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Which grass is greener?
Communities debate merits of synthetic versus natural grass

by David Boyce

As drought threatens California and global warming is expected to shrink the natural reservoirs in the Sierra snow-packs, the future of local team sports played on traditional but thirsty grass fields may be in question. Synthetic grass is increasingly poised as a substitute.

The Wildcats of Woodside High and the Bears of Menlo-Atherton High have been playing football and soccer on synthetic grass for five years. A synthetic soccer field is now in the works for middle-school students at Woodside Elementary School. And in Portola Valley, a local leader in official environmental consciousness, the town is planning to look at synthetic surfaces for soccer at Rossotti Field and baseball at Ford Field.

Grass fields still have aesthetic appeal but keeping them healthy means closing them when wet and resting them during off-seasons. Closed fields can be vexing to athletes of all ages seeking places to play year-round. This higher demand is raising the profile of synthetic grass.

• Rain or shine, synthetic grass is ready for action, though on hot days it can raise shoe temperatures and create a chemical smell of rubber tires. (To make the fields soft, recycled tires are frozen, shattered into tiny black pellets, and spread at the base of the "grass" blades.)

• The fields can improve traction and athletic performance, but falls can be harder than on grass and slides can inflict nasty rug burns, though some brands claim to be less prone to burning.

• Synthetic grass is durable and does not need irrigation or recovery periods, but the surface can tear and require attention to keep it soft.

How does synthetic grass measure up? What is lost and what is gained? Are real grass fields already artifacts? How does this trend fit with local concerns about the environment?

Grass has class

Professional sports are worlds apart from the merits of this or that surface for a local soccer field, but for what it's worth, pro football players are not sold on synthetic grass.

While it is used in 12 of the 31 stadiums in the National Football League, real grass is planted at the other 19. Stanford University chose real grass for the 2006 remodel of the football stadium.

The NFL Players Association in 2006 surveyed 1,511 players, representing all NFL teams, asking for their thoughts on the differences between playing on the two categories of surface.

Substantial majorities of players say synthetic grass is more likely to contribute to injuries, cause soreness and fatigue, and shorten their careers.

Under "additional comments," the players endorsed artificial grass only in cities with inclement weather. Real grass "prevents injuries" if the fields are well-maintained and closed to non-football uses, they say.

"Nothing can replace grass," says M-A varsity football Head Coach Bob Sykes. Given a choice between "picture perfect" grass and a synthetic field, he says, he would always choose grass. The catch, he says, is the expense, including the groundskeeper team the pros use to keep a grass field perfect.

A third way

The sand-channel field is a natural-grass option that doesn't require a groundskeeper team. With grass planted over sand, irrigation water drains quickly and the field is available for play more often.

Portola Valley spent $400,000 — including $110,000 in donations from residents and two soccer groups — to rebuild Rossotti Field as a sand-channel field.

A typical storm may put clay-based Russ Miller soccer field at Town Center out of action for two days, but Rossotti is ready for play in about eight hours, says Recreation Facilities Coordinator Tony Macias.

That convenience has a cost relevant to Californians in a time of water scarcity: water use goes up. Between May 2006 and April 2007, the 86,000 square feet of Rossotti Field required 2.8 million gallons of water, or 33 gallons per square foot.

By contrast, the soccer and baseball fields at Town Center needed 2.3 million gallons to irrigate 133,750 square feet, or 17 gallons per square foot.

Rossotti Field needs watering daily or a "dry grass" look sets in, Mr. Macias says. "I would say that Russ Miller (field) is like a camel. Rossotti Field needs a lot more attention."

Town staff did not have figures for expenses such as fertilizer, equipment upkeep, pest control and monthly seeding.

Keeping the carpet clean

Given the ongoing battle over facts between the synthetic and real grass industries, a neutral source of information is hard to find to compare annual maintenance costs.

During football season, Bruce Rollin, the Sequoia Union High School District's director of maintenance and operations, says synthetic fields need to be fluffed up monthly using a $60,000 ride-around sweeper. The bristles agitate the rubber pellets nestled at the base of the "grass" blades.

"The misconception (about synthetic fields) is that you don't have to work on them," he says. "Imagine people running around in your living room with cleats on."

The carpet, meant to last from seven to 10 years, shreds and wears out, he says. Occasionally cleats tear up seams that then need to be re-glued.

Mr. Rollin did not have available the annual maintenance costs for the fields.

The 2006 Guide to Synthetic and Natural Turfgrass for Sports Fields cites annual costs of $5,000 to $25,000, including labor, solvents to remove tough stains, and replacement rubber pellets. The upper end of that range would apply to fields that are "frequently televised" or "used for multiple sports," the guide says.

Performance boost

Regardless of rain or heavy usage, artificial grass offers a level surface and reliable traction. School-age athletes prefer it, Coach Sykes says.

"The (artificial) turf is better," says M-A junior Danny Jimenez, a varsity lineman for the Bears and a Menlo Park resident. "It doesn't get muddy. It's always dependable. ... Our cleats get a better grip on the turf."

M-A freshman and strong safety Alofangia Sakalia of East Palo Alto says he particularly likes synthetic grass in the fall and winter, when there's no mud and no slipping and sliding as there is on natural grass.

"Kids love what they can do on artificial (grass)," says Coach Sykes. "You're able to explode off the cut," he adds, referring to the sudden changes of direction made by a player running with the ball as he attempts to evade defenders. The artificial grass lets kids play closer to their potential, he says.

When the Bears have a grass-field game coming up, they practice on grass at M-A to adjust their timing for a slower game, Coach Sykes says.

M-A's synthetic field is in near-continuous use, says Athletic Director Pam Wimberly. "It's become a way of life here at M-A. You go out there and you just play on it."

NFL players complain of the potential for getting hurt. Are there more injuries? Ms. Wimberly says injuries at M-A have lessened since the synthetic-grass era began there.

NFL players' opinions notwithstanding, a 2007 study of American college soccer teams by the British Journal of Sports Medicine, using 2005 data from the National Collegiate Athletic Association Injury Surveillance System, concluded that play on natural and artificial surfaces showed no "major differences between the incidence, severity, nature or cause" of injuries for men or women.

Feeling the burn

One problem, at least on older synthetic fields, seems persistent.

"You burn," strong safety Alofangia says, referring to the skin abrasions that accompany a slide. "It hurts! It, like, takes your skin off!"

"If you fall, you better, like, hope you land on your pads or something," says lineman Danny Jimenez. One three-foot slide gave him what he thinks will be a permanent a scar on his elbow.

"It will tear your skin right off," Coach Sykes says. "It's kind of a small price for what you really get out of the surface."

The Woodside Elementary School District is spending $510,000 for a 48,000-square-foot synthetic field, says Assistant Superintendent Tim Hanretty. This "grass" will be FieldTurf, a product that "when tested, performs like grass" with respect to burns, according to a paper prepared by a committee of Woodside community members.

(The district is spending another $450,000 to put in a sand-channel grass soccer field of the same size for the K-3 students.)

There is concern about what happens when wounds and synthetic fields get together. "There's warmth. There's moisture. Bacteria can thrive in there. There's sweat, spit and blood," says Brad Fresenburg, a natural-grass specialist at the University of Missouri, in the November 2005 issue of Applied Turfgrass Science.

Before the season starts this year, the M-A and Woodside fields will be treated with a disinfectant. "What's come to light is, because it's not grass, we don't have the microbial (cleansing) action," Mr. Rollin says.

"I think my biggest complaint," says M-A's Ms. Wimberly, "is the disrespect that some people have, in the public, toward that facility." She was referring to people who drop chewing gum on M-A's fields and exercise their dogs there without cleaning up after them.

A recent study of six types of false grass and three of natural grass concluded that worries over microbes are not well founded.

The study, begun in 2002 by the Department of Crop and Soil Sciences at Pennsylvania State University, used swab tests on natural and synthetic grass. Staphylococcus aureus, a common cause of skin infections, tested positive on weight equipment, stretching tables, and human hands and faces, but not on natural or synthetic grass fields.

Storing carbon dioxide

The ability to photosynthesize — to use the sun's energy to generate oxygen and sequester carbon dioxide — is the exclusive province of living plant material, including grass.

If the Portola Valley Town Council were to decide to replace real grass at Rossotti Field with synthetic grass, a 2006 study shows that the town could make up for the lost CO2 sequestration ability by planting 1,638 conifer trees over 10 years.

The study was by the Athena Institute, an Ontario-based nonprofit that provides consulting services to factor in the environmental costs of capital improvement projects.

A common shortcut to planting trees is paying someone else to either plant them or engage in other greenhouse-gas reducing projects such as building windmills. For about $118 a year over 10 years, the town could "offset" the environmental cost of a synthetic soccer field, says David Coale, a manager at the Palo Alto-based environmental group Acterra.

Such an offset would be equivalent to taking 10 cars off the road, Mr. Coale says. "(It's) not very much, but it is good to start to put these things in context of what we will have to think about more and more in the future."