Marcelo F. Ortega, Environmental Geochemistry Group, E.T.S.I. Minas Madrid, Universidad Politécnica de Madrid, Alenza 4, E-28003 Madrid, Spain, Tel: +34 913 366 992, Fax: +34 913 366 948
Jerónimo E. García-González, Environmental Geochemistry Group, E.T.S.I. Minas Madrid, Universidad Politécnica de Madrid, Alenza 4, E-28003 Madrid, Spain, Tel: +34 913 366 993, Fax: +34 913 366 948
Luis F. Mazadiego, Environmental Geochemistry Group, E.T.S.I. Minas Madrid, Universidad Politécnica de Madrid, Alenza 4, E-28003 Madrid, Spain, Tel: +34 913 367 005, Fax: +34 913 366 948
Eduardo De Miguel, Environmental Geochemistry Group, E.T.S.I. Minas Madrid, Universidad Politécnica de Madrid, Alenza 4, E-28003 Madrid, Spain, Tel: +34 913 366 992, Fax: +34 913 366 948

Traditionally, the task of locating and quantifying subsurface accumulations of NAPLs present in the subsurface at contaminated waste or industrial sites has involved drilling and core-sampling the vadose zone and installing wells to collect samples of groundwater and free-phase products if present. Drilling, coring, pumping, preserving, transporting and analyzing solid and liquid samples are all expensive operations. If preliminary information regarding the location of the source zone and of the plume of contaminants is lacking or is insufficient, there is a clear risk that time and money will be wasted in drilling and installing wells in the wrong locations, where they will yield useless or misleading data. Non-intrusive, time-efficient surface techniques, i.e. soil vapor analysis, geophysical methods and radon measurements (emanometry) can be used to minimize this risk. The results of field experiments show that the activity of 222Rn is significantly reduced above pools of NAPLs due to radon’s preferential partition into the organic phase, and that the boundaries of the free phase plume are marked by an increase of radon signal above local background levels due to the accumulation – and subsequent decomposition – of uranium in the reducing environment around hydrocarbon pools. Since the diffusivity of radon in the subsurface is higher than that of most volatile organic compounds, emanometry is considerably less sensitive to depth and soil heterogeneity than surface soil-gas measurements, and is applicable even when the amount of organic vapors reaching the ground surface is very low or non-existent. All of the above suggest that radon monitoring can be effectively used to draw the surface trace of NAPL accumulations for a wide range of pollutants even in difficult geologic environments.

The Value of Characterizing the Hyporheic Zone at a Variety of Contaminant Sites

Mark Emmons, Resource Laboratories, LLC, 124 Heritage Avenue #10, Portsmouth, NH 03801, Tel: 603-436-2001, Fax: 603430-2100
Richard S. Behr, Maine Department of Environmental Protection, Station 17, Augusta, ME 04333, Tel: 207-287-6828, Fax: 207-287-7826
Troy Smith, Maine Department of Environmental Protection, Station 17, Augusta, ME 04333, Tel: 207-287-7786, Fax: 207-287-7826
Brian Beneski, Maine Department of Environmental Protection, Station 17, Augusta, ME 04333, Tel: 207-287-4858, Fax: 207-287-7826

In New England , groundwater flow paths generally terminate in the vicinity of surface water bodies.  Groundwater discharges often manifest themselves as distinct springs or as wetlands adjacent to a stream or river while in other instances the groundwater may discharge directly to the stream through the underlying sediments.  This zone of discharging groundwater is called the ‘hyporheic zone.’  Characterizing the chemistry of this discharging water provides useful information about upgradient contaminant sources and impacts to surface water bodies.  Using a push point ™ sampler, an inexpensive sampling device, one can assess the chemistry of discharging groundwater.   We discuss hyporheic zone characterization data from several contaminant sites to illustrate a variety of reasons why it is a useful component of a site investigation.  We present data from two sites where characterization of the hyporheic zone provided invaluable data about upgradient groundwater quality before installation and sampling of monitoring wells.   Evaluation of the hyporheic zone can also optimize subsequent monitoring well placement.   In one example, groundwater data from a small network of bedrock monitoring wells demonstrated the existence of a contaminant plume associated with a sludge filled quarry but limited funds precluded the downgradient delineation with additional bedrock wells.   However, the subsequent chemical characterization of the hyporheic zone along a small brook identified groundwater discharges more 1200 feet from the source.   Perhaps most importantly, historically investigators have largely relied on surface water samples to assess the impact of discharging contaminant plumes.  Characterization of the hyporheic zone may reveal the biota residing in the stream sediments are exposed to a very different chemical environment.  We present data from two sites where the hyporheic zone water quality data clearly demonstrates the surface water chemistry yields little about the chemical environment within stream sediments, the portion of the stream in which benthic organisms live.

Utilizing LNAPL Laboratory Testing Methods to Evaluate Mobility for Site Characterization & Selection of Remedial Alternatives

Brandon J. Fagan, PG, LSP, Haley & Aldrich, Inc., 465 Medford Street, Suite 2200, Boston, MA 02030, Tel: 617-886-7400, Fax: 617-886-7791
Michael Brady, PG, PTS Laboratories, Inc.,8100 Secura Way , Santa Fe Springs, CA 90670, Tel:  562-907-3607, Fax:  562-907-3610

Current progress by the EPA, API, RTDF and a wide array of researchers over the last 20 years have developed tools and models to characterize the potential mobility of NAPL, more specifically LNAPL for petroleum impacted site assessment. Conventional methods and modeling for the potential mobility has relied heavily on indirect indicators of LNAPL plume stability and mobility in soil utilizing well information, fractional concentration of organics in soil characterized with EPA methods, saturation profile modeling and other.  Laboratory test alternatives under consideration for direct quantification of LNAPL mobility in soil coupled with lines of evidence for the site are reviewed for practitioners use ranging from comparison of field saturation relationships to residual saturation capacities of the soil to methods to obtain results with more direct methods that include capillary pressure drainage relationships, analysis of the relative permeability of the LNAPL to flow in soil in the presence of groundwater, and methods for measurement using unsteady state constant flow testing and water flood pore volume exchange methods to quantify LNAPL drainage and imbibition. Methods of analysis such as these reinforce field observations and develop the understanding of the migration potential of a plumes source and boundaries with more direct quantitative procedures to support risk based approaches for land reuse.   Further, for feasibility analysis of site treatment, they can be instrumental in quantifying the potential performance of a remedial technology for LNAPL containment, recovery, and evaluation of the impacts of amendment and thermal modifications to LNAPL.

No-Purge Groundwater Sampling Evaluation at the Massachusetts Military Reservation 

Matthew Greenberg, CH2M HILL, 318D East Inner Road, Otis ANG Base, MA 02542-5028, Tel:  508-968-4670 x 2230, Fax:  508-968-4916, Email: mgreenb2@ch2m.com
Nigel Tindall, P.G., CH2M HILL, 318D East Inner Road, Otis ANG Base, MA 02542-5028, Tel:  508-968-4670 x 5620, Fax:  508-968-4916, Email: Nigel.Tindall@ch2m.com
Rose Forbes, P.E., Air Force Center for Environmental Excellence, 322 East Inner Road, Otis ANG Base, MA 02542-5028, Tel:  508-968-4670 x 5613, Fax:  508-968-4476, Email: rose.forbes@brooks.af.mil

The no-purge groundwater sampling methodology enables the passive collection of a groundwater sample from a discrete interval within a monitoring well screen without the pumping or purging required by conventional techniques such as low-flow sampling.  No-purge sampling relies upon the natural advective movement of groundwater through an open wellscreen. After sufficient time has elapsed for the sampling device to stabilize, the resulting sample is considered to be representative of the aquifer conditions immediately adjacent to the wellscreen. The primary advantage of using the no-purge technique is the cost savings associated with reduced sampling time, reduced equipment and materials, and elimination of purge water when compared to sample collection through conventional methods using pumps.  The feasibility of integrating the no-purge sampling methodology into a large groundwater monitoring program was evaluated at the Massachusetts Military Reservation (MMR) where at least 1,500 monitoring wells are sampled each year. With this many wells to sample, the cost benefits of integrating this technology into the monitoring program could be considerable.  Two types of no-purge sampling devices were tested and evaluated: the passive diffusion bag sampler (PDB) and the HydraSleeveÒ sampler.  A series of “side-by-side” sampling tests were performed that evaluated the performance of: (1) PDBs versus the traditional low-flow pump sampling techniques; and (2) PDBs versus HydraSleeveÒ samplers.  The testing consisted of a comparison of the analytical data generated using each sampling technique, a qualitative assessment of the useability of the sampling devices, and an evaluation of the potential cost savings of using no-purge techniques against the conventional low-flow pump methods.  In addition, the evaluation reviewed the overall benefits and limitations of the no-purge samplers tested against the traditional low-flow pump sampling techniques currently being utilized at the MMR.   

The Trace Metals and Natural Radionuclides in Seawater from around Oil Field Offshore Platforms. Environmental Study

Sergio F. Jerez Veguería, Universidade Federal Fluminense – UFF, Instituto de Química, Dpto. Química Analítica, Outeiro de São João Batista s/n, Campus do Valonguinho - Centro - Niterói - RJ - 24.020-150, Brazil, Tel: +55 (21) 2629-2142,  Fax: +55 (21) 2629-2143, Email: sfjerez@rdc.puc-rio.br
José M. Godoy, Pontifícia Universidade Católica do Rio de Janeiro, Depto. Química. Rua Marquês de São Vicente, 225 - Gávea, CEP - 22453-900. Rio de Janeiro - RJ – Brazil and Instituto de Radioproteção e Dosimetria, Comissão Nacional de Energia Nuclear. Av. Salvador Allende s/n - Jacarepaguá , CEP - 22780-160. Rio de Janeiro - RJ – Brazil , Tel: +55 (21) 3411-8073, Email: jmgodoy@rdc.puc-rio.br.

Offshore oil and gas production can cause a potential impact to the marine environment. Large volumes of aqueous waste are produced during oil and gas production and, normally, these are discharged, following treatment on the platform, to the sea. In this produced water the high concentrations of metals and naturally occurring radioactive materials (NORM) are often found and this contaminants are being introduced or have entered the sediment and water column near production sites. In this work the offshore seawater samples from the Bacia de Campos oil field were analyzed for  As, Ba, Cd, Co, Cu, Mn, Mo, Ni, Pb, V,  Zn, U, 226Ra, 228Ra and 210Pb. In this paper, a procedure for multielement determination of Cd, Co, Cu, Mn, Ni, Pb, V and Zn in seawater using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is described. The method involves chelation of the metals onto a iminodiacetate resin (Toyopear® AF Chelate-650M) in a column with the simultaneous matrix removal. U and Mo determinations were performed by ICP-MS with ultrasonic nebulizer in quantitative mode (external calibration) using 205Tl as internal standard. The samples (salinity ³ 3.5% p/v) were diluted 1:100 with Milli-Q water and acidified with HNO3 sub-distilled. Arsenic was determined by HG-ICP-MS. Using twenty liter of seawater, after radiochemical separation, the 210Pb was determined by beta counting of 210Bi, and 226Ra and 228Ra were determined by gross alpha and beta counting rate using a proportional 10-channel low-level proportional counter. In general, except for the sampling point immediately at the place of discards of produced water, the trace metals and radionuclides concentrations in the analyzed samples of seawater around de platforms are in agreement with the expected values for unpolluted water.

Focusing on the Collection of Representative Data

John H. Sohl, III, Columbia Technologies, 1448 S Rolling Rd, Baltimore, MD 21227, Tel: 410-536-9911, Email:  jsohl@columbiadata.com
Ned Tillman, Columbia Technologies, 1448 S Rolling Rd, Baltimore , MD 21227, Tel: 410-536-9911, Fax: 410-536-0222, Email: ntillman@columbiadata.com

Many site investigations rely on expensive analyses of a limited number of samples.  This process has proven to be a very costly process requiring multiple visits to a site.  It has also proven not to be an efficient way to assess risk or bring sites to closure.  This is largely due to the fact that the limited data are not fully representative of the entire site and therefore leads to a poor understanding of site conditions.

EPA is encouraging investigators to take a far greater number of measurements to ensure they get adequate coverage of heterogeneous site conditions.  These measurements don’t have to be expensive analyses.  The data can be collected using direct sensing tools like the continuous MIP, CPT or LIF sensors, or field analytical measurements.

The great advantage of using real time field measurements is that a field investigation can be more flexible collecting only data that focuses in on better characterization and risk assessment needs.  The biggest challenge on projects where a lot of data are collected is the real time processing and utilization of the data in directing the field investigation.

SmartData Solutions© is an integrated approach that allows all types of field measurements to be processed immediately so the entire technical team can participate in data review and the optimization of field decisions without them all having to be on site.  Data from mobile and fixed laboratories as well as direct sensing measurements are integrated into high resolution 3D images that can be updated and disseminated every hour.  The result of this process is a continuously evolving Conceptual Site Model that is posted to a secure webpage that all the parties can access and discuss.  This process results in a better supported and better tested site characterization and provides a more reliable data set for risk assessment.

Cleanup Standards and Goals for Urban Fill Soil

Bill Swanson, Vice President, P.E., LSP, CDM Inc., 50 Hampshire Street, Cambridge, MA 02139, Tel: 617-452-6274, Email: swansonwr@cdm.com
Pam Lamie, MPH, CDM Inc., 50 Hampshire Street, Cambridge, MA 02139, Tel: 617-452-6311, Email: lamiepo@cdm.com

Understanding background contaminant concentrations in urban soil is critical to expediting and economizing cleanup at urban/brownfield properties. The objective of this paper in support of a poster presentation is to examine metals and polynuclear aromatic hydrocarbons (PAHs) common to urban soil and to identify natural soil concentrations, historic fill soil concentrations and those concentrations that clearly indicate a site of release of contaminants or an outlier. This effort will detail common historic fill background concentrations versus distinct release concentrations or outliers in a form that can be readily used by a site assessment professional to screen urban sites.

The objective was accomplished by using approximately 5,000 samples of urban soil available to the authors and primarily subjecting the data to statistical analysis. The database available to the authors has generally been derived from sites in urban New England and, in particular, Boston . Moreover, findings elsewhere in terms of background concentrations of these contaminants in soil will also be provided to enhance the poster presentation. The mean values derived for key parameters were incorporated into risk assessment calculations to determine if the defined urban fill soil was also a significant risk.  By incorporating a large data set into an analysis, the authors developed a tool that can readily be overlaid by an analyst using a smaller, site specific data set particular to a given property or site under consideration. This overlay approach using a short list of key parameters provides the analyst with a powerful tool to determine how many data points, if any, occur beyond normal urban soil limits. A ninety (90) percent cut off point was selected as an allowable maximum and an upper confidence limit on the mean was calculated.  The metals addressed include arsenic, beryllium, chromium, nickel and lead.  PAHs are represented by benzo(a)pyrene and dibenzo(a,h)anthracene.

Can Fractured Bedrock Sites be Characterized Sufficiently to Recommend Viable Remedial Technologies?

Jim Vernon, ENSR, 2 Technology Drive, Westford, MA 01886, Tel. 978-589-3075, Fax 978-589-3100, Email: jvernon@ensr.aecom.com
Mark Kauffman, ENSR, 2 Technology Drive, Westford, MA 01886, Tel. 978-589-3071, Fax 978-589-3100, Email: mkauffman@ensr.aecom.com
Patrick Haskell, ENSR, 2 Technology Drive, Westford, MA 01886, Tel. 978-589-3095, Fax 978-589-3100, Email: phaskell@ensr.aecom.com

Despite advancements in biogeochemical data and geophysical tools, the distribution and transport of groundwater contaminants through crystalline bedrock fractures remains challenging to conceptualize. Groundwater flow can be restricted to a discrete subset of connected bedrock fractures, while contaminant transport may not be well correlated with the degree of fracture-zone hydraulic activity.  While characterizing hydraulic interconnectivity between source areas and receptors and between individual wells is a desired component of a conceptual site model (CSM), scale issues may prevent the identification of specific contaminant pathways or the prediction of contaminant concentrations throughout a site. This predicament extends into the identification of remedial technologies and the common lack of confidence in recommending a truly viable option.

This particular case study has been the subject of prior papers, demonstrating the sophisticated array and sequencing of investigatory tools applied to developing the CSM.  The site is coastal Maine, dominated by shallow metavolcanic and intrusive bedrock, with little overburden material.  Groundwater flow is controlled by bedrock fractures, lithologic contacts, or faults.  CVOCs discharged on site from past operations have been detected in wells at concentrations up to 4,000 micrograms per liter, with a heterogeneous and somewhat unpredictable and unexplainable spatial distribution. 

Investigations have included:  geologic and fracture mapping, surface and borehole geophysical surveys, whole-well and packer sampling, monitoring well installation and angled coring, rock matrix analysis for CVOCs, rock mass characterization, soil sampling, photolineament analysis, borehole radar investigation, hydrophysical logging, packer sampling, and water level monitoring.  A combination of conventional and less frequently-applied techniques has allowed an assessment of contaminant transport pathways in the source area, a refinement of the CSM for the overall site, and a more direct evaluation of remedial options.  However, despite the use of these tools and well-executed investigatory program, there are no remedial technologies that appear to have the potential to restore aquifer conditions.  This creates a situation where the optimum approach could be to simply continue protecting receptors from coming in contact with contaminated groundwater.  This paper critically evaluates what level of investigation is essential, before such a finding can be concluded.

Phosphorus Enrichment in Weihe River of China

Dr. Jialong Lu, College of Resources and Environmental Science, Northwest Agriculture and Forestry University, Yangling, Shaanxi 712100, China and Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003, Tel: 413-545-2739, Fax: 413-545-3958, Email: ljlll@nwsuaf.edu.cn or jialong@psis.umass.edu
Dr. Baoshan Xing, Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003, Tel: 413-545-5212, Fax: 413-545-3958, Email: bx@pssci.umass.edu

Phosphorus (P) is an essential element for plant growth, but it also is a key element for eutrophication of water bodies. The loss of P from agricultural soils leads to not only reduced utilization efficiency of fertilizers and high cost of agricultural production, but also to the P enrichment in surface and ground waters. In this study, water samples were collected at seven sampling locations along Weihe River on eleven occasions between March 2004 and March 2005. Total P (TP), molybdate reactive P (MRP) and total dissolved P (TDP) of the water samples were measured. Dissolved organic P (DOP) and total particulate P (PP) were calculated by the difference between TDP and MRP, and between TP and TDP, respectively. The results showed that the average concentration ranges of TP, MRP, DOP and PP in Weihe River were 0.18~1.48 mg P L-1, 0.018~0.38 mg P L-1, 0.019~0.23 mg P L-1and 0.074~1.28 mg P L-1, respectively. The average proportion of PP (58%) was higher than that of MRP (22%) and DOP (20%). The data of TP and MRP in this study exceeded the eutrophication threshold levels (0.1 mg L-1 for TP and 0.01 mg L-1 for MRP). Most likely, P in Weihe River is coming from the agricultural soils along the river banks, particularly in September due to the amount of rainfall. Therefore, it is important to have appropriate soil management to reduce soil runoff, thus, the output of P to Weihe River .  

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