CITY OF PRINCE GEORGE WELLS PROTECTION PLAN

CITY OF PRINCE GEORGE 

WELLS PROTECTION PLAN: 

FOR CN RELATED RISKS 

March 2015 

(Revised February 26, 2016) 

840-003-10

Submitted to: 

Dave Dyer 

General Manager, Public Works 

City of Prince George 

1100 Patricia Blvd. 

Prince George, BC V2L 3V9 

Phone: 250. 561-7663 

Submitted by: 

Bob Radloff, P.Eng. 

Principal 

R. Radloff & Associates Inc. 

1820 – 3 rd Avenue 

Prince George BC V2M 1G4 

Phone: 250.562.6861 

Fax: 250.562.6826 

& 

Marta Green, P. Geo 

Senior Hydrogeologist 

Summit Environmental Consultants 

Suite 200 – 2800 29 th Street 

Vernon, BC V1T 9P9 

Date Issued: March 25, 2015 (Revised February 26, 2016) 

File: 840-003-10 

This document was prepared solely for the use of the Client. The material in it reflects the Consultant’s best judgment in light of the information available to it at the time 

of preparation. Any use which a third party makes of this document, or any reliance on or decisions to be made based on it, are the responsibility of such third parties. The 

Consultant accepts no responsibility for damages, if any, suffered by any third party as a result of decisions made or actions based on this document. By making use of this 

document the Client expressly agrees that the Consultant’s employees and principals shall have no personal liability to the Client in respect of a claim, whether in contract, 

tort and/or any other cause of action in law. Accordingly, the Client expressly agrees that it will bring no proceedings and take no action in any court of law against any of 

the Consultant’s employees or principals in their personal capacity. These documents are the exclusive property of the Consultant and cannot be used or reproduced 

without written consent.

March 2015 

City of Prince George Well Protection Plan 

TABLE OF CONTENTS 

Executive Summary 

1 Introduction & Background 7 

1.1 Methodology 7 

1.2 The Nechako Aquifer: Location & Significance (Drinking water source description) 7 

1.3 Canadian National Railways Presence in the City of Prince George 10 

1.4 Hazardous Materials Moving Through CN’s Northern Corridor 12 

1.5 Delineation and Characterization of Water Sources 15 

2 Current Legislation & Emergency Procedures 26 

2.1 The City of Prince George 27 

2.2 Provincial/Federal Government 28 

2.3 CN 29 

3 Current Threats from CN Activity 31 

3.1 The Threat of Derailment-Related Spills 31 

3.2 The Threat of At Grade Crossings 34 

3.3 The Threat of Physical Impacts with City Wells 39 

3.4 Other Threats 39 

4 Mitigation and Response Measures 41 

4.1 Preventative Measures 41 

4.2 Response Measures 46 

4.3 Additional Studies 41 

5 Characterize Risks from Source to Tap 48 

5.1 Risk Assessment Procedures 48 

5.2 Risk Assessment Results and Recommendations 49 

5.3 Derailments and Collisions on Railway Tracks, Grade Crossings, and Track Switch 51 

5.4 Well Houses (Train Collision) 51 

5.5 General Hydrogeological Recommendations 52 

6 Conclusions & Recommendations 54 

Appendix A: Definitions 

Appendix B: Referenced Materials & Background Information 

Appendix C: Excerpt from Golder’s “Capture Zone Analysis, Contaminant Inventory and Preliminary 

Groundwater Monitoring Plan” (2003) 

Appendix D: Well Logs

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EXECUTIVE SUMMARY 

The purpose of this report is to provide the City of Prince George (the City) with an assessment of the risks 

associated with the Canadian National Railway (CN) operating within the Lower Nechako River Valley Aquifer 

(Nechako Aquifer), which is Prince George’s main well water source, and to suggest actions which could be 

undertaken by both CN and the City to mitigate these risks. 

The City retained R. Radloff & Associates Inc. (Radloff) to evaluate risks posed by hazardous materials from 

the CN facilities and rolling stock adjacent to three of the City’s water supply wells, PW 660, 605, and 601/602. 

Radloff was also asked to suggest protective measures for the wells from these potential hazards. Summit 

Environmental Consultants Inc. (Summit) was part of Radloff’s team, and was retained to provide senior 

hydrogeological expertise. 

The City of Prince George obtains approximately 95% of the water required for industrial and domestic use 

from three high-capacity wells: PW660, PW605 and PW602/601. These wells are located within the Lower 

Nechako River Valley Aquifer, which is recharged by surface water from the Nechako River, from precipitation, 

and run-off infiltration. Infiltration from all sources is through various layers that consist of coarse materials, 

including sand and gravel, with only trace amounts of fine material (silt). 

The Nechako Aquifer is a highly valuable natural feature, not only because of its high-yield and easy 

accessibility, but also because it produces water which tastes good, has ideal hardness levels, and has 

virtually no incidents of bacteriological contamination; a goldmine from a hydrogeological standpoint. However, 

given the coarse permeable materials that are characteristic of the area, the aquifer and the water supply are 

vulnerable to infiltration of hazardous materials. The loss of any or all of these wells, averaging $6m capital 

costs per well, would be catastrophic for the City in terms of quality of life, sustainable economic growth, and 

environmental damage. In the past 20 years, two of the City wells in the Nechako Aquifer have been closed 

due to contamination from spill-related (not involving rail) accidents. As such, the vulnerability of the currently 

active City wells needs to be taken seriously. 

As the City of Prince George is strategically located between Edmonton and Prince Rupert along east/west CN 

lines, and is the “Gateway to the North” along north/south CN lines, forecasts indicate significant growth in rail 

traffic. Despite the efforts of both the City and CN staff to mitigate the risks associated with transporting goods 

through the City, incidents and accidents involving “Dangerous Goods” do occur (11 documented in 2013, and 

12 documented in 2012 in Prince George). In addition, there was the major incident in August 2007 where a 

CN derailment occurred next to the Fraser River resulting in a fuel spill, a fire and an undetermined amount of 

diesel and gasoline seeping into the ground. 

The focus of interest for this study lies primarily between Mile 0 (Prince George CN Yard) and Mile 6.31 in the 

Miworth subdivision, between which the Nechako Aquifer is located. CN lines from Mile 0 to Mile 6.31 are 

situated beside or in some cases directly above the Nechako Aquifer. According to CN officials, the majority of 

dangerous goods currently move along CN rail lines north, east and south. Westward routes currently carry 

fuels, but if industrial interests to the west of Prince George are renewed, rail shipments could start to carry 

additional hazardous products. 

This report describes the various categories of hazardous and dangerous goods that have passed through 

Prince George on CN rail lines and their relative potential impact on the Nechako aquifer if a spill were to 

occur. While there is currently a lack of reported information, except when there is an incident or accident, 

recent regulations imposed by the Federal Transportation Safety Board (TSB) require municipalities to be 

provided with semi-annual summaries of dangerous goods transported through their communities. 

The work for this report focused on reviewing the City well sites and the well capture zone modelling prepared 

by Golder Associates in 2003, determining the vulnerability of the City’s water supply and the risk ratings to 

City wells, and developing recommended preventative and response actions. Modelling the well capture zone 

is important because it indicates the likely pathways and speed of spill infiltration towards the City wells. Based

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on this modelling and recommendations of the BC Ministry of Health, this report recommends well head 

protection measures, and that portions of the Nechako River near the wells be added to the City’s 

Groundwater Protection Area. 

The threat of derailment-related spills is viewed as the most significant threat to the City’s water supply, 

because of the close proximity of the CN lines to the at-risk wells. While spill risks themselves are assessed, it 

has also been determined that a derailment near a City well could cause City operators to be restricted from 

entering the well house and manually shutting down the well (shutdown of a well could significantly reduce the 

spill infiltration towards the well). Several factors that could affect the risk of rail derailments were assessed 

including, track maintenance and train travel speeds, potential collisions at three grade crossings, potential 

user errors at a switch location, application of track maintenance chemicals, and physical impact on a well 

house from a train derailment. 

Based on the assessment work, this report identifies 14 preventative or responsive actions that would mitigate 

the eventuality of a contaminant spill from a derailment (see table below). The City is identified for eight of the 

actions, CN is identified for three of the actions, and four of the actions require joint work between the City and 

CN. This report also concluded that the best results would occur with a commitment to communication, 

transparency and joint planning between the City and CN. 

Finally, in order to assist with prioritizing the recommended actions, this report provides a risk assessment that 

considers both the likelihood of a spill occurrence contaminating a well, and the magnitude of the 

consequence. In this risk assessment, the spill scenarios that have a high likelihood of occurrence and a high 

level of consequence result in a high priority for action. Derailments and collisions on railway tracks, grade 

crossings and track switches rated very high risk, and well house collision with derailed train rated high risk. 

Based on this, the following table summarizes the recommended actions by priority.

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Priority 

Action* 

Initiating 

Party 

Preventative (P) 

or 

Responsive (R) 

1 Remote pump shut-down capabilities and procedures (for the wells) City R 

1 Emergency water quality monitoring plan (spill incident) City R 

1 Remote operation capabilities and procedures (for the wells) City R 

1 

1 

Additional studies (i.e. groundwater flow direction study; updating 

numerical flow model of capture zones near CN tracks) focusing on risk 

and mitigation options. 

Additions to City’s Groundwater Protection Areas (wellheads and 

Nechako River) 

1 Reduction of train speeds CN P 

1 

Creation of a joint emergency response committee (to provide 

emergency plans and a contact list)* 

1 Enhancement of track maintenance CN P 

2 Creation of alternate supply capability (redundancy for PW605) City P/R 

2 Greater transparency and improved communication Joint P 

3 Minimization/elimination of at grade crossings Joint P 

4 Advance notification of dangerous goods are being transported CN P/R 

TBD 

TBD 

Installation of a ground seal (significantly reduces speed of infiltration) – 

option to be determined based on additional studies 

Installation of interceptor wells and trenches – option to be determined 

based on additional studies 

5 Installation of at grade crossing arms Joint P 

City 

City 

Joint 

* This would also include an addition to the City’s Emergency Operations Centre Procedures. 

City 

City 

P 

P 

R 

P 

P

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1 INTRODUCTION & BACKGROUND 

Despite the global economic downturn, Canada has experienced tremendous growth and resilience in the past 

10 years, especially in the north, as we have explored the rich heritage of natural resources our country has to 

offer. This growth has led to increased traffic through every medium of transportation, and in particular, on our 

national railways. However, growth never comes without a price, and this price is being paid by many 

communities which have, until now, been unprepared to deal with the increase in rail traffic, the higher 

likelihood that rail cars are carrying dangerous goods and the fallout when disasters occur, such as hazardous 

spills due to derailments, collisions, and leaks. 

The purpose of this report is to provide the City of Prince George (the City) with an assessment of the risks 

associated with the Canadian National Railway (CN) to the Lower Nechako River Valley Aquifer (Nechako 

Aquifer), Prince George’s main well water source and to suggest actions which could be undertaken by both 

CN and the City to mitigate these risks. 

1.1 Methodology 

The City retained R. Radloff & Associates Inc. (Radloff) to evaluate risks posed by hazardous materials from 

the CN facilities and rolling stock adjacent to three of the City’s water supply wells, PW 660, 605, and 601/602. 

Radloff was also asked to suggest protective measures for the wells from these potential hazards. Summit 

Environmental Consultants Inc. (Summit) was part of Radloff’s team, and was retained to provide 

hydrogeological expertise. 

This investigation included: 

1) Reconnaissance of the site. 

2) Review of CN’s products (hydrocarbons, chemicals), operation procedures (for example, speed control 

methods) and right-of-way maintenance procedures (such as, pesticides, rail tie preservatives) and 

the potential impact a derailment could have on the City’s wells including the migration of chemicals 

into the Nechako Aquifer and the effect a derailment may have on water system operations (for 

example, losing access to the wells or losing the ability to operate the wells). 

3) Review of the City’s current operation activities, physical infrastructure, and supervisory control & data 

acquisition system (SCADA) to identify vulnerabilities and an assessment of improvements to the 

components that would serve to better mitigate impacts on the City’s wells in the event of a trainrelated 

disaster 

1.2 The Nechako Aquifer: Location & Significance (Drinking water 

source description) 

The City of Prince George obtains approximately 95% of the water required for industrial and domestic use 

from three high-capacity wells: PW660, PW605 and PW602/601. These wells are located within the Lower 

Nechako River Valley Aquifer, which is located in the alluvial deposits of the Nechako River fan. The Nechako 

River Valley Aquifer is an unconfined aquifer comprised entirely of material from sand and gravel size up to 

cobble and boulders (Golder Associates Ltd., 2003), with a very shallow water table (

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comes from the Nechako River; the water migrates across the streambed through layers of fluvial sand, sand 

and gravel, and gravel before entering the well screens. 

The Aquifer Classification System for Ground Water Management in British Columbia as defined by the 

Ministry of Environment, classifies the Nechako Aquifer as 1A (See Figure 1), meaning that it is heavily 

developed and highly productive while also being highly vulnerable to contamination from surface sources. 

Figure 1: Aquifer Classifications 

http://www.env.gov.bc.ca/wsd/plan_protect_sustain/groundwater/aquifers/index.html 

The Type 1A Nechako Aquifer, as shown in pink and labelled 921A (15) on the Aquifer Classification Map 

(Golder Associates Ltd., 2006) in Figure 2, is a highly valuable natural feature. This is not only because of its 

high-yield and easy accessibility, but also because it produces water which tastes good, has ideal hardness 

levels, and has virtually no incidents of bacteriological contamination; a goldmine from a hydrogeological 

standpoint. Given these attributes, the City plans to maximize the use of wells PW660, PW605 and 

PW602/601 as demand increases in coming years. Currently, the maximum projected daily demand is 

155,800 m³/d (1804 L/s) for the three wells, with only one backup well (PW607) that could supply the city with 

9,219 m³/d (106.7 L/s) (Golder Associates Ltd., 2003). The raw water from each well is pumped to the City’s 

pump house at each respective well. The pump houses have chlorination and fluoridation facilities that treat 

and pump the water prior to distribution. The treated water is pumped either to a reservoir or directly pumped 

to individual homes and businesses. 

The drinking water source wells PW660, PW605 and PW601/602 are located north of the city core, adjacent to 

the Nechako River (Figure 2). Although there are potential back-up wells within the aquifer catchment, such as 

PW607, there are no other 1A equivalent wells within a reasonable distance. Thus, the loss of any or all of 

these wells would be catastrophic for the City in terms of quality of life and sustainable economic growth, not 

to mention the far-reaching, environmental damage to flora and fauna such an incident could result in along 

both the Nechako and Fraser rivers. 

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Figure 2: Aquifers in the Prince George Region 

Nechako Aquifer 

(Golder, 2010) 

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1.3 Canadian National Railways Presence in the City of Prince George 

Experts are forecasting increased product demand from the mining, forestry, oil, and gas industries as well as 

an increased flow in manufactured goods, many of which are being transported primarily via our national rail 

networks. For example, in 2011, more than half a million carloads/intermodal units moved over CN’s B.C. 

north corridor, with the vast majority passing through the CN Yard located between the southwest bank of the 

Nechako river and the City’s downtown core. 

As the City of Prince George is strategically located between Edmonton and Prince Rupert along east/west CN 

lines, it stands to benefit significantly from this economic growth and CN traffic on this line is expected to 

continue to increase. Specialized shipping capabilities, insulated containers and a 10 day supply chain 

advantage also make Prince Rupert a preferred port for time-sensitive materials. (Caruso, 2014) In addition, 

as ‘The Gateway to the North’, the City also experiences significant north/south rail activity. 

The focus of interest for this study lies primarily between Mile 0 (Prince George CN Yard) and Mile 6.31 in the 

Miworth subdivision, between which the Nechako Aquifer is located. CN lines from Mile 0 to Mile 6.31 are 

situated beside or in some cases directly above the Nechako Aquifer. While moving these rail lines is 

theoretically possible, it is unlikely to be economically or logistically probable. 

Historic Threats to the Nechako Aquifer by CN 

Despite the efforts of both the City and CN staff to mitigate the risks associated with transporting goods 

through the City, accidents do occur. 

In his Railway Occurrences (Incidents and Accidents) in Northern BC 2003 – 2013, James Haggerstone 

(2013), in consultation with CN, identified the dangerous goods (see below) that have either spilled or been 

involved in incidents in or surrounding the Prince George CN Yard. In 2013, involved products included the 

following: petroleum gas, fuel oil and diesel fuel; while in 2012 the products included: petroleum gas, sulphuric 

acid, sodium hydroxide solution, methanol, ethanol, environmentally hazardous substances, fuel oil and 

aluminum smelting by-products. 

In 2013, there were approximately 11 rail incidents in Prince George: 

Derailments in Yard: 8 

Collisions: 3 

Dangerous Goods Incidents: 5 

In 2012, there were approximately 13 rail incidents in Prince George: 

Derailments in Yard: 11 

Collisions: 2 

Dangerous Goods Incidents: 8 

Note: The Transportation of Dangerous Goods Act (Canada) lists Dangerous Goods as 

explosives, compressed and liquefied gases, flammable and combustible materials, oxidizing 

materials and organic peroxides, poisonous and infectious substances, radioactive materials, 

corrosives, and miscellaneous dangerous goods. 

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Table 1: Summary of Recent CN Yard Incidents (Prince George, BC) 

Year UN Name TSB Event Type 

2013 1075 Liquefied Petroleum Gas R13V0031 No spillage 

2013 1202 Diesel Fuel R13V0263 Leak 

2013 1202 Diesel Fuel R13V0056 Leak 

2013 1075 Petroleum Gas R13V30031 Collision-No leak 

2013 1202 Diesel Fuel R13V30021 Spill: 2,650 Litres 

2012 1824 Sodium Hydroxide Solution R12V0156 No Spill 

2012 1230 Methanol R12V0136 Leak 

2012 1202 Fuel Oil R12V0128 Leak 

2012 3475 Ethanol R12V0123 No Spill 

2012 3082 Environmentally Hazardous substances R12V0103 10-15 Litres spilled 

2012 1202 Fuel Oil R12V0113 No leak 

2012 3170 Aluminum Smelting By-Products R12V0053 Leaking Car 

2012 1202 Fuel Oil R12V0113 

2011 1202 Diesel Fuel R12V0135 No Leak 

1830 Sulphuric Acid 

1495 Sodium Chlorate 

2008 1075 Petroleum Gas R08V0171 

2007 1075 Petroleum Gas R07V0213 171,000 Litres 

1202 Diesel Fuel R07V0213 1,600 Litres 

2004 1830 Sulphuric Acid R04V0063 

Summary of Prince George CN Yard Incidents 2012-2013 (Caruso, 2014) 

In addition, major incidents have also occurred in the Prince George area, such as the CN derailment which 

took place on August 04, 2007 involving two locomotives, a flat bed, a gas tanker car, a diesel tanker, and two 

cars carrying lumber. A fire and forest fire resulted as the venting gas tanker burned and the locomotives and 

a flat deck jumped the tracks and slid down the slope to within several metres of the bank of the Fraser River 

(See Figure 3). 

Most of the 1,600 litres of diesel fuel and 171,000 litres of gasoline released from the derailed locomotive and 

tank cars were consumed in the fire; however, an undetermined amount seeped into the ground or flowed into 

the river. As a result of the collision and subsequent release of fuel, the British Columbia Ministry of 

Environment, issued a Pollution Prevention Order on August 17 2007. (TSB, 2007- R07V0213) 

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Figure 3: Post Collision Fire in the 2007 Incident 

Photo Credit: D. Mah / Prince George Citizen 

1.4 Hazardous Materials Moving Through CN’s Northern Corridor 

Environment Canada defines ‘Hazardous Materials’ (also referred to as ‘Dangerous Goods’) as materials of 

various forms (solid, liquid, gas, sludge or paste) which typically exhibit dangerous characteristics, such as 

toxicity, corrosivity or flammability and may pose a risk to human health or the environment. (Environment 

Canada, 2013) 

According to CN officials, the majority of dangerous goods move north, east, and south; they do not typically 

travel west at this time. Recent reductions in the westward flow of dangerous goods have occurred primarily 

due to the closure of all pulp mills west of Prince George. In terms of hazardous materials, the majority of 

westward cargos do, however, contain fuel. In addition, with renewed interest in mining to the west, materials 

such as Perchloroethylene, a highly toxic dense non-aqueous phase liquid (DNAPL) and a common product 

used in dry-cleaning and as an industrial degreaser, could very possibly be carried westward through Prince 

George. 

Due to the fact that potential hazardous materials could directly affect the Nechako Aquifer and the Nechako 

River, this report focuses particularly on the threat of liquid contaminants and how they would potentially 

interact with both the aquifer and/or surface water. It also assesses the potential release of these materials in 

the event of a physical impact from train derailments on the pumphouse structures themselves. 

In determining the potential impacts of liquid contaminants on both the aquifer and surface water, a critical 

property of the contaminant is its miscibility. The miscibility of a liquid is its ability (or lack of ability) to mix and 

form a homogenous solution with another liquid. 

Many common contaminants are liquids that do not dissolve readily in water (for example, the behaviour of 

oil), these liquids are known as Non-Aqueous Phase Liquids (NAPLs). Other contaminants are miscible and 

pose different impact risks. 

The characteristics and impacts of miscible contaminants and non-miscible contaminants (NAPLs) are further 

explained below: 

Light Non-Aqueous Phase Liquids (LNAPLs) 

Some common LNAPLs include products such as: gasoline, kerosene, jet fuel, and non-chlorinated industrial 

solvents (eg. benzene, toluene, xylene), most of which are known to have passed through the Prince George 

area. LNAPLs possess a density less than that of water and as a result their movement into the aquifer is 

greatly retarded by the water table itself. Dissolution into the water column can also be restricted by the 

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hydrophobic (i.e. water repelling) nature of the LNAPL compounds themselves. A ‘typical’ LNAPL dispersion 

into an unconfined aquifer is presented in Figure 4. Water table fluctuations can contribute to LNAPLs 

smearing or spreading to the lower depths of the aquifer. 

Figure 4: LNAPL Spill Behaviour 

Source: Adapted from Modeling Groundwater Flow and Contaminant Transport, 200 

Dense Non-Aqueous Phase Liquids (DNAPLs) 

Some DNALPs include chlorinated solvents such as Trichloroethylene, Perchloroethylene, Methylene 

Chloride, Trichloroethane, and Dichlorobenzene, all of which are listed as highly toxic hazardous materials 

commonly used in industry. 

As the name suggests, DNAPLs are heavier than water and therefore pose the greatest risk for sinking into an 

aquifer and causing contamination through the effects of gravity and capillary action (capillary action being the 

ability for a liquid to move against gravity due to the surface adhesion or cohesion between a liquid and the 

surface it is travelling against). DNAPLs are recognised by the EPA (1991) as a significant determining factor 

in site remediation. It was also noted that, “DNAPLs migrate through the subsurface under the influence of 

gravity and capillary effects created by multiphase fluid flow in geologic media. Therefore, DNAPLs can be 

present in different places than would be expected by simple mapping of the advective flow of groundwater, 

making them difficult to find and delineate.” (Interstate Technology & Regulatory Council, 2003) 

As Figure 5 demonstrates, DNAPL contaminants can readily move downwards and laterally into the aquifer. 

They are not retarded by the water table itself, but their movement can be limited by aquicludes, silt and clay 

layers. However, for interbedded fluvial (river) deposits, clay and silt layers are often discontinuous, allowing 

further penetration of the aquifer. 

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Figure 5: DNAPL Spill Behaviour 

Source: Adapted from Modeling Groundwater Flow and Contaminant Transport, 2000 

Note: Although fuel is typically thought of as being lighter than water, in transport when 

diluted by Bitumen, it has been known to act as a DNALP. 

Miscible Chemicals 

Despite the main threats to the Nechako Aquifer coming from NAPLs, as they are more damaging in the long 

term, it is also worth mentioning that miscible hazardous materials also travel through the potential risk area. 

Miscible liquids tend to readily dissolve in water and, as a result, can quickly mix with the water in the aquifer 

and well, if they are spilled within the well’s zone of influence. 

For example, in 2012, methanol (a miscible liquid) was found to be leaking in the CN Yard (TSB #R12V0136). 

In this circumstance, it did not pose an immediate threat to the aquifer but would need to be taken quite 

seriously in the event of more significant incident. Along with being highly flammable, in its liquid form 

methanol is also highly toxic, causing dizziness, headaches, drowsiness, intoxication, and potentially blindness 

and damage to the liver and kidneys (Thames River Chemical, 2009). Although methanol’s effects on the 

Nechako Aquifer could be short lived, as it would be diluted in the aquifer and transported by natural 

groundwater movement away from the area, the damage to human health could still be substantial. To fully 

quantify the effects that methanol or other similar chemicals could have, further studies by a hydrogeologist 

would need to be carried out. 

Hazardous Materials in the Prince George Area 

Due to past regulations, it has been difficult to ascertain exactly what hazardous materials have passed 

through the area, when they have passed, and in what volumes. Much of the time, the information related to 

the transit of dangerous goods was only reported after an accident, leak or spill had occurred, thus the data in 

this report is incomplete. From Transportation Safety Board (TSB) reports, it can be confirmed that both 

LNAPLs and DNAPLs, along with many miscible materials, have passed through the City of Prince George in 

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the past. It is also certain they will continue to travel through in the future. Recent regulations imposed by the 

Federal TSB require municipalities be provided with semi-annual summaries of Dangerous Goods transported 

through their communities. This will greatly assist municipalities, like the City of Prince George, in evaluating 

the risks. 

Table 2: Examples of Hazardous Goods which have passed through Prince George 

Density Phase in 

UN 

Name 

g/cm 3 

Solubility with Water 

Transport 

1075 Liquefied Petroleum Gasoline (LPG) .71 - .77 Liquid NAPL 

1202 Diesel Fuel and/or Fuel Oil .87 - .95 Liquid LNAPL 

1824 Sodium Hydroxide Solution (NaOH) 2.13 Liquid Miscible 

1230 Methanol (CH 4 O) .7918 Liquid Miscible 

3475 Ethanol (C 2 H 6 O) .789 Liquid Miscible 

3083 Perchloryl Fluoride (ClO 3 F) 1.4 Gas Liquid 1.4 DNAPL 

3170 Aluminum Smelting By-products (dross) - Solid Variable 

1830 Sulphuric Acid ( H 2 SO 4 ) 1.84 Liquid Miscible 

1495 Sodium Chlorate ( NaClO 3 ) 2.5 Solid Miscible 

Summary of Prince George CN Yard Incidents 2012-2013 (Caruso, 2014) 

This evidence, combined with an overall increase in rail traffic and in particular, rail traffic carrying dangerous 

goods, suggests that there is a strong potential threat to the vulnerable Nechako Aquifer. 

1.5 Delineation and Characterization of Water Sources 

Summary of Geology 

Surficial geology at the Lower Nechako River Aquifer consists of quaternary unconsolidated sands and gravels 

(of sizes that range to cobbles and boulders) that are underlain by till and generally fine-grained sediments, 

which are underlain by silts/till. It is in these glacio-fluvial sand and gravel deposits that the water supply wells 

are located. There is no confining unit (clay or silts) above the water bearing unit, that would have provided the 

drinking water source with some initial protection from surface spills and vertical migration through the 

unsaturated zone would be very fast (as quickly as 18 minutes) 

Summary of Wells 

Table 3 summarizes well construction details for the active production and sentinel (monitoring) wells, and 

Figure 6Figure 7Figure 8Figure 11Figure 13 are photographs of the well sites. All of the wells are located 

between the Nechako River and the railway line. All the water supply wells are housed in locked well houses, 

which are surrounded by a fence. 

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Table 3: Characteristics of the active water supply wells 

Estimated 

Estimated 

Actual 

Well 

PW601/602 

PW605 

PW660 

Year Completed 1981 1972 2005 

Depth to bottom (m bgs) (Note 1) 30 30 30 

Screened interval length (m) (Note 1) 0.3 0.3 0.3 

Length of laterals (m) (Note 1) 48 48 48 

Depth to water under non-pumping 

conditions (m bgs) 

1.76 4.9 4.5 

Typical depth to water during pumping (m 

bgs) 

4 7 8 

Thickness of aquifer (m) 46 46 41 (Note 3) 

BC Ministry of Environment Aquifer 

Number (and classification) 

92 (1A) 92 (1A) 92 (1A) 

Aquifer description sand and gravel sand and gravel sand and gravel 

Well seal (m) no no no 

Security 

well inside locked 

building and locked 

fence 



fence 



fence 

Typical pumping rate (Note 2) (L/s) 199 285 151.5 

Maximum well capacity (L/s) 1,079 1079 1079 

Notes: 

masl ‐ metres above sea level 

1) From Kuel (2005). Assumed to be equal to design of PW660. No original report of geology or well 

installation was available. 

2) Current average pumping rate 1995‐2001 (Golder 2003a). For comparison purposes only. 

3) Taken from PW607 in Golder (2003a), the vertical production well that was replaced by PW660. 

Golder Associates Ltd. (2003) developed 60-day, 1-year, 5-year, and 20-year capture zones (Figure 16 and 

Figure 17) using the numerical flow modelling technique for the three active water supply wells (PW660, 

PW605 and PW602/601). The City has designated Groundwater Protection Areas (Figure 19). 

The 60-day to 20-year capture zones are based on a numerical model. The capture zones cross the railway in 

three locations; but there is a large stretch of capture zone that stops just before the railway, based on 

modelling results. The BC Ministry of Health recommends a minimum well head protection zone of 100 m 

radius centred on each well head (BC Ministry of Health, 2010). Considering these issues, Radloff 

recommends adding a 100 m-radius protection zone around each well in the City’s Groundwater Protection 

Area, regardless of modelling results. As well, the model should be updated whenever pumping rates change 

significantly, and the Source Water Assessment and Protection Plan should also be assessed at such times. 

These recommendations are further discussed below. 

The Golder (2003b) figures do not show the Nechako River as being part of the capture zones. On page 14 of 

Golder’s 2002 report, they define a “specified” head and explain that the river bottom sediments are assumed 

to not significantly impede connection between the river and the aquifer. However, on Figures 15, through 21, 

in the report, the legend defines a colour for well protection area, and this does not extend over Nechako 

River. Assuming the text is correct, and based on our experience, the Nechako River to the wells is a flow 

path. Whether it is a direct flow path, or there is some reduction in chemical concentration is unknown. Based 

on this assessment, it is reasonable to include the Nechako River in the well protection area. 

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March 2015 


Well Vulnerability and Proximity to Rail infrastructure 

In considering vulnerabilities to the City’s water supply, the individual well infrastructure, and their 

hydrogeological setting must be examined. At an installed value of approximately $6 million per well, the loss 

of any of these wells in and of itself would be a tremendous financial blow to the City. 

In the past 20 years, two of the City’s wells, PW608 and PW606 which were located in similarly vulnerable 

aquifers, have been lost due to contamination from spill-related accidents. Furthermore, prior to 

decommissioning, a lengthy and costly attempt was made to preserve PW608. These losses highlight the fact 

that spill-related threats must be taken seriously and can result in costly economic and environmental 

consequences for the municipality. 

Note: These spills were not rail-related. 

These wells are in close proximity to both the railway line and the Nechako River (Table 4), which means they 

are highly vulnerable to potential pollution from land and/or water sources. Distance from other potential 

sources that will be discussed in this report is also presented in Table 4. 

Table 4: Well proximity to the Nechako River, railway, CN yard, and nearest rail crossing 

Well 

Distance 

from 

River 

Distance from 

Railway 

PW 660 82 m 183 m 

Distance from CN 

Yard 

CN yard is 3.8 km 

downgradient of well 

Distance from nearest upgradient 

rail crossing 

(measured from Figure 25) 

Rail crossing is 2.8 km 

upstream and adjacent to 

Nechako River capture zone 

Distance 

from 

nearest upgradient 

track 

switch 

2.0 km 

PW 605 15 m 92 m 



300 m and adjacent to 

capture zone 

2.8 km 

PW 602 21 m 24 m 



800 m and within capture 

zone 

4.0 km 

PW 601 60 m 103 m 



800 m and within capture 

zone 

4.0 km 

PW601/602 

These wells are referred to in tandem in this document due to the fact that 602 acts as a re-pumping station for 

601 and loss or damage to either would result in a much reduced supply of water to the entire downtown core 

of Prince George. Both wells are located between the western bank of the Nechako River and the CN tracks. 

The wells and their proximity to the rail line are shown in Figure 6, Figure 7,Figure 8 andFigure 9. 

PW602 is of particular interest because of its vulnerability to collisions and rail yard accidents; it is located in 

close proximity to the north entrance of the CN yard and is only 24 m from the track. As such, it could be 

vulnerable to direct train impacts in a derailment event. In such an event diesel fuel stored within the station for 

backup pumps could be released inside the station and flow in to the well casing. In addition there is potential 

for all spilled contents from CN rail stock to directly enter the well casing in an impact scenario. 

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March 2015 


Figure 6: Orthographic map showing the physical location of PW602 

Figure 7: PW602 Proximity to the CN lines 

PW602 

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March 2015 



Figure 9: PW601 Well Cross-Section 

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March 2015 


PW601 is 103 m from the CN tracks and is likely far enough from the tracks to preclude physical impact. This 

well is a Radial Collector type (Fehlmann or Ranney). (See Figure 10) 

Figure 10: Radial Collector Well 

Image adapted from: http://bennettandwilliams.com/ 

PW605 

PW605 is further away from the CN yard; however, the pump house sits within 100 m of the track and thus, 

could be vulnerable to damage from collisions. Up until recently the pumphouse has also stored a large 

volume of hydrofluorosilicic acid, used as a water fluoridation additive, which is extremely toxic even in low 

doses. It also houses large volumes of Sodium Hypochlorite, which disinfects the water system and diesel fuel 

for backup pumps. A train impact with this building could result in a spill of sodium hypochlorite or diesel fuel 

(less hydrofluorosilicic acid if this stored volume is removed) from the station contents into the well casing 

itself. In addition there is potential for all spilled contents from CN rail stock to directly enter the well casing in 

an impact scenario. 

PW605 is also a Radial Collector (Fehlmann) type well (See Figure 10). The well and its proximity to the rail 

lines is shown in Figure 11 and Figure 12. 

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March 2015 



Figure 12: PW605 Cross-section 

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March 2015 


PW660 

PW660 is located 183 m from the CN line and is sufficiently removed to preclude a direct impact from a train. 

However, like PW605 and PW601, this well is a Radial Collector (See Figure 10) with vulnerabilities to 

hazardous material spills in the nearby river and its source aquifer. The well and its proximity to the rail line are 

shown in Figure 13 and Figure 14. 


Figure 14: PW660 Cross-section 

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March 2015 


Ground Water Flow Regime 

The Nechako Aquifer is shown in the context of the larger community in Figure 15. As the figure demonstrates, 

the normal ambient (non-pumping condition) ground water gradient (i.e., the natural direction of groundwater 

flow) is in a south-east direction, flowing from the Nechako River under the city core towards the Fraser River. 

The wells at PW660, 605, and 601 draw water from this aquifer. As such, they impose a ‘zone of influence’, 

also referred to as a ‘capture zone’, on the local aquifer. These capture zones are illustrated in Figure 16 and 

Figure 17. Briefly, the operation of each well and the subsequent withdrawal of water from the aquifer at that 

location can cause the groundwater flow direction, in that localized well area, to be directed towards the well. 

The well capture zone is the area of the aquifer which directly feeds a particular well. The area of the capture 

zone tends to increase relative to the volume of water being pumped by the well in that location. This is an 

important characteristic that lends itself to the protection of these wells in spill events that may occur 

between the wells and the CN tracks primarily because a timely shutdown of the wells, shortly after 

such a spill event, would allow the ambient water flow direction to predominate and tend to move 

contaminants away from the wells themselves. 

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March 2015 


Figure 15: Ambient Groundwater Flow 

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March 2015 


Figure 16: Well Capture Zones for Current Pumping Rates 

Figure 17: Well Capture Zones for Maximum Projected Pumping Rates 

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March 2015 


2 CURRENT LEGISLATION & EMERGENCY PROCEDURES 

At the moment, there is no single document outlining the necessary procedures to protect the Nechako 

Aquifer, and its related potable water well systems, from damage and/or contamination from rail-related 

threats. However, there are many policies, bylaws, and emergency procedures which support and justify the 

development of such a document. 

For example, the Federal Government of Canada, in its Sustainable Management of Groundwater in Canada 

(a comprehensive study on groundwater management policies) reports that, “It appears that no authority at 

any level in Canada has assessed the sustainability of groundwater use under its jurisdiction or established a 

sustainable-management strategy in a way that fully meets these five goals” (Council of Canadian Academies, 

2009). The five goals for sustainability were identified as: 

1. Protection of groundwater supplies from depletion 

2. Protection of groundwater quality from contamination 

3. Protection of ecosystem viability 

4. Achievement of economic and social well-being 

5. Application of good governance 

Figure 18: Sustainable Groundwater Management Pentagon 

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March 2015 


In addition, the repeated theme throughout the federal report emphasized a trend towards municipal 

ownership of these management strategies. 

To date, the stakeholder organizations that have regulatory or administrative authority related to contamination 

issues and aquifer protection are discussed below: 

2.1 The City of Prince George 

As a first step towards protecting the aquifer, the City has designated areas within its limits as ‘Groundwater 

Protection Areas’. These areas are safeguarded with bylaws in the City of Prince George’s Official Community 

Plan (OCP) Bylaw 8383, 201. 

Figure 19: The City of Prince George’s Groundwater Water Protection Areas 

CPG_OCP_Bylaw_8383_Schedule_D1_Groundwater_Protection_DP_Areas, 2011 

Section 6.2 of the plan states a clear mandate “to protect well heads and aquifers from incompatible 

development that may lead to contamination of the City’s potable water supply.” (City of Prince George OCP, 

2011). Further, it goes on to define a long list of threats from new developments including the manufacture, 

processing, sale, storage, or distribution of petroleum products or allied petroleum products and waste or 

effluent as defined under the Environmental Protection Act. The plan also recognizes the risks posed by new 

effluent, storm water runoff, or other contaminated discharges to ground. 

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March 2015 


These bylaws do not currently apply to existing structures, such as the tracks or rail yards, or discuss the 

movement of goods through the protection areas (as shown above in Figure 19). However, Policies 6.2.4 – 

6.2.6 offer and encourage improvements to the current bylaws. 

“Policy 6.2.4 The City should consider refinement and additional groundwater protection areas for the 

catchment area of the City’s water supply wells, including but not limited to protecting areas immediately 

adjacent to the Nechako and Fraser Rivers upstream from the wells. 

Policy 6.2.5 The City may require developers/property owners to investigate, monitor and control (and where 

necessary remediate) land and groundwater contamination. 

Policy 6.2.6 The City should contemplate prohibiting all pesticide use within groundwater protection areas.” 

(City of Prince George OCP, 2011) 

In addition, Section 8.5 Groundwater Protection also offers provision for the development of further safeguards 

against contamination to the aquifer. 

“8.5.3 - Works may be required, including ongoing maintenance or repair, to preserve, protect, restore, or 

enhance the viability of the aquifer. 

8.5.4 - Protection measures may be required to preserve, protect, restore, or enhance the viability of the 

aquifer.” (City of Prince George OCP, 2011) 

The City has also taken the precaution of having sentinel wells installed adjacent to PW660. These wells are 

monitored to determine if contaminants are present in the aquifer. As such, they can serve as an early warning 

of contamination before groundwater reaches the production well. 

2.2 Provincial/Federal Government 

On a provincial level, the Government of British Columbia has received Royal Assent to move forward with its 

Water Sustainability Act. The act will replace the existing federal Water Act (1909) in 2015. One major tenant 

of this act is to regulate and protect groundwater use. However, at this stage, the language within the act is 

focused on over-arching principles of water management, rather than focusing on the specifics of dealing with 

aquifer contamination. 

In terms of emergency response, the provincial government has developed the Provincial Emergency 

Program, which was designed to educate the public and provide support to local government emergency 

planning, response and recovery. (Transportation Safety Board, 2005) In addition, Transport Canada offers a 

wide range of policies and plans for dealing with accidents, spills and collisions, especially those related to 

hazardous materials. Their Canadian Transport Emergency Centre offers a helpline for emergencies involving 

dangerous goods, and in 2012, they published the Emergency Response Guidebook. This documentation is 

intended to act as a solid starting point for the development of municipal-level plans. 

Unfortunately, any emergency response provided by the province only comes into play post-incident. Often, 

and particularly in cases dealing with vulnerable aquifers without protection works and methodologies, 

potentially irreparable damage to the aquifer could and likely would occur before the province would step in to 

provide aid. Furthermore, federal and provincial involvement in respect to dangerous goods spills rarely 

extends to aquifer clean-up or remediation. The cases of PW608 and PW606 are recent examples where 

federal and provincial aid was not obtainable for actions beyond dealing with the immediate surface damage 

(for example, removing rail cars and mopping up surface contaminants). 

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March 2015 


2.3 CN 

In recent years, CN has taken a very strong, public stance on its commitment to safety, especially in the wake 

of the negative press that rail companies have received over incidents such as the Lac-Mégantic disaster in 

2013. As a result, they have expressed a willingness to cooperate and partner with local communities in the 

development of plans to protect public safety. 

In addition, there has been a public outcry for greater transparency regarding the types of materials which are 

being transported, especially in regards to dangerous goods. As a result, an announcement was made in 

January 2014 that starting in April 2014, rail companies would have to submit quarterly reports (every 90 days) 

summarizing ALL materials carried though municipalities (globalnews.ca, 2014).The City of Prince George 

issued formal requests to CN staff to receive these reports in February 2014. 

However, upon meeting with a CN representative on July 14 th , 2014, Radloff were informed that CN is under 

no obligation to report to municipalities as this information is already reported at a Federal level. The City was 

encouraged to request information from the Transportation Safety Board. Future discussions with CN or the 

TSB should clarify the scope of responsibilities for reporting under the new regulation. 

CN also has a wide variety of safety plans and policies in place to mitigate the risk of derailments, leaks and 

collisions. Some of these include: 

 

 

 

 

 

Speed restrictions such as the Visual Sight Rule, which regulates the speed of trains travelling within 

Mile 0 to Mile 1 of the CN yard in Prince George. These regulations require that the engineer be able 

to stop the train in half the distance they can see. Typically this means the trains are travelling around 

20-25 km in this zone (See Figure 20). 

Regular inspections on cars within the rail yard every 24-48 hours for leaks and spills. 

Compliance with Transport Canada’s rail safety regulations including regular reporting to the 

Transportation Safety Board. 

An Emergency Response Procedure that involves reporting to the Provincial Emergency Program. 

Liaising with the local fire department to provide specialist training and to report spill incidents 

NOTE: The phone calls to report spills are currently done mostly as a courtesy with no 

intervention necessary. No formal record of these calls is kept. 

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March 2015 


Figure 20: CN’s Speed Restriction Zones 

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March 2015 


3 CURRENT THREATS FROM CN ACTIVITY 

Based on the above information, it is relatively clear that there is a significant level of risk to the Nechako 

Aquifer and its related wells. The aquifer itself is a unique natural feature necessary to the current and ongoing 

development of the City of Prince George. Existing legislation, at all levels of government, does not adequately 

mitigate the risks or provide City staff and/or senior government authorities with a clear plan of action if a 

disaster were to occur. As a result, it is important to understand and outline specific threats which could lead to 

spills and to develop appropriate response plans. 

3.1 The Threat of Derailment-Related Spills 

Derailments are viewed as the biggest threat to the Nechako Aquifer both because these accidents have the 

greatest potential to allow significant quantities of hazardous materials to escape containment and because of 

historical precedent. In addition, the severity of the derailment could either limit or entirely prevent city 

operations personnel from entering the affected area to initiate damage-limiting actions (for example, manually 

switching off well pumps to minimize the migration of contaminants through the aquifer). 

Due to the fact that all of the at-risk wells and the aquifer itself exist in close proximity to the CN lines, they are 

all at risk from the: 

a) Threat of a derailment-related spill. 

b) Possibility that city operators will be restricted from access to the well locations due to a trail 

derailment in proximity to a well house (in other words, operators may be unable to enter a well house 

that has been struck by a train to manually shutdown or restart a well). 

Golder’s Predictive Contaminant Models 

In 2003, Golder Associates published a Capture Zone Analysis, Containment Inventory and Preliminary 

Groundwater Monitoring Plan for the City of Prince George. In this document, Golder ran predictive 

contaminate modelling in order to evaluate the consequences that a long-term or sudden release of 

contaminants would have on the municipal water supply wells. 

One of the six (6) scenarios included the impact of a sudden release of methyl tert-butyl ether (MTBE) spill 

from a train derailment within the PW660 capture zone. MTBE, a gasoline additive and potential carcinogen, 

was selected because it represented the largest commodity shipped by CN in 2001 (over 900 million litres), it 

is highly mobile (miscible) in groundwater, and it is resistant to breakdown in comparison with other gasoline 

components, like benzene. (Golder, 2003). In addition, Health Canada states that concentrations of MTBE 

above 0.015µg/L (milligrams per litre) would render water undrinkable. 

The model concentrated on 3 wells within the aquifer capture zone, PW660 (then named “Proposed Fishtrap 

Island Collector Well”), PW601, and PW605. 

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March 2015 


Figure 21: Predictive Contaminant Models for PW660, PW605, and PW601 

In the study, Golder’s models found that the concentration of MTBE would reach undrinkable levels almost as 

soon as the contaminant plume reached the wells, and that it would continue to increase for at least 5-7 

months. Further details regarding the methodology and results can be found in an excerpt from the original 

report in Appendix C. 

Figure 22: MTBE Release from Train Derailment, PW660 Concentration 

5 

Relative Concentration (%) 

4 

3 

2 

1 

0 

0 50 100 150 200 250 300 

Time (days) 

Adapted from Golder, 2003 

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March 2015 



10 


8 

6 

4 

2 

0 

0 50 100 150 200 250 

Time (days) 



5 


4 

3 

2 

1 

0 

0 50 100 150 200 

Time (days) 


Note: MTBE is no longer transported on CN lines. However, the principles of this miscible 

contaminant’s impact on area wells could be applied to gain a general understanding of how 

other potential contaminants which have not specifically been analysed. 

Track Failures: Speed & Maintenance Issues 

The threat of derailments cannot be discussed without some attention being given to the relative risk of track 

failures. These failures could occur along any stretch of rail and are an endemic risk associated with the 

existence of all railways. 

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March 2015 


In a 2012 study produced in the USA, an Analysis of Causes of Major Train Derailment and Their Effect on 

Accident Rates, the authors found that in all speed ranges, broken rails and welds were the leading cause of 

derailment on main lines. However, the study also noted that while speed was not the leading cause of 

derailments, it had the most significant impact on the severity of the derailment in regards to property damage, 

casualties, and environmental effects. 

As mentioned in a previous section, CN currently imposes speed restriction rules in an attempt to mitigate the 

severity of potential derailments in and around the CN Yard. However, no information is currently available on 

the methods, frequency, or reporting of CN’s rail maintenance in the at-risk area, nor has any official dialogue 

occurred between CN and the City to recognize and establish special protective measures around the aquifer 

and wells. 

3.2 The Threat of At Grade Crossings 

The Transportation Safety Board’s yearly reports repeatedly highlight the fact that any point at which a road 

intersects a railway track, the risk of derailment increases. 

There are three (3) locations between Mile 0 and Mile 6.31 where, according to the Transportation Safety 

Board, there is an increased risk of derailment due to at grade crossings (See Figure 25). Two of the crossings 

are located at Mile 6.31 and Mile 5.35 along the only major road through the Miworth area, while the third 

crossing is located on Crieff Place at Mile 2.76 within Wilson Park. 

All three (3) crossings are marked by crossbucks, have a CN emergency number posted nearby, and have 

automatic warning devices, with alternately flashing red lights to warn automobile drivers and a bell to warn 

pedestrians. These warning measures begin about 30 seconds before the train arrives at the crossing. None 

have crossing gates, which act as a physical barrier against vehicles entering the crossing directly before or 

during a train’s passage. In addition, trains travelling through these graded crossings are under Signal 

Protocols, which means they are not limited to a specific speed unless indicated by a signal. 

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March 2015 


Figure 25: Potential Collision Locations 

Mile 2.76 

The first crossing at Mile 2.76 poses some risk as there is no clearly-posted speed limit and a potentially high 

level of traffic from park users and the private gravel pit exists. In addition, this crossing is in the closest 

physical proximity to the wells as PW605 is located nearby (upstream) and PW601 is approximately 800 

metres downstream of the crossing location. Train speeds at this location are lower than at the two other at 

grade crossings discussed below. 

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March 2015 


Figure 26: The At Grade Crossing at Mile 2.76 

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March 2015 


Mile 5.35 

The second crossing at Mile 5.35 has a posted speed limit of 30km/h (reduced from the speed limit of 50km/h 

on either side of this location). This crossing sees relatively high train speeds, as well as significant residential 

and recreational traffic and this is likely to increase in the future. Although this crossing is not particularly close 

to the river, it is worth noting that a side track which ends in a storage facility is located nearby. There is a 

further discussion of the risks associated with this facility in the following section. 

Figure 27: The Graded Crossing at Mile 5.35 

Mile 6.31 

The crossing at Mile 6.31 potentially poses the highest risk of the three, as it is extremely close to the Nechako 

river (see Figure 28 and Figure 29), has the highest train speeds, and the posted road speed limit on the north 

side of the crossing changes to 70km/h. 

If a hazardous material were to enter the river at this point, it could begin to move into the aquifer very rapidly 

depending on the nature of the spill substance. Whether or not the substance in question would enter the 

aquifer from the river would depend on a variety of factors including the nature of the substance itself (as 

mentioned above) and/or if the city operators were able to turn off the well pumps. For example, if an LNAPL 

was spilled at this location, it may float by and continue down the river, while a DNAPL spilled at this same 

location may move along the bottom and into the aquifer. 

Derailments and spills at Miles 5.35 and particularly Mile 6.31 are considered the highest risk incident 

locations based on their potential to impact all three (3) main wells. This impact could occur from a direct spill 

to the Nechako River at these locations. A large spill at either of these locations into the river proper could 

result in contaminants moving into the aquifer towards PW660, 605, and 601 in a relatively short time. 

As illustrated in Figure 16 and Figure 17, the river water feeds the aquifer for each of these well locations. In 

the event of a river water contamination event, the contaminants could access each aquifer capture zone in a 

manner consistent with the contaminant’s physical properties. In this scenario, collective travel times to the 

well could be the shortest in comparison to all other contamination scenarios. 

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March 2015 


Figure 28: The At Grade Crossing at Mile 6.31 

Figure 29: Miworth near the Otway Nordic Centre 

Adapted from: googlemaps.com 

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March 2015 


3.3 The Threat of Physical Impacts with City Wells 

As previously mentioned, two of the City’s wells, PW602 and PW605, are in very close proximity to the tracks 

themselves (within approximately 23 m and 92 m respectively). This puts these wells at risk from a direct 

collision if a train were to derail. Based on the sheer mass of the train cars, with or without any accompanying 

explosions or fires, it is possible the pump house, its contents, or its controlling mechanisms would be 

destroyed or rendered inoperable. 

There is also the possibility that the pumping mechanisms themselves may continue to function. If a resulting 

spill were to occur with the pumps still operable, there is presently no remote means of shutting down the 

pumps and preventing the wells from pumping hazardous materials directly into the City’s water supply from 

the exposed well casing. Furthermore, the sodium hypochlorite used to chlorinate the water supply and/or the 

fuel for the back-up diesel units in both PW605 and PW602 could also potentially spill or be pumped at an 

unregulated rate into the water supply system in this scenario. In addition there is potential for all spilled 

contents from CN rail stock to directly enter the well casing in this impact scenario. 

3.4 Other Threats 

There are other additional threats to the aquifer which must be considered and are discussed in the following 

subsections. 

Upstream Contamination 

It is extremely difficult to mitigate all the risks posed by upstream contamination on a major river system. 

However, typically, the further away a spill/leak occurs, the more time emergency staff will have to instigate 

defensive plans and procedures such as turning off the well pumps. However, investigation of spill potential 

upriver of the City is beyond the scope of this study. The threat from this spill source has been identified in 

Section 3 of this document as a potential future study need. 

Application of Track Maintenance Chemicals 

In 2003, Golder Associates Ltd. published a report identifying a risk of contamination from “herbicides that may 

be applied to the right-of-way and creosote used to preserve the railway ties.” However, there was little to no 

data to quantify these potential risk factors. In addition, there is no evidence to suggest that this issue was 

investigated further. 

The City requested data from CN regarding the use of any track maintenance chemicals in February 2014. In 

August 2014, CN informed the City that they employ professional herbicide application companies, but 

currently the City has received no additional information from CN. 

The purpose of gathering this data is to develop a comprehensive picture of the chemical types (including 

quantities and frequency of application) which could potentially leach into the groundwater within the 

Groundwater Protection Area. This information will allow the City to knowledgeably assess the risks posed by 

these chemicals and, in partnership with CN, look at potential mitigation measures. These measures could 

range widely from the implementation of new bylaws to a request for the use of more environmentally-friendly 

products. 

Track Switch 

User errors are often a major cause of accidents when trains are required to switch to a different track. Outside 

of the CN Yard itself, there appears to be only one switch in the subject area, which is located near the Mile 

5.35 grade crossing (see Figure 25). Currently, there is no information on how frequently this switch is used. 

The switch and signals are owned by CN and located near a private crossing into a decommissioned sawmill, 

while the side track and facility are privately owned by a concrete production company. 

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March 2015 


Figure 30: Location of the Track Switch at Mile 5.35 

Figure 31: Private Storage Facility near the Mile 5.35 Grade Crossing 

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March 2015 


4 MITIGATION AND RESPONSE MEASURES 

With a thorough understanding of the most immediate threats, all interested parties will be able to undertake a 

number of immediate and long-term actions to both prevent and prepare for the eventuality of a contaminant 

spill. However, the best results will occur when there is communication, transparency, and joint planning 

between the City and CN. Some of the measures and responses discussed are summarized in Table 5 below. 

Table 5: Summary of Key Mitigation & Response Measures 

Action* 

Initiating 

Party 


or 


Remote pump shut-down capabilities and procedures (for the wells) City R 

Emergency water quality monitoring plan (spill incident) City R 

Remote operation capabilities and procedures (for the wells) City R 






Reduction of train speeds CN P 

Creation of a joint emergency response committee (to provide emergency 

plans and a contact list)* 

Enhancement of track maintenance CN P 

Creation of alternate supply capability (redundancy for PW605) City P/R 

Greater transparency and improved communication Joint P 

Minimization/elimination of at grade crossings Joint P 

Advance notification of dangerous goods are being transported CN P/R 





Installation of at grade crossing arms Joint P 

*All these actions are assumed to be in or around the at-risk area. 

** There may be an opportunity for a joint approach where parts of the CN r/w may benefit 

from ground seal. 

City 

City 

Joint 

City 

City 

P 

P 

R 

P 

P 

4.1 Additional Studies 

The modelled capture zones show that the 60-day capture zone extends past the CN tracks; however, the 

limitations of Golder’s report (2003) included some uncertainty with groundwater flow direction and hydraulic 

gradients “especially at greater distances from the river”. Installing data loggers in monitoring wells and a 

water level monitoring station in the Nechako River, and tracking water levels for at least one year, will help 

assess actual groundwater flow in these two key areas. This will allow for completing a detailed groundwater 

flow direction study in two locations: between CN tracks and PW660, and between the CN tracks and PW605. 

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March 2015 


In addition, it would be important to update the numerical flow model to assess the capture zones specifically 

in the vicinity of the CN rail tracks, once actual groundwater and surface water levels in these two areas have 

been monitored. Given that models are based on assumptions, an independent review of the numerical model 

may also be prudent. 

Further, it is necessary to evaluate potential mitigation options such as interceptor wells vs lined trench 

protective measures in conjunction with the groundwater hydrogeological models for PW660, PW605, and 

PW601. These studies would assure the most effective measures are selected and costs are appropriately 

quantified. 

Defining risks related to CN spill incidents beyond the City’s boundaries are outside the scope of this 

assignment. A further assessment by hydrogeologists of the potential risks due to a rail spill into the Nechako 

River upstream of the City may have merit due to the speed with which contaminants could be transported into 

the City’s aquifer by this point of entry. 

4.2 Preventative Measures 

Benjamin Franklin once said, “An ounce of prevention is worth a pound of cure.” This is especially true when 

dealing with aquifer contamination. A municipality faced with a compromised well can look forward to 

exorbitant clean-up bills (with minimal financial support from other levels of government), loss of public 

confidence in both the water supply and decision makers, long-term temporary or permanent loss of the 

affected well(s), and potential health and environmentally-related legal action. 

In a worst case scenario, the City could lose the entire aquifer and all its related wells. DNAPL contaminated 

sites for example, which are discussed in An Introduction to Characterizing Sites Contaminated with DNAPLs 

(ITRC, 2003) have one of the biggest challenges in the field of environmental remediation because DNALPs: 

 

 

 

 

 

 

 

behave in an relatively unpredictable fashion as they are effected by minute variations in subsurface 

pore size distributions, soil texture, soil structure, and mineralogy 

often go undetected with standard investigation techniques such as soil borings and monitoring wells 

some investigation measures can expand the zone of chemical contamination or develop misleading 

chemical concentration data 

typically require very small concentrations to render water ‘unsafe’ 

can become more soluble in water over time, and thus, more toxic 

migrate through the subsurface under the influence of gravity and capillary effects so that they can be 

present in different places than would be expected by simple groundwater mapping 

often require costly remediation 

Fortunately, there are a wide variety of preventative measures which can be put into place to mitigate the risk 

of a derailment or collision-related spill: 

Installation of Interceptor Wells & Trenches 

Interceptor wells and lined trenches can be used to prevent the migration of contaminants into and within an 

aquifer. The efficiency of either method depends upon: 

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March 2015 


 

 

 

In Situ Soil Types: Lined trenches and/or curtain drains are typically more successful than interceptor 

wells in granular soils. 

Depth of the Aquifer: Typically interceptor wells are most cost effective at deeper depths. 

Contaminant Type: For DNAPL or miscible contaminants, the entire aquifer depth could be at risk, 

making deeper penetration to the aquifer necessary. 

Further study would be required in conjunction with aquifer modelling to fully evaluate these alternatives. 

Installation of a Ground Seal 

Installation of ground seals around active well sites (expanded well seal) may be a plausible measure to 

prevent contaminant access to the aquifer if installed prior to a spill. The specifics of this solution should be 

investigated on a well to well basis. 

Generally speaking, the wider the area of surface seal, the greater the reduction of contamination and the 

greater the lead time afforded to respond to a spill event outside the perimeter of the seal. In addition, surface 

seals in the aquifer will not eliminate groundwater contamination completely unless the rail line itself is 

underlain by an impervious layer of soil liner material which is connected to the seal, making a complete seal 

difficult to achieve in the absence of CN cooperation. A possible ground seal approach to PW660 is 

demonstrated in Figure 32 and Figure 33. 

Figure 32: Ground Seal Concept Drawing for PW660 

See Figure 33 for a cross-section view of Section 1 

Page | 43

March 2015 


Figure 33: Ground Seal Cross-Section Concept for PW660 (Section 1: Figure 32) 

Creation of Alternate Supply Capability (Redundancy) 

If any of the aforementioned wells were rendered inoperable, either by choice (to prevent contaminant 

penetration into the aquifer) or by accident (in the event of a well impact), there is the option of utilizing backup 

wells. For example, if well PW660 was rendered inoperable, PW607 and PW632 are positioned to provide a 

limited supply to Pressure Zone 2. The transition to PW607 could be performed manually if the operator is able 

to physically access the pumphouses. In addition, there are two other wells (PW621 and PW624) which could 

assist in meeting water usage demands in an emergency as a backup to PW605. 

Unfortunately, one limitation to this response is that the quality and quantity of the water from these wells is 

very poor and their use could not be considered as a long-term solution. The water from PW607, for example, 

has been found to have high iron and high manganese. These wells should be considered only as emergency 

supply measures which would need to be implemented in conjunction with restricted water use. 

PW660/605 Redundancy: Plans are currently in place to create a backup system for PW605 using PW660 

through the installation of an underground supply main. This will provide a back-up supply to PW605 in the 

near future (once construction is complete). It is recommended that this effort be supplemented by provision 

for remote operator control of transfer from PW605 to PW660 supply as well as provision of improved 

automatic control of the PRVs linking Pressure Zone 2 to Pressure Zone 1. 

Greater Transparency & Improved Communication 

The biggest challenge in developing any sort of response to the potential threat of a contaminant spill is that 

the City is not currently being provided with information about the nature and frequency of the dangerous 

goods passing through the CN Yard. This information must be communicated in order to prepare adequate 

and appropriate emergency responses. 

In addition to dangerous goods, the City also needs access to information such as: 

 

 

the speed of trains travelling through the at-risk area 

reports on accidents and incidents within municipal boundaries 

Page | 44

March 2015 


 

reports on track maintenance within the at-risk area, including any pesticides, herbicides, and track 

maintenance chemicals which could leech into the soil 

the current status of the track switch and storage facility near Mile 5.35 

In return, CN could benefit from a greater understanding of what emergency services are available and which 

operations staff could be contacted to access the wells (for example, in the event of a spill that requires the 

pumps be shut-down). 

Reduction of Train Speeds 

Although reducing the train speeds in the at-risk area may not prevent a derailment from occurring, according 

to the data provided in previous sections, reducing the speed on the trains could limit the extent of the damage 

(severity of spill). This may be possible if CN were to extend the Visual Site Rule beyond the Mile 1 mark to 

include the entire at-risk area. There are likely additional speed reduction options available that should be 

explored with CN. Greater transparency and communication, as detailed above, would greatly assist in this 

regard. 

Enhancement of Track Maintenance 

Although CN’s track maintenance in the at-risk area is an unknown factor, special acknowledgement that this 

at-risk area needs particular and more frequent attention could help to mitigate the highest known derailment 

risk factor. CN has informed the City that it employs professional herbicide applicators, but greater 

transparency on the part of CN in regards to the ongoing reporting of these measures to the City would also be 

useful. 

Additions to the City’s Groundwater Protection Areas 

The BC Ministry of Health recommends a minimum wellhead protection zone of 100 m radius from a wellhead 

(BC Ministry of Health 2010). Therefore, it is recommended that the 100 m radius areas around the wellheads 

be added to the City’s Groundwater Protection Areas. 

In addition, since the Nechako River is a recharge boundary to groundwater, the river should be included in 

the wells’ capture zones and added to the City’s Groundwater Protection Areas. This will include hydraulic 

modelling of the Nechako River to show the limits of the capture zones upstream of the Nechako River for 

various time-dependent well protection areas (50-day, 1, year, 5-year, and 20-year are the groundwater 

protection area times-of-travel used). 

Minimization/Modification of At Grade Crossings 

Elimination of the Miworth crossings, either by moving the road itself or by creating a fly-over, would 

significantly reduce the risk of a collision, thus mitigating the risk of upstream contamination close to the 

aquifer. Ideally, these measures could be applied to all three (3) at grade crossings. In order of priority, 

crossing mitigation should occur as follows: 

1) Mile 6.31 

2) Mile 5.35 

3) Mile 2.76 

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March 2015 


Installation of At Grade Crossing Arms 

At grade derailment risk can be reduced through the introduction of crossing arms. In the event that elimination 

of the at-grade crossings cannot be achieved, the introduction of at grade crossing arms activated by train 

proximity should be provided at the three (3) locations. 

4.3 Response Measures 

Below are some response measures and tools which can assist in mitigating the risks to the water supply 

system. Some of these relate to the prevention or minimization of contaminant entry into the aquifer, while 

others relate to mitigating impacts once the contaminant has already entered the aquifer or well. 

Creation of a Joint Emergency Response Committee 

As mentioned in the previous section, a movement towards greater transparency regarding the transportation 

of dangerous goods would be beneficial for both the City and CN. Concerns raised by the public can be more 

adequately addressed with improved access to information, and in particular, in the knowledge that the City 

and CN are working together to develop swift and appropriate mitigation measure both before and after an 

event were to occur. 

At the moment, various branches of government and CN have each developed independent emergency 

response plans, however, the best possible scenario is a response that includes contacting and mobilizing all 

parties and resources under the banner of one agreed response plan. 

In addition, the City’s Emergency Response Plan (Emergency Operations Centre Binder) should be updated to 

reflect the potential spill-related scenarios identified in this report. 

Remote Pump Shut-Down Capabilities and Procedures (for the wells) 

As previously mentioned, the pump stations for PW605 and PW602 are at risk of being physically impacted by 

a train during a derailment. At the present time, these pump stations are not sufficiently alarmed or 

electronically supervised to: 

1) determine that a catastrophic event has occurred when operators are not in attendance 

2) permit instantaneous shutdown of these pump stations remotely 

Creation of a sufficient Supervisory Control and Data Acquisition (SCADA) capability for operators to shut 

down pump station operations is considered the highest priority. It should be noted that early shut down of well 

pumping operations also serves to minimize a contaminant’s penetration into the aquifer for most spill events. 

This is because cessation of pumping restores the normal ambient groundwater flow and results in 

contaminants moving away from the wells. Subsequently, improved shut-down capacity should also be 

provided for PW660 and PW601. 

It is also noteworthy that, in addition to the time advantages afforded by SCADA remote shut down capacity, 

this capability also permits the Operator to remotely monitor the system should continued operation be 

possible when access to a pump station’s location is precluded by emergency response considerations. 

Emergency Water Quality Monitoring Plan 

An emergency monitoring plan should be developed to detect and address incidents. This plan should include 

the well network, constituents to be tested, and intervals at which monitoring should take place (in accordance 

with the respective types of hazardous constituent spills). 

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March 2015 


Advance Notification when Dangerous Goods are Transported 

One option which could be explored is an early warning/reporting system from CN to the City regarding 

dangerous goods which will be passing through the CN Yard. Since rail cars are already individually equipped 

with GPS tracking (as is often used to track international shipments by sea), it may be possible that CN would 

know weeks or even months in advance about future dangerous good shipments. 

The advantage of advanced notice is that, if a spill were to occur, these records could allow responders to 

immediately choose the course of action best suited to combat the particular contaminant in question. The 

obvious drawback of this measure is that public opinion may be quite negative if statistics as to the nature and 

frequency of these hazardous goods were to be released. 

At the moment, CN is not open to this information being made public for security and propriety reasons. 

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March 2015 


5 CHARACTERIZE RISKS FROM SOURCE TO TAP 

5.1 Risk Assessment Procedures 

This section presents the results for the risk characterization from Source to Tap (BC Ministry of Healthy Living 

and Sport 2010). Risk is “the combination of the likelihood that a hazard will occur and cause harm, and the 

extent and degree of that harm,” and risk can be quantitatively evaluated by multiplying the likelihood of a 

hazard occurring by the consequence of that hazard (BC Ministry of Healthy Living and Sport 2010). 

To determine potential risks, two ratings were applied to each potential contaminant: 1) likelihood of 

occurrence (i.e. the probability that the event will occur and the contaminant will migrate to the aquifer and 

existing production wells); and 2) magnitude of consequence. Table 6 and Table 7 outline how each level is 

determined. The product of the likelihood of occurrence multiplied by the magnitude of consequence is then 

used to determine the risk to drinking water, as shown in Table 8. 

Table 6: Assignment of risk categories – Likelihood of occurrence 

Level Description Probability of Occurrence in Next 

10 Years 

A Almost certain - is expected to occur in most circumstances >90% 

B Likely - will probably occur in most circumstances 71-90% 

C Possible - will probably occur at some time 31-70% 

D Unlikely – could occur at some time 10-30% 

E Rare - may only occur in exceptional circumstances

March 2015 


Table 8: Risk (Likelihood-Consequence) Matrix 

Consequence 

Likelihood 

1 

Insignificant 

2 

Minor 

3 

Moderate 

4 

Major 

5 

Catastrophic 

A (almost certain) Moderate High Very High Very High Very High 

B (likely) Moderate High High Very High Very High 

C (possible) Low Moderate High Very High Very High 

D (unlikely) Low Low Moderate High Very High 

E (rare) Low Low Moderate High High 

5.2 Risk Assessment Results and Recommendations 

The Contaminant Risk Summary Table (Table 9) summarizes the risks identified for the City of Prince 

George’s high-capacity drinking water wells (PW 601/602, PW 605 and PW 660), with risk levels specific to 

each potential contaminant source. The project work identified three very-high-risk contaminant sources, one 

high-risk contaminant source, and two low-risk contaminant sources. Also included are some 

recommendations. 

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March 2015 


Table 9: Contaminant risk summary 

Source 

Potential 

Source 

Potential Contaminants of 

Concern 

Likelihood of Occurrence 

(fromTable 6) and rationale 

D (Unlikely). 

Magnitude of 

Consequence 

(from Table 7) 

Risk to 

Drinking Water 


1 

Derailments 

in CN yard 

Hydrofluorisilicic Acid, Sodium 

Hypochlorite, Liquefied 

Petroleum Gasoline, Diesel Fuel 

and / or Fuel Oil, Sodium 

Hydroxide Solution, Methanol, 

Ethanol, Perchloryl Fluoride, 

Aluminum Smelting By- 

Products, Sulphuric Acid and 

Sodium Chlorate* 

In 2012 and 2013, there were 11 and 

eight derailments in the CN yard, 

respectively. The following is a list of 

the contaminants that were spilled 2012 

and 2013: Petroleum Gas, Diesel Fuel, 

Sodium Hydroxide Solution, Methanol, 

Fuel Oil, Ethanol, Environmentally 

Hazardous Substances, Aluminum 

Smelting By-products, Sulphuric Acid 

and Sodium Chlorate. 

The geology in the area is permeable 

(sand and gravel), no low permeability 

layer (silt or clay) is present above the 

water-bearing sands and gravels. The 

aquifer in the vicinity of the CN Yard is 

thus vulnerable to contamination. The 

CN yard is between 1.8 and 3.8 km 

away and downstream from the existing 

wells. There are no immediate plans for 

new wells; however, in future (>10 

years), the City may decide to install a 

well closer to the CN yard. 

2 (Minor). 

Future wells 

would need to 

avoid CN yard. 

Low 

2 

Derailments 

on railway 

track and 

train 

collisions 










C (Possible). 

The last known derailment in Prince 

George was in 2007, eight years ago. 

The nearest railway to an existing 

production well is 24m (to Well 602). 

The geology in the area is permeable 

(sand and gravel), no low permeability 

layer (silt or clay) is present above the 

water-bearing sands and gravels. 

4 (Major). The 

City has four 

wells; therefore, 

loss of all wells 

with one 

derailment is 

unlikely. 

Very High 

(within 60 

days**) 

3 

4 

5 

Grade 

crossing 

accidents 

Well houses 

(train 

collision) 

Track 

maintenance 

chemicals 


















Sodium Chlorate* and 

Hydrofluorisilicic Acid, and 

Sodium Hypochlorite 

Unknown Herbicides and 

Pesticides 

C (Possible). 

In Prince George in 2012 and 2013, 

there were two and three collisions, 

respectively. The nearest grade 

crossing is 138 m to Well 605. The 

geology in the area is permeable (sand 

and gravel), no low permeability layer 

(silt or clay) is present above the waterbearing 

sands and gravels. 

E (rare). 

In Prince George in 2012 and 2013, 

there eight and five dangerous goods 

incidences, respectively. The nearest 

railway to a well house is 24 m (PW 

602), and the well houses have not 

been hit by a railroad (the most recent 

well was installed in 2005, or 10 years 

ago. Therefore, the likelihood of a 

railroad moving 24 m off a rail is rare. 


City has four 



with one 

derailment is 

unlikely. 


City has four 



with one 

derailment is 

unlikely. 

Very High 

(within 60 

days**) 

High (within 1 

day**) 

D (Unlikely) 2 (Minor) Low 

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March 2015 


Source 

Potential 

Source 

Potential Contaminants of 

Concern 

Likelihood of Occurrence 

(fromTable 6) and rationale 

Magnitude of 

Consequence 


Risk to 

Drinking Water 


6 Track switch 






C (Possible) 4 (Major) Very High 





*This list of potential contaminants of concern includes what is known to be transported in the Prince George area, but more unknown 

potential contaminants of concern are also likely being transported (see Table 2 for more information) 

** Time frame provided is from Golder’s (2003) capture zone analysis. 

Below is a discussion of the sources (as listed in Table 9) that are deemed to pose high and very high 

contamination risk to the City’s high-capacity drinking water wells. 

5.3 Derailments and Collisions on Railway Tracks, Grade Crossings, 

and Track Switch 

The risk from derailments and collisions on railway tracks, grade crossings, and track switches is rated “very 

high” based on a combination of “possible” likelihood and “major” magnitude of consequence. 

A “possible” likelihood was given because the last known derailment in Prince George was in 2007, eight 

years ago. The nearest railway to an existing production well is 24 m (to PW602). The railway is on the edge 

of the Golder modelled “capture zone”, the geology in the area is permeable (sand and gravel) and there is no 

low permeability layer (silt or clay) is present above the water-bearing sands and gravels; therefore, any 

contamination on the surface will migrate quickly to the aquifer, and into the production wells. 

A “major” consequence was given because if the collision led to a spill of contaminants from the train, these 

could enter the well and pollute the aquifer directly. The well would be lost for future use. Replacing the well 

would be costly, and service would be compromised. 

The following actions are recommended regarding these very-high-risk sources: 

1) As a first next step, we recommend a focussed assessment of risk and mitigation options for very high 

risk on a well by well basis. 

2) The water quality results for the three high-capacity wells indicate that water quality is very good in all 

wells, and that little to no treatment is needed. Groundwater chemistry information for higher-potential 

collision sites is recommended as a baseline to assess how future derailment incidents could influence 

the water quality of the wells and the Nechako River aquifer. For example, should a spill of methyl tertbutyl 

ether MTBE occur in future, it would be helpful if the groundwater had been sampled for MTBE 

before the spill so that the background level is known. One monitoring well per higher potential 

collision site is sufficient. For the list of analytes, the list of chemicals that are transported through the 

area via rail should be attained from CN, from which a shorter (more realistic) list of constituents can 

be selected. Repeat baseline sampling once every 5 years. 

5.4 Well Houses (Train Collision) 

The risk from trains colliding with the well houses is rated “high” based on a combination of “rare” likelihood 

and “major” magnitude of consequence. 

Page | 51

March 2015 


A “rare” likelihood was given, the nearest railway to a well house is 24 m (PW 602); and the likelihood of a 

train moving 24 m off a rail, spilling, and contaminating the production wells is rare. 

A “major” consequence was given because if the collision led to a spill of contaminants from the train and/or 

chemicals stored in the well house, these could enter the well and pollute the aquifer directly. The well would 

be lost for future use. Replacing the well would be very costly, and service would be compromised. 

In addition to the recommendations outlined for source 2, 3 and 6 above for very high risk items, the following 

actions are recommended for the high-risk items: 

1) Reduce the risk of train derailments and collisions, where possible (train speed reduction, enhanced 

maintenance, etc.). 

2) Do not store large volumes of chemicals or fuel in the well houses. 

5.5 General Hydrogeological Recommendations 

The following is a list of general hydrogeology-related recommendations for source protection related to CN 

Rail risks to City of Prince George wells: 

 

Include well log information for the three wells in source protection and emergency plans. In the event 

of an emergency, knowing the details of aquifer, well, and pump will help improve response planning 

(for example, when designing remediation strategies). Therefore, Radloff recommends including 

detailed well logs for PW 601/602, PW 605, and PW 660 in an appendix to each source protection 

plan and all emergency plans. Information to include in an appendix is as follows: 

o 

o 

o 

o 

pump details (e.g. depth to pump intake, pumping rate, pump model); 

water levels (pumping and non-pumping conditions); 

the stratigraphy (e.g. depths of finer or coarser layers); and 

well construction (e.g. depth and length of screens and laterals, where applicable). 

 

 

Update the groundwater model under various pumping scenarios to determine how long it will take for 

potential spills to reach the aquifer and wells from areas that are vulnerable to pollution (i.e. areas at 

risk for derailments or other accidents and spills). This “reverse particle tracking” process will help 

determine from what distance remote pump shut-down will work during efforts to prevent migration of 

chemicals to pumping wells after a spill. 

When considering mitigation options at high and very high risks, consider: 

o 

Applying a buried horizontal bentonite seal to slow infiltration of pollution in areas that are 

deemed vulnerable to derailment, collisions and spills, and also in the areas around the three 

wells (PW 601/602, PW 605 and PW 660). Bentonite carpets are an option, but these are thin 

and might still allow some degree of infiltration (e.g. if the impact of the collision breaks 

them). High-priority areas may require thicker or buried seals. The ground seals are 

suggested for all of the wells, including monitoring wells, because these can act as 

preferential pathways. The City should prioritize the application of ground seals around each 

production well because (1) any spills in these areas would enter the well system very quickly 

and (2) seals will be easier to apply at the well locations (as opposed to near the pollution 

areas that are vulnerable to derailment, collisions and spills) because the City owns the land 

and negotiations with CN Rail might not be required. 

Page | 52

March 2015 


o 

If possible, in higher potential collision areas, install trenches next to the railway line to 

prevent spills from seeping into the aquifer. These trenches should be a few metres from the 

railway line and the areas between the railway line and the trenches should be sealed with 

bentonite powder and sand (in a 1:3 ratio) to prevent the spills from entering the aquifer. 

 

 

 

 

 

 

Emergency plans should be completed for each high and very high risk, including the necessary 

groundwater and soil remediation plan for each contaminant spill that might be caused by railway 

transportation of chemicals and products. For example, consider installing monitoring wells now to 

allow emergency workers to go in and install dewatering pumps, identify or set up areas to which the 

water can be pumped, and complete some discharge planning now. Remediation contractors should 

be involved in the design of these plans. 

The City has designated Groundwater Protection Areas (Figure 19) but the railway tracks are shown 

to be on the edge of the Groundwater Protection Areas, and the Nechako River is not included. The 

Groundwater Protection Areas are based on modelling during simulated pumping conditions. Given 

the consequence of a spill along the railway, a more conservative approach may be in order, than 

relying on one groundwater numerical model. We therefore recommend: 

Adding a 100 m radius around each well to the City’s Groundwater Protection Area. The BC Ministry 

of Health recommends a minimum wellhead protection zone of 100 m radius from a wellhead (BC 

Ministry of Health 2010). 

Adding the Nechako River to the well protection zone. The Nechako River is a recharge boundary to 

groundwater and should therefore be included in the wells’ capture zones. This task will include 

hydraulic modelling of the Nechako River to show the limits of the capture zones upstream of the 

Nechako River for various time-dependent well protection areas (50-day, 1, year, 5-year, and 20-year 

are the groundwater protection area times-of-travel used). 

Completing a detailed groundwater flow direction study in two locations: between CN tracks and PW 

660, and the CN track and PW 605. The modelled capture zones show that the 60-day capture zone 

extends past the CN tracks; however, the limitations of Golder’s report (2003) included some 

uncertainty with groundwater flow direction and hydraulic gradients “especially at greater distances 

from the river”. Installing dataloggers in monitoring wells and a water level monitoring station in the 

Nechako River, and tracking water levels for at least one year, will help assess actual groundwater 

flow in these two key areas; and 

Updating the numerical flow model to assess the capture zones specifically in the vicinity of the CN rail 

tracks, once actual groundwater and surface water levels in these two areas have been monitored. 

Given that models are based on assumptions, an independent review of the numerical model may 

also be prudent. 

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March 2015 


6 CONCLUSIONS & RECOMMENDATIONS 

The City of Prince George benefits greatly from the use of the highly productive yet vulnerable Nechako 

Aquifer. This aquifer is subject to the risk of contamination due to the transportation of dangerous goods on the 

CN railway. Well house structures that extract the water from the aquifer are also at risk of direct impact from a 

derailed train. Specific risks related to rail transport of hazardous materials by CN in or near the City of Prince 

George’s wells were delineated in this report, as well as possible means of mitigating these risks. 

While it is possible for the City to affect many mitigation measures unilaterally, these measures will be most 

effective if implemented within the envelope of improved communication and cooperation with CN. 

Specific recommendations for mitigation measures should be considered for each high and very high risk. 

Table 10 provides a list of possible actions, as an example. Table 10 also provides the initiating party, the type 

of mitigation (preventative or responsive) and related priority. 

Table 10: Options for Mitigation & Response Measures 

Priority 

Action* 

Initiating 

Party 


or 


1 Remote pump shut-down capabilities and procedures (for the wells) City R 

1 Emergency water quality monitoring plan (spill incident) City R 

1 Remote operation capabilities and procedures (for the wells) City R 

1 

1 






1 Reduction of train speeds CN P 

1 

Creation of a joint emergency response committee (to provide 

emergency plans and a contact list)* 

1 Enhancement of track maintenance CN P 

2 Creation of alternate supply capability (redundancy for PW605) City P/R 

2 Greater transparency and improved communication Joint P 

3 Minimization/elimination of at grade crossings Joint P 

4 Advance notification of dangerous goods are being transported CN P/R 

TBD 

TBD 





5 Installation of at grade crossing arms Joint P 

City 

City 

Joint 

* This would also include an addition to the City’s Emergency Operations Centre Procedures. 

** There may be opportunities for CN to participate in ground seal measures. 

City 

City 

P 

P 

R 

P 

P 

Page | 54

Appendix A 

Definitions

Canadian Emergency Transport Centre – CANTEC 

Canadian National Dangerous Goods Official – CNDGO 

Collision - means an impact, other than an impact associated with normal operating circumstances, between 

ships, rolling stock or aircraft, or between a ship, rolling stock or aircraft and another object; 

Dangerous Goods - means any product, substance or organism included by its nature or by the 

Transportation of Dangerous Goods Regulations in any of the classes listed in the schedule to the 

Transportation of Dangerous Goods Act, and includes the dangerous materials listed in Schedule I to the 

Dangerous Bulk Materials Regulations and dangerous goods referred to in subsection 3(1) of the Dangerous 

Goods Shipping Regulations, that are transported in bulk by ship; ( please also refer to UN Numbers on next 

page) 

Dangerous Goods are often also referred to as: Dangerous Materials, Hazardous Goods or Hazardous 

Materials 

Derailment - means an accident whereby one or more wheels of rolling stock leave the rails, other than by 

reason of an explosion or a collision; 

Dense Non-Aqueous Phase Liquids – (DNAPLs) liquids with densities greater than that of water and is 

immiscible in or does not dissolve in water. Some examples of DNAPLs are: chlorinated solvents such as 

trichloroethylene, methylene chloride, trichloroethane and dichlorobenzene. (Wilson & Clark, 1994) 

Grade Crossing: (also level crossing or railroad crossing) an intersection where a railway line crosses a road 

or path at the same level, as opposed to the railway line crossing over or under using a bridge or tunnel. 

Light Non-Aqueous Phase Liquids – (LNAPLs) are liquids with densities less than that of water. Some 

examples of LNAPLs are: gasoline, kerosene, jet fuel, xylene, and non-chlorinated industrial solvents like 

benzene and toluene. 

Non-Aqueous Phase Liquids – (NAPLs) organic liquids that are relatively in-soluble in water. 

Reportable Railway Accident - (RRA) means an accident resulting directly from the operation of rolling stock, 

where: 

(a) a person sustains a serious injury or is killed as a result of; 

(i) being on board or getting on or off the rolling stock, or 

(ii) coming into contact with any part of the rolling stock or its contents, or 

(b) the rolling stock; 

(i) is involved in a grade-crossing collision, 

(ii) is involved in a collision or derailment and is carrying passengers, 

(iii) is involved in a collision or derailment and is carrying dangerous goods, or is known to have last contained 

dangerous goods the residue of which has not been purged from the rolling stock, 

(iv) sustains damage that affects its safe operation, or

(v) causes or sustains a fire or explosion, or causes damage to the railway, that poses a 

threat to the safety of any person, property or the environment; 

Reportable Railway Incident –(RRI) means an incident resulting directly from the operation of rolling stock, 

where: 

(a) a risk of collision occurs, 

(b) an unprotected main track switch is left in an abnormal position, 

(c) a railway signal displays a less restrictive indication than that required for the intended movement of rolling 

stock, 

(d) an unprotected overlap of operating authorities occurs, 

(e) a movement of rolling stock exceeds the limits of its authority, 

(f) there is runaway rolling stock, 

(g) any crew member whose duties are directly related to the safe operation of the rolling stock is unable to 

perform the crew member’s duties as a result of a physical incapacitation that poses a threat to any person, 

property or the environment, or 

(h) any dangerous goods are released on board or from the rolling stock; 

Standard Reflectorized Crossing Sign – SRCS 

Transportation Safety Board of Canada – TSB 

UN Numbers or UN IDs - four-digit numbers that identify Dangerous Goods, and articles in the framework of 

international transport. Some Dangerous Goods have their own UN numbers while groups of chemicals or 

products with similar properties may receive a common UN number A chemical in its solid state may receive a 

different UN number than the liquid phase if their hazardous properties differ significantly. UN Numbers can 

be searched using the online: Emergency Response Guide Book ERG2012.

Appendix B 

Referenced Materials & Background Information

Arabshahi, H., Polysou, N. Geotechnical Assessment: Proposed Fishtrap Island Collector Well and 

Hart/Nechako Water Supply Improvements, Prince George, BC. 2003. AMEC Earth & Environmental Limited. 

Prince George, BC. 

A Water Sustainability Act for BC: Legislative Proposal Overview. 2013. Water Protection and 

Sustainability Branch, Ministry of Environment. Victoria, BC. 

Barkin, P.L., Saat, R., Liu, X. Analysis of Causes of Major Train Derailment and Their Effect on Accident 

Rates. 2012. Transportation Research Record: Journal of Transportation Research Board, No. 2289, 

Transportation Research Board of the National Academies. Washington, DC. pp.154-163. 

BC Ministry of Environment, Lands and Parks and Ministry of Health (BC MOE). 2000. Well Protection Toolkit. 

Victoria: Province of British Columbia. Available from 

http://www.env.gov.bc.ca/wsd/plan_protect_sustain/groundwater/wells/well_protection/acrobat.html 

BC Ministry of Health, 2010. Source to Tap Comprehensive Drinking Water Source To Tap Assessment 

Guideline. http://www.health.gov.bc.ca/protect/source.html 

Brown, L., Dakin, R.A., Foweraker, J.C., Holmes, A.T., Livingston, E., 2014. Ground Water Resources of 

British Columbia, Water Stewardship, Ch.13: Case Histories. Water Protection and Sustainability Branch, 

Ministry of Environment. Victoria, BC. 

Bursztyn, P. Material Safety Data for: Methanol. 2012. Thames River Chemical, Burlington, ON. 

Bursztyn, P. Material Safety Data for: Sodum Hydroxide (Caustic Soda 25% solution). 2009. Thames River 

Chemical. Burlington, ON. 

Bycraft, S., Frolander, G., Sellers, M., Smith, R. Spill Plan: Dangerous Goods Spill Response Plan. 2003. 

City of Richmond, BC. 

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City of Prince George Official Community Plan Bylaw No.8383. 2011. The City of Prince George. Prince 

George, BC. 

Committee on Ground Water Cleanup Alternatives. Alternatives for Ground Water Cleanup. 1994. National 

Research Council, National Academies Press. Washington. D.C., p. 315. 

Dense Nonaqueous Phase Liquids Team. An Introduction to Characterizing Sites Contaminated with 

DNAPLs. 2003. The Interstate Technology and Regulatory Council. Washington, DC. 

Giles, D. Municipal Leaders Discuss Railway Safety with Transportation Minister. 2014/01/23. Global News. 

http://globalnews.ca 

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George, BC 

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Superfund Ground Water Forum, U.S. Environmental Protection Agency. Washington, DC. 

Kreye, R., Ronneseth, K., Wei, M. Aquifer Classification System. 2013. Ministry of Environment. British 

Columbia. http://www.env.gov.bc.ca 

Kuehl, G.A., Stowe, S.M. Installation Report: Fishtrap Island Collector Well Design and Construction 

Project 04-49. 2005. International Water Supply Ltd., Collector Wells International, Inc. Prince George, BC.

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Collector Well). 2006. Golder and Associates Ltd. Burnaby, BC. 

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Appendix C 

Excerpt from Golder Associates Ltd. Report 2003

March 2003 - 3-35 - 022- 1784 

Chemical Storage / Low from spills or leaks on 

( releases on resi I residential properties. 

Abandoned Water Supply 

Wells 

water quality (risk can be 

better defined wit 

1 recommended studies). 1 

Predictive transport modellin 

term or sudden release of co 

Six different contaminatio 

the detailed and chemical c 

risks for each municipal 

variety of possible contam 

such as releases from a sn 

while others are represent 

description of the six cont 

Scenario #1 - Impact of a 

within the capture zones for 

PW605. 

consequences that a long- 

1 water supply wells. 

sed on the results of 

ment of key contaminant 

e selected to represent a 

zones. Some scenarios, 

e of long-term releases, 

an accident or spill. A 

rnent on the CN rail line 

llector Well, PW601 and 

Scenario #2 - I of infiltration from a snow dump located within the 

capture zone fo 

Scenario #3 - Impact of a sudden gasoline release from a tanker truck accident within 

the capture zone for P 

Scenario #4 - Impact of a release of jet fuel from an above ground storage tank at a 

helicopter charter service within the capture zone for 

Scenario #5 - Impact of a gasoline or diesel release from an underground storage tank 

at a gas station within the ca

March 2003 022- 17 84 

Scenario #6 - Impact of chlorophenol groun 

treatment facility within the capture zone fo 

r contamination at a sawmill / wood 

As described in the detailed contaminant inventory, 6% is located in an area of 

high-risk land use where there ave been numerous documented cases of existing 

groundwater conta 

ecause the risk of groundwater contamination within the 

capture zone of 

but is known to have occurred, no 

contaminant scenarios were mo 

As discussed in the subjective con 

identified within the capture zones for 

no scenarios were considered for t 

ation, the contaminant risks 

are considered low; therefore, 

The contaminant trans 

developed for the Cit 

simulate the transpo 

municipal well captu 

longitudinal dispersi 

transverse vertical di 

(Gelhar et al., 1992) 

dissolved chemicals 

simulated in the rno 

are highly specific t 

the necessary aqui 

does not exist to o 

released in each s 

movements of co 

groundwater flow model 

model scenarios, a 

etardation due to sorption of 

ogical degradation, were not 

n and degradation processes 

inants in question. Because 

retardation and degradation 

'nant constituents could be 

s were not included in this 

typically slow down the 

wngradient concentrations. 

sources could arrive at the 

redicted by the model. 

In the model, each contaminant source wa ted as a constant concentration 

boundary with an arbitrary concentration of assigned at the source hation. 

The model assumed that the contaminants were released at the water table and therefore 

the model did not account for the additional time that may be required for the 

contaminant to migrate from groun surface to the water table. The contaminant 

transport model was run until the contaminant hmes n.%ched near steady-state 

conditions. Contaminant breakthrough curves, representing the change in contaminant 

concentrations over time, were calculated for each municipal well listed above. The

March 2003 - 3-37 - 022-1784 

breakthrough curves are expressed in terms o 

concentration divided by concentration assig 

lative concentrati 

to the source, or 

Contaminant plumes for Scenario 

plumes for Scenarios 4, 5 and 

curves simulated for the municip 

3 are shown on Figure 33, while contaminant 

wn on Figure 34. The contaminant breakthrough 

for each scenario are r~vided in Appendix VII. 

With the exception of BE, each of the contaminants described above are characterized 

by numerous chemica 

or example, gasoline is comprised of a number of 

constituents, including benzene, toluene, x lene, ethylbenzene, and so on. Each 

individual chemical constituent has roperties that effect its fate and transport 

when it is released to the environ or illustrative purposes, one chemical 

constituent was selecte resentative of eac 

the representative parameter is one ore conservative, or mobile (is. the least 

affected by the processes of reta 

tential constituents. 

For example, benzene was select 

representative parameters 

ighest human health risk 

associated with the contamination event. 

For each of the key indicator para 

source concentration at t 

constituent. Using the breakthro 

of the key indicator paramete 

Canadian Drinlung 

each of the six transport scenarios. 

it was assumed that the 

ve, the resultant concentrations 

assessed relative to the 

Scenario #1 considered the release o 

rail line within the capture zones of 

and PW605. The reason 

largest commodity shipped by CN 

MTBE is a gasoline additive that is 

MTBE resists b 

While no Canadian Brin 

Drinlung Water ( 

train derailment on the CN 

and Collector Well, PW6Q1 

is is that it represented the 

(over 900 millions litres). 

rice in groundwater, 

omponents, like benzene. 

ritish Columbia 

ocia

March 2003 022- 1784 

For this scenario, three separate releases were simulated, one for each of the three wells. 

For each well, it was assumed that the E was released on the portion of the rail line 

located closest to the well. 

If a spill of MTBE were to occur alo the rail line near the proposed Fishtrap Island 

Collector Well, it would be located ide of the current capture zone but within the 

projected average capture zone. Therefore, average pumping conditions were 

used in this simulation. 

The contaminant plume predicte 

xtmds east from the derailment 

location (Figure 33). After the rele 

nt concentrations at the Proposed 

Fishtrap Island Collector 

.I% of the source 

concentration after approx 

relative concentration is then 

predicted to gradually increase to a steady-state value o ut 2.4% after about seven 

BE, with a reporte 

, this would result in a 

steady-state concentration signifi g water guidelines. 

Concentrations at the well would lik 

king water guidelines almost as soon 

as the plume reaches the well. 

If a spill of MT E were to occur along the rai 

within the current capture zone. 

simulation. 

601, it would be located 

ditions were used in this 

The simulation predicts that in the event of a release, the contaminant plume would 

extend southeast from the derailment ocation (Figure 33). After the release, the 

contaminant concentrations at 

to increase to .I% of the source 

concentration after approximately one month. he dative concentration is then 

predicted to gradually increase t a steady-state value of about 5.3% after about five 

months. This would predict a steady-state E concentration significantly above 

drinking water guidelines, with drinking water guidelines likely being exceeded as soon 


If a spill of MTBE were to occur along the rail line near 60% it would be located 

outside of the current capture zone, but within the projected average capture zone. 

Therefore, projected average pumping conditions were used in this simulation.

March 2003 022- f 7 84 

The simulation indicates that in the event of a release, t e contaminant plume would 

extend northeast from the de gure 33). After the event, the 

contaminant concentration at 

to increase to 0.1% of source 

concentration after approximately two w e relative concentration is then 

predicted to gradually increase to a steady-state value of about 1.3% after about three 

months. This would predict a steady-state 

ation significantly above 

drinking water guidelines, with drinking wate 

y being exceeded as soon 


We understand that at one 

snow dump near Foothills 

We understand that the fa 

portion of the resulting s 

snowmelt from exist 

chromium, copper, 

Water Quality Gul 

potential to adverse1 

The site of the propose 

PW607 but within the 

pumping rates were used in this simulation. 

prnent of a proposed 

, with a significant 

., 1998; Dayton & 

ts associated with 

metals (aluminum, 

ritish Columbia 

t would have the 

outside of the current capture zone for 

ere fore, projected average 

Based on the simulation (Figure 33), the resulting contaminant plume is predicted to 

extend northeast from the propose 

Following the start of snowmelt, the 

contaminant concentration at 

icted to increase to 0.19% of the source 

concentration after approximately two 

relative concentration is then predicted 

to gradually increase to a steady-state 

ut 5.5 % of source concentration within 

ten years. 

Though several contaminants of concern are ~e~ent in the snowmelt, benzo(a)pyrene 

was selected as a key indicator arameter because it has been found above water quality 

guidelines in snowmelt (refer escribed above). &~ed on a solubility of 

0.003 mgL, benzo(a)pyrene concentrations would exceed Canadian Drinhng Water 

Guidelines (0.01 u@) after approximately 8 mmhs. Depending on the presence of

Appendix D 

Well Logs

CITY OF PRINCE GEORGE WELLS PROTECTION PLAN

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