Advocating for Synthetic Turf on Athletic Field Surfaces in Sunnyvale 

Turf Athletic Fields: Pros and Cons  

Details, Details, Details 

This is the core of the issue.  What are the pros and cons of using Synthetic Turf (we'll call it Turf) vs using Grass on athletic fields?  We have tried to gather information on the following items, including current information, and out of date information, being circulated by people opposing the use of turf.  We've provided links so you can read it yourself. 

Usage and Availability:  The City of Sunnyvale closes grass athletic fields Dec - Mar for all scheduled use, no exceptions.  A rotating field or two is available during this time, if it is dry enough, for neighborhood use. No practices, games etc can be scheduled by any organization during these four months (ie, Grass fields are only available for youth and adult sports for 8 months out of the year.) Turf fields are open year-round.

Sunnyvale closes grass fields if there has been significant rain (generally 0.5" or more) in the forecast.  Wet grass fields get damaged during use.  Turf fields do not close in the rain. 

Grass fields cannot be densely used, meaning a lot of children on them at the same time, nor can they be used for repetitive training (think cones) in one spot for very long. That causes damage to the grass that takes weeks to grow back out.  Turf fields can have larger numbers of players on the field and repetitive actions do not damage the field.  

City of Irvine's Great Sports Park which has 17 natural grass fields and 8 turf fields, recently compared usage and reported four times the hourly usage on turf fields when compared to grass fields.   

Synthetic Field Conventional Field

2,427 hours per year 741 hours per year

Like in Sunnyvale, usage of this park in Irvine is at capacity so they are converting two grass fields to turf and you can read their analysis here. 

Morgan Hill Outdoor Sports Center recently analyzed it's usage at the request of the City of Morgan Hill and found turf fields are used about 3.5X the rate of it's grass fields.  Their turf fields are at capacity while the grass fields are not. 

One turf field has the usage capacity of about 4 grass fields AND is usable 12 months of the year.  This stat is found in study after study.

Cost: Maintenance and Lifetime

Sunnyvale's grass fields are very poorly maintained, unfortunately almost all community grass fields are.  There are holes, sprinkler issues, weeds, bumps and dry patches.  You can see some sample pictures above and below. 

Turf turf has a higher initial installation cost, typically between $1-2 million depending on the current state of the site. This is about twice the cost of the initial installation of a well made grass athletic field.  However, yearly maintenance costs are 10x for a grass field due to need for fertilizer, weed and insect spraying, mowing, water etc.  When approving the refurbishment of their athletic fields, Fremont Union High School District examined costs and estimated that over the 10-year lifespan, the costs will be 30 to 50% (per FUHSD head grounds keeper) less for turf than  grass surfaces. 

The City of Irvine recently approved changing two of their grass fields in their large complex and calculated that  "At an average estimated installation cost of under $2 million per field, revenue and maintenance savings pay back the investment in under two years."  You can read their analysis here.

Athletic use includes needing lines painted for sports play.  On grass fields, the nonprofits serving the children playing have to paint the lines every few weeks. On a turf field the lines are 'built into' the field.  Laying out fields and painting lines is a significant financial burden on the youth sports organizations both financially and in volunteer hours needed. 

Water:

Turf saves about 2 million gallons of water per field compared to a grass field.  Sunnyvale has a requirement from water suppliers to reduce per capita use.  During the last drought, watering of grass athletic fields was cut back and the fields were even worse than usual.  The next drought is coming.

We have heard several people say that artificial turf doesn't actually save water because you have to use drinking water to wash it and to cool it off on hot days.  Fair Oaks park does not have sprinklers.  It is not recommended to install sprinklers as part of a new artificial turf field, and that hasn't been the practice for new fields for many years. 

Plastics/PFAS:  PFAS (nicknamed Forever Chemicals) are a serious environmental concern.  As a result many industries have removed them from their product and their manufacturing processes, a welcome trend that is accelerating due to community pressure.  The turf industry has followed this trend and current generation turf is available from several manufacturers that is manufactured without PFAS.  This is not a comprehensive list of the options available but literally the main manufacturers that pop up on a simple internet search and have an installed base in our area. You can read their information on the links below. 

Astroturf

Field Turf and Field Turf PFAS statement

TenCate

Several organizations wanting to ban turf because of concerns about PFAS have shared an article on a turf field specified to be PFAS free in Portsmouth NH, installed in 2022. The Portsmouth community expressed concern that it was not PFAS free as required and several news articles were published about it.  The City of Portsmouth commissioned a independent scientific study of the installed field to put community concerns to rest.  In a multipage report the summary was that any PFAS found were below what was found in soil. 

"As shown in Table 1, there were no detectable concentrations of PFAS in the FieldTurf, synthetic turf carpet pre-treatment sample." and

"Of the synthetic turf components, the grass/carpet and infill material would be expected to be the two components in which there will be physical contact. The carpet sample had no detectable PFAS in the pre-treatment sample. Post-treatment samples showed very low level, trace concentrations (as evidenced in Table 1 as “J”, estimated values) of a limited number of PFAS. When compared to the health-based soil screening levels, all concentrations were orders of magnitude below the target benchmark levels, thus indicating no significant risk from exposure to these compounds."

Testing for PFAS and what to compare the levels to is an ongoing discussion. PFAS are unfortunately found just about everywhere, including on natural grass and soil. It is logical to compare PFAS to levels currently in soils and the turf levels are consistently lower. 

Recycling/Reusing:  Again a short internet search finds several companies that recycle their artificial turf, including the carpet and the infill.  One recycling plant is in Lincoln CA!!  Infill is cleaned and reused, carpet is broken down into pellets and recycled into new products.  Cal Berkely and the Atlanta Falcons both recently had their artificial turf field recycled in Lincoln for example. 

Field Turf Recycling

TenCate Recycling

Injuries and User Preference

People against the use of artificial turf regularly state that professional athletes (NFL, FIFA soccer teams) prefer to play on grass over artificial turf.  They are comparing turf to grass fields that are used on average for a couple of hours per week and not all months of the year.  It is not uncommon for the grass in these fields to be completely replaced once or twice per year. Athletic fields in our communities need much, much more use that that.  Comparing profession sports to community fields is simply an invalid comparison.  See the pictures of our fields above and below for example. 

Fremont Union High School District did a survey of its users and strong majorities, generally 2:1  preferred the turf fields.  

There are many, many scientific studies comparing rates of injury on grass fields vs turf fields in many sports. The conclusions vary depending on the methodology and the age of the study.  A meta-analysis (study of studies), concluded that, specific to foot and ankle injuries, more studies (52%) found that artificial turf was safer or equivalent to grass.

• • Playing Surface and Injury Risk: Artificial Turf Vs. Natural Grass (Griffith G. Gosnell, Brett A. Gerber, Gregory P. Guyton and Heath P. Gould)

    • Studies were more likely (52%) to conclude that turf was safer or equivalent to grass:

      • Foot and Ankle injury risk was evaluated in 25 total studies with 12 (48.00%) finding higher injury rates on artificial turf, 10 (40.00%) finding no difference in injury rates, and 3 (12.00%) finding higher injury rates on natural grass [44].

    • The overall findings of a study review confirm that “The comparison of artificial turf and natural grass suggests that injury rates are equivalent in most cases.”

• The most recent US soccer study, comparing turf to grass is “Comparison of Injuries Sustained on Grass and Artificial Turf by USL1 Mens Soccer Team,” which concluded:

  • Overall, the incidence of injuries per athlete exposure was significantly lower on AT than NG. Injuries subdivided into location demonstrate statistically lower rates of head/neck, upper limb, and lower limb injuries on AT. Additionally, with regards to type of injury, the rate of contusions and central/peripheral nervous system injuries were statistically lower AT.

And note that these grass fields were generally college or professional club fields with a much higher level of maintenance that our community use fields. 

Injuries are definitely a concern for players no matter what the surface, turf has a shock absorber pad under the carpet and impact tests are a part of the installation of any turf field.  An community grass field is significantly harder than a turf field.  A recent study looked at that. 

• Young players suffering head-to-ground impact on grass have more – and worse – symptoms than those on artificial turf, UT Southwestern study finds 

Heat

Concerns that Turf is hotter than grass have some basis in fact.  Depending on how and where (air, surface etc) temperatures are taken turf athletic fields can be a few degrees or tens of degrees warmer than natural grass. Newer infills are also ensuring lower temperatures on turf fields. Turf has been shown to cool very quickly with cloud cover, water etc. as a result turf fields are not considered to contribute to heat islands. A heat island must retain heat and release it over a long time.  A turf field has very little thermal mass and cools quickly. 

Water is not used to cool off artificial turf fields.  New fields do not have sprinklers as part of the installation.  Fair Oaks park does not have sprinklers.  

Managing heat risk for practices and games is something that every sport has guidelines on and as the air temperature goes up then breaks, water, and decreased practice time is mandated regardless of the surface. 

Field Capacity/New Sports

The City of Sunnyvale has a large demand for athletic fields that it cannot meet. It commissioned a survey this summer to gauge that need, however the survey has not yet been reported back.  Why is this being considered before we have that information?

Replacing a single grass athletic field with a turf field is like building additional fields. Our community needs and wants more athletic fields but we do not have the land to build more fields.  We need fields that provide more access.

Conclusion 

Turf fields provide a uniform playing surface that is less affected by external factors, such as rain and quality of maintenance. This improves the safety and fairness of the game and reduces the risk of injuries and errors for the tens of thousands of Sunnyvale residents who use these fields daily. 

With respect to the city's parks, other than the athletic surfaces, the rest of the parks will remain natural, landscaped and ideal for pets, animals, insects, and aesthetics, negating that argument from the opposition. 

An investment in turf fields is 10 years of consistency, 95% water savings, saving the city millions of gallons, a reallocation of staff to other vital parks and rec maintenance activities.  The pros of turf fields clearly outweigh the cons, as they provide a safer, fairer, and more sustainable playing surface for sports, rare closures due to weather allowing the city to increase revenue. As well as the support of every youth athletic program in Sunnyvale.   

Turf fields are a better choice than natural grass for athletic surfaces in our community. 

This is why the High School district voted to replace all high school athletic surfaces with current generation synthetic fields with natural infill. This is why a large facility like the Great Sports Park in Irvine continues to replace grass fields with turf fields.  This is why we need to retain this option. 

The City of Sunnyvale has a study issue that directed staff to research the issues and come back with a report to council.  Why is this ban even being considered before this information is received?

Pictures of various City of Sunnyvale athletic fields over the last few years 

Unfortunately this is the usual state of the City of Sunnyvale grass fields

Damage done to Serra park by city mowers after a sprinkler issue.  The day before a baseball tournament was to be played there. 

Please speak up in support of artificial turf in our community!