Author: Billie R. Dugger, GIS Program Manager, PBS&J
Post, Buckley, Schuh & Jernigan, Inc., in conjunction with MACRO Consultants, Bangkok, Thailand, were contracted by the Pollution Control Department of the Kingdom of Thailand to assess the environmental impacts resulting from disposal at numerous solid waste disposal sites.
The assessment was performed by first locating all of the sites, collecting data about each of the sites, developing an assessment criterion, and by weighting the factors of the assessment criterion, spatially overlaying the data in order to rank the landfills according to the most serious combination of conditions to isolate the sites with the highest pollutant potential to cause harm to the human population and/or natural environment.
The tasks consisted of first researching the locations of active and previously active disposal sites within the study area of northwest and central Thailand. Global Positioning System technology was utilized to capture boundary information for each of the sites. Approximately 50 sites were located.
Assessment criteria for the 50 sites were then established and the necessary data to support the assessment was collected. Some digital data was available but most information was available in hard copy format only and required conversion to a digital format in order to perform the ranking analysis.
Based upon these criteria, the 50 sites were evaluated and reduced to 15 sites determined to have the highest potential for impacts to the health of the public and environment. Conventional surveys were conducted at each of the 15 sites in order to collect more accurate boundary data. Topographic data was also collected at this time and three test wells were drilled at each site to provide accurate soils and hydrogeologic feature data.
The criteria was again weighted and the remaining 15 landfills were again ranked according to potential hazard to the health of the surrounding population and potential for contamination. This final ranking of sites was provided to the client, Pollution Control Department, along with remediation plans for each of the sites.
Thailand is a country situated in Southeast Asia sharing its borders with such unruly neighbors as Cambodia in the south, Laos in the northeast and the newly opened Burmese Border in the west. The climate varies from moderate to tropical and the vegetation follows suit. The landscape of Chaing Mai in the northwest province is reminiscent of North Carolina, rolling foothills with deciduous vegetation. Phuket, on the contrary, located in the southern province, an island resort with a tropical climate. Often referred to as "the tourist destination of Asia"1, Thailand has historically relied upon tourism and agriculture as a means of economic sustenance. Thus, a majority of the of the waste disposed of consisted highly of biodegradable substances. Much like the United States post World War II, Thailand is now beginning to industrialize and the waste being generated as a result is unquestionably more volatile with potential to cause impact to human health as well as the natural environments. The primary concern is for contamination of many of the countries public drinking water supplies. Much of the water currently consumed by the human population is bottled by private industries.
Post, Buckley, Schuh & Jernigan, Inc., in conjunction with MACRO Consultants, Bangkok, Thailand, were contracted by the Pollution Control Department of the Kingdom of Thailand to assess the impacts resulting from disposal at 50 landfill sites in the northwest and central provinces of Thailand.
These sites would be ranked according to criteria established and the 15 sites deemed most likely to adverse impacts to the health of the surrounding population and natural environment would be further assessed with a refined ranking analysis and more accurate site specific data resulting in candidates for remediation plans.
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The ranking criterion for the initial 50 sites were developed based upon the preliminary database design generated by MACRO Consultants. The criterion would need to take advantage of data which would be available thus the database design supported the ranking criteria. The following dataflow diagram illustrates the Preliminary Database Design Document generated by MACRO Consultants:
Following review of the preliminary database design document, I travelled to MACRO Consultants offices in Bangkok, Thailand in order to assist in the integration of the GIS databases in establishment of the ranking criteria. This effort involved all team members including Le Kim Luat and Kuhn Sompong of MACRO Consultants, and Mr. Bob Mackey, Mr. Geoff Burke and myself of PBS&J. The following ranking criteria is the result of several drafts with considerable input from all of the team members.
The scope was also refined at this time to reflect the teaming responsibilities for the GIS staff involved on t the project. The final scope for the project consisted of PBS&J providing peer review in the initial tasks of data collection and database design and then to perform the ranking analysis resulting in an interface of the GIS data with the contaminant modeling program.
The initial ranking analysis was performed by MACRO Consultants and the results of that ranking along with the databases utilized in the assessment were then provided to PBS&J for review. The results of that analysis and the databases utilized are summarized in the following sections.
As you will notice, this database varies somewhat from the preliminary database design although the ranking criteria established by the team is still supported. The ranking analysis database provided by MACRO Consultants to PBS&J is too lengthy of an image for this media of publication but will be made available at the time of presentation of this document at the Annual Esri User Conference in San Diego, CA in July of 1997.
A similar analysis will be performed with the GIS data provided and the results will be compared with those previously provided by MACRO Consultants. As of teh publication date of this document, no site boundary information has been
received by PBS&J from MACRO Consultants. PBS&J Geotechnical staff is currently in the field drilling wells on the sites identified by MACRO Consultants in the preliminary analysis. The results of the sampling efforts will be combined with the GIS data collected thus far in order to simulate groundwater flow and solute transport. Remediation plans will be generated for the highest ranking sites, based upon the results of this analysis.