Produced-water VOC, HAP emissions concern Rocky Mountain regulators

July 6, 2009
Increasing volatile organic compound and hazardous air pollutant emissions from a growing number of private and commercial produced-water surface disposal facilities, using evaporation ponds, are raising regulatory and public concerns in the Western US. Various studies have identified VOC emissions as contributors to ground-level ozone formation.

Increasing volatile organic compound and hazardous air pollutant emissions from a growing number of private and commercial produced-water surface disposal facilities, using evaporation ponds, are raising regulatory and public concerns in the Western US. Various studies have identified VOC emissions as contributors to ground-level ozone formation.

Currently the US Environmental Protection Agency regulates VOC under the Clean Air Act (CAA).

VOC and HAP emission odors and vapors may raise health concerns for operators and the public, especially near populated areas.

Increasing urbanization and more stringent state and federal regulations aimed at protecting human health and the environment from harmful HAP is making it more difficult for owners and operators of produced-water disposal facilities using evaporation ponds to meet VOC and HAP emission limitations.

Current VOC and HAP estimation methods required by regulators in Colorado, Utah, Wyoming, New Mexico, and Montana may overestimate VOC and HAP emission levels. This overestimation creates a controversy among regulators, concerned public, environmentalists, and owners of produced-water facilities over the continued viability of evaporation ponds as a produced-water disposal method.

Existing and emerging engineering controls may reduce or destroy VOC and HAP before their release into the ambient air. These control technologies could increase produced-water disposal facility profitability and potentially generate sufficient revenue to cover or at least help defray their capital cost.

Produced water

Produced water represents the largest waste stream volume generated by the oil and gas industry during exploration and production. Each year the US generates about 20 billion bbl of produced water.1 The Western US, including Wyoming, New Mexico, Colorado, Utah, and Montana (Fig. 1), produced 2.6 billion bbl in 2002.1 This volume is about four times the yearly culinary water consumption of the Salt Lake City metropolitan area.

Produced water is defined as water extracted from the earth’s subsurface during exploration and production of oil and gas. This water may include geologic formation water, injection water, and chemicals added to the formation to stimulate production or improve oil-water separation.

Produced water generated from oil, natural gas, and coalbed methane production may contain compounds harmful to humans and wildlife, including potential toxic hydrocarbons and trace metals, which require proper disposal.3

Current practices of produced-water disposal include surface discharge such as evaporation ponds, reinjection into the subsurface with injection wells, reuse, and land application.1 4

Surface discharge

Regulators have a particular concern with surface discharge to evaporation ponds because of potential emission of reactive VOC and HAP into the ambient air. Studies have found that these emissions are precursors to ground-level ozone formation when reacting with nitrogen oxides (NOx) in the presence of sunlight.

The CAA in 40 CFR 51.100(s) defines reactive VOC very broadly as “any volatile compound of carbon…that participates in atmospheric photochemical reactions.”

The agency has indentified several VOC, including methane and ethane, as having negligible photochemical reactivity and, if properly quantified, operators of emitting facilities are allowed to subtract these from total VOC emission estimates.

EPA has designated many urbanized areas in the Rocky Mountain region, such as metropolitan Denver and the Northern Front Ranges of Colorado, as nonattainment areas. These areas are noncompliant with the 8-hr federal ground-level ozone standard levels as listed in the National Ambient Air Quality Standards (NAAQS).5

The government established NAAQS (40 CFR 50) to cover ozone (with VOC and NOx as precursors) and other harmful air pollutants to protect human life and health (primary standards), and vegetation, animals, and property (secondary standards).

The five Rocky Mountain states have seen a rapid increase in the number of disposal facilities using evaporation ponds. This presents environmental compliance challenges to both regulators and facility owners.

Reasons that have fostered the growth in private and commercial produced-water disposal facilities include the relatively dry climate, availability of low-cost land, and low costs to operate and maintain evaporation ponds. Operating costs range from $0.01 to 2.50/bbl of produced water.1

Disposal facility layout

Fig. 2 shows a typical layout of a private or commercial produced-water disposal facility using evaporation ponds in the Rocky Mountain region. The main components include:

  • Condensate and oil recovery tanks.
  • Separation basins, with or without baffles, used as oil-water separator systems.
  • Skim pits.
  • Evaporation ponds.

Oil and gas field operators truck or pipe produced water containing oil, natural gas condensate, and chemicals from the production and exploration sites to private or commercial produced-water disposal facilities.

At the facility, oil-water separators, by gravity, separate the condensate and oil, usually 1-2% by volume, from the bulk produced water. The separation basins, constructed of concrete, fiberglass, or steel, can be either open to the atmosphere or have a permanent or floating roof to help limit VOC emissions.

The disposal process then involves piping the produced water to one or more skim pits. These pits are relatively small open-air basins designed to separate additional oil or condensate not captured in the oil-water separators.

From the skim pit, produced water typically enters one or more lined evaporation ponds generally in series and 1-10 acres or more in surface area. Some ponds may have portable misting towers, sprinkler systems, or commercial snowmakers to enhance mechanically water evaporation.

Vacuum trucks collect oil and condensate from the oil-water separators and skim pits for temporary storage in oil or condensate tanks before shipping to market or further processing.

Table 1 summarizes VOC and HAP emission rules in Colorado, Utah, Wyoming, New Mexico, and Montana. The table excludes rules for the EPA-regulated disposal facilities on Native American tribal land in these states.

Rules in Colorado

The Colorado Department of Public Health and Environment regulates evaporation ponds as stationary sources of VOC subject to Air Quality Control Commission Regulations No. 3 and No. 7.

These regulations define evaporation ponds as any open-air surface impoundment for the purpose of solids settling, residual oil skimming, or water evaporation. CDPHE provides guidance to facility operators on how to quantify emissions of VOC and HAP to ambient air.6

The accompanying box shows an example calculation for VOC and HAP emissions, based on a mass-balance equation that uses water sampling analysis of:

  • Total petroleum hydrocarbons (TPH) that include gasoline range organic (GRO) compounds, diesel range organic (DRO) compounds.
  • Benzene, toluene, ethylbenzene, and xylene (BTEX).
  • Methanol added by well operators to natural gas processes to prevent freezing during winter months.
  • Other contaminants as determined appropriate by operator knowledge of the waste water stream.

The mass-balance equation assumes that 100% of the TPH concentration contained in the produced water volatilizes to the atmosphere as VOC and establishes the maximum potential to emit.

Section 112(b) of the CAA lists BTEX as HAP; and therefore HAP require a similar mass balance.

Facility operators need to sample the TPH, methanol, and BTEX compounds after the primary oil-water separator and upstream of the evaporation ponds.

AQCC Regulation No. 7 states that no source shall dispose of VOC by evaporation unless the facility uses a Reasonably Available Control Technology. The RACT analysis includes an evaluation of available economically feasible technologies that would provide maximum VOC emission control at regulatory agency acceptable levels.

CDPHE requires use of enhanced gravity separation or VOC-destruction technologies. It does not consider conventional gravity-separation technologies and natural biodegradation as viable RACT for facilities, but these technologies could potentially be employed by facilities whose business model is characterized as industrial waste water treatment, which is typical of most commercial facilities accepting produced water for treatment and disposal.

AQCC Regulation No. 3 requires facilities emitting VOC emissions of more than 2 tons/year in an attainment area (1 ton/year in a nonattainment area) to submit an Air Pollution Emission Notice every 5 years.

HAP emissions must be reported as discussed in Regulation No. 3, Part A, Appendix A based on different scenarios and depending on the BIN classification of the pollutant, such as 50 lb/year (Scenario 1 and Bin A) to 5,000 lb/year (Scenario 3 and Bin C).

Facilities must obtain a construction permit before construction if they will emit more than 5 tons/year of VOC in an attainment area or 2 tons/year in a nonattainment area. They also may need an air-quality model.

A facility requires a federal Title V operating permit under the CAA if its VOC emissions are greater than 100 tons/year, or emits 10 tons/year of single HAP, or 25 tons/year combined HAP.

CDPHE may subject a facility to a maximum $15,000/day/violation fine for failing to report emissions, or failing to obtain a valid construction or operating permit (Table 1).

Rules in Utah

Facilities in Utah require a permit if the emissions exceed 5 tons/year of reactive VOC, 500 lb/year of single HAP including benzene, toluene, ethylbenzene, xylenes, n-hexanes, and methanol, or 2,000 lb/year of combined HAP, as per the Utah Administrative Code R307-401-9 “de minimis” threshold (Table 1).

Similar to Colorado, Utah Division of Air Quality estimates the total VOC emission based on a simple mass balance assuming that 100% of TPH, BTEX, n-hexanes, or methanol escapes into the ambient air. Nonpermitted facilities that exceed the de minimis may be fined $10,000/day/violation. UDAQ identifies the required water sample point as the outflow of the oil-water separator.

Most Utah produced-water disposal facilities using evaporation ponds are in Grand and Uintah counties. Grand County passed Ordinance No. 476 in 2008 that limits the total VOC emission from all disposal facilities in the entire county to 50 tons/year. The county also charges a $0.10/bbl monitoring fee for produced water entering disposal facilities.

Rules in Wyoming

The Wyoming Air Quality Standards and Regulations Chapter 6 provides guidance for stationary sources of VOC and HAP emissions. It requires a permit for major sources (CAA Title V) of air pollutants that emit 10 tons/year or more of single HAP, 25 tons/year or more of combined HAP, or 100 tons/year or more of other regulated pollutants.

As shown in Table 1, Wyoming Department of Environmental Quality requires new facilities to collect and analyze water samples for TPH-GRO, TPH-DRO, BTEX, and methanol. Required sampling frequency could be up to a sample every 2,000 bbl of produced water accepted by the facility for disposal.

Potential emission estimates are based on the assumption that 100% of the TPH, BTEX, and methanol volatilize.

Rules in New Mexico

New Mexico MAC Title 20, Chapter 2, Parts 70, 72, and 74 (NMAC 2009), establishes limits for existing and new facilities. New stationary sources of VOC need a permit if the emission rates are greater than 10 lb/hr or 25 tons/year.

It bases VOC emission estimates on water concentrations of TPH and HAP and 100% volatilization of hydrocarbons from the water.

Rules in Montana

The Montana Department of Environmental Quality regulates and enforces major and minor sources of HAP under the federal Title V program.

Title V bases limits on major sources as those emitting 10 tons/year of any HAP or 25 tons/year of any combination of HAP. The minor-source permitting threshold for Montana is 25 tons/year of any HAP. Therefore, a facility may require a Title V permit without first obtaining a Montana Air Quality Permit if the calculated potential to emit is between 10 and 25 tons/year.

In general, most major sources require both an MAQP and a Title V permit.

Fate of VOC, HAP

It is important to understand the fate of TPH (including BTEX and n-hexane) and methanol in produced water to determine the potential effects of VOC-HAP emissions on the ambient air and the competing mechanisms that reduce TPH and methanol volatilization (Fig. 3).

The composition of TPH determines its propensity to separate from soil, sediments, water, or air.

In general TPH in produced water may exist as:

  • Free floating or dispersed droplets.
  • Dissolved compounds.
  • Volatile gases.
  • Sorbed to organic or inorganic suspended solids or sediments.

A large portion of TPH can be free floating or a dispersed oil fraction, usually with droplet size greater than 0.45 µm. A facility can separate this readily from the bulk water using specific gravity differences or other physical processes.

The remaining portions of TPH are susceptible to volatilization and may escape into the atmosphere. Sorbed TPH may form particle coatings and may follow the fate of suspended solids, which tend to settle out and be trapped in sediments.7

Depending on the water geochemistry, other mechanisms may reduce the amount of TPH and in turn VOC and HAP in produced water. These may include: 7 8

  • Biodegradation due to microbial activity.
  • Oxidation and reduction reactions due to changes in pH and dissolved oxygen driven by photosynthesis and biological respiration.
  • Photolysis, which is decomposition due to exposure to sunlight.
  • Hydrolysis, which is chemical reactions with acid and bases in water.
  • Precipitation or mineralization.

These competing mechanisms in concert with temperature changes, diffusion and convection mechanisms, water retention time, evaporation basin depth, oil film thickness, and differential water solubility of hydrocarbons may reduce formation of VOC and HAP.9

In fact, these complex biological, physical, and chemical processes can degrade and deplete TPH compounds within the evaporation pond and therefore may significantly reduce the propensity for volitization. In addition, many produced-water disposal facilities are in regions where air temperatures may fall below freezing for several months. As a result, ice or snow may cover ponds for several months especially during late fall, winter, and early spring thus inhibiting VOC and HAP emissions.

The inclusion of methanol in VOC mass balances assumes erroneously that it volatilizes completely into the ambient air. Table 2 shows that methanol is very soluble in water (infinite miscibility) and tends to remain dissolved in water as determined from the low Henry’s constant (0.0027 atm l./mol).

Also, BTEX has a higher tendency to partition from air (Henry’s constants between 5.2 and 6.7 atm l./mol) as compared to methanol, but much lower than n-hexane (Henry’s constant of 122 atm l./mol).8 9 Based on the chemical data presented in Table 2, one needs more rigorous estimates to accurately represent methanol and TPH contributions to VOC and HAP emissions.

Waste water collection

Colorado approves the EPA AP 42 (Chapter 4.3) “Waste Water” method as an alternative approach for estimating VOC emissions.6 9 This method uses well established mass transfer correlations and emission equations to estimate VOC emission rates from oil and gas waste water treatment facilities containing hydrocarbons.

This method may require additional sampling of the produced water such as biomass, oil film thickness, wind speed, etc. (with concomitant sampling and laboratory analysis costs), but it could be more accurate for estimating VOC emissions than the simple mass balance described previously.

Methanol calculations

Total VOC and HAP estimates include methanol because of its wide use as antifreeze in oil and gas extraction operations. Methanol, however, is very soluble in water and has a tendency to remain dissolved rather than volatilize.

A comparison of the AP 429 and the CDPHE6 methods shows the difference in the estimated results using the two methods.

For both methods, the calculation includes data from a produced-water disposal facility in Colorado.

The scenario used for the AP 42 method is typical of produced-water disposal facilities using evaporation ponds in the Rocky Mountain region and includes the following assumptions:

  • A nonmechanically aerated evaporation pond.
  • An oil film thickness on the pond greater than 1 cm.
  • No outlet, flow through, in the pond.
  • A well-mixed evaporation pond.
  • No significant removal of VOC by biodegradation, adsorption, or other forms of degradation.
  • 10-day residence time.
  • No significant loss in water volume.

The assumptions determined the theoretical equations as reported in AP 42 for computing the methanol emission rate (N).9

To estimate N, the first step is to calculate the gas-phase mass transfer coefficient kg (Equation 1 in equation box) and the overall mass transfer coefficient in the oil phase Koil (Equation 4). Equations 1-3, 4, and 7-10 determine the emission rate N.

Table 3 shows the emission estimation parameters used for the AP 42 computations. The calculated emission rate was 0.291 g/sec of methanol, which corresponds to about 10 tons/year of methanol.

Example 2 in the accompanying box shows the CDPHE6 estimation method assuming 100% loss of methanol.

Comparison of the AP 42 (10 tons/year) and the CDPHE6 (137 tons/year) methods indicated that the 100% methanol volatilization assumption overestimates the VOC emission by about 93%.

Air canisters

Both Utah and Wyoming DEQ approve air canisters as VOC and HAP emission sampling methods. Air canisters collect VOC and HAP by automatically drawing ambient air into evacuated stainless steel canisters for a predetermined time.

This relatively simple method may provide a good comparison with the simple mass-balance estimate, as previously discussed.

The state agency must approve the selected air-sampling protocol before its use. The direct air measurement method may present some challenges including selecting representative sampling locations based on prevalent wind direction, wind speed, and local weather conditions.

CDPHE does not currently approve air canisters as an alternative VOC estimation method. However, they may approve flux chambers.

Flux chambers

Some facilities have used flux chambers for measuring fugitive VOC from open water bodies containing hydrocarbons.

The method usually involves the placement of the flux chamber directly on the water surface to establish the flow rate for drawing air from the chamber and measure the VOC emission rate.10

Remote sensing

Remote sensing is an emerging technology that oil and gas refineries have widely used for detecting fugitive emissions. Currently, it is being tested as an alternative emission estimation tool.

This technology combines laser-based instruments, such as light detection and ranging, with VOC absorption techniques for determining VOC flux estimations, such as Fourier transform infrared, etc.

Remote sensing technologies are expensive but some field applications have shown promising results.11

Engineering controls

Some facilities have employed successfully several commercially available engineering controls for recovering and reducing VOC and HAP.

Generally, engineering controls include a single treatment technology or a combination of technologies that fall into the following four categories based on the process employed:12

  1. Physical, which relies on physical means such as gravity (driven by density differences, oil droplet size, etc.), and filtration to separate oil and water.
  2. Biological, which uses microbes to biodegrade or biotransform hydrocarbons.
    • Chemical, which includes enhanced sorption, precipitation, etc.
    • Thermal, which uses high temperatures to destroy or remove VOC and HAP.

Physical separation technologies only can recover free floating and dispersed oil from the bulk water. These separation technologies can be divided into two main groups: conventional gravity separators and nonconventional or enhanced gravity separators.

Conventional oil-water separators involve gravity separation of immiscible fluids as modeled by Stoke’s Law.7

Stoke’s Law states that an oil droplet’s rise rate depends on the difference in density between the oil droplet and its surrounding fluid, the surrounding fluid viscosity, and the droplet size.

Equation 11 shows that oil droplet size has the largest effect on the separation efficiency of these types of separators because it is proportional directly to the rise rate to the power of 2. Hence, larger droplets will rise much faster and will have a better chance to separate from the bulk water.

In addition, the larger the difference in specific gravity between the oil mixture and the bulk produced water, the better the separation process.

An important design consideration in these oil-water separators is the residence time of the produced water to accomplish the desired separation efficiency. Emulsifying agents can inhibit this efficiency, which depends on the chemical conditions such as pH, and surface tension and composition such as colloidal matter and salinity of the bulk produced water.

In addition, pumps, valves, pipe restrictions or other devices used for transporting produced water can cause shearing or breaking of oil droplets that can decrease separation efficiency.

Conventional oil-water separators may include tank-type separators such as gun barrels, and API-type gravity separators (rectangular, square or circular in shape) with or without design modifications such as coalescing plates.

Design modification in an API separator can increase separation efficiency by increasing coalescing rates of oil droplets, which can enhance the rise rate of oil droplets and require a shorter residence time and in turn a smaller system footprint.

Table 4 lists the oil-removal capabilities of different types of oil-water separators by droplet size.13

Conventional API separators with coalescing plates are more effective at separating oil droplets larger than 40 µm, whereas more energetic processes such as centrifugal separators can remove oil droplets greater than 2 µm in diameter.

Enhanced gravity separators include:

  • Centrifugal separators, such as spinning bowl, hydrocyclones, etc.
  • Forced-air devices (induced air flotation (IAF), induced gas flotation (IGF), and dissolved air flotation (DAF)).
  • Mass transfer units such as air stripping, activated carbon, etc.
  • Filtration devices.

Centrifugal separators use centrifugal force to enhance gravity separation by spinning the fluid in a rotating bowl. The lighter oil will collect toward the inside of the bowl, whereas the heavier fluids, including solids, will tend to move toward the outer edge of the bowl.15

Some centrifugal systems may include perforated disk stacks16 or internal fin packs17 inside the bowl to increase separation efficiency.

The ECONOVA system provides differential pressure control of the oil-water interface, to handle oil slugs effectively and optimize oil dehydration.17

Hydrocyclones use the same principle as centrifugal separators, but spinning of the fluid, not the vessel, accomplishes separation.

Spinning results from pressurizing the fluid and forcing it to rotate against the walls of a cone-shaped chamber. As the fluid moves toward the bottom of the hydrocyclone, it swirls faster. The lighter oils collect in the center of the vessel and exit through one end, whereas the heavier fluids and solids will move toward the walls and exit through a second opening in the hydrocyclone.1

Forced-air or gas devices use mechanically driven pressurized air or gas bubbles that attach to oil droplets and force them to rise by buoyancy force to the top of the water. At this point, various conventional methods can remove them.

Chemical separation technologies use chemical sorption processes, or air stripping techniques to transfer oil or VOC from one phase to another, for example liquid to solid or gas to liquid.

Also companies have used ultrafiltration to physically separate out small droplets of oil and solids from produced water (Table 4).

Biological processes using microbes of bacteria (such as bioreactors) are also employed to transform or biodegrade toxic organic compounds to less or nontoxcic organics.

Abatement technologies may employ heat, such as thermal-oxidizers, heater treaters, flares, or chemical agents to destroy VOC and HAP.

These methods although effective in reducing VOC may destroy valuable commodities that could be recovered and sold for profit.

Emerging technology

The separation technologies previously described can effectively separate free floating and dispersed oils. They are, however, unable to remove dissolved hydrocarbons that may represent a large portion of the VOC.

One emerging separation technology uses conventional oil-water separation technologies in combination with a vapor compression, turbulent flow, flash evaporation treatment system to handle a wide range of produced and flow back waters.

The system removes and recovers marketable hydrocarbons and alcohols. It produces clean, distilled water for use at drillsites for completions fluids makeup, surface drilling, or discharge directly into environmentally sensitive areas.

Operators in the Pinedale anticline of Wyoming have used this technology to exceed established water-quality standards. It soon will also be in operation in the Piceance basin of Colorado.17

Acknowledgments

The authors thank Cynthia Madison, WDEQ, Tim DeJulis UDEQ, Sam Speaker, NMDEQ, Julie Merkel, MDEQ, and Scott Patefield and Carissa Money, CDPHE for providing information and reviewing this article for accuracy.

References

  1. Veil, J.A., et al., A white paper describing produced water from production of crude oil, natural gas, and coal bed methane, US Department of Energy Technology laboratory, Contract No. W-31-109-Eng-38, 2004.
  2. Boysen, D.B., et al., “Creative strategies for produced water disposal in the Rocky Mountain region,” 9th Annual International Petroleum Environmental Conference, Albuquerque, NM, Oct. 22-25, 2002.
  3. Jackson, R.E., and Reddy, K.J., “Trace element chemistry of coal bed natural gas produced water in the Powder River Basin, Wyoming,” Environmental Science Technology, Vol. 41, No. 17, 2007, pp. 5,953-59.
  4. Benko, K.L., and Drewes, J.E., “Produced water in the western United States: geographical distribution, occurrence, and composition,” Environmental Engineering Science, Vol. 25, No. 2, 2007, pp. 239-46.
  5. Air pollution Control Division, 8-hour Ozone Nonattainment Area Changes—Fact Sheet. CDPHE (2007a), effective Nov. 20, 2007.
  6. Produced Water Evaporation Ponds, Emission Estimate and Control Requirements, CDPHE (2007b), June 26, 2007.
  7. Chapra, S.C., Surface Water-Quality Modeling, McGraw-Hill Co. Inc., New York, 1997.
  8. Sawyer, C.N., et al., Chemistry for Environmental Engineering and Science, 5th edition, New York: McGraw-Hill, 2003.
  9. Waste Water Collection Treatment And Storage, 5th Ed., Vol. 1. EPA AP42, 1995 at http://www.epa.gov/ttn/chief/ap42/ch04/index.html; May 20, 2009.
  10. Eklund, B., “Practical Guidance for Flux Chamber Measurements of Fugitive Volatile Organic Emission Rates,” Journal of Air & Waste Management Association, Vol. 42, 1992, pp. 1,583-91.
  11. Literature Assessment of Remote Sensing Technologies for Detecting and Estimating Emissions for Flares and Fugitives, Environ International Corp., 2008-90, prepared for Texas Commission on Environmental Quality, Work Order 582-07-84005-FY08-09, 2008.
  12. Denman, T.A., and Star, S., “Overview of the produced water system at the Prudhoe Bay unit-Alaska, North Slope. In Ray, J.P., and Engelhardt, F.R., Editors, Produced Water. New York: Plenum Press, Technological/Environmental Issues and Solutions, 1992, pp. 569-91.
  13. Frankiewicz, T., “Understanding the Fundamentals of Water Treatment, the Dirty Dozen—12 Common Causes of Poor Water Quality,” 11th Produced Water Seminar, Houston, Jan. 17-19, 2001.
  14. Leung, W.W-F., Industrial Centrifugation Technology, New York: McGraw Hill, 1998.
  15. Alfa Laval—disc stack centrifuge technology, Alfa Laval, 2009 at http://local.alfalaval.com/en-us/key-technologies/separation/separators/dafrecovery/pages/dafrecovery.aspx, May 26, 2009.
  16. Personal communication, ECONOVA, Inc., Apr. 28, 2009.
  17. 212 Resources, Inc. at http://www.212resources.com/, Apr. 14, 2009.

The authors

DicataldoGennaro Dicataldo ([email protected]) is a consulting engineer at Stantec Consulting Inc. His work involves remediation technologies (including oil-water separators), water-quality modeling of toxic trace elements, and water and waste water treatment and facilities design. Dicatado holds a BS and MS from Brigham Young University and a PhD in civil and environmental engineering from the University of Utah. He is a registered professional engineer in Utah and Wyoming.
RichinsGary H. Richins ([email protected]) is the corporate environmental manager for Dalbo Holdings Inc. He holds a BS and MS in zoology and wildlife biology from Brigham Young University and is a Certified Wildlife Biologist.
SpiroffKerry J. Spiroff ([email protected]) is a project manager for Montgomery Watson Harza Consulting Inc. He has 30 years of experience in the energy, municipal, and industrial areas. Spiroff is currently leading several produced-water disposal facilities projects in the intermountain west. He holds a BS in civil engineering from Iowa State University and an MS in structural engineering from the University of Missouri, Columbia. He is a registered professional and structural engineer in Utah.
NelsonMark B. Nelson ([email protected]) is director of mechanical engineering at ECONOVA Inc. with more than 25 years of experience in industrial and municipal waste water treatment including oil-water separation technologies. Nelson holds a BS in mechanical engineering from the University of Utah. He is a registered professional and structural engineer in Utah.