March 24, 2009
Thank you for your email regarding synthetic turf and the City’s sport fields. I share your concerns about sustainability, public safety, and neighborhood livability.
I asked Parks Bureau staff to address your specific concerns, and explain why they believe synthetic surfaces are a reasonable way to address some of the significant challenges Portland Parks & Recreation faces in meeting the increasing demands on our athletic facilities.
The supply of City-owned sports fields doesn’t begin to adequately serve the growing number of youth and adults wishing to play. As a result, many of our natural grass fields are over-used, and during the rainy season become full of divots and ruts, making them unsafe.
We believe an appropriate mix of synthetic turf and natural grass fields citywide will allow us to satisfy the growing demand and provide a variety of safe and environmentally sound surfaces for Portlanders to play on.
Responses to the specific concerns you raised are included below:
- • Temperature- Our research indicates that high temperatures that occur on synthetic turf are primarily at the ground level, and dissipate quickly. Fortunately, Portland has a relatively few high heat days where this effect would be of concern, so Parks has not found it necessary to irrigate.
- • Safety- According to recent studies, newer turf fields have an outstanding safety and performance record. Shock attenuation measurements for synthetic turf are comparable to well-conditioned natural grass fields. In terms of safety, synthetic turf functions better than natural grass in several major categories: 66% fewer neural injuries, 50% fewer cranial/cervical injuries, and 33% fewer third-degree injuries.
- • Chemical Substances/ Metals- Rubber crumb is often used to fill synthetic turf surfaces. Ambient rubber is made of ground-up recycled tires and contains some metals. Ambient rubber is not used within the Portland Parks system. The infill used at Delta Park’s Strasser field is made of recycled tires that have been broken down using a special cryogenic freezing process. This process eliminates heavy metals.
- • Lead- There has been considerable controversy surrounding the amount of lead in synthetic fields. Portland Parks, in conjunction with Multnomah County Health, Oregon Health Services, Portland's Bureau of Environmental Services and Portland Public Schools, initiated extensive testing of fields at Mary Reike and at Strasser. Their findings showed lead levels well within current EPA guidelines, even on the aging surface at Reike. The testing process was so thorough, their procedures are being considered for submission and future adoption by the ASTM and the EPA .
- • MRSA or Staphylococcus-A recent study performed by Penn State University concluded that level of microbes in turf fields is lower than that found in natural turf, because synthetic surfaces are a less favorable host than natural grass.
- • Lifespan- The advancements in the synthetic sport field industry with new fibers, backing and infill have significantly increased the lifespan of synthetic sport fields. A single strand monofilament polyethylene fiber was installed at Delta Park. This fiber shows 20 times the wear test capabilities as the original fiber. The Bureau hopes to realize 15+ years from this advancement, even with heavy programming.
There is really no direct comparison between replacement of Parks sports fields and a professional sports franchise, such as the Qwest field you mentioned. Professional teams can budget for field replacement on a nearly annual basis. These replacements are as much cosmetic as they are to provide the highest safety possible for the multimillion dollar investment in their athletes. Discarded professional surfaces are nearly always donated to other facilities, such as schools and parks, for reuse.
- • Financing- Portland Parks & Recreation plans for the replacement of each synthetic surface by capturing the usage fees from that facility for the cost of replacement.
- • Recycling- Portland Parks strives to reuse and recycle turf materials it replaces. Agri-Plas Inc., a plastic recycling company located in Brooks Oregon, took all of the old carpet and backing from Delta Park’s Strasser field in the fall of 2008. It was melted down to create nursery pots. The original infill of Columbia River sand and cryogenic crumb rubber was re-used as a very thin top dressing on the surrounding natural turf fields at Delta Park, after being tested for lead or heavy metals.
- • Sustainability- Our highly utilized grass fields quickly develop divots and ruts that require frequent repairs and maintenance throughout the playing season to maintain safety and playability. Natural grass fields have to be closed during the rainy months of December, January, February and March due to unsafe conditions.
The Bureau does not intend to replace all of its grass athletic fields with synthetic turf. They will be strategic, targeting their efforts on the highest use areas where grass cannot meet the demand, including parks adjacent to high schools, regional parks and or tournament level facilities. We believe an appropriate mix of synthetic turf and natural grass fields will allow us to satisfy the growing demand and provide a variety of surfaces for Portlanders to play on.
Thanks again for your e-mail.