J. Olcott, Envirogenics Health and Safety Services, LLC, Hamilton, NJ; J. Dennison, Princeton Analytical, Flemington, NJ.
Evaluating the indoor air pathway from contaminated soils and groundwater has become a mandatory part of environmental remedial action work plans in several states, including new Jersey, Pennsylvania, New York, and Massachusetts. This approach to subslab and indoor sampling and analysis methods, as well as a tied approach to risk assessment of the indoor air quality, closely follows the Johnson and Ettinger model as well as the Environmental Protection Agency’s “Draft Guidance for Evaluating the Indoor Air Pathway from Contaminated Soils and Groundwater.“ Several case studies will be presented.
S. Rucker, H.C. Nutting Co., Cincinnati, OH.
When tourist destinations such as museums and theaters undergo renovation, it is good business to conduct air quality and nondestructive materials testing prior to commencing work. Often, these institutions want to minimize service interruption during renovation. What industrial hygiene test methods help support this goal? Hazardous materials surveys, indoor air tests, and nondestructive testing on building materials combine to yield insight on building performance. The results show the locations where building systems are underperforming and link problems to sources. This information becomes integral to project planning and construction sequencing.
How is this accomplished? Hazardous materials surveys identify the quantity and location of protential problems. Preconstruction air quality tests establish baselines and evaluate occupant health concerns. Nondestructive building materials tests identify microscopic failures that are responsible for indoor air pollutants. A method for prioritizing work comes from linking hazardous materials to building system failures, using air tests to determine the severity for unhealthy building conditions. Management uses this information to establish priorities.
At a cost of between 10 cents and $1.50 per ft/2, testing is inexpensive when compared to renovation costs between $200 and $400 per ft/2. The results of two museum assessments will be presented. Findings illustrate the importance of working with building systems (envelope and mechanical) as an integrated whole, and understanding performance even when it may differ from design. For public institutions, this protocol can minimalize service interruption and demonstrate proper management.
S. Roda, S. Clark, P. Succop, University of Cincinnati, Cincinnati, OH.
The ability to use a field portable X-ray fluorescence (XRF) analyzer for field measurement of lead in dust wipe samples could contribute to more timely results and potentially lead to a reduction in the cost of lead hazard control activities. XRF has been established successfully for the estimation of lead on painted surfaces in and around structures. Investigations have also evaluated XRF instrument use for detecting lead in air, leading to the development of NIOSH Method 7702. More recently, XRF analysis of lead in soil and dust wipes for field application has been reviewed, but the accuracy and precision of results still remain in question, particularly for dust wipes from instrument to instrument. Portable XRF technology has advanced rapidly, particularly in an attempt to provide reliable results for the field analysis of lead in dust wipes for clearance samples and formation of mobile on-site laboratory capabilities. New instrument designs, addition of X-ray tube applications, and increased sealed source strength are all industry attempts to provide greater capabilities for XRF lead testing and other elemental analysis. However, it is important to understand if there are differences among XRF instruments due to basic performance characteristics relative to the wipe material used for sample collection, including size, thickness, effects of moisture, sample particle size distribution, sample lead source, and sample homogeneity — none of which has ever been thoroughly addressed. Therefore, we will present data from experiments investigating wipe sampling material, moisture, and sample matrix effects, based on an evaluation of new instrument designs, detectors, and radiation sources.
H. Houng, Taiwan EPA, Taipei, Taiwan.
The solid waste generated in Taiwan is estimated at over 23 million tons per year: 8 million tons of municipal waste and 15 million tons of industrial waste. Municipal waste has been treated with incineration and other methods, such as sanitary landfill, resource recycling, and waste separation, without much difficulty. But how to handle industrial waste in this technologically fast-growing region was becoming increasingly challenging. One of the critical deficiencies in industrial waste management in Taiwan was hazardous waste treatment, storage, and disposal (TSD) facilities. Inadequate grasp of information on industrial waste streams also contributed to the difficulty in developing new TSD facilities. To promote environmentally friendly industries and eradicate illegal dumping, an effective surveillance program with a real-time monitoring system on the waste flow and its destination is essential. Established in 2000 in Taiwan, the National Industrial Waste Control Centeruses state-of-the-art Internet technologies and employs real-time tracking and online control of industrial waste ¾ hazardous waste in particular. In addition, global positioning systems, geographic information systems, personal digital assistant devices, and bar coding systems were installed to enhance the functions of the center. Today, over 12,000 generators, 700 haulers, 200 treatment facilities, and 20 final disposal facilities are required by law to report their activities involving waste management to the center. As of 2005, over 14.6 million tons of industrial wastes — 96% of the estimated annual yield (15.1 million tons) — were reported. With the establishment of this industrial waste control center, with a technology-based, real-time waste tracking system, Taiwan EPA has effectively reduced illegal dumping as well as promoted TSD facilities.
S. Maberti, T. McHugh, J. Connor, Groundwater Services Inc., Houston, TX.
Vapor intrusion from affected soils and groundwater into overlying structures has been identified as a potential mechanism for human exposure to volatile organic chemicals. The enforcement of the Environmental Protection Agency and state guidance for evaluating vapor intrusion to indoor air, together with the OSHA mandate to protect workers’ health, are rendering the assessment of this pathway an important aspect of workplace evaluation. Background indoor air concentrations can contribute to incorrect conclusions regarding the presence of subsurface vapor intrusion impacts at buildings’ overlying affected soils or groundwater. To assist in distinguishing actual vapor intrusion impacts from background indoor air sources, this paper presents site investigation and data analysis methods that have been used successfully in evaluating vapor intrusion pathways. These methods include (1) collection of indoor and below building foundation air samples and comparison with background measurements, (2) vertical concentration profiling of soils and groundwater to estimate attenuation factors, (3) statistical correlation between indoor air in target and background buildings, (4) use of tracer gases to evaluate potential for vapor intrusion, and (5) measurement of pressure gradients across the building foundation to understand driving forces for transport across it. Due to the physicochemical characteristics of the volatile organic compounds, in the event of vapor intrusion, the chemical composition in indoor air would be comparable to that of subsurface vapors. Similarly, indoor air conditions above the affected soil or groundwater zone must be measurably distinct from background data and evidence a stronger relationship to subsurface vapors than background sampling points. Failure to detect appropriate relationships indicates that indoor air quality is dominated by background sources rather than vapor intrusion effects. These tools have been applied at a number of corrective action sites. In many cases, they have demonstrated that indoor air conditions previously attributed to subsurface vapor intrusion are, in fact, attributable to background indoor air sources.
H. Martin, EAI Inc., Jersey City, NJ.
Indoor air quality (IAQ) is an important consideration for both health and liability. Vapor barriers such as high-density polyethylene (HDPE) sheet products or fluid applied membranes can both play a key role in the prevention of hazardous vapor intrusion into buildings. IAQ can be both an odor nuisance and a real carcinogen that must be regulated. In many cases in the United States and abroad, various new construction projects are built on brownfield sites, where there is a known contamination in either the soil or groundwater. Vapor barriers can prevent the migration of hazardous vapors into a building, and they can also be used in conjunction with full or partial remediation of a site to limit the liability of the owner and occupant. The issue will be addressed with a two-pronged approach. First, case studies will be presented where vapor barriers were shown to provide long-term benefits for indoor air quality. Second, current regulations in a few select states (regarding the use of vapor barriers) will be discussed with respect to the increasing need to prevent vapor migration into buildings. In closing, there is proof that vapor barriers can provide a benefit for both new construction and for retrofitting, thus warranting attention from the environmental profession and community.
E. Cahill, EMSL Analytical, Westmont, NJ.
The need to determine asbestos content in soil and rock arises in many diverse situations. Unfortunately, the problems associated with soil analysis are as diverse as the scenarios surrounding them. Many of the problems associated with soil analysis are related to particle size and homogeneity. To be conducive to microscopic analysis, an ideal sample is a fine powder with particulate that is of uniform size. Homogeneity in a sample is also very important, since typically only a small portion of a given sample is analyzed. There are two main (and radically different) approaches to dealing with the issues of asbestos in soil analysis. The selection of the method is invariably a compromise, due to the advantages and disadvantages of each. Sieving is an approach that separates the sample components based on size. Each size fraction is weighed then analyzed by a method suitable for that size. Stereomicroscopy is used for material too large to mount on a slide. Polarized light microscopy (PLM) and even transmission electron microscopy (TEM) is used for finer particulate. With milling, all components of the sample, including stones and twigs, are milled to a size conducive to microscopic analysis. The milling scenario is useful in the case of naturally occurring asbestos (NOA). This is because asbestos often is in the rocks and stones that are part of the sample and the milling process will release it. Additionally, this method is desirable because the milled sample is amenable to TEM prep procedures. TEM is often necessary to find the asbestos that is present as very small unconsolidated fibers (due to weathering) that can be beyond the limit of resolution of a light microscope. These procedures will be discussed using situational examples and results.