T H E I M P A C T O F N A T U R A L G A S & C O A L B E D M E T H A N E O N G R O U N D W A T E R I N A L B E R T A

FACT SHEETProtecting WaterProducing Gas

Protecting Water, Producing GasHow the production of natural gas, including coalbed methane, might impactgroundwater in Alberta and what is being done to minimize the risks

In 2005 more than13,000 conventional natural gas wells weredrilled in the provinceand about 4,000 weredrilled or completed forcoalbed methane (CBM).Each of these wells andthe pipelines associatedwith them can impactwater in various ways.

The sources of gas inAlberta are changing and so are the potentialimpacts. As conventionalnatural gas production inAlberta declines andprices increase, companiesare developing unconven-tional gas sources such as CBM,tight gas and shale gas.

Landowners are concerned that theaquifers supplying their water wellswill be affected by such develop-ment, especially the drilling of wellsinto shallow formations where thewater is fresh. Some of this worrystems from the fact that many CBMwells had already been drilled beforethe government had sufficient infor-mation about groundwater. Some

landowners believe that groundwaterquality is being affected as a result asthis activity.

Differences between conventional and unconventional gasConventional natural gas is found in pore spaces in porous formationssuch as sandstone or limestone andis mainly composed of methane.

It is usually produced from deeprock formations where the water is salty. Some new unconventional

gas sources are also very deep (over 1,000metres) but an increas-ing number are shallowand may be less than200 metres below thesurface. The annual out-put from an unconven-tional gas well is, onaverage, much lowerthan that from a con-ventional well, as the gasdoes not flow as freelythrough the formation.As a result, a higherdensity of wells is oftenrequired to produce aneconomic volume of gas.

Rapid increase in gas wells

As can be seen from Figure 1, thenumber of producing gas wells hasincreased two-and-a-half times overthe past decade, even though naturalgas production began declining in2001. This upward trend in thenumber of wells being constructed is likely to continue, as an increasingproportion of gas is produced fromunconventional sources.

Number of wells Billion cubic metres100 000

80 000

60 000

40 000

20 000

096 97 98 99 00 01 02 03 04 05

40

80

120

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0

Producing gas wells Production

More than 350,000 oil and gas wells have been drilled inAlberta since production started, which is about one well forevery ten people living in the province.

▲ Figure 1: Marketable Gas Production in Alberta and ProducingWells, 1996–2005.

SOURCE: ALBERTA ENERGY AND UTILITIES BOARD, EUB 2005 YEAR IN REVIEW

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The importance of groundwater protectionWithin Alberta, 90 per cent of ruralresidents rely on groundwater fortheir water supply. The Paskapooaquifer, which overlies the Ardleycoals, supplies 100,000 water wells.Water wells for domestic and agricultural use are generally shal-lower than gas wells (see Figure 2),but there may be connectionsbetween fresh water aquifers andgas-bearing formations.

Alberta Environment and theAlberta Energy and Utilities Board(EUB) have rules designed to protect shallow groundwater – thatis, water that is above the base ofgroundwater protection. For exam-ple, the EUB requirements for thecementing of casings on oil and gas wells are intended to prevent gas from getting into groundwater.New rules have been developed toaddress unconventional gas produc-tion. As can be seen in Figure 2, thebase of groundwater protection isgenerally deeper in the west of theprovince than in the east.

More information is neededon fresh groundwater While the number of oil and gaswells has grown rapidly, the size ofAlberta Environment’s groundwatermonitoring network was reduced inthe 1990s. It now has about 200observation wells (half the number

it monitored 15 years ago) and one-third the number of monitoringwells currently found in Manitoba.Alberta has not invested enoughover the last decade in collectinginformation about the condition ofthe province’s fresh groundwater, toensure that water is not withdrawnfaster than it is flowing back intothe aquifers. Studies of the Paskapooand Ardley formations are currentlyunderway to reveal more about

shallow aquifers that might beimpacted by CBM development.

The EUB now requires companiesto take measurements of (or log) theupper part of new oil and gas wellsand to submit this information sothat the EUB can learn more aboutthe extent of shallow strata, includ-ing aquifers (EUB Directive 43).New requirements in place for CBMproduction are described below.

Metres0

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Typical Water Wells CBM Wells

Base of groundwater protection

Note: Exaggerated vertical scale; dip on strata 1-2°

Paskapoo

Scollard/Ardley

Horseshoe Canyon

Belly River

Mannville

Colorado / Lea Park

An important term to understandwhen dealing with governmentand gas development is the“base of groundwater protec-tion.” It describes the boundarybetween fresh (non-saline) andsalty (saline) water. In Alberta it isusually between 150 and 600metres deep where saline wateris defined as having more than

4,000 milligrams per litre of total dissolved solids. The term“dissolved solids” describes the level of salts in the water.Shallow groundwater often hasless than 500 milligrams per litreof total dissolved solids,which is the recommended maximumlevel for drinking water.

Base of groundwater protection

Figure 2: Cross-Section Showing CentralAlberta’s Main Coal-Bearing Formationsand the Base of Groundwater Protection

SOURCE: THE PEMBINA INSTITUTE. 2007. BASED ON FIGURES FROM ALBERTA ENERGY AND UTILITIES BOARD.COAL SEAMS ARE FOUND IN THE SCOLLARD/ARDLEY, HORSESHOE

CANYON, BELLY RIVER AND MANNVILLE FORMATIONS.

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Conventional natural gasProduction of conventional naturalgas from deep formations may leadto the production of saline water asthe well is depleted (this can happenright from the start of production, or a year or more later in the case of more prolific gas wells). This “produced water” is piped or truckedto an injection well, which returns thewater deep underground well belowthe base of groundwater protection. If a produced water pipeline leaks thesoil will be contaminated with saltwater, which will damage the soilstructure and prevent plant growth.The company responsible must thusclean up all spills and leaks. In 2005there were 179 incidents associatedwith water being piped from oil and gas pipelines in the province;that is one incident for every 117km of produced water pipeline.

Some conventional gas wells areabove the base of groundwater protection and may produce somewater as the wells age. At present,Alberta Environment does not regu-late the production of fresh waterfrom shallow conventional gas wells,but has stated that, in the future, therules that apply to the diversion offresh water from CBM wells will alsoapply to shallow conventional wells.

Coalbed methaneWith the expansion of CBM devel-opment, much of the attention hasbeen focused on the potential forimpacts on fresh groundwater.

One-third of the recommendations of the government’sCoalbed Methane/Natural Gas in CoalMulti-StakeholderAdvisory Committeerelate to the protection of groundwater and arebeing implemented bythe government. Thepotential impacts ofCBM developmentdepend on whether thecoal seams are shallow ordeep and whether theycontain water or are dry.The majority of coalseams in the HorseshoeCanyon formation are dry (except at thenortheast corner of theformation, southeast ofWetaskiwin); those in theMannville formation are deep andcontain saline water; the shallowArdley coals (which partly underliethe Paskapoo aquifer referred toabove) are sometimes dry, but may contain fresh or saline water.Figure 3 shows the main coal-producing formations.

If coal seams contain water, thiswater must be pumped out toreduce the pressure in the coal sothat the gas can flow to the surface.At present all produced water mustbe sent for deep well disposal. If toomuch water were pumped fromcoals above the base of groundwaterprotection, it might draw water

from shallow aquifers that are usedfor water wells. Landowners alsoworry that gas may migrate from thecoal into groundwater as a result ofsuch activity.

Government rules to protect freshgroundwater include the 2006requirement for baseline water welltesting before a company drills aCBM well that will be above thebase of groundwater protection, andlimiting the volume of non-salinewater that any oil or gas well canproduce without a licence. Specialrules apply to the fracturing of shallow coals and to the diversion of fresh water from a CBM well.

Potential impacts of gas productionThe production of different gas sources may impactwater differently.

▲ Salty water being piped from wells for under-ground storage may leak causing damage to crops. SOURCE: THE PEMBINA INSTITUTE

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Importance of baselinewater well testingIn case shallow groundwater is laterimpacted by the production ofCBM, it is important to have infor-mation about the baseline conditionsof the water before CBM wells aredrilled. Since May 2006 AlbertaEnvironment has required compa-nies drilling for CBM above the baseof groundwater protection to offer totest all water wells within 600 metresof a proposed gas well, in the man-ner set out in their protocol. Wells ata greater distance from a proposedgas well may also be tested in somesituations. The water well must betested for yield, and water samplessent to a laboratory to be tested forbacteria, certain minerals and salinity(as measured in total dissolvedsolids). If there is any free gas in the water well, a gas sample must betaken and analyzed for compositionand the isotopic characteristics of the gases. The company must give acopy of the laboratory analysis to thelandowner; the landowner shouldcarefully store this record of baselineconditions in case there are laterproblems with the water well. TheEUB enforces baseline water welltesting (see Directive 35). AlbertaEnvironment set up a scientific panelto review the baseline testing resultsand intends to report before the endof 2007 on whether the standard fortesting needs to be improved.

Concerns about fracturing of coal seamsIf the coal seams contain water, this must be pumped off to allowthe gas to flow. Even if the seams donot contain water, they must usuallybe fractured. Fracturing involvespumping a fluid or an inert gas

(usually nitrogen in the case of dry CBM wells) down the well atextremely high pressures for a fewminutes to create or extend naturalfractures in the coal so that the gascan flow more easily to the well bore(the hole drilled to reach the gas). Some landowners fear that sub-stances used for fracturing mightenter shallow groundwater and that the fractures might make it easier for gas to migrate from thecoals into groundwater.

The EUB does not allow any toxicsubstances to be used for fracturingwells drilled above the base ofgroundwater protection. It is knownthat shallow fractures tend to extendhorizontally in shallow zones(whereas they extend vertically atdepth) but companies are still learn-ing how shallow fractures propagate.Thus, the EUB has set limits onfracturing of formations shallowerthan 200 metres, and set up a tech-nical review committee to examineshallow fracturing (see Directive 27).

▲ Figure 3: Coalbed Methane Target Zones in Alberta.SOURCE: ALBERTA ENERGY AND UTILITIES BOARD

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Diverting fresh groundwaterIf a company wants to produce gasfrom a coal seam that contains waterabove the base of groundwater protection, it must apply to AlbertaEnvironment for a licence to divertthe water. Before a company canobtain a licence, it must conduct a technical review of groundwaterresources in the area and submit it with their application. AlbertaEnvironment is developing plans to allow a company to withdraw alimited amount of water (probablyless than 30 m3/month per well or 100 m3/month per section) by following a code of practiceinstead of applying for a licence.This volume would allow thewithdrawal of up to 1,200m3/year per section under thecode. For comparison, any waterwell drilled for household purpos-es is allowed to withdraw up to1,250 m3/year without a licence.

Complaints related to water wells andcoalbed methaneSometimes landowners thinkthat changes in the yield or quality of the water in theirwater well are due to CBMdevelopment, but it is difficult to prove. From January 2004 to November 2006, AlbertaEnvironment’s Central andSouthern Regions received 55 complaints about water wells where there was mentionthat the problem might be dueto CBM production. In themajority of cases no linkage toCBM could be found, but tencases are still under investigation.

Issues related to using produced waterAt present producedwater is normally re-injected deep under-ground to ensure that thesalts in the water do notharm the environment.However, Alberta Envir-onment is consideringwhether to allow non-saline water to be used, ifit meets certain standardsand will not contaminatesoils, shallow ground-water or surface water.The level of salinity that is acceptable partlydepends on how thewater is to be used. For example, if water isused for irrigation, it isimportant to evaluate not only the salinity ofthe water but also thesodium adsorption ratioof the soil and the salttolerance of the crop.

▲ Figure 4: Production of coalbed methane is expected to rapidly increase.SOURCE: ALBERTA ENERGY AND UTILITIES BOARD

The government introduced some new measures to protect shallow water in2006 but more needs to be done. Some key recommendations are listedbelow. A detailed list can be found in the full report Protecting Water,Producing Gas.

The Pembina Institute calls on the government to:

1) Extend the protection of groundwaterto include somewhat saline aquifersthat could be used in times of drought.

2) Greatly expand the province-wide groundwater monitoring system.

3) Increase the requirements on industryto conduct water well testing prior todrilling gas wells.

4) Improve the system for handling and reporting on water well complaints.

5) Ensure long-term funding to enablesustainable, integrated managementof the province’s groundwater.

Some Key Recommendations

Shale gasShale gas is probably at thesame stage of development inAlberta as CBM was five yearsago, and production of gasfrom shale is likely to increasein the future. There are manyzones containing shale in the formations that underlieAlberta, and the industry is looking for “sweet spots”(areas that will be economic to produce). As the EUB doesnot currently have a separatecode for shale gas, it is not possible to identify where shalegas is being produced. In theU.S., where three to four percent of total gas productioncomes from shale, some forma-tions produce water (fresh orsaline) while others are dry. Shaleneeds fracturing to release the gas.As with CBM, this may be donewith water or other substances. Alsolike CBM, if the shale formationscontain water, this water must bepumped out to reduce pressure sothat the gas can flow to the wellbore. A high well density may be

required to access the gas, but wherethe shale formations are deep, paddrilling (with several wells on onesite) may be possible, as is done withdeep CBM. If the pressures are suit-able, shale gas may be commingled

in the well bore with gas from otherformations, so a company may notalways need to drill new wells todevelop shale gas. The rules for conventional natural gas productionapply to shale gas.

Want more information?In addition to this document, thePembina Institute has also publishedProtecting Water, ProducingGas – Frequently AskedQuestions (4 pages) and a detailed report, Protecting Water,Producing Gas: Minimizing theImpact of Coalbed Methane andOther Natural Gas Productionon Alberta’s Groundwater(122 pages), which examines themany ways gas production may affectfresh water. It includes recommenda-tions on how industry, government and landowners can help protect fresh water aquifers. The report,

which includes references for all theinformation in this summary, can befound on the Pembina Institute website.This report was made possible bygrants from the Alberta EcotrustFoundation and the Walter andDuncan Gordon Foundation. Supportour work. For more information or to make a donation to the PembinaInstitute please visit www.pembina.org.

See also the Alberta Environment website for information on CBM atwww.waterforlife.gov.ab.ca/coal/index.html and the EUB website atwww.eub.ca/portal/server.pt.

www.pembina.orgAPRIL 2007

▲ Figure 5: There are many zones containing shale in the formations that underlie Alberta and the industry is looking for areas that will be economic to produce. SOURCE: ALBERTA GEOLOGICAL SURVEY AND GEOLOGICAL SURVEY OF CANADA

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