By Bruce Clark

A geographic information system (GIS) is a computerized system that integrates, analyzes, and models data from maps, surveys, photos, reports, and other sources, and produces graphical maps, reports, and plans to support the decision-making process. Think of it as a visualization tool.

Using GIS
Assume a client needs a new landfill or transfer station, and embarks on an in-house siting study. Certainly, the outdated and costly way would be to manually review hundreds of pages of parcel ownership at the tax assessor’s office. Spending hours taking copious notes, reviewing maps one by one, as well as reports of all sorts concerning the locations of wetlands, airports, water supply wells, lakes, sinkholes, and conservation areas.

Then, after painstakingly drawing a new map or series of maps displaying all of the important siting factor data and sensitive areas, an engineer would start measuring, manually, the distances from all of the sensitive features to any specific parcel area of interest for the facility.

This work probably would be completed in about six months at a high cost. However, the accuracy could be questionable, as there is so much data to digest. If an engineer had to check out four other potential parcels, it could add another four months of work. In contrast, if the municipality has computerized much of basic reference information and a GIS system is used for that same assignment on all four parcels, the work could be completed in about two months or less, and likely produce far more accurate, useful, and readable information for the decision-makers.

If someone wants to know who owns certain parcels and how large they are, the information is accessible through the system with a few clicks of the mouse. Want to see all power corridors, every permitted potable water well, every housing subdivision, floodplain, and wetland? No problem—it’s right in the GIS database.

The GIS operator decides which layers of information to present. It is all manipulated electronically, so there is no labor-intensive drafting to prepare new drawings each time for different analyses. So, what is eight months of saved time worth to the client in dollars, especially when there might not have been eight months to figure out the problem?

How GIS Can Help Clients
Not many solid waste departments have their own GIS; for many, it isn’t necessary. However, many municipal governments have invested in a GIS for their planning, zoning, and public property regulatory functions. These departments can be helpful in that they typically already have computerized a large amount of data for their GIS. This includes parcel ownership, permitted wells, parks, municipal boundaries, and other geographic details.

Planning departments with large staffs may be willing to manipulate some of this data for clients. Typically though, a siting study encompasses a huge variety of information, some of which may have to be gathered from other sources and integrated into the city’s basic GIS. Other types of information pertinent to waste facility-siting studies include location of and data about:

• Private and public airports
• Power corridors
• Floodplains and wetlands
• Geology and known sinkholes
• Historic preservation sites
• Other solid waste disposal facilities
• Housing subdivision boundaries

Planning departments usually can’t devote the resources needed to acquire all of the other necessary data in the time frame a client requires.

Some consultants have their own GIS and have been using it to assist municipalities with water resource studies and other environmental assignments. These systems are generally comparable in features and fully compatible with versions used by the municipalities. In many cases, a better solution for the client is to bring in an engineering firm to conduct the entire siting study. The firm will interface with all of the municipal departments as needed, acquiring their databases and data from other outside sources (i.e., the state agencies) as needed.

This teaming arrangement allows a municipality’s solid waste manager and staff to focus more on evaluation of the costs and environmental impacts of alternative solutions rather than the process of number crunching—and typically in a very cost-effective manner.

Success Stories
The following success stories in municipal solid waste management illustrate the power of a GIS to help provide managers with efficient solutions for complex operational issues that formerly required a disproportionate amount of personnel to solve.

The Orange County Integrated Waste Management Department (IWMD) in Santa Ana, CA, needed to identify any addresses in which it presently provided service under the franchise hauling agreements that were outside of the county unincorporated area. The purpose of the study was to determine if any waste collected by franchised haulers and attributed to the county unincorporated area did not originate in the county, and therefore should not be included in the county unincorporated area Disposal Reporting System data.

To determine whether or not the haulers were collecting waste in incorporated areas, engineers mapped the customer addresses supplied by the franchised haulers utilizing a GIS database.

Using the customer lists provided by the haulers and GIS boundary data from the county, SCS geocoded the addresses to create a master map indicating the location of all addresses presently served by the franchised haulers. The data set was then filtered to identify those addresses outside of the county unincorporated area.

A second project example of engineers using GIS occurred when the Orange County IWMD needed to identify opportunities for increasing self-haul recycling and diversion from its three active landfills. In order to identify optimal pricing and expected diversion, it was necessary to gather baseline information about not only the origin and quantities of self-haul materials that were disposed at the three active landfills, but also the distance, time, and costs associated with transporting these self-haul materials from each origin to one of the three landfills and to other diversion facilities.

Engineers utilized a GIS database to locate the centroids of each city, and geocoded the addresses of each landfill and diversion facility to determine the distance from each centroid to the solid waste facility. This information was used to estimate the average transport distances and time, depending on the geographic area in which the waste originates.

Other Uses for a GIS
A GIS has many other uses in this industry where the ability to manipulate, simplify, and “visualize” large amounts of data is key to optimizing operations and complying with permit conditions. These uses include:

• Assessing landfill settlement patterns
• Describing ground water quality variations
• Monitoring the effectiveness of liners and slurry containment walls over time
• Visualization of landfill emission patterns
• Monitoring fugitive odor
• Emissions tracking gas collection well quality fluctuations
• Mapping of collection customer locations and complaints
• Locating and characterizing industrial and hazardous waste generators
• Conducting collection routing efficiency studies
• Siting of recycling collection point locations
• Three-dimensional (“3-D”) visualizations
• Incorporating geographical positioning system (GPS) data for precision waste filling in landfills

Conclusion
The ability to visualize and manipulate data with a GIS can lead to better decisions, improved community relations, and greater efficiency, all of which enhance the value of services provided to clients.

Bruce Clark, PE, DEE, is a project director with SCS Engineers in Tampa, FL.

MSW - Elements 2007