# May 2014

Scott Wilson USEPA Office of Water 

# Overview of PEA Authorities 

# for Water Associated with Oil and Gas Extraction

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# How Can Extraction of Oil and Gas

Impact Water Resources?

• Concerns about potential impact to surface waters

– For example, shale gas wastewater contains high concentrations of total dissolved solids (salts), and may also contain various organic chemicals, inorganic chemicals, metals, and naturally occurring radioactive materials (NORM)

• Concerns about potential endangerment of water supplies

– If diesel fuels are used, hydraulic fracturing fluids may contain benzene, toluene, ethylbenzene or xylene (BTEX) compounds which are highly mobile in ground water and are regulated under the national primary drinking water regulations

• Sustainability of water resources

– Water sources used for horizontal hydraulic fracturing often come from public water sources, or directly from ground or surface waters

– Recycling flowback/produced water is becoming more common in areas where water availability or disposal is limited

2

# Federal Water Authorities Applicable

to Oil and Gas Extraction

Clean Water Act

• National Pollutant Discharge Elimination System Permitting and National Pretreatment Program

• Effluent Limitations Guidelines and Standards (ELGs)

• Water quality criteria and 

### standards Safe Drinking Water Act

• Underground Injection Control Program Class II regulations

• Hydraulic fracturing (HF) using diesel fuels

• Produced water/flowback injection

3

# The Clean Water Act

• Established the National Pollutant Discharge Elimination System (NPDES) permitting program

• Prohibits the discharge of pollutants, unless authorized 

### by NPDES permits

• Requires permits to contain limits for:

– Best Available Technology Economically Achievable

• Effluent Limitations Guidelines (ELGs) have been established by EPA for most industries



### – Water Quality based limits are required when technology based limits along aren’t sufficient5



## CWA Programs to Control Industrial Discharges

POTW Industry Industry National Pretreatment Program (“indirect dischargers”) National Pollutant Discharge Elimination System (NPDES) discharge permits (“direct dischargers”)NPDES

permit Water Quality
Based Effluent Limits State Water Quality Standards Technology
- Based Standards (Effluent Limitation Guidelines)

Technology
Based Effluent Limits 

# Clean Water Act

For Direct Discharges into Waters of the U.S.

(e.g., rivers, streams)

Permit by local entity (POTW) National Pre
Treatment Standards
Local Limits For Indirect Discharges (into sewers)

6

## Oil and Gas Extraction Effluent



## Limitations Guidelines (ELGs) 40 CFR

Part 435

– Onshore Subcategory

• No discharge



### – Striper Subcategory

• Produces <10 bbl/day oil

• Oil and grease 35 ppm



### – Ag and Wildlife (western)

• Discharge if of good enough quality



### – Coastal Subcategory

• No discharge



### – Offshore Subcategory

• oil and grease 29/42 ppm

# Agriculture and Wildlife Use

Subcategory

• Discharges are currently authorized in some western states

– mostly from oil extraction



### • States vary on what meets the “good enough quality” limits in the ELG



### • TDS limits vary from 150 ppm to 10,000 ppm based on cattle watering

• Whole effluent toxicity limits applied in many cases

# Challenges with Current ELGs

• Onshore Subcategory

– No pretreatment standards

• Coal Bed Methane

– not under Part 435 ELG



### - Where no applicable ELG, permit writers must include limits based on case - by
- case, “best professional judgment” basis.

– EPA began studying the need for an ELG in 2006

– States permit inconsistently using:

• Coal Mining ELGs

– Eastern states

• Agriculture and Wildlife Subcategory

– Rocky Mountain States

• No discharge

– New Mexico, Oklahoma, Texas



### • Centralized Waste Treatment Facilities

– Current regulations at Part 437 do not include pertinent limits

• Subcategories: Metals, Oils, Organics, and Mixed Wastes

• Example: Oil and Grease limits are 38 ppm avg./127 ppm max.

# Revisions to Oil and Gas Extraction ELGs

• In Fall, 2011, EPA announced it was initiating a rulemaking to develop pretreatment standards for shale gas extraction discharges under the existing oil and gas ELGs

– POTWs are not equipped to treat all pollutants in unconventional O&G wastewater

– EPA plans to propose new standards for public comment in Fall 2014

• In Fall, 2011, EPA announced it was initiating a rulemaking to develop ELGs for coalbed methane extraction discharges

– Based on review of information collected to date EPA proposed to discontinue this portion of the rulemaking (August 2013)

• EPA may not be able to identify a nationally applicable treatment technology that would be economically achievable

• A final determination will be made considering public comments

10

# Water Quality Criteria Issues

• Many states have not adopted dissolved solids or chloride water quality criteria

– Ionic components vary significantly by source

• Produced water
- chlorides

• Coal Mines
- bicarbonate and sulfate



### – Currently revising recommended chloride criteria

• Starting peer review process in 2014



### – Conductivity has been suggested as a surrogate

• Inexpensive and easy to measure

• Not as effective as addressing specific ions



### – Developing methods to address bromide in 

### discharges to better protect drinking water (trihalomethane)

# Safe Drinking Water Act

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# Safe Drinking Water Act

Authorities

• EPA’s central authority to protect drinking water is from the Safe Drinking Water Act (SDWA)

• SDWA requires EPA to set legal limits on the levels of 

### certain contaminants in drinking water

• SDWA also requires EPA to protect underground sources of drinking water (USDWs) from contamination caused by 

### underground injection

• SDWA § 1431 contains provisions to address imminent and substantial endangerment

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### Potential Fluid Migration Pathways 1. Faulty injection well casing 2. Annulus between casing and the well bore 3. Migration through confining layers from injection zone 4. Vertical migration through improperly abandoned and completed wells 5. Lateral migration from within injection zone into a protected portion of USDW 6. Direct injection of fluids into or above a USDW

14 Abandoned Well

Confining Layer Injection Zone Injected Fluid Confining Layer

USDW 1

2 3

4 5 6

USDW 

# UIC: Prevent Endangerment of

USDWs

### • EPA UIC Program established six classes of wells (Classes I

– VI)

• Class II wells inject fluids associated with oil and natural gas extraction including:

– Fluids brought to the surface in connection with natural gas storage operations, or oil or natural gas extraction (e.g., produced water) Class II
- D

– For enhanced recovery of oil or natural gas (e.g., well stimulation) Class II
- ER

– For the storage liquid hydrocarbons (usually as part of the US Strategic Petroleum Reserve) Class II
- S



### • UIC programs may not unnecessarily interfere with or impede oil and gas production activities 

# SDWA Underground Injection Control

Program

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# UIC Well Classification

Well Class Function Inventory Class I Hazardous industrial and

municipal wastes 650 Class II Fluids related to oil and

gas production 168,000 Class III Solution mining (e.g. salt,

uranium) 21,400 Class IV Shallow hazardous waste

–

only used for remediation activities 24 sites

Class V Shallow injection of

nonhazardous fluids 500,000

– 650,000 (Estimate

– precise inventory is unknown) Class VI Geologic sequestration of

carbon dioxide N/A
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# Class II Well Requirements

Injection of oil and gas production fluids 

# Key Protective Requirements: Construction and Siting

 Cased and cemented to prevent movement of fluids into underground sources of drinking water
 Construction and design of well (casing, tubing, and packer) varies 

### Monitoring and Testing

 Internal and external mechanical integrity test
 Periodic monitoring and reporting 

### Recordkeeping and Reporting

 Plan for safe plugging and abandoning of wells 17

# Energy Policy Act 2005

• SDWA: Congress revisited SDWA definition of “underground injection” and exempted hydraulic fracturing except when diesel fuel is used(section 1421(d)(1)(B)):

– (i) the underground injection of natural gas for purposes of storage; and

– (ii) the underground injection of fluids or propping agents (other than diesel fuels) pursuant to hydraulic fracturing operations related to oil, gas, or geothermal production activities.

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# Guidance on HF with Diesel

Fuels

• Published the Permitting Guidance for Oil and Gas Hydraulic Fracturing Activities Using Diesel in February 2014.

• Outlines for EPA permit writers, where EPA is permitting authority:

– Requirements for diesel fuels used for hydraulic fracturing wells,

– Technical recommendations for permitting those wells, and

– A description of diesel fuels.

• Recommendations built on best practices from industry and state oil and gas programs.

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# HF Guidance (Cont’d)

• Description of Diesel Fuels:

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# Five CAS Numbers:
Diesel Fuel / Diesel Fuel No. 1 (68334
- 30
- 5) Diesel Fuel /

Diesel Fuel No. 2 (68476
- 30
- 2) Fuel Oil No. 2

/ Diesel Fuel (68476
- 34
- 6) Fuel Oil No. 4

/ Diesel Fuel No. 4 (68476
- 31
- 3) Kerosene /

Marine Diesel Fuel (8008
- 20
- 6)

### EPA Website: http://water.epa.gov/type/groundwater/uic/index.cfm Code of Federal Regulations: Underground Injection Control Regulations 40 CFR 144
- 148: http://ecfr.gpoaccess.gov/cgi/t/text/text
idx?sid=d6ee71a544eca89c533c825135913f13&c=ecfr&tp 

### l=/ecfrbrowse/Title40/40cfrv22_02.tpl 

# More Information about the UIC Program

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