Meeting Summary

Topic: Meeting with Purestream Technology about Treatment Technologies 

Relevant to the Unconventional Oil and Gas Industry

Meeting Date: 08 November 2013

Participants: Lisa Biddle, Jesse Pritts, Karen Milam (EPA/EAD)

Meghan Camp, Sarah Hays (ERG)

Amy Hansen, Todd Ennenga (IPAA)

On 08 November 2013, the U.S. Environmental Protection Agency (EPA) held a meeting 

with Purestream Technology1 to discuss treatment technologies relevant to the unconventional 

oil and gas extraction industry. Todd Ennenga and Amy Hansen, represented Purestream 

Technology. Discussion topics included:

• Water management options for the unconventional oil and gas (UOG) industry;

• Comparison of treatment and reuse; and

• Purestream Technology treatment options.

Attachment 1 lists the meeting participants.

Purestream Technology Background

Purestream Technology (Purestream) was founded in 2009 and operated wastewater 

disposal ponds in UT and WY. Purestream partnered with approximately 400 researchers at Utah 

State University, who are experts in thermal management, and created the AVARA mobile 

treatment unit, which is a vapor recompression technology. Purestream licensed AVARA 

technology and to-date, the largest commercial installation of the AVARA treatment system is in 

the Fayetteville shale formation (AR).

Total Water Management Scenario

Purestream presented the following three water management options used by 

unconventional oil and gas (UOG) operators:

• Once-through use and subsequent disposal – Operators have the option to dispose 

of UOG wastewater at underground injection disposal wells or centralized waste 

treatment facilities (CWTs).

• Treatment and reuse in fracturing fluid - Operators have the option to reuse UOG 

wastewater in subsequent fracture jobs, which sometimes requires mixing with 

 1 More information on Purestream Technology is available online at: http://purestreamtechnology.com/
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freshwater to obtain the correct water quality characteristics. Purestream noted 

that operators usually only need to remove solids and oil & grease to meet reuse 

water quality requirements.

• Treatment and discharge – Operators have the option to treat UOG wastewater to 

meet effluent discharge limits set by the state or EPA and then discharge directly 

to surface water2

UOG Wastewater Treatment Considerations

.

Purestream recognizes that transferring UOG wastewater is typically the highest cost 

component associated with managing and/or disposing of UOG wastewater. However, 

Purestream focuses on the treatment component of managing and/or disposing of UOG 

wastewater. Purestream noted that treating UOG wastewater has the following benefits:

• Reduces the demands for fresh water;

• Reduces the amount of UOG wastewater requiring disposal3

• Reduces transportation associated with transferring UOG wastewater to disposal 

locations

; and

4

.

However, Purestream noted that industry has the following concerns with treating UOG 

wastewater:

• There are many treatment technologies and hundreds of water treatment vendors 

to choose from, so evaluating the options can be challenging for UOG operators.

• There is not one technology that fits every treatment need. Each basin has 

different characteristics (e.g., economics, wastewater pollutants) and there are 

even different characteristics within some basins (e.g., Bakken). 

• The cost of treatment must compete with the cost of underground injection 

disposal, which is typically the cheapest disposal option (except in Pennsylvania).

• Although long term contracts are attractive to water treatment providers, they are 

not attractive to UOG operators.

The following describes some of the major drivers for operators when deciding whether 

or not to reuse UOG wastewater in subsequent fracture jobs:

• Quality of influent water - Purestream noted that the most common problem with 

the quality of influent water is the elevated concentration of TDS, which requires

brine handling and disposal. Other pollutants of concern include hydrogen sulfide 

(H2S), bacteria, and oil & grease.

 2 Treatment and discharge is the disposal method implemented at the Southwestern facility in the Fayetteville shale 

formation (AR).

3 For example, western Texas, central Arkansas, and portions of the Marcellus shale formation have specific 

restraints on the quality and quantity of UOG wastewater that can be disposed of at underground injection disposal 

wells.

4 For example, an operator would need approximately 300 truck trips to transfer half of the volume of flowback 

from a 125,000 bbl fracture job to a disposal location.
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o TDS - The AVARA treatment unit’s maximum influent TDS 

concentration is 280 mg/L, which is the threshold for keeping solids 

saturated so that brine handling and disposal is not necessary (i.e., disposal 

via UIC is still appropriate). An alternative to brine disposal is to use the 

brine in other UOG processes (e.g., as a kill fluid)5

o Hydrogen sulfide (H2S), bacteria, and oil & grease - These constituents 

may require a pretreatment step (e.g., oil/water separator, UV disinfection) 

upstream of the AVARA treatment unit to remove these constituents

.

6

• Required quality of effluent water

.

• Volume of influent water

• Chemical costs

• Energy source

• Disposal, sourcing, transportation costs

Purestream also identified the following variable drivers that may or may not play into 

the UOG operator’s decision about whether or not to reuse UOG wastewater:

• Location of Field – Operators may have the option of managing and/or disposing 

of UOG wastewater via existing infrastructure in the field.

• Existing Regulations – Operators may need to consider the regulations that apply 

to surface discharge, above ground storage pits, in-ground storage pits, etc.

• Reuse Options – Operators in different locations may have different infrastructure 

and options in place to aid in reusing UOG wastewater. For example, in the 

Eagleford, Fayetteville, and western Texas shale formations, operators are 

pursuing the hub and spoke concept (i.e., centralized waste treatment with piping

and/or trucking of treated water back out into the field for reuse).

When planning for reuse, operators consider space restrictions and whether they will use 

centralized or mobile treatment to treat the UOG wastewater to a quality that is sufficient for 

reuse. Depending on the quality of the wastewater and the type of treatment implemented, if any, 

operators may consider blending wastewater with freshwater prior to reuse in a subsequent 

fracture job. Operators also consider which storage and transportation methods they will use to 

during reuse. Operators may store wastewater in above- or in-ground storage tanks, which can be 

highly regulated in some states (e.g., leak detection system and/or lining requirements). 

Operators must also transfer wastewater to and from treatment as well as from the producing 

well to the next well to be fractured. Finally, operators must determine what disposal options 

they will need (e.g., solid waste, concentrated brine, sludge).

Purestream identified multi-site water balance as another important component of UOG 

wastewater reuse. Operators must consider the following components when evaluating the water 

 5 Purestream described that an operator fractures a well and as they’re plugging each fracture stage, they use a heavy 

brine to act as a barrier and prevent water from flowing back up before they set the plug. Typically, operators 

purchase clean brine for this (KCl), but brine can be used as an alternative. 6 In the Fayetteville shale installation, aerated pits containing aerobic bacteria naturally remove ammonia in 

wastewater prior to treatment in the AVARA system.
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balance: on-site fracturing fluid storage, fracturing fluid demand, on-site flowback storage, 

transportation (e.g., percentage transported by truck versus by pipe), availability of off-site 

storage (e.g., percentage stored in water tanks versus impoundments versus brine tanks), and 

fresh water supply options (e.g., groundwater, surface water). All of these components play into 

an operator’s decision about whether they will recycle or dispose of UOG wastewater. 

Purestream acknowledged that it takes a lot of time and effort for operators to decide what reuse 

option works best for them. However, Purestream stated that it is becoming easier for operators 

to reuse because reuse now offers a low liability and low cost option for obtaining water.

Purestream stated that there is untapped potential in reusing water for beneficial reuse. 

For example, Arkansas could use treated UOG wastewater for agriculture, irrigation, or cattle 

water. EPA noted that they are aware of conventional oil and gas wastewater that is used for 

beneficial reuse, but not UOG wastewater. Purestream agreed that they are also not aware of any 

UOG wastewater that is beneficially reused. EPA asked Purestream if there are other industries 

where there are roadblocks to reuse. Purestream responded by saying that there are not 

roadblocks to reuse in other industries, the problem is that operators do not know all of their 

options for reuse until they become more popular options.

Technology History and Overview of Purestream Treatment Technologies 

Purestream provided a brief overview of the history of UOG wastewater treatment 

technologies. Three years ago, technology focused on large desalination plants and reverse 

osmosis. These technologies are only effective with low influent TDS concentrations, so they are 

not feasible for UOG wastewater. Beginning approximately eighteen months ago, technology 

shifted focus to the smaller scale evaporators, selective ion removal technologies, and 

crystallization (see descriptions below).

• Smaller scale evaporators are capable of treating between 1,000 to 2,500 barrels 

per day and create distilled quality effluent water as well as a concentrated brine 

stream. The evaporators can be constructed as mobile or semi-mobile units and 

therefore, reduce the amount of trucking associated with transferring water to 

treatment locations.

• Selective ion removal technologies are used to target and remove specific ions 

from an influent stream. One example of this type of technology is 

electrocoagulation.

• Crystallization treatment is capable of treating less than 10,000 barrels per day of 

wastewater and requires a market for the byproduct (e.g., road salt), otherwise it is 

not a cost effective treatment option. Purestream noted that crystallization is 

popular in the Marcellus shale formation.

Purestream introduced three levels of their treatment technologies: high end, middle of 

the spectrum, and low end. Purestream’s AVARA treatment unit is at the high end of the 

treatment spectrum. The AVARA treatment is capable of reducing the concentrations of TDS 

and heavy metals while producing a distilled quality effluent. Purestream’s IGF and IGF+ are at 

the low end of the spectrum. These technologies are capable of reducing the concentrations of 

TSS, oil and grease, and iron while producing an effluent water quality that is typically 
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acceptable for reuse. Purestream noted that they don’t focus on treatment technologies that lie in 

the middle of the spectrum (e.g., electrocoagulation, reverse osmosis, filtration). More details 

about the Purestream treatment technologies are described below.

• IGF Treatment Process – This treatment process uses air flotation and polymer 

addition. As the air bubbles float to the top of the vessel, particles attach to them 

and are skimmed off of the top of the column. Approximately 1% of the total 

volume is removed by the skimmer. Clean water exits the IGF for reuse or further 

treatment in the AVARA. The IGF is a completely automated system. 

• AVARA Treatment Process – The AVARA treatment process is a low pressure, 

light weight, low energy (3 phase 480 B-300 kW power source) (AVARA 1000) 

vapor recompression unit. The AVARA unit ultimately boils water to concentrate 

salts, but keeps the solids saturated in the liquid phase by running just below the 

260,000 to280,000 mg/L solids precipitation point. Operators have the option of 

blending treated water to achieve higher TDS if that is a requirement of reuse 

water (for subsequent fractures). The AVARA treatment is remote controlled. 

There is also a mobile app available.

Purestream also noted that they were awarded a DOD grant to use this treatment for military 

applications to treat groundwater to potable water quality. The treatment system created for this 

purpose is very small (10’ x 8’ x 6’).

AVARA Treatment Application in the UOG Industry and Other Operations

Purestream field tested the AVARA treatment unit at multiple locations in Texas (i.e., 

Sonora, TX; Tilden, TX; Wheeler County, TX) and each test system was converted into a 

commercial operation. Purestream also installed an AVARA treatment unit for Southwestern 

Energy in the Fayetteville shale formation in Arkansas. Southwestern is treating a portion of 

their wastewater using the AVARA treatment unit rather than reusing all of it because they are 

not drilling enough wells to reuse 100% of their wastewater. Purestream noted that the AVARA 

treatment facility is less expensive for Southwestern to operate than trucking wastewater to 

injection wells because there are few underground injection wells located nearby. Purestream 

also noted that the Southwestern AVARA facility is one of the only treatment systems that is 

discharging directly to surface water instead of discharging to POTW.

Purestream noted the following active treatment units at UOG operations:

• Arkansas: AVARA treatment system is currently operating.

• Pennsylvania: One treatment system is currently operating and another system is 

being shipped because the operator needs the capability to treat a larger volume of 

water.

• Texas: A treatment system will be shipped soon.

• Oklahoma: A treatment system should begin operating next week.

• Wyoming: A treatment system is being finalized for use in this location.
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• Canada – Purestream has pilot technologies set up for a couple of oil and gas 

operators.

Approximately 2 years ago, Purestream deployed an AVARA treatment unit to North

Dakota for use in the Bakken shale formation. However, the high TDS concentrations in the 

Bakken wastewater (around 200,000 mg/L) proved difficult for the AVARA unit. The treatment 

system produced very small volumes of clean water compared to the large volume of brine 

requiring disposal. Purestream noted that Bakken operators are beginning to focus more heavily 

on the feasibility of reuse, and want to be reusing 70% of their high TDS UOG wastewater. 

Purestream is hopeful that they may be able to provide a technology that is capable of removing 

certain pollutants (e.g., hydrocarbons, TSS, oil and grease) to provide reuse quality water, rather 

than trying to achieve distilled water effluent quality. 

Purestream noted that they are also working with ethanol plants, hog farms, poultry 

producers, distilleries, and the nuclear industry to see if their treatment technologies are a good 

fit for these industries.

Potential Additional Data Sources

Purestream shared PowerPoint slides with EPA after the call via email (on 11/8/13). Ms. 

Amy Hansen, from Purestream, also mentioned that EPA may want to contact John Ventura

regarding water data that he has collected across the U.S. Ms. Hansen also noted that Purestream 

is willing to share water quality data with EPA.
Attachment 1

Table A-1. List of Meeting Participants

Name Affiliation Phone Email

Amy Hansen Purestream Technology

Todd Ennenga Purestream Technology

Lisa Biddle US EPA 202-566-0350 Biddle.Lisa@epamail.epa.gov

Jesse Pritts US EPA 202-566-1038 Pritts.Jesse@epa.gov

Karen Milam US EPA 202-564-9752 Milam. Karen@epa.gov

Meghan Camp ERG 703-633-1684 Meghan.Camp@erg.com

Sarah Hays ERG 703-633-1661 Sarah.Hays@erg.com