James M. Evans

Estimating the Acute Toxicity of Produced Waters to Marine Organisms Using Predictive Toxicity Models

Common ions in effluents can be toxic to aquatic organisms over a wide range of salinities. Although the toxicity of high salinity (hypersaline) solutions and low salinity (hyposaline) solutions may be due to osmotic conditions, toxicity may also be the result of specific ion concentrations. Therefore, even in effluents of normal freshwater or marine salinity, common ion toxicity to aquatic organisms may occur in the absence of other toxicants. Little historical data exist on the toxicity of specific ions to freshwater or marine test organisms. Because of the paucity of data on the toxicity of common ions in produced waters, the Gas Research Institute (GRI) sponsored a research program to examine the toxicity of major ions to aquatic test organisms. The goal of this research is to quantify the relationships between common ion concentrations and organism response (mortality), and then to use these empirical relationships to develop models that would allow the prediction of organism response based upon known ion concentrations.

Movement of Arctic Grayling and Mountain Whitefish during an Open-Cut Pipeline Water Crossing of the Wildhay River, Alberta

ABSTRACT For 22 days, we tracked the movements of radio-tagged Arctic grayling and mountain whitefish before, during and after the open-cut installation of a natural gas pipeline underneath the Wildhay River, Alberta. During the study, radio tagged fish were often sedentary (40% of daily observations). Most of the recorded daily movements occurred within the first three to four days after surgical implantation of radio-transmitters. Since there was no identifiable avoidance pattern by fish relative to increased sediment load, the few movements by downstream fish related to construction were probably motivated by disturbances such as blasting or equipment movement. The absence of any avoidance response is attributed to the relatively low suspended sediment concentrations during construction, the lack of habitat alteration, and natural events (spring run-off or storm events) causing equal or greater periods of sediment exposure.

Overview of the River and Stream Crossings Study

Publisher Summary Construction in and around watercourses can disturb aquatic systems and cause changes to the physical, biological and (to a lesser extent) chemical components of aquatic ecosystems. The River and Stream Crossings Study was undertaken in order to improve the understanding of the biological effects of sediment released during open-cut pipeline water crossing construction, measure the effectiveness of isolated pipeline water-crossing techniques, and develop a defensible sediment effects assessment framework for open-cut pipeline water crossings. The study involved the monitoring of suspended sediment and biological effects at a series of open-cut and isolated pipeline watercourse crossings throughout Canada and the United States. The results of the studies increase the current understanding of the nature of sediment entrainment during crossing construction and the potential adverse effects on fish, benthic invertebrates and fish habitat. Predictive models were developed to estimate the potentially adverse effects. These models provided the basis of a sediment-effects framework that could provide pipeline planners, construction contractors and regulatory agencies with an easy-to-use tool for estimating the adverse effects of pipeline watercourse crossing construction on aquatic biota.

Control Device Monitoring for Glycol Dehydrator Condensers: Testing and Modeling Approaches

The Maximum Achievable Control Technology (MACT) standards for the oil and natural gas industry are expected to be proposed in early 1997, with promulgation later in the year. These standards will include control device monitoring requirements to show that controlled sources are in continuous compliance with the MACT standard. Since condensers are the most widely used control option for glycol dehydrators, the monitoring requirements for condensers are of particular interest; this requirement may include recording the condenser outlet temperature. Performance testing on all condenser units may be required to establish the appropriate site-specific temperature that indicates whether a unit is achieving the desired level of control. Computer modeling is a less expensive and more flexible alternative for establishing this temperature and defining a site-specific condenser curve, but this approach has not previously been validated through field measurements. Gas Research Institute (GRI) has initiated a field condenser test program to collect the data necessary to validate the use of computer programs, such as GRI-GLYCalC TM and commonly available process simulation packages, in predicting glycol dehydrator vent condenser efficiency. A series of nine test, at seven sites have been conducted to collect these data. This paper will present the results of the field testing (performed on several different condenser types, including air-, glycol-, and water-cooled systems), and make comparisons to the modeling results. The paper will also include general information on the key process parameters affecting condenser performance.

Field-based research on elemental mercury spills

Natural gas industry sites have been contaminated in the past by elemental mercury (Hg) from gas flowmeter manometers. Flowmeters (metering stations) are located throughout the natural gas distribution system at wellheads, at gas processing plants, along gas transmission lines, at underground gas storage facilities, and at points of end use. Field site instrumentation has occurred at six field research sites located in natural gas production areas of the United States. These field research sites, located in Louisiana, Pennsylvania, and New Mexico, are representative of diverse climatic, geologic, and hydrologic conditions.In situ hydraulic conductivity measurements on these sites represent a range of 10−4 to an estimated 10−10 m/s. Mean annual precipitation ranges from near desert (extremely negative annual water budget) to subtropical (extremely positive annual water budget). Geologic materials found on the six sites include stratified alluvial clays, weathered bedrock, and coarse sands and gravels. Each of these sites has had documented spills of elemental Hg and has been instrumented with stainless steel monitoring wells, each of which has a dedicated stainless steel and Teflon sampling pump. These monitoring points have been sampled quarterly in an effort to develop fundamental information on the transport and fate of Hg in the shallow subsurface, under a range of climatic, geologic, and hydrologic conditions. Both field-filtered and unfiltered groundwater samples have been collected as part of the quarterly sampling effort to determine the potential role of colloid-borne Hg transport in shallow groundwater systems. Data collected from five consecutive quarterly sampling efforts at the New Mexico and Pennsylvania sites suggest that there has been no apparent adverse impact to shallow groundwater in the immediate vicinity of the research sites. A quarterly monitoring program is currently under way at the two Louisiana sites.

Use of Fourier Transform Infrared (FTIR) Instrument for Air Toxic Compound Screening and Quantitation in the Natural Gas Industry

In response to the 1990 Clean Air Act Amendments, the Gas Research Institute is investigating emissions of air toxics from natural gas industry sources. As part of this effort, air toxic emissions data has been collected for various gas industry sources using a combination of measurement methods, including extractive Fourier Transform Infrared (FTIR). The FTIR protocol used during, the program was initially developed along with quality control/quality assurance (QA/QC) procedures to meet the needs of the air toxics measurement program. Since there are no validated measurement methods currently available for quantifying aldehyde emissions from engines, GRI initiated a field test to validate the extractive FTIR method for measurement of these species using U.S. EPA Method 301 Field Validation of Pollutant Measurement Methods for Various Media. FTIR and other measurement methods were used in the field to collect air toxics data from sources located at a sour gas plant, as well as internal combustion (IC) engines at compressor stations. At the sour gas plant, emissions were monitored for IC engines, gas turbines, heaters, boilers, and tanks, as well as other sources. This paper presents a summary of the extractive FTIR measurement method, the development of the measurement protocol and reference spectra, and how the method was used in the field for data collection. Also included is a summary of the results using FTIR during the first four measurement campaigns, and a discussion of the FTIR validation effort using EPA Method 301 procedures.