Hawley Elisabeth L, Kresic Neven, Wright Alexandra P, Kavanaugh Michael C
Malcolm Pirnie, Inc., Emeryville, CA 94608, USA.
J Air Waste Manag Assoc. 2009 Mar;59(3):332-42. doi: 10.3155/1047-3289.59.3.332.
Several states have recently considered altering disposal requirements for chromated copper arsenate (CCA)-treated wood waste, particularly Florida, where CCA-treated wood waste is disposed in unlined construction and demolition (C&D) debris and Class III municipal solid waste (MSW) landfills. The primary concern is the potential for CCA-treated wood waste to elevate arsenic levels in groundwater downgradient of the disposal sites. To address this concern, we evaluated the impact of past disposal practices of these wastes in unlined Florida C&D and Class III landfills by conducting a statistical analysis of two sets of groundwater data compiled by the Florida Department of Environmental Protection (FDEP). The databases contain water quality data from C&D and Class III landfills in Florida covering 15 yr of record from February 1992 through February 2007 and together provide the most complete datasets to evaluate this issue. Comparative statistics of the different population groups in the databases showed that the arithmetic mean concentrations of total arsenic were in most cases higher in background wells than in wells downgradient of the landfills. The statistical analysis indicates that past disposal of CCA-treated wood in C&D and Class III landfills in Florida has not increased arsenic levels downgradient of the landfills. Policy decisions regarding the continued disposal of CCA-treated wood waste as a nonhazardous waste in unlined landfills must therefore be based on a scientifically sound assessment of potential future impacts. Quantitative predictions of future impacts are difficult and pose several scientific challenges. Therefore, future management decisions should be based on a more accurate and comprehensive risk analysis that assesses the risks and benefits of different alternatives and takes into account the natural attenuation capacity of soils and aquifer solids for arsenic and the practical limitations of managing this waste stream as a hazardous waste.
最近，有几个州考虑改变对铬化砷酸铜（CCA）处理过的木材废料的处置要求，尤其是佛罗里达州，在该州，CCA处理过的木材废料被处置在无衬里的建筑和拆除（C&D）废墟以及III类城市固体废弃物（MSW）填埋场中。主要担忧在于，CCA处理过的木材废料有可能使处置场地下游地下水中的砷含量升高。为了解决这一担忧，我们通过对佛罗里达州环境保护部（FDEP）汇编的两组地下水数据进行统计分析，评估了这些废料过去在佛罗里达州无衬里的C&D和III类填埋场中的处置做法所产生的影响。这些数据库包含了佛罗里达州C&D和III类填埋场的水质数据，记录时间从1992年2月至2007年2月，长达15年，共同提供了评估该问题最完整的数据集。数据库中不同群体的比较统计数据表明，在大多数情况下，背景井中总砷的算术平均浓度高于填埋场下游井中的浓度。统计分析表明，过去在佛罗里达州的C&D和III类填埋场中处置CCA处理过的木材并没有使填埋场下游的砷含量增加。因此，关于继续将CCA处理过的木材废料作为非危险废物在无衬里填埋场中处置的政策决策，必须基于对未来潜在影响的科学合理评估。对未来影响进行定量预测很困难，并且带来了几个科学挑战。因此，未来的管理决策应基于更准确和全面的风险分析，该分析要评估不同替代方案的风险和益处，并考虑土壤和含水层固体对砷的自然衰减能力以及将这种废物流作为危险废物进行管理的实际限制。
