petro-chemical product which uses mostly virgin materials, some of the materials can be made from recycled content(e.g. rubber granules infill and shock pad)

Transport

Natural instant lawns have short shelf lives and can only be transported shorter distances, or they are planted from seeds which have minimal transportation costs.

Generally speaking synthetic turf is transported long distances (even if it is supplied by a local company the manufacturing of the product is often performed overseas) resulting in high transport costs.

End of Life

Natural grass does not have a definitive end of life however may be replaced to enhance the current surface. Disposal is not normally required.

Ends up in landfill where it takes a long time to break down. High disposal costs.

Soil

Natural grass improves the soil by stimulating biological life and by creating a more favourable soil structure.

Heavily compacting the soil before installing synthetic turf damages soil structure, soil microbes and soil life.

Dust stabilisation

Well maintained grass captures dirt and dust from the atmosphere.

During severe drought periods and tight water restrictions natural grass can deteriorate and dust may become an issue.

Covered surfaces are effective dust stabilisers and synthetic turf will provide dust stabilisation even through drought periods.

Heat dissipation

Natural heat dissipation. Heat is absorbed by turf grass. Cools the surrounding environment.

Heat reflection. Absorbs and radiates heat. Heats the surrounding environment. Can be uncomfortable and unsafe in hot weather conditions. Colour of the synthetic turf may influence the level of reflection.

Noise

Grassed areas present an irregular soft surface which makes them effective at reducing noise levels.

Synthetic turf fibres absorb some noise but not as much as natural grass.

Glare

Natural grass assists to soften and reduce reflected light, lessening glare.

High levels of glare can be created from sunlight and floodlight depending on the type of surface used.

Biodiversity and Habitat

Provides natural environment for organic biodiversity in the soil.

No organic biodiversity due to compacted base and synthetic surface.

Step 5 Social impacts

Have you considered the social impacts associated with the playing surface?

As mentioned previously the various sports are at different stages of adopting synthetic turf and consequently the perception in the community of using synthetic surfaces is mixed. For sports such as hockey and tennis where the use of synthetic surfaces has been commonplace for many years there is a general acceptance of the practice. However with other sports such as Australian Rules football, cricket and rugby league there may be some trepidation in the shift to synthetic turf surfaces.

When considering your options consultation with the state and national sports bodies is always recommended as they should be able to provide you with examples of similar projects that have been successfully implemented and suggestions on how to deal with any resistance within a community.

The following points are subjective and are based on discussions with players, officials, researchers, product suppliers and visual inspections of a range of sites by the consulting team, but do offer some insight into the various qualities both surfaces offer.

Natural grass

  • Cooler feel particularly in summer
  • Softer and more forgiving
  • Variable quality depending on the soil type and maintenance regime
  • Traditional and served the various sports well for many years
  • Natural and calming feel
  • Pleasant smells e.g. freshly cut grass
  • Visually appealing if well maintained
  • Provides environmental benefits in terms of carbon absorption and contribution to biodiversity.

Synthetic turf

  • Consistent surface
  • Warmer and subject to glare when sunlight is present
  • Consistent quality and set maintenance regime
  • Modern and innovative product
  • Artificial and unnatural feel
  • Strong odour particularly for synthetic turf with rubber granule infill
  • Visually appealing as it looks ‘green’ all of the time
  • Suitable in many types of weather conditions
  • Durable and low maintenance
  • Provides environmental benefits in terms of water savings and reduced maintenance.

Step 6 Health impacts

Have you considered the Health impacts of the playing surface?

Injuries

Due to the limited reported research to date on injuries on the latest versions of synthetic turf, there is little consensus on whether the risk of injury is greater than on natural turf surfaces. The main report gives a detailed account of the knowledge on injuries between the surfaces. However, the following are properties that could contribute to an increased injury risk and need to be considered.

Abrasion/friction – burns, abrasions, and grazes

Natural grass
  • As natural grass is generally soft and non-abrasive, this property is usually only a problem for injuries when the ground has become bare and dry. This can be avoided with good management practices.
Synthetic turf
  • The surface needs to satisfy the requirements outlined by the sport’s governing body to reduce this type of injury.
  • Most fibres are relatively non-abrasive so the choice of infill is critical, sand based infill will be more abrasive than rubber but rubber can cause friction burns if sliding is a characteristic of your sport.

Traction – knee and ankle sprains, and muscle strains

Natural grass
  • The current evidence suggests that the choice of grass type is important for traction as too much traction has been linked to an increased risk of severe knee injuries and too little of muscle strains and facial fractures.
  • Couch grass has been associated with a higher level of rotational traction than rye grass resulting in an increase in knee injuries.
Synthetic Turf
  • Similar to abrasion, the surface needs to satisfy the requirements outlined by the sport’s governing body to reduce traction injuries.
  • Footwear plays a major role in the amount of traction a player experiences, so you need to consider if you are going to impose footwear rules on users to reduce the injury risk.

Shock absorbency – concussions, fractures, shoulder dislocations

Natural grass
  • The shock absorbency on natural turf fields comes from a combination of grass cover combined with the soil composition and is usually not a problem unless the ground is very hard and dry.
Synthetic turf
  • The selection of an appropriate shockpad with the synthetic surface is important for this property; too soft causes fatigue-related injuries and too hard can result in traumatic head injuries from falls.
  • The playing characteristics of the sport are also critical, for example are the players falling on the surface or just running over the top of it?
  • Some synthetic surfaces have increased the amount of infill to increase the shock absorbency and satisfy requirements; however, it can become a problem if the surface is not very regularly maintained.

Heat

The heat difference between natural and synthetic turf surfaces is significant and needs to be considered in the selection of a surface.

Natural grass
  • Grass dissipates heat and naturally cools the environment so there is rarely a heat-related injury on natural grass.
  • Most sporting bodies have heat policies in place to counteract heat-related injuries.
Synthetic turf
  • Synthetic turf surfaces appear to create an increase in the heat island effect above the surface, which has implications for heat–related injuries, particularly in junior players.
  • The selection of a heat-resistant fibre and a non-black infill will help reduce the risk of heat-related injuries.
  • Work is being undertaken in Australia and will provide greater guidelines in 2012.

Other health considerations

As mentioned under the environmental considerations section above there have been some concerns raised about the health risks of the crumbed rubber infill used in later synthetic surfaces. There is a need to check the quality of the rubber supplied if this type of infill is being considered.

Step 7 Life cycle management

Have you considered the management needs and lifecycle cost of the playing surface?

Life cycle costing is a key asset management tool that takes into account the whole life implications of planning, acquiring, operating, maintaining and disposing of an asset.

The process is an evaluation method that considers all ownership and management costs.

These include:

  • Concept and definition
  • Design and development
  • Manufacturing and installation
  • Maintenance and replacement
  • Support services
  • Retirement, remediation and disposal costs.

There are four primary principles to consider when assessing life cycle costs:

  • Recognise that a facility development project begins at the concept and pre-planning stage and is complete when the asset is sold or the site returned to its original condition;
  • Examine the full cost of each project component across the life of a project rather than choose the cheapest option. This may mean a higher initial outlay but lead to reduced ongoing operational, maintenance and disposal costs and a net lower total ownership cost;
  • Life cycle costings consider all of the economic and financial costs associated with constructing, procuring and operating a facility at a level for which it was originally planned; and
  • Developing a life cycle cost analysis is an intrinsic part of your overall asset management strategy.

Life cycle costing will help you to get the most out of your facility by making sure construction, redevelopment, or asset replacement is achieved at the lowest “whole of life”cycle cost. Life cycle cost analysis may mean you trade higher initial construction or plant costs for lower future operating costs. The Department of Sport and Recreation has a comprehensive resource tool that enables facility developers to develop life cycle cost reports and understand the full cost impact of owning and managing a facility and should be followed when assessing the life cycle costs of natural grass and synthetic turf options.

For the purposes of this decision making guideline, a series of capital, operating and replacement costs have been prepared for each of the sports included in the scope of this study namely:

  • AFL/Cricket
  • Bowls
  • Hockey
  • Rugby
  • Soccer
  • Tennis

In terms of construction costs a comparison was made between various standards of natural grass and synthetic turf suitable for community and elite level sporting activity. Comprehensive cost estimate calculations have been prepared and based on 2011 cost estimates show that the costs to construct synthetic turf facilities are significantly higher in all sports studied and in some cases are more than five times the cost.

Although the common perception is that synthetic turf requires limited maintenance and hence operating costs, this is not necessarily the case.  

Many synthetic turf surfaces require significant levels of maintenance and in some cases higher levels of maintenance in comparison to natural grass alternatives. The cost of the maintenance equipment is a substantial contributor to the operating cost, although it could be spread across multiple venues.

Unlike natural grass, synthetic turf must be replaced at the end of its useful life. This varies from sport to sport and the timeframe in which it is replaced is dependent on a number of factors. These include the level of usage, level and type of maintenance undertaken on the surface, weather conditions and the performance requirements expected from the surface.

Comparison of annual operating costs to maintain natural grass (community level) and synthetic turf

Sport

Natural grass (community)

Synthetic turf

AFL/Cricket

$43,700

$50,000

Hockey

$22,350

$10,000 (sand filled)

Lawn Bowls

$17,500

$10,000

Rugby

$38,000

Soccer

$27,250

$25,000

Tennis

$9,500

$4,000

Please note that these figures are indicative only and should not be used in place of a proper quote or quantity surveyor estimate.

Summary decision time

Make a decision on the best suited playing surface.

The information in this guide, as well as the detailed report ‘Natural Grass v Synthetic Turf Study’, was intended to help you arrive at an informed decision as to which surface type is best suited for your needs. Each surface type has their advantages and disadvantages and individual circumstances will require different solutions.

Other key steps in the planning process that should be undertaken before committing to the project include a needs analysis, feasibility study and management plan.

For more information regarding this guide or strategic planning principles, please contact one of our officers below:

Kent Burton
CSRFF Officer
Telephone 61 8 9492 9759
Facsimile 61 8 9492 9711
Email Kent Burton

Page reviewed 08 July 2019