Western Div Comments Coalbed Methane EIS

The American Fisheries Society was established in 1870 and is the country�s oldest and largest organization of professional fisheries biologists and scientists. The Western Division (WD) was established in 1948 and includes 13 State and Provincial Chapters throughout the western U.S. and Canada with some 3,000 members.

Occasionally the WD comments on regional fisheries issues deemed important and relevant to Division members. In this case, the decision to do so was driven by previous comments from the Montana and Colorado-Wyoming Chapters regarding draft documents pertaining to coal bed methane (CBM) development in the Powder River basin, and subsequent discussions between WD and Chapter officers about coal bed methane (CBM) development in the West. The regional nature of current and potential CBM development, the general paucity of specific information about the many fish species, habitats, and ecosystems potentially affected by large-scale CBM development, and a perception that aquatic resource issues deserve greater attention, all prompted the decision to coordinate a larger WD involvement.

Attached (see below) are additional comments from the WD on the Final Environmental Impact Statement and Proposed Plan Amendment for the Powder River Basin Oil and Gas Project (FEIS) issued by your agency. These comments were prepared according to Western Division by-laws and several steps were taken to ensure that comments were science-based, meaningful, and consistent with WD by-laws. The Environmental Concerns Committee solicited reviews from expert members throughout the WD Division, WD officers and the Policy Review Committee provided oversight of the commenting process and deemed it appropriate for the time available, and all WD officers had an opportunity to review the comments.

While the following comments are specific to CBM development in the Powder River basin in Wyoming, they are generally applicable to proposed CBM developments in the Powder River and Tongue River basins in Montana, and almost certainly elsewhere. They are derived from the collective diversity and expertise of Western Division members and based on an intimate, and arguably unparalleled, familiarity with fisheries resource issues across the West. While it would be disingenuous to imply that these comments represent all possible views or perspectives among WD members regarding CBM development, individuals well versed with the technical and biological issues presented in the FEIS have prepared them. I am satisfied they have provided legitimate, technically sound, scientifically based, and constructive comments on this important document.

Comments generally focus on several elements of the FEIS that deserve additional attention as CBM development progresses. Important questions remain about water quality and risk assessment to aquatic biota, the adequacy of NPDES permitting requirements, and implementation of an effective monitoring, mitigation, and adaptive management process.

Because the WD is not formally protesting the FEIS, it is understood that BLM is not obligated to accept or respond to these comments. However, because the Mitigation, Monitoring and Reporting Planning Process Implementation section (Appendix D) implies commitment to an adaptive management approach for CBM development, I remain optimistic our comments will be considered fully by decision and policy makers throughout the CBM development process.

In light of limited information about aquatic habitats and their biota, relationships between produced water and aquatic environments, and the certainty that new information will become available as development and monitoring occur, I commend and support implementation of an effective adaptive management element so critical to responsible mitigation and environmentally sound development of CBM resources.

Water Quality and Quantity

The sub watersheds with the greatest number of sensitive fish species are the Upper Tongue River (7 of 10 possible), the Upper Powder River (7 of 10 possible), and the Little Powder River (5 of 10 possible) (Table 3-54). Of existing wells, 6.8% are in the Upper Tongue sub watershed, 23% in the Upper Powder, and 15% in the Little Powder (Table 2-2). The project will place 6.6% of new wells in the Upper Tongue, and only 5.1% in the Little Powder; however, 48% of the new wells will be located in the Upper Powder sub watershed (Table 2-1). The potential adverse effects on sensitive fish species might therefore be disproportionately high in the Upper Powder River. However, the FEIS it is generally poor at identifying the status and potential impacts to native non-game fish species and amphibians. This seems to be due in part to a lack of baseline information on abundance and life history information for these species. Nonetheless, the FEIS does indicate indirect effects on health and reproduction in most of the species might occur due to disposal of production water. Information regarding aquatic macroinvertebrates is even sketchier.

The project is expected to produce 1.2 million acre-feet of water in the Upper Powder River subwatershed. The primary method of production water management will be by infiltration impoundments (60%); 30% will be given passive treatment for oxidation and precipitation of iron. Of the water sent to infiltration impoundments, 28 % is expected to evaporate, 57% to infiltrate, to groundwater, and 15% to resurface. This means that, during the life of the project, approximately 100,000 acre-feet of production water can be expected to enter surface flows after percolating through the soil. The quality of this water might be problematic. Table 4-6 indicates that a SAR 13.4 is predicted for minimum flow conditions in the Upper Powder, exceeding proposed SAR limits of 2 (most restrictive) and 10 (least restrictive) (Table 4-2). In addition, several trace elements in CBM production water (Tables 3-2 and 3-3) exceed various toxicity-screening values recommended by Suter and Tsao (1996). These are summarized in the following table:

The FEIS suggests that effects of CBM production water on surface water quality, and consequently on fish, will be minimal. However, Salt Creek, which is augmented by production water from oil and gas fields, and provides the majority of flow to the Powder River in low-flow conditions, is acknowledged to cause some level of toxicity to Cereodaphnia and fathead minnows. This begs questions about potential impacts when an additional 18,000 CBM wells are established in the Upper Powder River. The potential for evaporation to increase concentrations trace elements in impounded water is also not well characterized, and degradation of sediment quality is not addressed at all.

Tables depicting ambient water quality data are absent, including information on metals, suspended solids and total dissolved solids. Throughout the document, conductivity is used to gage effects on aquatic organisms, rather than the more useful TDS.

Some statements appear incorrect, which raises concerns that other incorrect conclusions or statements may be embedded in the document. Because data needed to evaluate the statements is not presented, it is difficult to resolve this issue. For example, the FEIS states:

The saline quality of the produced water would likely precipitate dissolved metals in the water column, such that sediments beneath CBM produced water containment reservoirs would potentially receive increasing concentrations of organic and inorganic forms of dissolved metals over time. (p. 4-227)

The foregoing sentences are incorrect in three respects. First, metals like copper and cadmium, for example are more toxic in saltwater than in freshwater. This is because the increased ionic strength (concentration) of salt waters has saturated binding sites, increasing the bioavailability of the metal ions. Secondly, precipitated metals reaching the sediments are not dissolved, but particulate. And thirdly, metals like selenium do not behave similarly to metals like barium, copper, and cadmium, and do not precipitate readily with any substances.

Receiving waters in streams and rivers may become less turbid because produced water is relatively low in sediments. This decrease could be detrimental to fish that depend on turbid waters and may allow for more aggressive invasion of exotic species (p. 4-239).

Later, it stated that increased road building likely will export more sediment to streams during rainfall events, and that the increased flow likely will increase sedimentation due to scour. Effects, if any, will vary between watersheds and species, some species favored by increased turbidity and others not. This section ends by mentioning that TMDLs could be applied if sedimentation becomes a problem, while noting that none have yet been developed. Because numeric water quality standards generally do not exist for siltation or increases in the percentage of fine particulates in the gravel, it will be difficult to promulgate TMDLs until these standards are developed.

Concentrations of TDS in CBM discharge range between 270 and 2,720 mg/L (Table 3�2). Discharges higher than 2,000 mg/L may cause adverse effects on invertebrates, as described by Chapman et al. (2000). (p. 4-240)

Although references were cited, there was no explicit mention of effects threshold for fish, and it is unclear why the lowest LOEC for TDS for fish and invertebrates was undefined in the FEIS.

The FEIS is written in a manner that prevents reviewers from independently evaluating of the data. The omission of explicit reference to estimated surface water concentrations and comparison to effects threshold is an example that prevents peer review of the FEIS� inference base. For example:

When mixing with discharges of CBM produced water, is modeled, salinity, as measured by EC, in receiving waters is predicted to increase in the Upper Tongue River, Crazy Woman Creek, Clear Creek, and Middle Powder River subwatersheds during low flow. Salinity is expected to decrease in the Upper Powder River, Little Powder River, Salt Creek, Antelope Creek, Upper Cheyenne River, and Upper Belle Fourche River sub-watersheds during low flow.

Also there is no basis for the following inference and the reader cannot determine whether this statement is opinion or based on data:

Fish present in Salt Creek, such as the fathead minnow, flathead chub, longnose dace, plains minnow, sand shiner and white sucker, are all likely tolerant of high salinities and would be more tolerant of increases in salinity in other sub-watersheds. Other species found within the sub-watersheds with lower salinities may be less tolerant of increases in salinity. (p. 4-240 to 4-241)

The FEIS clearly suggests concern about the risks posed by bicarbonate to aquatic life:

A recent study by the Montana Department of Fish, Wildlife, and Parks (Skaar 2001) described concerns relating to sodium bicarbonate toxicity to aquatic life in the Powder and Tongue Rivers. Fish and macroinvertebrates could be negatively affected by elevated levels of bicarbonate in the receiving sub-watersheds. Concentrations of bicarbonate are generally higher during low flow, and lower during high flow, resulting in greater accumulations and enhanced effects on aquatic life during low flow periods. The study suggests that bicarbonate levels should be monitored for their potential effects on aquatic life, especially fish. (p. 4-241)

A thorough review of the existing literature may disclose that there are sufficient data to address risks rather than simply monitor concentrations. Monitoring only documents concentrations and not impacts. It is not difficult to model bicarbonate concentrations and to compare these to the literature on effects. Based on the following statements it appears the BLM may have produced these data, but if so, it is unclear why they were not presented.

Low, moderate, and high probability thresholds were modeled for each river to establish lethal limits to the fathead minnow; these limits can then be generally applied to many species of fish. These thresholds could be used to initiate a monitoring program for bicarbonate in the sub-watersheds of the Project Area that would receive CBM produced water (p. 4-241).

Selenium also appears to pose potentially significant risk potential to aquatic life:

Selenium could reach harmful levels for fish over the life of the project. It is anticipated that concentrations of selenium in containment impoundments would be higher than in the stream and river systems within the 10 subwatersheds in the Project Area because of evaporative concentration over time.(p. 4-242). Containment impoundments receiving discharges of CBM produced water would have NPDES monitoring requirements for selenium because of its bioaccumulative nature (p. 4-242).

The FEIS recommends monitoring while acknowledging concentrations could be hazardous. Although monitoring is important, it should not be the �action� arising from a determination of potentially significant impact. There is a very substantial literature concerning the aquatic toxicity of selenium, and the BLM could facilitate these calculations, if they had modeled selenium concentrations in the affected environment.

The FEIS makes numerous references to metals, but it is unclear whether reference is specific to selenium and barium or to other metals (e.g., copper, zinc, cadmium, lead). In addition, the FEIS makes an incorrect comparison when inferring risks to aquatic life by referencing water quality standards for human health. EPA has water quality criteria for all environmentally important metals and these should be used instead (see http://www.epa.gov/waterscience/pc/ambient2.html)

All concentrations of trace elements were uniformly low and were below the primary and secondary maximum contaminant levels for drinking water established by EPA (p. 4-241).

The FEIS does not provide enough information to deduce risks to aquatic life from water temperature. The range of produced water temperatures is not important; rather, the temperatures predicted to occur at different times of the year in the receiving streams as a result of the produced waters, in comparison to the temperature requirements of the resident species is the question. . Special attention should be given to critical functions such as spawning and egg incubation, because these are critical functions that are especially temperature dependent.

The temperature of CBM discharge water varies throughout the Project Area and ranges between 12 and 29�C with a median of 19�C. The temperature of streams within the Project Area can range from 0�C during winter to 25�C or more during summer; therefore, changes in temperature are not expected to be dramatic but would vary depending on the location of CBM discharge (p. 4-2420).

Cumulative Effects are addressed on pages 4-64 through 4-69 and focus mainly on the alternatives and especially on groundwater impacts. The surface water analysis is very qualitative and the lack of specific data precludes determining whether cumulative impacts will cause adverse impacts. The FEIS� analysis concerning cumulative impacts of produced waters to surface waters is set forth as follows:

Both mining and development of CBM result in the collection and discharge of water to surface drainages. Mine inflow water is first stored in sediment ponds to reduce sediment picked up in the pit. Much of this water is used for dust suppression and is not discharged to surface drainages, except during certain storm events. The discharge water from sediment ponds potentially would have higher TDS values and be of lower quality as a result of sediment mixing and concentration by evaporation. CBM discharges are essentially sediment-free (as produced from CBM wells), although discharge to surface drainages can increase sediment loading caused by increased stream erosion (p. 4-67).

A more useful quantitative analysis would estimate pollutant loadings, singly and then collectively for the cumulative analysis by watershed. Existing monitoring data would be used to estimate loadings from existing sites, and then the cumulative loadings by watershed would have been based upon the assumption that new loadings would be similar to existing loadings. Because the FEIS did not highlight any additional mitigation on produced water loadings to surface waters, it must be assumed that future loadings are predictable from extant loadings.

Appendix I contains the Water Management Plan. Detection limits for chemical analyses are specified on page I-7. The recommended detection limit for total petroleum hydrocarbons (TPH) of 1 mg/l is too high to be useful for monitoring purposes. Woodward et al. (1983) showed adverse effects to juvenile cutthroat trout growth and survival with chronic exposure to concentrations as low as 39 ug/l and considered 24 ug/l a safe concentration. A detection limit less than 30 ug/l would be desirable. Likewise, the detection limit for selenium, currently set at 5 ug/l, should be less than 2 ug/l.

The proposed mixing model for surface water and CBM produced water described in the EIS and in greater detail in the Surface Water Technical Document appears to be a good first cut for screening purposes. If appropriate conservative criteria are applied, results of the mixing model will allow potential "hot spots" to be identified for additional, more intensive and sophisticated hydrologic and toxicological investigation while simultaneously identifying regions of less concern. If subsequent monitoring indicates adverse impacts to the aquatic communities in situations in which a "hot spot" was not identified, more intensive and sophisticated hydrologic modeling would also be appropriate.

However, we encourage applying the mixing model to individual major ions (Na+, K+, Ca2+, Mg2+, HCO3‑, Cl‑, SO42‑), in addition to the electrical conductivity modeled thus far. Because the toxicity of major ions to aquatic biota varies considerably, conductivity is a not a reliable predictor of toxicity. 3. The discussion of the toxicity of CBM product waters to aquatic organisms generally lacked specificity.

Although the authors acknowledged that the concentration of total dissolved solids (TDS) and conductivity are not the best predictors of toxicity (p. 4-240), they did not discuss individual ions that allow more reliable predictions of toxicity. The Mount et al. (1997) model is discussed (p. 4-240) but is not used to predict potential toxicity to aquatic organisms in receiving waters. We recommend analysis of individual ions in the mixing model, and then applying Mount et al. (1997) model to those results to predict potential toxicity.

Toxicity of elevated concentrations of TDS, chlorides, sulfates and sodium to Ceriodaphnia spp. and fathead minnows (Pimephales promelas) in Salt Creek is briefly mentioned (pp. 3-165,166). However, toxicity of CBM product waters does not appear to be discussed anywhere else. Forbes et al. (2001, 2002) demonstrated acute and chronic toxicity of some CBM product waters and receiving waters in the Powder River Basin (PRB) to Ceriodaphnia dubia, Daphnia magna and/or fathead minnows. Those reports are publicly available but not mentioned in the analysis of potential effects to aquatic species; and they could be used to screen for "hot spots" in conjunction with the BLM's current mixing model.

In several places in the report, increases in stream flows due to CBM product water discharge are discussed as causing potential effects to aquatic species (e.g., Table S-2, p. xxxix). However, the potential effects of dampening of daily and annual cycles in stream flow and associated water quality characteristics (e.g., temperature; turbidity; concentrations and ratios of major ions) are not directly discussed. This dampening of flows and physical-chemical composition might directly affect resident biota and/or alter community composition.

The authors directly addressed some of the concerns about the potential impacts of increased salinity on aquatic communities. However, they never directly addressed the potential impacts of decreased salinity due to the influx of lower-salinity CBM product waters into receiving waters. This situation is most likely to occur in the eastern portion of the PRB (e.g., Belle Fourche River drainage), as predicted by the BLM's mixing model. Clearwater et al. (2002) recommended that this tendency to "dilute" those surface waters be considered just as important as the tendency for CBM product waters in the western portion of the PRB to "salinate" surface waters, because of the potential impacts of "dilute" water to resident biota that are adapted to more saline water.

NPDES Regulation

The preferred alternative is a combination of Alternative 2A and Alternative 1. Emphasis for water handling for Alternative 1 is untreated surface discharge, while Alternative 2A emphasizes infiltration. The Preferred Alternative encourages treatment of produced water, where feasible and practicable. An estimated 9 to 52 percent of CBM produced water would �contribute� [directly] to surface water. The FEIS states that water quality changes downstream of produced water discharges would be �notably changed� and notes that NPDES permits would be relied upon to maintain compliance. This defers the degree of protection to the NPDES process raises the issue of whether numeric water quality criteria, narrative water quality criteria, or biocriteria are available and enforceable for the stressors identified in the FEIS as significant.

The FEIS explicitly states that it is depending on NPDES permits and Total Maximum Daily Loads issued by the WDEQ to determine compliance and remediation for water quality risks. For example:

Concentrations of salts and metals, particularly barium and selenium, may increase in the containment reservoirs receiving CBM produced water discharges, as water evaporates over time. Direct effects (toxicity) to waterfowl could occur, depending on the quality of the produced water. CBM produced waters discharged to off-channel containment impoundments would require an NPDES permit issued by WDEQ, which would establish effluent limitations that would be protective of use by wildlife and livestock. Concentrations of selenium within the impoundments would be monitored as a requirement of the NPDES permit, primarily because of the large volume of water that could be potentially discharged, and the bioaccumulative nature of selenium. Typically, the concentration of selenium in the produced water is fairly low and is normally less than Wyoming water quality standards. However, water quality could reach levels of concern for selenium and other constituents when inflow to the impoundments ceases, and NPDES permit monitoring requirements no longer apply (p. 4-226).

Apparently the BLM monitoring and compliance process relies on WDEQ to monitor compliance and to enforce compliance with water quality regulations. Because the WDEQ does not necessarily have water quality standards for all of the stressors identified as posing potentially significant impacts, the �safety net� is incomplete. This process appears inadequate for accurately quantifying those risks that are significant and those that are not. For example, States usually have numeric criteria for turbidity and narrative criteria for suspended solids, but most have not adopted biocriteria as water quality standards, so they cannot be used to monitor cumulative impacts or the singular impacts of such factors as flow. For changes in substrate particle size, there usually are no standards. Also, the states only can use TMDLs to control cumulative effects.

In Table S-2 (Summary of Effects by Alternative, under Surface Water, Alternative 1, p. xxxiii), the authors imply that, because National Pollutant Discharge Elimination System (NPDES) discharge permit limitations are intended to protect aquatic life in receiving waters, water quality standards and designated uses would not be degraded if an NPDES permit has been granted for a CBM product water discharge. This idea is also mentioned on p. 4‑235. However, the Wyoming Department of Environmental Quality (WDEQ) NPDES permits for CBM product water discharges do not require biological testing, which integrates known and unknown components in the water. Therefore, a permitted discharge might still adversely impact biota in the receiving water. Moreover, surrogate data can be used to obtain an NPDES permit for a CBM product water discharge from WDEQ. Unfortunately, WDEQ's current criteria for selecting those surrogate water quality data appear to be spurious (Clearwater et al. 2002).

Both Wyoming and Montana will impose anti-degradation requirements; yet the FEIS predicts increases in TDS, sediment and metals, so these statements should be reconciled, though this may simply be a matter of defining degradation.

A policy judgment to focus on irrigation uses of surface waters is stated on page 4-69 that could easily be interpreted as a conscious decision to minimize analyzing effects on aquatic biota and habitats:

A major beneficial use of surface water in the Project Area is the production of irrigated crops.

Therefore, the surface water impact analysis focuses on the potential effects to the suitability for

irrigation of surface waters in the Project Area from proposed discharges of CBM produced water.

The analysis of the potential effects of TDS (based on conductivity) was comprehensively modeled. Elevated TDS would be mitigated, where required via NPDES permits, using the following:

Use of active treatment, such as reverse osmosis, or ion exchange systems, to amend the produced water to meet water quality standards prior to discharge would be emphasized. Some level of active treatment would be implemented in all sub-watersheds except for the Upper Belle Fourche River sub-watershed. (p. 4-77).

The FEIS states the following concerning impacts to water quality and quantity: These effects include: (1) changes in timing and quantity of stream flows; (2) changes in sedimentation; (3) changes in concentrations of salts in streams; (4) changes in concentrations of metals (such as barium, selenium); (5) changes in temperatures; (6) accidental spills of fuels or drilling fluids; (7) changes in species diversity; and (8) transboundary effects on water quality.

A fundamental premise of the FEIS is that the discharges will meet requirements of NPDES permits issued by Wyoming�s Department of Environmental Quality. This is perhaps the documents main weakness (the other is cumulative impacts analysis) with respect to impacts on surface water quality and aquatic life.

Risk Assessment

The FEIS does not provide the data needed to determine if conclusions concerning risk magnitude are valid, and data upon which the risk assessments are based need to be presented for review. While the document makes it apparent that stream flow, total dissolved solids, suspended and settleable sediment, turbidity, and selenium, pose potentially significant risks to aquatic life (i.e., fish, invertebrates, algae), the information needed to quantify risks to these biologic elements is generally lacking.

Where the FEIS acknowledges potential risks to aquatic biota arising from total dissolved solids, sediment, flow, and selenium, neither remediation or monitoring are recommended to address those potential impacts. However, because the risks are not quantified, it is impossible to decide whether the risks are so substantial that the produced waters need further treatment or not.

Assessing a project of this magnitude with potential ecosystem level impacts effects would best be approached with a quantitative cumulative impact analysis. While this would require a substantial modeling effort to predict concentrations of many substances in individual streams, it was apparently not considered for those elements the FEIS indicated posed risks (i.e., flow-induced changes in aquatic habitat, total dissolved solids, sedimentation, and selenium).

Monitoring, Mitigation and Adaptive Management

There are no provisions for conducting acute and chronic toxicity testing upstream and downstream from CBM product water discharges during and after CBM development. Although tissue residues in fish will be monitored (p. 4‑398), those analyses will not provide reliable predictions of adverse effects due to increased or decreased concentrations of major ions in the receiving waters.

Although potential impacts to aquatic biota were mentioned in various places in the EIS, they do not appear to have been factored into the decision to proceed with CBM development. A transparent decision tree did not appear to be implemented when BLM chose to proceed with CBM development. A decision tree does not appear to have been outlined for evaluating results of the post‑CBM development monitoring. Without this, continued CBM extraction and additional development appears to be a fait accompli that will not be halted.

Given the juxtaposition of more intense well development in a potentially vulnerable sub watershed, a monitoring program that allows adaptive management of production water treatment methodologies and evaluates project effects on biota seems prudent, and Appendix D describes the monitoring effort that is anticipated for the project area. In addition to identifying a process to secure adequate funding for implementation, we suggest the following elements be given serious consideration to ensure the effectiveness of this critical development component.

Baseline (i.e.; pre-project) fish and invertebrate IBIs, and water and sediment chemical analysis at

designated sites; existing monitoring stations can be used to the extent possible, but new stations will

probably need to be identified to provide meaningful coverage. Toxicity testing with CBM production water, using fathead minnows and Cereodaphnia, with an emphasis on early life stage survival, growth,

and development; bioaccumulation and reproduction in adults; and effects of contaminants in conjunction

with an appropriate range of water temperatures.

Periodic monitoring after wells are installed at the same locations baseline data was collected to evaluate

long-term trends in aquatic populations and communities.

Water quality in all ponds, including closed containment reservoirs, should be monitored on an annual

basis. A protocol should be developed to determine for each discharge if CBM produced water should be

discharged into closed containment reservoirs, based on salt and metal concentrations and the potential for

these contaminants to reach unacceptable levels through evaporative concentration in the future life of the

impoundment.

For purposes of adaptive management, the FEIS should answer the following questions: Will the

discharge of CBM produced water be discontinued if salt and/or metal concentrations pose a threat to

aquatic species and migratory birds? If so, what concentrations will trigger cessation of the CBM

discharges? If discharge is ceased, what measures will be taken to remediate contaminated exposed

sediments when the impoundments dry up?

The monitoring plan should specify responsibility for water quality sampling and stream channel

monitoring. Additionally, the monitoring plan should state what actions will be taken if this monitoring

shows adverse effects to riparian habitat and/or fish and wildlife, and specify what resources, in terms of

staff and funding, would be required to ensure compliance with mitigation measures as well as

compliance with the Clean Water Act and if such resources would be available to ensure compliance to

avoid, reduce, or minimize adverse effects to fish and wildlife resources.

References

Clearwater, S.J., Morris, B.A., Meyer, J.S. 2002. A Comparison of Coalbed Methane Product Water Quality Versus Surface Water Quality in the Powder River Basin of Wyoming, and An Assessment of the Use of Standard Aquatic Toxicity Testing Organisms for Evaluating the Potential Effects of Coalbed Methane Product Waters. Report submitted to Wyoming Department of Environmental Quality. University of Wyoming, Laramie Wyoming.

Forbes, M.B., Clearwater, S.J., Meyer, J.S. 2001. Acute Toxicity of Coalbed Methane Product Water and Receiving Waters to Fathead Minnows (Pimephales promelas) and Daphnia magna. Report submitted to Wyoming Department of Environmental Quality. University of Wyoming, Laramie Wyoming.

Forbes, M.B., Morris, B.A., Meyer, J.S. 2002. Acute and Chronic Toxicity of Coalbed Methane Product Waters and Receiving Waters to Ceriodaphnia dubia. Report submitted to Wyoming Department of Environmental Quality. University of Wyoming, Laramie Wyoming.

Mount, D.R., Gulley, D.D., Hockett, J.R., Garrison, T.D., Evans, J.M. 1997. Statistical models to predict the toxicity of major ions to Ceriodaphnia dubia, Daphnia magna and Pimephales promelas (fathead minnows). Environmental Toxicology and Chemistry 16:2009-2019.

Suter, G.W. II; C.L. Tsao. 1996. Toxicological benchmarks for screening potential contaminants of concern for

effects on aquatic biota: 1996 revision.

Woodward, D.F., R.G. Riley, and C.E. Smith. 1983. Accumulation, sublethal effects, and safe concentration of a

refined oil as evaluated with cutthroat trout. Arch. Environ. Contam. Toxicol. 12:455-464.