MEMORANDUM

TO: Record

FROM: James K. O’Connell, ERG

DATE: 18 February 2015

SUBJECT: 2014 WEFTEC Conference Materials (DCN SGE01069)

On September 27th through October 1st, 2014, ERG attended the WEFTEC Conference in 

New Orleans, LA. Conferences notes from select sessions are provided below.
205: Upstream Oil and Gas Treatment and Residuals

Evaluating Leachability of Residual Solids from HF in the Marcellus Shale

Stephanie Countess (CDM Smith) (VT Masters work)

Natural gas provides 24% of US energy needs

32% of US reserves are in shale formations

Solids Management

- Onsite burial (in lined pit)
- Landfill disposal

- Land application

Inorganics – main elements of concern:

- Marcellus Shale geochemistry (Ca, Cl, Ba, Br, Na, Sr)

- Produced water composition (Al, Fe, Li, Mg, Mn, P, K)

- Reg requirements (Be, Co, Ag)

GOAL: Leaching potential for elements of concern in natural disposal environments

CWT in PA – sampling facility (game Stephanie samples)

- 1.2 MGD capacity, zero discharge

- Treatment objectives: remove metals (Ba, Fe, Sr), reduce TSS

Waste handled separately (produced water, drilling mud)  chemical treatment  effluent 

solidification  waste to landfill

- Focus: Raw solids (no treatment), solidified sludge (generated at CWT)

X-ray diffraction on mineral composition: 

- Raw: quartz, barite, calcite, clay

- Solidified sludge: quartz, barite, calcite, clay, halite, ...

Methods: acid digestion of solids and microwave assisted acid digestion of solids

- Limitations: silicon, sulfate may interfere

- Results: Barium results aren’t clustered – which means, we need to be careful in how we 

measure this parameter

MAJORITY OF SAMPLES:

Raw: Ca, Ba, Na, Fe

Solidified sludge: Ca, Na, S

How do solids relate to flowback? (see photo)
Leaching Potential Methods

- Toxicity characteristic leaching procedure (TCLP)

- Synthetic precipitation leaching procedure (SPLP)

Hazardous Waste Classification:

- TCLP limits were higher than all measured values in raw or solidified (no exceedances). 

- **Conclusion: solids are non-hazardous in terms of their inorganic content.

Ca, Mg, Mn – under TCLP, we see a higher leaching potential for these elements; leaching is greater and 

could be of concern when trying to limit environmental leaching

SPLP – resulted in smaller amounts of leaching

- Compared soluble to EPA drinking water standard

o Exceedances of Al, Ba, Pb, S, TDS (of drinking water quality)

Conclusions: 

- digestion method affects quantification of select elements

- Elements that aren’t in flowback may still be in solids

- Raw solids and solidified sludge are non-hazardous in terms of inorganics

- Acidic extraction fluid enhances elemental leaching

- Suggest mono-disposal of solids for UOG operators
Future Research

- Characterize organics

Stephanie Countess, EIT

scount@vt.edu

Graduate Research Assistant @ VT 

Q: What is mono disposal?

A: Co-disposal is being disposed of with other wastes (e.g., municipal landfill)

Mono disposal is disposing of residual solids by themselves (e.g., buried onsite in lined pit)

Q: What CWT Facility?

A: 45 minutes southeast of Pittsburgh

Handle waste for a lot of major drilling operators in area
Generation of Oil and Gas Source Water from AMD Using Liquid-Liquid Extraction

Rick Peterson (Battelle Memorial Institute, Columbus OH)

PetersonR@Battelle.org

Frac Fluid: 

- Slickwater (smaller proppants; higher pressures)

- Linear gel (thicker fluids; larger proppants; lower pressures)

- Crosslinked gel (borate or organometallic linkages)

Gel fracks – more sensitive to chlorides, etc (require higher quality)

Acid Mine/Rock Drainage (AMD, ARD)

- Generates sulfates and metals in solution

- High TDS and iron stream that continues in perpetuity

- Attractive O&G source water

o >300 Mgal AMD/ARD enter local streams each day

- Untreated AMD/ARD is not suitable for source water in UOG fracturing fluid
Hydroflex 

- based on liquid-liquid extraction

- residual TOC has been <10 mg/L

- IX process, but advantage is greater surface area (faster kinetics)

- Low viscosity, hydrophobic extractant allows high mixing, improving performance over IX resins

Sulfate rich water  solid separation (bag filter)  sulfate extraction (mix with extractant and allow to 

phase break) – high recovery >99%  stripping (add Na2CO3)

Sulfate effluent: <250 mg/L (99% recovery)

Sodium sulfate concentrated solution, expected 6-10 wt% solution (byproduct)

Lab-scale system (batch testing, continuous testing)
Low ionic strength and high hardness impaired phase disengagement

- Sulfate – 600 to 900 mg/L

- Iron – 0.5 to 2 mg/L

- Calcium – 60 to 100 mg/L

- Magnesium – 20 mg/L

- TDS – 1100 to 1300 mg/L

FINDINGS:

- Reduced mixing improved sulfate removal

- Calcium carbonate precipitation allows sulfate removal targets to be met in single extraction 

stage (CaCO3, SO4 products)

Field Unit

- being run by “Winter ... “ operating company

o Feed sulfate: 420 mg/L

o Residual sulfate: 98 – 140 mg/L

Water for O&G industry:
- AMD source water: optimize sulfate removal in extraction section; minimize entrainment of 

extractant components

- Flowback recycle: validate utility of sulfate byproduct for softening of flowback waters; optimize 

operation of sulfate stripping section to produce a marketable product (soften water)

Q: For amount of flow treating, what is footprint?

A: 1 stage is 6-8’ wide and 15-16’ long and 6’ tall

100 gpm requires ~5 stages

Q: regeneration of IX liquid – what’s process and what’s lifetime?

A: reverse ion exchange – 8% NaCl solution in 4 stripping stages; run countercurrent

Swap sulfate with carbonate

Degradation of extractant: mainly in losses in water; some potential for oxidation

Q: Would this technology remove sulfate from seawater and be cost competitive with NF, etc?

A: Not something Battelle’s done. No testing yet.

Q: What are you doing with treated water?

A: Existing AMD site; operating under their discharge permit – currently going through 2 granular 

activated carbon beds; 7000 gallon tank to ensure no sheen on ponds; retaining for ~1 hour for caution 

to ensure meeting discharge requirements.
Case Study: Cost Benefit Analyses of Centralized Treatment vs Mobile Decentralized Treatment for 

Produced Water from an UOG Development in the Rocky Mtn Region (Niobrara)

Tom Sandy, CH2MHILL (Rebecca Maco, Lindsay Atkinson – CH2MHILL; Ken Nichols – Devon Energy –

NOT DEVON ENERGY PROJECT)

[Paper focuses on cost benefit analysis]

Reuse – treatment of water and blending, not straight reuse

Crosslinked gels were used for hydraulic fracturing in these Niobrara wells.

2000 + wells (each requires 10 – 15 bbls drilling; 160,000 bbls fracking)

40% flowback (out of 160,000 bbls) within 40 days of completion of well

Fully produced in 4-5 hour time frame

40 – 50 bbl produced water/day

Water Reuse:

- Storage (upstream equalization, downstream storage)

- Conveyance/transport (point of production through treatment to end use)

- Treatment (centralized, mobile)

Water Quality in Niobrara:
- Primary targets for treatment:

o TSS

o Oil and grease

o Iron

o Bicarbonate

o Phosphate

o Boron

- Goal: remove ~80% of influent targets

Centralized Treatment
Oil/water separation (DAF)

TSS removal 

Chemical preicipiation (lime)

Solids handling (filter press)

Compared to the following technologies:

- Fountain Quail

- Purestream

- Rock Water

- Concorde Energy

- Omni Water

Client wanted at least 10,000 bpd treatment.

Selected 2 technologies (vendor A, vendor B) to compare to centralized treatment concept.

Capital and operating costs:
NPV analysis: centralized treatment is lower cost than decentralized (vendor A or vendor B). Costs are 

close at 10,000 bpd, but as you get higher flow rates (bpd), NPV cost ($ million) becomes higher faster 

for decentralized.

Payback comparison of centralized treatment: payback period (months): combined cost of raw water 

and PW disposal ($/bbl) at 10,000 bpd, 30,000 bpd, and 50,000 bpd
Economics of Centralized vs Mobile Treatment:

- Flow-dependent

- Lifetime of development is longer

- Need to understand water chemistry

- Dependent on transport and storage of water 

Q: Given parameters designed for, which were most important? What drove treatment?

A: fracking water can handle low water quality. 

1. These wells had low TDS concentrations (30,000 mg/L) – you could blend out TDS just by storing 

water the right way

2. Oil and grease – central gathering station had 3 stage separator and heater treater (<100 mg/L 

oil and grease)

3. Organics – use chemical precipitation

Mobile: oil/water separation, chemical precipitation

- Only thing they didn’t have was membrane on back-end of treatment (only necessary for higher 

TDS wastewater)

Q: What’s typical distance and how many drilling sites would the centralized facility serve?

A: ~2000 wells in this oilfield (in grid over 120 sq acres); wells are relatively close to each other; 

oil/water separation in clusters of 7 wells, then send all water to central gathering station, gathering 
station is location of treatment. Same gathering station would allow for sending treated water back to 

operator.

One operator would own all wells.

Q: Have they built it?

A: No. Client is currently beginning development phase (10 – 15,000 bpd generated) – based on that, 

they’ll decide if they want to invest in building centralized treatment (30,000 bpd). For first ~3 years, will 

use one of the treatment options.

- Client says – why would I spend $$ building treatment facility when I could spend $$ drilling a 

new well and make $$? And pay service provider for treatment.

Q: Transportation of water to centralized facility vs. transportation of water with mobile facilities?

A: During exploration, hauling water to well for drilling; haul water to disposal site. During development, 

clustering wells and mobile treatment unit will treat flowback and produced water; bring in another 

mobile unit for next cluster, etc. Eliminate hauling.

Economic model captures elimination of hauling.

Q: Were there traces of parameters from slickwater in flowback?

A: Heater treater separators would remove slickwater inputs (with soluble organics).

Biggest issue: boron! Borate is very difficult to remove from water.

- One method of treatment: use polymer to react in small amount to precipitate boron as a gel 

just to remove it from the water.

No surface discharge.

All water being deep well injected.
327: Novel Approaches to Treatment for Water Reuse

A Compact, Efficient, and Expandable Title 22 Treatment System for Small Water Systems

P.M. Hytowitz, C. Grace, J. Turner

San Simeon, CA WWTP (nearby Hearst Castle)

SEP – recycled water project

- Updated aeration reactors

Title 22 – CA regulation – quality and treatment requirements where water will have human contact

Some equipment has been certified as Title 22 approved

- Amiad AMF2 microfiber technology – 36K filter system

- Ultura HiPOx (AOP) – using O3 or H2O2 react to form hydroxyl radicals

o GOAL: destruction of BOD, COD, TOC (organics)

o Complete oxidation; no hazardous products

o San Simeon uses this AOP treatment

43200 GPD (half of system flow) – Title 22 system

- 14’ x 50’ total Title 22 system

Recycle line allows them to dilute flow during high flow when turbidity could be a problem.

Influent turbidity ~2.5 to 4 NTU; effluent turbidity ~0.5 NTU (June 2014 sample results)

6 to 8 deliverers delivering Title 22 to hotels and HOAs.

San Simeon system – planning to expand because of great need for water; also looking into pumping to 

storage tank or piping to locations (instead of trucking).

Capital cost: 4.81 per GPD

Operational cost: 0.46 per GPD

Q: During high rain events, is recycled water being stored elsewhere?

A: Don’t know how often storage tanks are being purged to ocean outfall. Hasn’t been issue b/c water is 

in high demand and not a lot of high rain events.

Water is free to customers.

People can only take water if they are certified to handle Title 22 water.

Q: What was training process like?

A: 2 day training where manufacturers (Amiad, HiPOx) came in and taught 3 operators at WWTP.

Q: Adding disinfection residual?

A: No – no chlorine added; but water is being recycled fairly regularly. If there wasn’t quick turnover, 

probably would add disinfection.

Q: What do hotels use water for? How do they operate?
A: Irrigation, primarily. Don’t know if they pump it or distribute it on weekly basis.

Q: Any other treatment technologies reviewed?

A: media filters, membranes; all treatment had large footprint issue; UV – disinfection also looked at 

(cost was high).

Q: Amiad cartridge filter lifetime?

A: Municipal application is much better for cartridges. Standard lifetime = 5 years.
Effectively Managing the Impacts of Source Water Quality Variations on Downstream Recycled Water 

Treatment Plants

A.E. Towey (East Bay Municipal Utility District), J.M. Hake, E.R. Gardner, J.A. Augustine

East Bay Municipal Utility District (EBMUD)

- Eastern San Francisco Bay Area

- 1.3 million people served (water)

- 650,000 people served (wastewater )

Source Water: Water Pollution Control Plant (treatment: ___)

- EBMUD North Richmond Water Recycling Plant (NRWRP)

- EBMUD RARE Water Recycling Plant (MF and RO treatment before boilers)

Effluent ammonia and turbidity – problematic

Heat exchangers are very sensitive to ammonia (1 mg/L target)

- Biological (aeration, good MCRT – for nitrification)

- (If Biological doesn’t work) Chemical – add chlorine to bind ammonia

Regulatory compliance issues (Turbidity permit limit: 2 NTU)

2012: Water Quality Study to Improve Secondary Effluent Quality

Focus: ammonia

Nitrification: consumes 7.14 grams of alkalinity for each gram of ammonia-nitrogen that you’re 

converting to nitrate.

MCRT: Nitrifiers typically require 10-20 MCRTs

- Cooler weather requires longer MCRT

DO: nitrification requires additional oxygen to oxidize ammonia to nitrate

pH: nitrification is pH dependent and can decline below 6.8 SU

DO influent increasing, ammonia decrease (Basin 2) - expected

DO influent increasing, ammonia increase (Basin 1) – unexpected (could mean there’s unequal air 

distribution between 2 basins)

Take Home Message:

- Improvements to secondary system may be more cost effective than improvements to 

tertiary treatment system (if issue of inconsistent secondary wastewater coming into 

tertiary plant is problem).

Q&A:

1. Move caustic addition upstream; May look into adding something other than caustic.

2. COD and BOD – plant is meeting NPDES requirements; didn’t look into carbonaceous 

relationship to ammonia in detail.
3. Winter months – sustained effluent ammonia (equalization tank doesn’t help much)

4. 2 aeration basins – 1 engine driven blower; 1 VFD blower (target: 1-2 mg/L oxygen) – if DO 

drops, should kick up speed of this blower, sometimes this operates 100% and still need more 

aeration; discussed adding another blower.

5. Other planned improvements? Yes, feasibility study for expanding recycling facilities.
Sidestream Wetland Treatment to Improve Pond Water Quality at the City of Santa Clara Central Park 

Pond

N. Hawk (City of Santa Clara), A.P. Briggs

Santa Clara Central Park Pond (in middle of Silicon Valley)

- 113,000 people

- 1.2 MG large pond

- PROBLEM: Algae blooms (chronic issues) and odor

- 17% of water portfolio in Santa Clara is recycled water

- Worked with GHD for this project

- Influent to pond: effluent from advanced treatment facility (RO) that receives water from a 

nearby WWTP. Effluent from advanced treatment facility goes through reuse pipelines and 

that is where pond receives water (from pipeline on bridge).

Design Approach: 

- Chose pipeline from bridge

- TREATMENT: filtration VS constructed wetlands (P removal 1 mg/L; ammonia removal rate 3 

mg/L)

o Filtration: CONS visual barrier, high cost; PROS no chemicals

o Constructed wetlands: CONS: high cost; PROS blend in with area, no chemicals, low 

energy

 Repurpose upper pond for wetlands; or use manmade island and repurpose 

as wetland

 Constructed wetlands – cheaper NPV ($500k) vs filtration ($691K)

o Regulatory process (can take ~2 years)

o Recycled water piping requirements (e.g., set distances from potable water lines)

KEY Wetland System Design:

- Turnover rate (flowrate needed to turnover entire pond volume in appropriate timeframe)

- Nitrogen removal rates

- Phosphorous removal rates

- 2-cell upflow system

- Wanted to mitigate high labor intensive conditions of pond.

- Cell 1 (where most of solids would come in) had flushable collector and lateral (pipes) in 

bottom of pond to remove solids that collect in bottom of pond.

- Remote access for control panel to check constructed wetlands parameters/operating 

conditions.

RESULTS: system started in end June – early July

- Turbidity consistently <10 NTU (typically 2 NTU)

- Monitoring: ph, temp, turbidiy, ammonia, tkn, nitrate, phosphorous, BOD, COD, DO, ORP, 

TDS, coliform

Q&A:
1. This was the first type of project of its kind; other surrounding cities may opt to install a similar 

system because of similar issues with their ponds.

2. No discharge from pond – only evaporation; would TDS be problem (influent TDS ~500 mg/L; 

effluent TDS: 2-5 mg/L). They’ll need to monitor for TDS to ensure there’s no buildup; will look 

at TDS long-term.

a. SFPOC (?) also has similar system. Good resource

3. Expect to need to dredge pond every ~5 years; will likely determine when dredging needs to be 

done based on WQ monitoring data and visual observation of pond (not based on control panel 

monitoring).
Innovative universal MF/UF Membrane Design Approach Applied to the Full Scale Wastewater Reuse 

Project in Southern California

H. Hyung, G.D. Wetterau, R.B. Chalmers, E. You, D.W. Cutler

7 – 10 year lifetime for membranes

Membrane market: Pall, GE, Evoqua, Basf, Toray, LG, Koch, DOW, Econoity

CDM Smith applied universal MF/UF design to wastewater reuse plant in Santa Barbara, CA. Same 

concept also being applied to other projects.

- El Estero WWTP (Santa Barbara, CA)

- GOAL: Replace tertiary filtration facility with MF/UF membrane filtration to improve 

effluent.

- 11 MGD CAS (conventional activated sludge) plant

- Feed water: secondary effluent from wwtp

- 3 MGD average treatment capacity from MF/UF treatment (93% recovery)

Q&A: 

1. GE, Pall, etc – objected to this approach for membranes

2. Pumping systems – feed water is set; backwash has VFD (variable flow detection?) to 

accommodate different flow conditions

3. Smart Wrap: from CDM (?); flex fiber wrap to accommodate different membrane modules; 

future discussions about universal skid design
Turning Difficult to Treat Wastewater Effluent to Reclaim Water: Practicality of Using Different 

Membrane Treatment Processes

Z. Farinelli, S.Z. Abdullah, T. Gregonia

Trickling filter plant effluent

AI WWTP (Canada) and the Annacis Research Centre

175 MG/year (?) treatment using trickling filters

April – September 2012 pilot testing

GOAL: reduce potable water consumption

3 systems to compare (no names provided)

- 1 MF; 2 UF systems

Clean in place (CIP)

British Columbia requirements:

- BOD5 <10 mg/L

- Turbidity: <2 NTU (24-hr avg); <5 NTU (peak)

Results:

- Turbidity: always <1 NTU; influent as high as 10 NTU

- Suspended solids: always <5 mg/L; influent up to 8 mg/L

Resistance vs. Time plot:

Red dashed line = backwash; blue dashed line = recovery cleaning necessary to restore permeability 

(permeability recovered up to 95%)

- Aggressive chemical cleaning with System B

- (System C) Not possible to maintain stable condition without using chemical cleaning, but 

more conservative cleaning was used (compared to System B)

Full scale chemical consumption: between 5 and 50 m3/year (from System A, B, and C)

Operation: safety and chemical handling had to be considered

CONCLUSION: MF and UF membrane systems treat trickling filter effluent; min 200 um screen should be 

used to reduce need for chemical cleaning.

Q&A: 

- Project got “shelved”, so they didn’t end up choosing a membrane to use; cost would likely 

drive the decision since all performed to meet standards.

- Day to day maintenance across 3 units: fully automated systems (required little O&M)
Development of Advanced Treatment System Using Biofiltration and oxone-AOP for Agricultural 

Water Reuse

Y.J. Yune et al.

Full-scale demonstration in South Korea

Korea Future Regulations (for Discharge?):

TN (nitrogen) <10 mg/L; future: <5 mg/L

TP (phosphorous) <0.5 mg/L or <0.2 mg/L; future: <0.05 mg/L

GOAL: develop advanced treatment solution for these future regulatory requirements

- Low level of TN and TP

- Non-biodegradable organics

- Antibiotic resistant bacteria

WWTP in Yong-In City, South Korea

- Primary treatment  SBR  first biofilter  ozone – AOP  second biofilter  reservoir

- 1000 m3/day (183 gpm) for this system

- Biofilter: more tolerant to cold than other systems (top: nitrification; bottom: 

denitrification); can add methanol to first biofilter; second biofilter is for polishing

- Ozone System: micro-bubble ozone (5-20 um) = higher specific surface area; 10 minute 

contact time before pumping to second biofilter

o Remove non-biodegradable organics and inactivate antibiotic resistant bacteria

o Dosage: 16 mg/L ozone; 1.8 to 2.5 g O3 per g COD

o Ozone contact time: 5 min
RESULTS: 

- TN able to meet 3 mg/L (project goal) effluent in summer and winter (and also meet future 

reg requirement of 5 mg/L)

- TP ~0.075 after first biofilter (no additional removal with AOP); TP able to be below 0.05 

after second biofilter

- Orgnic compounds (COD) effluent < 8 mg/L from AOP and second biofilter

- Antibiotic resistant bacteria – tetracycline

o Applied ozone of 7 mg/L (10 min contact time) reduced antibiotic resistant bacteria 

significantly (as compared to <=5 mg/L).

- Removal percentages:

o BOD: 87%

o COD: 56%

o SS: 93%

o TN: 74%

o TP: 86%

lyj@bkt21.com

BKT Booth 8829 (Hall I)

Q&A: 

- Automated backwash on biofilter every two hours.
- BAC could also be an option.

- Ozone residual – heating system to remove remaining ozone from ozone contactor, so there 

should be no remaining ozone going into secondary biofilter.

- Antibiotic bacteria – where is evidence for these existing in agriculture? Water quality for 

agriculture isn’t that high, but concern about public health because water will be stored in 

reservoirs and could have human contact.

- No economic data available.

-
404 – Innovative Treatment and Modeling of Mine Water

Startup and Commissioning of a Full-Scale Selenium Treatmnet Facility for Mine Water Treatmnet

Drinking water selenium MCL: 50 ug/L

American coal mine:

NPDES Limits: selenium: 4.7 ug/L (monthly avg); 8.2 ug/L (daily max)

Biological fluidized bed reactor – most feasible treatment at this facility

Full scale plant operational in 2013

- Flow range: 700 to 2800 gpm (1900 avg design flow)

- Handling flow from 3 outlets with varying flow, nitrate, and selenium levels

- Selenium total, average influent : 22 ug/L (mostly selenate (most oxidized form))

-

3 outfalls  Blend tank  heat exchanger  FBR  ballasted sand clarifier  MBBR tank  effluent

Filtrate tank  gravity thickener  solids conditioning tank

Biological selenium treatment: 

- heterotrophic bacteria reduce Se (IV) to Se (0) anoxic

- GAC media

- N, P, trace metals (nutrients needed)

- Min temp 50F

- pH between 6 and 8

FBR System:

- Biological FBR with GAC media

- Fluidization for bed expansion – efficient mass transfer

- 3 FRP columns (14’ diameter, 30’ H)

- 30 minute HRT

Sodium nitrate – added in case influent nitrate dropped below 2 mg/L

Ballasted Sand clarifier system:

- Removes elemental selenium as insoluble solids and biomass

- Gravity sand filtering; uses sand for ballast

- 2 units: 1400 gpm each

MBBR System:

- Mainly for BOD polishing and raising effluent DO
- 2 tanks with 1 hr HRT (hydraulic retention time) (75000 gal each)

Solids Handling System:

- 2 Plate and frame filter presses (65 ft3 each); 2 cycles per day

- Solids conditioning tank: 20000 gal

Flow: 

- Observed avg: 2100 gpm

- Average design flow: 1850 gpm

- **Operating at max design flow

Nitrate - Nitrogen : drives reaction because all nitrogen has to be removed before removing any 

selenium.

FBR:

- Acclimation phase: 8 weeks

- Max limit: 8.2 ug/L and Avg limit: 4.7 ug/L

o during acclimation, some effluent values were above this, but after acclimation, all 

values were below max limit and mostly below average limit

- maintain ORP between -150 and -200 mV

- some high iron (above avg limit of 1.57 mg/L) because of chemical addition as coagulants

o decided that a mix of iron and aluminum as coagulant was best.

- COD effluent typically <30 mg/L, but max of 70 mg/L (influent ~60 mg/L)

- Selenium influent ~15 to 20 ug/L; effluent <= 8.2 ug/L (daily max limit), typically < 4.7 ug/L 

monthly average limit

- Long-term Al, Fe, TSS, and pH typically met limits.

Operational Challenges:

- FBR bed height difficult to control (affects Se removal), accumulation of silts in beds (solution: 

monitor bed heights daily)

- Heat exchangers flow meters – difficult to keep min temp in winter (and flow meters) – because 

scaling from silt (solution: more cleaning)

- Control dosing on MicroC pumps (b/c nitrate loadings in influent were lower than design)

- Clarifier polymer dosing (b/c inadequate mixing with service water)

4 MGD WTP for Se treatment at North American surface coal mine.

Process train: FBR – ballasted sand clarifier (remove biomass containing insoluble Se) – MBBR (residual 

organics polishing).

WTP operational for >1 year and meeting low Se limit as well as meeting other parameter limits.

Solids are sent to solids waste landfill for disposal as nonhazardous waste (TCLP showed Se < 1 mg/L)

MBBR raises DO to >= 6 mg/L prior to discharge.
Why biological instead of IX?

- IX system had resins with capacity for Se (but high sulfate in this wastewater competes with Se).

Why FBR instead of conventional?

- FBR requires shorter HRT than conventional (fixed bed biological growth) – which gives you cost 

savings.

Plant location confidential.
Moving Bed Biofilm Reactor for Selenium Removal from FGD and Mine Effluents

Caroline Dale et al.

Mine waters

Flue gas desulfurization from power plants

Selenium reduction (Se (VI)  Se (0)

Denitrification (anoxic conditions) – occurs before selenate reduction

Selenate and selenite reduction (anoxic conditions)

MBBR: moving bed biofilm reactor

- Carriers provide large protected surface for bacteria development

- Can operate with same support material for >20 years

- No backwash needed

- Tolerates high TSS concentrations in feed

- Used for denitrification >20 years

Selenium analyses: ICP-MS

Selenium speciation: HPLC-ICP/MS

Total Se in mine water (coal mine): 38 ug/L

Total Se in mine water (copper mine): 560 ug/L

COAL MINE

**Achieved <5 ug/L at HFT 2.3 hours (down to 6C)

50 to 80% removal of Se after MBBR1

Influent – 37 ug/L)

COPPER MINE

**achieved 10-25 ug/L after filtration

** 6 – 20 ug/L after chemical treatment

**selenite and selenate <1 ug/L

Influent – 560 ug/L

FGD WATER

**15-40 ug/L after filtration

**10-20 ug/L after chemical treatment

**selenite and selenate <2 ug/L

Influent – 240 ug/L
Conclusions: 

- MBBR technology applicable for FBD and mine wastewater

- Solids separation is critical to capture small Se particles

Q: How are you controlling oRP?

A: Through COD dosing (operate similar to FBR reactors)

Q: Unexpected findings in this work?

A: Having complete selenate and selenite reduction and still have Se total above permit limits.

- Doesn’t look like nitrate have as much interference with selenium treatment as was originally 

thought.

- Cost is comparable per load concentrations compared to other Se treatment (500 and 1000 ug/L 

would be more difficult b/c limited by surface area...but advantage is they’re not limited by TSS 

influent).
Innovative Application of Water Quality and Flow Modeling to Design a Softening, UF/RO and Brine 

Handling System for Copper and Gold Mining Wastewater Treatment in the Peruvian Andes

A.A. Burbano, S. Sansom

Tailings basin/pond – location in Andes (>4000 m elevation)

- Occasional overflows, go to rivers that can be pulled from for drinking water

- Need to lower water levels in Tailings Storage Facility (TSF) to avoid overflows, especially in rainy 

season.

- New stringent discharge regulations (ECAs – more stringent)

o Advanced treatment (RO) required

- Few key constituents: sulfate (biggest problem), phenols, nitrogen compounds, TDS

Pockets in tailings dam with different WQ

- Large WQ monitoring program around am

No biological treatment going to be used.

Sulfate concentration in tailings basin was increasing every year (900 mg/L).

TDS concentrations also increasing in tailings basin (>2000 mg/L). The mine used water as part of 

operation – flotation process to remove copper and process is affected by too high TDS.

Phase I WTP: CO2 injection system for pH neutralization  multimedia filters

Phase II WTP: RO needed to be added; Phase I was influent water; needs additional chlorination and 

GAC for polishing; brine treatment needed

- (Influent is effluent from Phase I) UF  RO  GAC  (chlorination) limestone conditioning

- Brine treatment off of RO treatment

Design Questions:

- Size of WTP?

- Main flow contributors to TSF?

- Effect of returning RO brine to TSF?

- Acceptable TDS limit in TSF?

ISSUES:

- TSF was only location to put the brine – couldn’t use drying ponds or other brine treatment at 

this location.

- >99.5% of influent sulfate ends up in brine – and it’s going back into the TSF

- High TDS can cause issues on RO membranes fouling
- Used 95th percentile for in/out numbers to eliminate outliers (e.g., disregard max storm and be 

more reasonable about what will likely occur)

- Depending on type of treatment, would depend on what tailings going into TSF looked like.

- 3 Million m3 flow into tailings pond (150 L/s)

Hydrodynamics RO modeling software

- Conventional soda ash softening – not viable because water has no carbonate and chemical cost 

of adding carbonate was not economical

- Brine treatment: GE equipment (AquaCell – EDR membrane + 2nd stage RO)

Compliance – measured in river, not at point of discharge; so had to worry about WQ of river to 

determine whether or not in compliance.

- Iron, manganese, and phenols were already above permit limits in river.

Expensive to meet 300 ug/L selenium; so pushing for 500 – 1000 ug/L limit instead (in new permit).

Arturo.burbano@mwhglobal.com
Q: What about quality of tailing pond? How will discharge of brine back into TSF affect its WQ?

A: discharge could affect TSF WQ significantly – salinity could double if plant operated 100% of time 

(which doesn’t happen). Which is why brine treatment is so important.
527: Forward Osmosis: An Emerging Technology in Brine Treatment

Application of FO in Industrial and Domestic WW Treatment and Potable Reuse

B.D. Coday (PhD candidate), R.W. Holloway, T. Cath (CSM)

Oil and gas: can operate FO as “attached to bit” (move around in basin and treat water as needed) or as 

centralized treatment.

OMBR (Osmotic membrane bioreactor)

- FO in activated sludge tank

- LIMITATIONS: salt accumulation in activated sludge (reduces driving force over time)

Couple OMBR and ultrafiltration (UFO)

- ADVANTAGES: reduced FO bioreactor salinity

- System: ~300 L

Water Flux: temperature corrected water flux (LMH)

Sodium chloride draw solution

- Increase in bioreactor salinity where no UF was paired with FO; membrane needs to be cleaned; 

some irreversible fouling occurred (because of high calcium concentrations).

- No TP (total phosphorous) in RO permeate throughout study

- ~20 Trace organic compounds within influent

o Bioreactor removed 12/20 trace organics by >80%

o FO membrane rejected 14/18 trace organic compounds >90% (did not reject DEET, 

acetaminophen, bisphenol A, etc)

o RO membrane rejected 10/12 trace compounds by >95%.

o WHOLE SYSTEM (UFO-MBR): 19/20 trace compounds rejected >95% (did not remove 

bisphenol A, DEET, TCEP)

Engineered Osmosis for O&G WW (B. Coday)

- EIA (osmotic dilution, OD and engineered osmosis, EO)

- Study limited to O&G pit water

- HTI partnered

- SYSTEM: FO system, RO brine reconcentration, NF polishing (Osmotic dilution for HF brine)
- O&G pit water: 7 mS/cm

- Compared to deep well disposal (comparing to transporting to deep well disposal wells)

FO SYSTEM

- FO energy demand: 15 kWh/m3

- Membrane cleaning: 1/month

- Membrane lifetime: 3 years

RO SYSTEM

- Energy demand: 6.5 kWh/m3

- Membrane cleaning: 1/week (?)

- Membrane lifetime: 3 years

Traci 2 – developed by EPA; compares treatment technology against 10 environmental impact 

categories

- Compared deep well disposal to regional water reuse (RWR - OD) and regional water reuse 

(RWR - EO).

- OD – higher environmental impacts than EO system.

- EO (engineered osmosis) has high energy impacts; OD (osmotic dilution) has high brine impacts.

-

Haynesville – conc. Salt diluted with fresh water (free salt available for FO process – takes this piece out 

of environmental impacts).
UFO-MBR: 

- Excellent nutrient removal and trace organic removal by dual process.

- Promising technology for direct potable reuse and in oil and gas industry

- Oil and gas results (See Photo)

o Future: Attempting to couple this with life-cycle costing assessment

Sponsors: AQWATEC at School of Mines

Q&A:

- Would rejection of salts, etc be problematic over time? Likely decrease diffusion rates with this 

build-up; concentrate contaminants that get past FO membrane.

- UF-MBR: what’s salinity of UF permeate? Bioreactor salinity <2 g/L (which will go through UF 

system); could potentially limit reuse of water for irrigation.

- Over last 3 – 4 years, oil and gas has become more interested in this technology to take FB and 

PW chemicals out before desalination process.

Q: Application in oil and gas that Brian is aware of?
Industrial Brine Concentration Using Forward Osmosis

R. Zuback (Oasys Water)

Osmotically driven membrane processes (ODMP)

- Less concentrated feed solution transfers molecules across a membrane; concentrate 

feed/dilute brine

- Draw solution used to pull fresh water out of feed; draw solution draw back out of process 

resulting in a clean stream.

FO

- Taking advantage of osmotic gradient across membrane; no pressure added

- 4 Streams: Feed, concentrate, diluted draw solution, concentrated draw solution

o Pull concentrated draw solution to leave fresh water as product

- Feed flows countercurrent down membrane to draw solution (brine concentrate: 280k (10# 

brine))

- Ammonia bicarbonate draw solution

- Target water that typically would use thermal evaporation

- Membrane, draw solution, (draw solution recovery: thermal recovery)

Oasys Membrane Brine Concentrator

- Competes with thermal evaporation/crystallization (not RO – RO targets lower % total dissolved 

solids); MBC targets >5% TDS percentage

- Target <500 mg/L; concentrating up to 280k TDS (clean, reusable brine)

- Oasys starts where RO starts (regarding TDS content)

- Shale gas produced water – ideal for this treatment (50 – 100,000 mg/L TDS influent)
Oasys Focus:

- Oil and gas (produced water and flowback (high TDS)

- Power (FGD brine, blowdown) – low TDS process water, usually pre-treated

Case Studies:

Permian, Colombia, Mississippi Lime, Eagle Ford, Marcellus, PDOman, AU CSG, Bakken

- Marcellus Shale and Permian Basin (TX)

Marcellus Shale:

- >1400 bbl treated in 6 months

- 14000 mg/L influent hardness 

- 75000 mg/L TDS influent

- 180000 mg/L TDS brine

- <500 mg/L TDS fresh water (product water)

Permian Basin (Midland, TX):

- 1200 hrs, 100 bpd

- 5000 mg/L hardness influent

- 100000 mg/L TDS influent

- 220000 mg/L TDS brine
- <500 mg/L TDS fresh water (product water)

Cost advantage over thermal treatment: 59% advantage

National Oilwell Varco (NOV) partnered with Oasys MBC (4,000 bpd with pretreatment (ClearFlow)); 

producing 10# brine and fresh water.

FGD ZLD Application
Partnership with Beijing Woteer (first power project) in China.

FO: alternative to evaporators and “next step” treatment after RO

rzuback@oasyswater.com

617-620-6435

Q&A:

- NORM typically removed in pretreatment and disposed of.

- Physical/chemical characteristic of draw solution and recovery rate? Ammonium bicarbonate 

(~6 molar); maintaining nearly 100% of draw solution within closed loop.

- Pretreatment: chemical precip (hardness removal); settling/clarification, small amounts of 

oxidation

- Flux is not productive metric for measuring b/c FO not meant to treat same waters as RO (see 

white paper for more info)

- See organics in system but no signs of microbial growth or biofouling (<100 mg/L concs of 

methanol, used for antifreezing)

- 15% cost savings compared to thermal evap alternative for FGD treatment.

- RO brine concentrate (reject) streams: one of Oasys’ markets

o Right now, Oasys focusing on ZLD by applying FO to RO brine

- What about small, RO systems? Depends on size/flow rate.
Forward Osmosis concentration and ZLD for Industrial Wastewater

K. Lampi (Hydration Technology Innovations, LLC)

Located in OR and AZ

FO Draw Solution: focus on monovalent salts

e.g.:

10000 mg/L feed

4700 mg/L draw...

140000 mg/L concentrate

Draw solution recovery options: thermal process; reverse osmosis (HTI’s preferred method); NF, ED, 

freeze crystallization

FO: ideal for feed streams with high TSS; don’t eliminate fouling, but easily can remove fouling layers

- Use FO as pretreatment to RO

- Don’t think FO has strong desalination application

- Use FO as mass exchanger for water (dilute brine, concentrate dirty stream)

- Use FO because draw solution is free (seawater for algae concentration or shipboard graywater 

concentration)

- Use FO because draw solution regeneration is free (cooling tower process)

**If RO or UF works well standalone, use it. If RO fouls, consider FO
Chevron feed spacer (pre-treatment) before RO.

Landfill leachate capital cost ($7,500/m3 to treat)

Organics go through membrane and buildup in draw solution; SOLUTION: put small nano system bleed 

off stream to keep draw solution clean.

Oil and Gas – wastewater fed to maxx exchanger (80% water recovery); pump out of pit; using NaCl or 

CaCl in fracking solution – use as draw feed in FO unit.

Haynesville and Eagle Ford projects.

- Showing best scenario

-

- Total FO recycle cost: $3.29 /bbl

- Disposal and trucking of drilling waste: $3.76/bbl

- RO max influent TDS: 80k mg/L; so FO limited to 80k mg/L

- Osmosis Assisted RO (HTI developed)

- 22000 mg/L feed (NaCl equivalent) of 700 m3/day

Q&A: 

- HICor: ~35,000 mg/L TDS (FO: 10 kWh/m3; HICOR: 4-12 kWh/m3)

o Net electricity: 15-30 kWh/m3 (convert to bbl)
528: Salinity Management in Water Reuse

Pilot Scale Testing of the Precipitative Softening-Secondary 

B. O. Mansell, Philip Ackman, C. Tang, Philip F. (UC-Riverside) (Sanitation Districts of LA County)

Sanitation Districts of LA County

- Joint water pollution control plant (400 MGD) – ocean discharge

Saugus WTP – no solids handling (sent to and handled at Valencia)

Salt-sensitive crops: avocado, strawberry

- TMDL for chloride = 100 mg/L

- Current effluent Cl: Valencia: 127 mg/L; Saugus: 110 mg/L

- Addition of MF (pretreatment) and RO (chloride removal) of side stream from Valencia; mix back 

with remaining effluent to discharge.

- At max design flow, 1 MGD RO concentrate will be produced

FOCUS OF TALK: 

- Precipitative softening + SRO (secondary RO)

- MR (92% recovery)  primary RO (85% recovery)  softening and filtration (add lime or sodium 

hydroxide)  secondary RO (75% recovery, where baseline was 50%)

- Similar trends with Ca, Ba, and Sr – Ba and Sr co-precipitate with CaCO3.

- Mg not usually a concern with scaling for pH levels you typically run RO at (need pH: 10.5 SU to 

ppt Mg).

Pilot Testing: 

- Not done at Valencia, done at similar facility that was more conveniently located.

- Softening (sodium hydroxide) and filtration (cartridge filter) system.

- Normalized specific flux (gfd/psi) over time: secondary RO system results

- CIP (clean in place): done after ~300 hours

- Chloride removal: SRO feed (637 mg/L)  SRO permeate (11 mg/L) – 1 sample

bmansell@lacsd.org (Bruce)

Q&A: 

- pH feed SRO: <8 (7.5) SU; alkalinity feed SRO: <100 mg/L; 93% sulfuric acid

- sludge volume from precipitative sludge processing: N/A

- Cost comparison between sludge handling process and IX, etc: yes. Decided not to do softening 

because it’s not economical.

- SRO: running at 75% recovery

- Use of hydroxide: may cause particulate fouling in RO
Pilot-Scale Testing of IX for Chloride Removal from Recycled Water

Naoko Munakata (Sanitation Districts of LA County)

Saugas and Valencia WTPs

- NDN = nitrification & denitrification

- TMDL for chloride = 100 mg/L

Valencia: MF  primary RO  secondary RO  deep well injection

Ion Exchange (IX) and Nanofiltration + IX Options

- Anion exchange resin (HCO3-) (loading)

- Regeneration with 5% HCO3- solution

- (competitive loading): chloride and sulfate presence in water  results in more sulfate removal 

than chloride before SO4-2 vs Cl-1

Scenario 1: Valencia effluent  IX

Scenario 2: Valencia effluent  MF  NF (permeate going to IX has lower sulfate)  IX

NF permeate: tertiary effluent treated with MF and NF

- NF permeate (Chloride: 130 mg/L; sulfate: 10 mg/L; bicarbonate: 180 mg/L)

- Tertiary effluent (Chloride: 130 mg/L; sulfate: 175 mg/L; bicarbonate: 250 mg/L)

Results (Tertiary Effluent):

- Saw that they were getting lower and lower bed volumes before needing to regerate over time; 

meaning that they weren’t regenerating the column appropriately (were leaving chloride in bed 

after regeneration)

- 120 BV treatment of tertiary effluent before regeneration

o 2 BV rinse with RO permeate

o Avg chloride removal 98%

o Recovery 92%

Results (NF IX Effluent):

- 192 BV treatment of tertiary effluent before regeneration

o 3 BV rinse with RO permeate (because more chloride to regenerate)

o Avg chloride removal 98%

o Recovery 96%

Avg waste volume (MGD) system chloride removal (%)

SRO 0.32 88

IX 0.33 98

NF IX 0.16 77
Annualized cost (capital and O&M):

IX: <$16M

NF IX: >$16M

**Regenerant drives cost of IX

**Regenerant (lower than IX) and MF/NF cost drives cost of NF IX; although regenerant costs less, 

MF/NF outweighs cost savings from lower regenerant.

Conclusion: MF  RO  SRO (baseline) is what District decided to go with.

nmunakata@lacsd.org

Q&A:

- District thought about sodium hydroxide; problem with recycled water is that you have cations 

(Ca, Mg) – which will form precipitates and form coat surface.

- 5% chosen to minimize solubility of bicarbonate.
Fracking and Produced Water Management as a Proving Ground for Innovative Desalination 

Treatment

B. Alspach, J. Polce, M. DeMarco (ARCADIS) , Dr. Kerry Howe (Univ. NM)

Definitions

- Produced water salinity: 100 – 400,000 mg/L

- Multiple plays within a basin

Monterey Shale – “current production limited; tremendous potential”

- Seismic concerns

Barnett Shale:

- Avg daily water ~ 11 MGD

Wastewater management:

- Discharge to receiving body (DBP production from bromide)

- Deep well injection (seismic concerns, gw contamination)

- Reuse

- Treatment

- Combinations of above

Reference Costs:

NF & RO: $2 / kgal

Mechanical vapor compression MVC: $1.9/kgal

Multi effect distillation MED: 3.80/kgal
Multip stage flash distillation MSF: 4.40/kgal

(CSM 2009 paper “Produced Water Treatment Technologies)

Energy Costs:

NF & RO: $11-16 kWh/kgal

Mechanical vapor compression MVC: 31 – 45 kWh/kgal

Multi effect distillation MED: 30 kWh/kgal

Multip stage flash distillation MSF: 70 – 112 kWh/kgal

Lower flows make thermal processes more feasible.

RO TDS influent limit: 70,000 mg/L

Recovery much lower at high salinity (RO)

Fouling potential with particulates, organics, scalers

 RO in PW treatment not very common.

FO - tested and deployed (<2.50/bbl)

Mobile MVC, MVR Processes – becoming common (<$5/bbl)

Dewvaporation/AltelaRain – tested and deployed (low energy

 No waste heat, which is why these costs are lower than CSM paper

FO: Water Desalination Report (3/5/12) - Oasys

GE Mobile Evaporator – being sold to different O&G operators (1 produced and installed in field thus 

far)

Dewvaporation: AltelaRain
Kill fluid – prevents outward flow from well; requires brine

CASE STUDY:

- Solution must be heavier than force exerting upward P
- Only viable to use RO permeate where you have O&G activity nearby

- Produced water desalination system sells all concentrate as kill fluid (in Eagle Ford, TX; 

confidential operator); operator adds salt to concentrate to get to correct, higher salinity for 

O&G use for kill fluid.

Completion fluid – protects hardware from damage; typically comprised of brine

Fracturing fluid – increasingly comprised of saline water

Brent.alspach@arcadis-us.com