Synthetic Turf Field Replacement: A Case Study
The Project at a Glance:
- Project and Client: Sycamore Valley Park, Town of Danville
- Scope of Project: Replacement of 5.2 acres of synthetic turf
- Project duration (design through construction): December 2011 – August 2012
- Number of Bidders: 6
- Bid Range: $1.0M – $1.3M
With synthetic turf fields now firmly ‘in the mainstream’, many cities have them in their inventory of park facilities. There’s a lot to like about them. Maintenance is easier than a conventional turf field, they save a LOT of water, and they’re so durable they’re practically bullet proof. They can be used from dawn till dusk, (neighbors permitting), and where lighting is included, even more! As a result, they quickly become among the most coveted in a City’s inventory of sportsfields. But what do you do when the fields finally wear out? This article presents a case study.
Danville’s Sycamore Valley Park contains over 5 acres of synthetic turf dedicated primarily to soccer and baseball use but also accommodating softball, lacrosse and other uses. Since installation in 2003 these fields saw upwards of 2300 hours of use per year! Eventually all this use (and years of sunshine) took their toll and in places the turf fibers had been worn almost completely away. The time had come to replace them. The Town had options with respect to how to proceed, including negotiating directly with a vendor but ultimately chose to employ a competitive bid process. Callander Associates was selected to assist the Town in the development of construction documents. Plan preparation began in the end of 2011 and was completed before the end of February, 2012. The team included Geoforensics Inc., a geotechnical engineering firm and Protech, a materials testing laboratory. Key project considerations included;
The ‘recycleability’ of synthetic turf did not receive the attention in 2003 that it does today. The expectation was that the used turf would go to a landfill or be re-used in ‘trickle down’ applications, like paddocks, miniature golf courses and the like. Since these first fields were built a lot of investment has gone into identifying the most carbon neutral methods of manufacturing and disposal. The recycled content, and recycle-ability of synthetic turf fields is much higher today and methods have been developed by enterprising contractors that allow infill material to be removed, sorted and re-used. As the design consultant for the Sycamore project our obligation included specifying that all waste materials were disposed of in a legal manner, and establishing a budget for the disposal of this material. Protech testing laboratories evaluated the turf and infill to determine its chemical composition and determine its waste category. This information was then shared with a number of waste disposal facilities to determine if they could accept the material and the cost of disposal per ton. The laboratory analysis, waste category determination and waste disposal requirements were then made a part of the contract requirements. Disposal cost information shared by the waste disposal facilities was factored into the engineers estimate and helped in establishing the overall budget.
The prevailing wisdom in synthetic turf field design is that the fields live or die according to how well their drainage systems function. As drainage and soil stability have an inverse relationship, there is a built in conflict in base prep. The ideal field has been laid in to the precise grades required on the plans, without any overworking of the drainage layer (base rock). Overworking the rock to achieve grades can result in a poorly draining field, the bane of the industry. These same considerations come into play in replacing a worn synthetic turf field. Replacing the synthetic turf at a sportsfield is bit akin to replacing the carpet in a home, it just doesn’t make a lot of sense if the base isn’t going to last as long as the new surface on top of it. One of the first steps in turf replacement therefore is an evaluation of the existing drainage. Sources of information including empirical testing (perc. tests conducted by the geotechnical engineer) and anecdotal (reports of drainage problems from first hand observers). Perc. tests conducted at Sycamore demonstrated that the base still had excellent drainage. Subsurface drainage lines were camera’ed to ascertain their condition and found to be intact and in good shape. Only one spot in the field was reported to have suffered from slow drainage. This exact spot was subjected to a perc. test and found to have adequate drainage and it has since been assumed that any standing water seen at this location may have occurred during an extreme storm event (over 10 year event) and may have been partially caused by drainage onto the field from above. With documentation that the base was in good condition the plans called for leaving the base in place, with only minor amounts of material placed as needed to achieve planarity. To close the loop, the plans required that the contractor ‘camera’ up to 500 feet of the drainline after their work was complete, and as selected by the Town Engineer to confirm that no pipe had been crushed as a result of construction activities.
Timing of Field Closure
As the premier soccer facility in the Town of Danville, taking the fields off-line had to done carefully. An aggressive but achievable schedule consisting of 60 working days + 12 Saturdays was established. The unconventional addition of Saturdays was necessitated by the Towns requirement that the field be available for the annual Mustang soccer tournament in mid-August. Though they never needed to exercise it, the Town set liquidated damages at $3,500 per day.
As implied previously, the base of a synthetic turf field is the single most critical component of the field. Careless operations by the contractor can adversely impact the drainage characteristics and planarity. A primary concern at Sycamore Valley Park was keeping the rock in the best possible condition throughout the project. Towards this goal unique requirements were imposed, including limiting field access during turf removal to lightweight vehicles with turf tires, and specifying that vehicles were allowed only on sections of the field still covered by the old synthetic turf. The concept is akin to ‘painting your way out of a room’. Where vehicle travel was concentrated at the field access point steel plates were used to prevent rutting. With an estimated 680 tons of turf and infill material to off-haul, these, and other measures were critical to the preservation of the baserock.
Turf Type Selection
As no specific turf manufacturer had been identified as preferred, meetings were held with Town staff to discuss turf criteria and identify key traits. This information was used in preparing specifications to allow the general contractors to solicit multiple bids for the turf. The project benefitted from a very favorable bid climate. ‘Recession pricing’ was still in effect, the size of the project allowed for some economies of scale to be realized, and the attractiveness of the facility to vendors due to its high visibility are all thought to be contributing factors in a very competitive bid. Pricing for the turf came in at $3.20/SF and $3.10/SF for the monofilament and slit film infields respectively. It seems unlikely that pricing comparable to this will be seen any time in the near future and it’s not suggested to use these figures for budgeting purposes.
Due to the novelty of the project type, an amendment had to be made to the bid documents. Namely, the requirement that the contractor have experience in two other turf replacement projects of equivalent size had to be dropped as none of the bidders possessed this experience at the time. Conventional synthetic turf installation experience requirements were substituted. It is anticipated that the original wording, requiring experience with turf replacement at two equivalent sized facilities would be a reasonable qualification requirement today.
The Completed Facility
Operations are back in full swing at Sycamore Valley Park and the new turf has been well received. Through the combined efforts of the Town, contractor and design consultant the facility was back on line in time to host the 2012 Mustang Soccer tournament and the Town can now look forward to years of uninterrupted use on the new turf!
Written by project team members Mark Slichter and David Rubin. This case study was one of the featured articles in the CPRS Winter 2014 Magazine!