GEOSS Support for Decision-Making in the Coastal Zone: Managing and Mitigating the Impacts of Human Activities and Natural Hazards in the Coastal Zone

A workshop series organized by the GEO Coastal Zone Community of Practice

Earth Observation Support for Sustainable Tourism in Small Island States
March 9-11, 2011, Puerto Rico

Coal Ash Disposal in Puerto Rico

Ruth Santiago and Comité Dialogo Ambiental, Inc.
P.O. Box 518, Salinas, Puerto Rico 00751.

The secondary use of 300,000 tons per year of coal combustion residuals (CCRs) from the AES Coal Combustion plant in Guayama, Puerto Rico as fill material at construction sites above a sole source aquifer in the vicinity of public supply water wells and densely populated, flood prone areas poses risks of imminent and substantial endangerment to human health and the environment. Many CCR disposal sites are located just north of mangrove forest systems such as the Jobos Bay National Estuarine Research Reserve, a National Oceanic and Atmospheric Administration (NOAA) designated facility.      

Analytical test results of AES CCRs indicate alpha particles of 9.9 pCi/g, nearly twice the levels of CERCLA applicable or relevant and appropriate requirements (ARARs), in addition to 5.7 pCi/g of beta particles and high levels of arsenic and other metals.  A Texas A&M University study indicates that all coal combustion by-products possess unique properties based on the composition of the coal ash and production processes. The authors indicate the need for further research and that the AES CCRs, “should not be used as a pavement base of structural foundation until the chemical stability potential is satisfactorily addressed.”

A University of Puerto Rico study indicates the need for corrosivity testing, evaluation for expansion due to moisture, leachate composition studies, tests to determine organic impurities and elasticity index, checks for potential impact to groundwater and the possibility of radioactive components, determination of achievable compressive strengths, flowablility tests, corrosion potential in high humidity, detailed feasibility study, examination of the CCRs high abrasion potential, risk of saturation, testing with a field component taking into account potential degradation and strong alkaline characteristics. The authors cited the large variations in CCRs, moisture content, damage to plant transpiration and photosynthesis from CCRs, percolation to groundwater risks, susceptibility to collapse that increases with inundation stress such as rising water tables, elevated sulfur levels and swelling damage. The use of CCRs near water bodies with low flow rates such as swamps or marshes may cause local environmental damages.  EPA has long recognized that unlined disposal sites over shallow ground water with nearby wells pose risks to human health and the environment. Various studies have documented deformities in wildlife due to CCR contamination of habitats.

A fugitive dust screening assessment indicates that CCRs pose risks of exceeding National Ambient Air Quality Standards. CCR dust can be carried over long distances and settle on ground or water. Effects can include alteration by CCRs of nutrient balance of coastal waters, depletion of soil nutrients, damage to ecosystems and farms.