A Helping Hand

Geographic Information system (GIS) technology has been used by various industries since the mid-'90s. In recent years, the solid waste sector has discovered important applications for GIS. Whether it's used to help site a landfill or design a recycling program, the technology can improve the efficiency of planning waste facilities and services.

What is GIS?

GIS is a computerized system that integrates and analyzes data from a variety of sources — such as maps, surveys and photos — to produce graphical maps, reports and plans to help the decision-making process. Think of it as a visualization tool.

A siting study is one application that the solid waste industry has found for GIS. Assume that a public sanitation department needs to build a new landfill, transfer station or other major facility, and embarks on a siting study.

One way to conduct the study would be for someone to manually review hundreds of pages of parcel ownership information at the tax assessor's office. This would involve taking copious notes and reviewing, one-by-one, maps and reports of nearby sites such as wetlands, airports, water supply wells, lakes and sinkholes.

After painstakingly drawing a new map or series of maps that contain all of the important siting data and sensitive areas, the person conducting the study would manually measure the distances from all of the sensitive features (if the person could even interpret them after combining everything into one drawing) to specific areas of the proposed facility.

If everything fell into place, this process would likely take about six months to complete. The study would also expend significant resources in the process. Furthermore, the accuracy could be questionable, since there is so much data to consolidate and evaluate. Having to investigate other potential parcels could easily add months of work.

In contrast, by using GIS technology, the same assignment could be completed in about two months and would likely produce far more accurate and useful information for decision-makers. If someone wanted to know who owned certain parcels and how large they are, the information would be accessible with a few clicks of a computer mouse. What if someone wanted to see all power corridors, every permitted potable well, or all nearby housing subdivisions, floodplains and wetlands? No problem — that information would be in the GIS database as well.

GIS users decide which layers of information they need and manipulate them electronically, eliminating the need to prepare new drawings each time a further round of analysis is needed.

How Can I Get a GIS?

Not many solid waste departments, or private waste companies for that matter, have their own GIS, nor is it necessary. However, many municipal governments have invested in GIS for their planning, zoning, utility and public property regulatory functions. These departments can be helpful in that they have incorporated a large amount of data — such as parcel ownership, permitted wells, parks and municipal boundaries — into their GIS.

Typically, though, a siting study encompasses a large variety of information, some of which may have to be gathered from other sources and integrated into the GIS. Other types of information that a planning department may not have readily available, but that are important in siting studies include:

  • private and public airports;
  • known sinkholes;
  • power corridors;
  • floodplains;
  • historic preservation sites;
  • other solid waste disposal sites; and
  • housing subdivision boundaries.

Using a Consultant

In many cases, consultants can be brought in to conduct the entire siting study. The consulting firm interacts with planning and other departments as needed to acquire their databases and data from other outside sources, such as state agencies, as needed.

The right consultant can “make sense” of all the data, maximize its use and clarify potential adverse environmental impact issues. This team arrangement allows a solid waste manager and staff to focus more on the information itself, rather than on the process of collecting it.

Case Studies

Recently, Orange County, Fla., used GIS for a preliminary screening study to identify potential sites for a new landfill. Although the county has another 20 years of capacity at its existing facility, continued development of the county will only make suitable parcels harder to come by. The process began with the county establishing certain criteria for the landfill.

The county needed a landfill with the capacity to operate for at least 40 years and that had a .25-mile to .50-mile buffer around it. Based on that criteria, the county and its engineering consultant decided that a site of approximately 2,000 acres was needed.

The county then selected 10 regulatory-based siting criteria to screen out areas that were not a match for the future landfill. Screening criteria included keeping the landfill a certain distance from airports, water supply wellfields, flood plains, parks, developed areas, schools and known sinkholes.

Orange County provided this information to its consultant in a computerized database that was loaded into the consultant's GIS.

Using the GIS's built-in queries and comparative functions, the areas that met the criteria were identified within a day or two. To finish the assessment, the county's property tax assessor database also was loaded in the GIS, making it easy to quickly identify the owners of all land parcels composing each area that met the screening criteria.

The GIS technology was then used to automatically prepare color maps of the county indicating the six areas that met the screening criteria and size. A draft report was prepared that summarized the areas' characteristics, size, parcel owners and wetland impacts.

The whole process was completed in about two months. Without a GIS to aid the process, it would have taken several months in a best-case scenario. GIS's ability to process data quickly and present it in a concise and effective graphic format allowed Orange County officials to efficiently assess their options and receive rapid feedback to specific questions about areas of interest and sensitivity.

For example, when the county wanted to assess a smaller minimum landfill area, having all of the data in the GIS made it very easy to do so. Ultimately, the county determined that some of the potential sites, although they met the screening requirements, would not be pursued for future landfill locations, primarily due to the extensive amount of wetlands that would be affected and the associated mitigation costs.

Helping a Recycling Program

In another solid waste application that showcases the benefits of a GIS, a U.S. trade association and its consulting team are using it to coordinate with a nationwide recycling system that promotes product stewardship. The team has been able to analyze population databases from every state and identify areas with a certain minimum population density.

It then used the GIS to analyze the most efficient transportation routes between existing collection centers and aggregation centers and, eventually, to a handful of processing centers. Additionally, the GIS technology was able to approximate a location for a new processing facility that could reduce transportation costs.

Using the powerful mapping function of the GIS, the consultant produced graphics that highlighted the results of the data assessment in an understandable manner. Another consultant on the team has begun the cost assessment phase of the study. Should the analysts need mapping of combinations of facilities, routes or material quantities, it can be done easily and quickly.

In the end, the work on the recycling study will be completed in a matter of months, and at a lower cost than if it had been attempted through manual analysis. Additionally, if the data had been compiled by hand, the results would have been heavy with contingencies due to the sheer volume of information.

Other Uses

A GIS has many other uses in the solid waste industry, especially when the ability to “visualize” the data is key to optimizing operations and staying in compliance with regulations. These uses include:

  • analyzing landfill settlement patterns;

  • monitoring groundwater quality variations;

  • leakage monitoring — slurry containment wall;

  • analyzing landfill emission patterns and monitoring fugitive odors;

  • tracking fluctuations in landfill gas collection well quality;

  • marking customer locations and complaints;

  • pinpointing industrial and hazardous waste generators;

  • tracking post closure activities at many landfills;

  • undertaking collection routing efficiency studies;

  • noting recycling collection site location; and

  • producing three-dimensional visualizations.

The ability to visualize and manipulate data to specific needs with a GIS can lead to better decisions and greater efficiency, which can all add up to cost savings at your solid waste facilities and in your planning efforts for future facilities.

Robert Gardner is a senior vice president and national solid waste practice leader for SCS Engineers in Norfolk, Va. Bruce Clark is a project director in the firm's Tampa, Fla., office.