From Golf Course Management, February 1993

The development of golf courses on completed solid-waste disposal sites has become increasingly commonplace. One reason for this increase is that landfills are usually not considered prime property, which means they can be purchased at a lower price. But despite the lower cost of the land, there are additional developmental and operational costs associated with building courses on these sites. These include management of settlement, leachate (liquids) and gases.

Of specific concern to golf course developers is the negative impact of landfill gas (LFG) on course landscaping (i.e., oxygen displacement in the root zone). LFG is a byproduct of the anaerobic microbial decomposition of the organic materials buried in waste disposal sites. It typically is made up of 50 percent to 60 percent methane, 40 percent to 50 percent carbon dioxide and trace amounts of various other gases, some of which are slightly odorous. The methane in LFG is similar to pipeline natural gas and can be explosive under certain conditions.

Because of the odorous and potentially explosive characteristics of LFG, the federal government and many states have specific legislation addressing the control and disposal of these gases. And more recently, environmental concerns over the contribution of LFG as a **greenhouse- gas also have resulted in the development of legislation for its control.

Systems to extract LFG from disposal sites are typically made up of a series of vertical extraction wells installed directly into the solid-waste materials. In these systems, a network of horizontal header piping collects the LFG and removes the liquids that condense when the moist LFG cools within the horizontal piping. A vacuum blower station then delivers the collected LFG to either a flare for disposal or an engine generator or some other device for recovery or use.

The layout of LFG systems must be coordinated with the landscaping, irrigation system and surface runoff drainage system plans. With these considerations, the best time to integrate the layout of the LFG collection system is during the golf course design phase. At this time, the location of the extraction wells and collection piping can be planned so that they mav all be situated away from fairways, greens and tees to allow access for operation and maintenance activities without disruption of play.

Timing of construction for the LFG collection system is important to reduce the impact on the course*s construction. Experience has shown that the best time for this work is between rough and final grading. The vertical extraction wells are installed using a drilling rig. a process that generates solid-waste spoil materials that must be loaded and trucked off site for disposal.

The horizontal collection piping is installed in trenches 3 feet to 6 feet deep that are dug using backhoes or excavators. a process that also produces spoil materials. Access manholes or vaults are set to accommodate final grading. But care must be taken by the grading, landscape and irrigation system contractors to avoid damaging access vaults.

Daily and weekly access to the LFG collection well field is required to properly check and periodically adjust system performance. These routine visits are accomplished by a one- or two-person technician crew carrying portable field meters and equipment. Travel around the course is typically via lightweight trucks or carts. Level D safety requirements dictate that hard hats, boots and gloves be worn. Care also is taken not to interrupt play, which can result in a reduction of the field crew*s productivity.

Routine monitoring can show when site settlement has broken or blocked LFG collection piping. When this occurs, the ability of the system to collect LFG can, be reduced or diminished. Locating and repair of these areas involves mobilizing a rig, backhoes or excavators onto the golf course site to expose the buried pipe. Care must be taken to minimize the ~impact of :these activities on landscaping and irrigation facilities. This can be accomplished by laying plywood sheets to limit damage.

Many former solid-waste disposal sites have been successfully developed into golf courses. Though regulatory requirements often require control of the LFG generated from these sites, coordination of the design, construction and operation

of LFG collection systems with course planners and operators can provide for minimal impact on course features – and ultimately course play.