Prof. Gretchen L. Wainwright, P.E.
Civil Engineering Technology, Environmental
Management and Safety
CAST
Presentation Topics
 Hydrofracking Chemicals
 Wastewater Composition
 Flowback Water
Management Options
 Stormwater Protection
 Disposal Options
 Conclusions
Water Use Data in Susquehanna Basin
 Total water use: 716.0 million gallons
(6/1/08 to 5/21/10)
 209.2 mgal from public water
supply (29%)
 506.8 mgal from surface water
(71%)
 Average total volume of fluid used
per well: 3.3 mgal/well
 2.8 mgals of fresh water (85%)
 0.5 mgal of reused flowback (15%)
 Average recovery of flowback: 10.0%
(30 day)
 Total amount of flowback reused or
sent to disposal
 Reuse 44.1 mgals
 Disposal 21 mgals
Substances added to water during
fracturing process
 Proppant (frac sand)
 Oxygen scavengers
 Friction reducers
 Scale inhibitors
 Foaming agents and
 pH adjustment agents




antifoam agents
Emulsifiers and deemulsifiers
Gellants and gel breakers
Biocides
Corrosion inhibitors
 Surfactants
 Viscosifiers
 Cross linkers
 Stabilizers
 Iron control
 Breakers
Fracture Fluid Composition
ADDITIVE TYPE
MAIN COMPOUND
PURPOSE
Dissolve minerals and
initiates cracks in rocks
Bacterial control
Prevents corrosion
Diluted acid (15%)
Hydrochloric or muriatic
Biocide
Corrosion inhibitor
Glutaraldehyde
n,n-dimethyl formamide
Breaker
Ammonium persulfate
Delays pbreakdown of gel
polymers
Crosslinker
Borate salts
Maintains fluid viscosity at
high temperature
Friction reducers
Polyacrylamide, Mineral oil Minimize friction between
the fluid and the pipe
Gel
Guar gum or hydroxyethyl Thickens water to suspend
cellulose
the sand
Fracture Fluid Composition
ADDITIVE TYPE
MAIN COMPOUND
PURPOSE
Iron control
Citric acid
Prevent precipitation of
metal oxides
Oxygen scavenger
Ammonium bisulfate
Remove oxygen from fluid
to reduce pipe corrosion
Proppant
Potassium or sodium
carbonate
Silica quartz sane
Scale inhibitor
Ethylene glycol
Sirfactant
Isopropanol
Maintains effectiveness of
other compounds
Keeps fractures open
Reduces depostion on
pipe
Increases viscosity of fluid
pH adjustment
Wastewater Sources
 Frac flowback water
 High flows for short duration
 10 – 40% of frac fluid recovered
 Most recovered in first 1-2 weeks
 TDS quickly climbs to 30,000 – 200,000 mg/L
 Contains numerous chemical additives and naturally
occurring constituents, including NORM
 Produced Water
 Lower flows (2 to 30 bpd per well)
 Potentially very high TDS (100,000 to 300,000 mg/L)
 Continues to flow for the life of the well
Flowback Water
Cumulative Amount over Time
Flow Rate versus Time
Flowback Water Quality
Constituent
Low
(mg/L)
Medium
(mg/L)
High
(mg/L)
Ba
2,300
3,310
4,700
Ca
5,140
14,100
31,300
Fe
11
52
134
Mg
438
938
1,630
Mn
2
5
7
Sr
1,390
2,100
6,830
Hardness
17,900
49,400
90,337
Radioactivity
ND
ND
ND
TDS
69,400
175,600
248,000
Flowback Water Management Options
 Direct reuse without treatment (blending)
 Blending of flowback with fresh water for subsequent use
 Minimal cost with increased potential for well plugging issues
 On-site treatment and reuse
 Re-condition water by chemical or filtration treatment
 Moderate cost with minimized potential for well plugging issues
 Off-site treatment and reuse
 High transportation costs with same benefit as on-site treatment
 Off-site treatment and disposal
 High transportation and disposal costs
Water Storage
 Storage options:
 Centralized
impoundment
 Single-pad
dedicated
impoundment
 Frac tanks
Storage based on
ultimate scale of
operations (long vs.
short term)
NY State SPDES Regulation Proposed Terms
for HVHF related to Water Storage
 Clean water can be stored in surface impoundments
(pits)
 Cuttings resulting from drilling conducted with “air or
fresh water” can be stored in pits
 Flowback water and produced water CAN NOT be
stored in surface impoundments
 Must be stored in a closed-loop system of tanks
 Volume of a single pit can not exceed 250,000 gals;
total volume of pits can not exceed 500,000 gals
 Pits must be lined
On-Site Controls to Prevent Stormwater
Contamination
 Operator must apply for coverage under the general HVHF
SPDES general permit
 Covers construction activities, fracturing activities, and post-
drilling activities
 Must have a Stormwater Pollution Prevention Plan (SWPPP)
 Operator must have a Spill Prevention Control and
Countermeasure Plan (SPCC Plan)
 Closed-loop tank system must be used to manage drilling
fluids and cuttings
 Disposal, recycling or reuse of flowback water must be
approved by NYS DEC
 Transporters must have a Part 364 permit
SWPPP Requirements
 Operator must evaluate alternatives for the HVHF




additives that are “efficacious but which exhibit
reduced aquatic toxicity and pose less risk to water
resources and the environment”
Secondary containment must be provided
Must maintain a list of additives on site
Ensure proper transport and disposal of wastewater
Structural and non-structural Best Management
Practices (BMPs)
On-Site Treatment Options
 Blending and dilution with direct discharge (POTWs)
 No pollutants are removed
 Chemical treatment
 pH adjustment  precipitation of metals/sulfates
 Does not remove salts
 Filtration/Membrane Treatment
 Micro/nano/ultra-filtration
 Reverse osmosis
 Removes many compounds, but membranes can become fouled at
higher concentrations
 Thermal/Evaporative Technologies
 Can remove virtually all compounds, but very expensive
Parameters of Concern when Reusing
Flowback Water
 Total dissolved solids (chloride) – interference with




friction reducers
Total suspended solids – down hole plugging
Metals (barium and strontium) – may form
precipitates
Sulfates and carbonates – may form precipitates
Bacteria – down hole plugging
Ecologix: Integrated Treatment System
 Mobile DAF system that
removes suspended solids,
fats, oils and greases from
wastewater, produced
water, and frac water. It
uses chemical and air
addition to separate, float
and remove sludge.
FracTreat™ Mobile Precipitation System
from Siemens Water Technologies
On-Site Treatment




Necessary to be able to re-use the flowback water
Primarily removes dissolved and suspended solids
Performed in mobile package-type systems
Generally will not adequately treat wastewater to
enable direct discharge
 Technology based discharge requirement under 40 CFR
Part 435 – Oil and Gas Extraction Point Source Category
is “no discharge of any pollutants from any source
associated with production, field exploration, drilling,
well completion or well treatment”
 Sludges generated also require further dewatering and
disposal
Off-Site Treatment and Disposal
 HVHF SPDES permit applications must include a
Fluid Disposal Plan covering the life of the well
 Requires certification from disposal facility that




available capacity exists
Identifies alternative and contingent disposal options
Contains estimates of chemical concentrations of
flowback and production water over the life of the well
Identifies all chemical additives to be used by name,
purpose and type, and amount
MSDSs for additives included
POTW Requirements
 Before a POTW can accept Flowback Water it must:
 Have an approved pretreatment program
 Notify DEC of intent to accept flowback water
 Perform a headworks analysis that demonstrates that
the POTW can remove the contaminants expected to be
present, including TDS, NORM, Ba, Br, BTEX, and other
additives
 Submit to a permit modification to include appropriate
monitoring and effluent limits
Flowchart for
acceptance of
High Volume
Hydraulic
Fracturing (HVHF)
wastewater by
publicly owned
treatment works
(POTWs)
Conclusions
 NYS DEC has done a good job developing
requirements that will ensure:
 adequate and appropriate treatment of flowback and
produced water
 the protection of stormwater throughout all phases of
well construction and operation
 the protection of water resources
 Hardest part is yet to come – implementation and
oversight of these regulations
References
 Siemens Water Technologies, Warrendale, PA. FracTreat and Simatic are
trademarks of Siemens, its subsidiaries or affiliates.
http://www.water.siemens.com/en/oil-gas/upstream/fractreat/Pages/default.aspx
 Ecologix Environmental Systems, Alpharetta, GA
http://www.ecologixsystems.com/system-its.php
 “Water Treatment Solutions for Marcellus Natural Gas Development”,
presentation by David Yoxtheimer, P.G., PennState Marcellus Center for
Outreach and Research.
 “Sustainable Water Management for Marcellus Shale Development”,
presentation by Radisav D. Vidic, Ph.D., PE, Department of Civil and
Environmental Engineering, Swanson School of Engineering, University of
Pittsburgh.
 Proposed Express Terms 6 NYCRR Parts 750.1 and 750.3, Obtaining A
SPDES Permit and High-Volume Hydro Fracturing (HVHF),
http://www.dec.ny.gov/regulations/77383.html
 Revised Draft SGEIS on the Oil, Gas and Solution Mining Regulatory
Program (September 2011) http://www.dec.ny.gov/energy/75370.html