Module 5 – Threats to Drinking Water Sources – Threat Activities and Conditions
“Waterborne pathogens can pose a problem to drinking water supplies, recreational waters, and source waters for agriculture, and aquaculture
– From Threats to Sources of Drinking Water and Aquatic Ecosystem Health in Canada, National Water Research Institute, a Directorate of Environment Canada’s Environmental Conservation Service, NWRI Scientific Assessment Report Series No. 1, 2001
production. Sources of pathogens include wastewater effluent, urban runoff, agricultural manure and wastewaters and wildlife. A drinking water incident in Milwaukee in 1993 killed 54 people and made 400,000 sick. From 1974 to 1996 there have been over 200 outbreaks of infectious diseases in Canada associated with contaminated drinking water.”
“Scientists and managers at the National Water Research Institute identified a list of 13 water quality related threats to sources of drinking water and
– From Executive Summary, Threats to Sources of Drinking Water and Aquatic Ecosystem Health in Canada, National Water Research Institute, a Directorate of Environment Canada’s Environmental Conservation Service, NWRI Scientific Assessment Report Series No. 1, 2001
aquatic ecosystem health. Four of the threats: nutrients, acidification, endocrine disrupting substances (EDS) and genetically modified organisms (GMOs) were recently addressed . . . the remaining nine threats were pathogens; algal toxins, pesticides; long-range atmospherically transported pollutants; municipal wastewater effluents; industrial wastewater discharges; urban runoff; solid waste management practices; and water quantity changes affecting water quality due to climate change, diversions and extreme events.”
Learning Expectations
By the end of this session you should be able to:
- Compare the term ‘threat’ and the term ‘drinking water threat’
- Compare the term drinking water ‘concern’ and drinking water ‘issue’
- Identify the differences between a drinking water ‘threat’ and drinking water ‘risk’
- Recognize some of the threats to groundwater and surface water in the Ausable Bayfield Maitland Valley Source Protection Region
- Understand there are 22 prescribed activities or conditions identified in Ontario that could pose a threat to drinking water sources
Section One – Module Content
Learning Expectations and Activities
Chapter 5 of the Maitland Valley and Ausable Bayfield Assessment Reports is called Potential Impacts from Climate Change.
Chapter 4 of the Maitland Valley and Ausable Bayfield Assessment Reports is called Vulnerability, Threats and Risks.
Unit 1 – Water Quality – Appreciating the Threat Potential
What is a water quality threat as opposed to a water quality risk?
What is a water quality concern compared to a water quality issue?
What contaminants typically threaten our drinking water?
What makes an activity a low, moderate, or significant threat to municipal drinking water sources?
Unit 2 – Water Quality Threats Inventory in our Region
What is a Threats Inventory?
How is the inventory conducted?
What are point source and non-point sources of pollution?
How are threats evaluated?
Scoping
Aggregating threats
Focusing on ‘Contaminants of Concern’
Unit 3 –Water Quality Threats Analysis – After Inventory and Evaluation
Rating the hazard levels
Constructed preferential pathways
Unit 4 – Wrapping It Up
Review: Threats analysis in the source Protection Planning process
Field learning
Self-assessment on learning goals
More Help
Logging and Linking: Next steps, continuing questions, unresolved issues
Activity 1 – Evaluation of Previous Session and Self-Assessment of Learning
Goals
- How do you feel about the progress of the learning program so far?
- Are you meeting the learning goals you set for yourself?
- Is there too much time spent on some things?
- Too little time spent on others?
- Do you need more review of foundational concepts?
- Or, do you need more technical detail?
- Let your group know during dialogue time provided in this module or let your facilitator know through the survey or by using the ‘parking lot’ discussion board at the front of the room or discussion with staff at sourcewaterinfo.on.ca.
Activity 2 – Field Learning Findings
Title: Whither weather
Last module, we looked at determining vulnerability in areas near wellheads and intake zones, significant recharge areas and highly vulnerable aquifers.
At the beginning of today’s session, or during a break, share your findings or thoughts about how extreme weather events might impact these areas.
Or, if you chose the field learning assignments about sinkholes, or the one about pathways and contaminants, briefly share with the group verbally or
through other means (e.g., a display or fact sheet).
Unit 1 – What contaminants are potential drinking water threats?
This is the first of two modules related to drinking water threats (e.g., chemicals and pathogens) and what is involved in reducing the risk that those threats could contaminate our drinking water.
When we talk about threats it is important that we not turn our dialogue to one source, or one enterprise, or one sector – we are all part of the solution when it comes to protecting our drinking water sources and we must begin by considering best management practices in the areas with which we are most familiar – our own sector.
It is also imperative that we talk about classes of threats – such as pesticides – and not individual businesses, individuals or properties.
We have an obligation and requirement to respect all the pertinent legislation related to confidentiality and personal information. However, we can talk about general threat activities because we know class threats (such as gasoline or oil) exist – that’s a reality. A threats inventory can help us understand what already exists in our watershed so we can responsibly plan on how to ensure that those threats don’t contaminate.
Before looking closely at the issue of water quality threats let’s consider the question, ‘What happens if contaminants reach drinking water sources?’
Source: U.S. Geological Survey
Activity 3 – Multimedia Presentation
Title: What is the cost of not protecting water?
Read a short article or video, such as the documentary ‘Water Under Fire,’ related to a world, national or local threat which resulted in contamination of a water source.
Using a chart, answer the following questions:
What happens when water has not been protected?
List examples of contamination’s effects on human health from global to local?
Based on the presentation, and/or fact sheets distributed to your group, fill out chart about incidences of contamination of water sources.
Share some of your thoughts with the larger group so they can fill out their chart. Was there any incident missing?
What has happened when water has not been protected?
Globally
Asia
Africa
Europe
Eastern Europe
Oceania (Australia, New Zealand, etc.)
North America
South America
Antarctica
Canada
Ontario
Ausable Bayfield and Maitland Valley Source Protection Region
Activity 4 – Small Group Activity
Title: Identifying if a contaminant is a point source or a non-point source
Source: Waterwise.com
Review the definition of ‘point source’ and ‘non-point source’ pollution. Your facilitator will give you about a dozen activities that occur in the Ausable Bayfield Maitland Valley Drinking Water Source Protection Region. As a group, decide if those activities have the potential to generate ‘point source’ or ‘non-point source’ contamination.
Discuss the activities that your municipality is involved in each day.
Potential Contaminants
Point Source (single source, easier to identify origin source e.g., Municipal Wastewater Treatment Plant Discharge, Industrial Plant Discharge, etc.)
Non-Point Source (multiple sources, harder to identify origin of source e.g., pesticide sprayed on land, urban or rural stormwater runoff, storm water runoff from a construction site, landfill leachate, etc.
Activity 5 – Group Activity
Title: Identifying contaminants as pathogens or chemicals
Using examples of potential contaminants write down in this table whether they are examples of ‘pathogens’ or ‘chemicals.’
Pathogen or Chemical?
Pathogen
Chemical
Activity 6 – Presentation – Title: Threat or Risk?
Threat or risk?
Before we go further into the ‘threats inventory’ and ‘risk assessment’ processes, it’s important that we understand the terminology and can
differentiate between ‘threats’ and ‘risks.’
When we talk about a ‘drinking water threat’ or a ‘significant drinking water threat’ we’re not using synonyms. When it comes to Ontario’s drinking water source protection, these two terms carry different meanings. It is important to remember that a threat is a threat no matter what management accompanies it.
That threat may be a low, moderate, or significant threat depending on circumstances (e.g., quantity and location) and on the vulnerability of the land where it takes place (for instance, on sandy soil or clay soil; near a municipal well or far away from the well); etc.
Consider gasoline for instance. Gasoline would be defined as a drinking water ‘threat,’ no matter where it was stored or how it was managed. However, it could also be considered a drinking water ‘risk’ when other factors such as the vulnerability rating of the setting where it is stored and the integrity of container it is stored in are considered.
A significant drinking water threat poses more risk than a moderate or low threat activity.
A significant threat to drinking water sources, therefore, is determined through a risk assessment process.
- Take a look at these two examples:
Example One: Lawn pesticide on the ground.
Example Two: Lawn pesticide in a new, state-of-the-art tank.
Which of these is a threat?
Example One? Example Two?
Both? Neither?
Discuss.
- Based on information provided by a facilitator or presenter, answer the following questions:
a) What do we mean when we say a threat is ‘intrinsic’?
b) What do we mean when we say a threat is ‘realized’?
c) When does a threat become a greater risk?
d) What is the difference between a ‘drinking water threat’ and a ‘significant drinking water threat’?
Activity 7 – Presentation – Title: Concern or Issue?
Let’s add some more words and concepts to your growing understanding of drinking water source protection: A parent or guardian might tell their teenager that “your declining grades at school are a concern for me,” or they might say that “your grades are an issue for me.” In this case the words ‘concern’ and ‘issue’ mean basically the same thing. But when it comes to source protection planning the words ‘issue’ and ‘concern’ have different meanings.
- Define a drinking water concern:
- Provide an example of a drinking water concern:
- Define a drinking water issue:
- When does a ‘concern’ become an ‘issue’?
- What is a contaminant of concern?
- What is the difference between a ‘contaminant of concern’ and a ‘drinking water concern’ in terms of drinking water source protection planning?
- What is the difference between a drinking water concern and a drinking water
issue?
Activity 8 – Small Group Activities
Title: TRIC? Threat or Risk, Issue or Concern?
TRIC – Threat, risk, issue, or concern
The following are some activities to help you further develop your understanding of what is meant by a drinking water threat or risk; concern or issue. Your facilitator may decide to use all of these activities or just some of them – and you may return to these activities in future modules as review of these important terms.
Understanding of these concepts is important for foundation building as we progress and learn more about risk assessment and threats analysis later on.
In a small break-out group complete one of the following exercises related to drinking water threats and risks.
After completing your activity in the small group share with the larger group.
Activity 8A – Small Group Activity – Title: Define Threats and Risks
Based on information provided by your facilitator or presenter prepare definitions for the terms you have been given.
Group Definition
Source Protection
Planning Definition
Drinking Water Threat:
[Chemical]
Drinking Water Threat
[Pathogen]
Drinking Water Risk:
Activity 8B – Small Group or Pair Activity
Title: Threats and Risks: What’s similar? What’s different?
Using theVenn Diagram write in the differences and similarities between a drinking water ‘threat’ and a drinking water ‘risk.’
Activity 8C – Small Group or Pair Activity
Title: What’s different? What’s similar? Concerns and Issues
Using the Venn Diagram, discuss and write down some differences and similarities between a drinking water ‘concern’ and a drinking water ‘issue.’
Activity 8D – Small Group Activity
Title: Metaphor Mania (or, Simile Superstars)
In your small break-out group, develop zany analogies to tell the difference between:
Concern and Issue
Threat and Risk
For instance:
A threat is like a baseball in a child’s hand – there’s no risk it will break a window until the child throws it.
A parent or guardian has a concern that their child is not doing enough homework – they know there is an issue when the report card documents they have not reached expectations.
Using appropriate and inoffensive comparisons, describe a concern and an issue; a threat and a risk.
An analogy for a concern is …
An analogy for an issue is …
An analogy for a threat is …
An analogy for a risk is …
Activity 8E – Small Group Activity
Title: A person of few words
Take a term and capture its meaning in five words or less:
Drinking Water Threat: _
Drinking Water Risk: _
Drinking Water Concern: _
Drinking Water Issue: _
Activity 8F – Small Group Activity
Title: TRICky – Threat or Risk, Issue or Concern? What’s similar? What’s
different?
Using a Venn Diagram with four circles identify those things that are common to a ‘Concern, Issue, Threat, Risk’ and those things that are separate.
Activity 8G – Small Group Activity
Title: TRIC [Threat or Risk, Issue or Concern] Board Game
Your facilitator will provide you with cards listing activities or land uses.
Determine whether it is a Concern or Issue, a Threat or a Risk.
Activity 9 – Group Activity
Title: Applying Your Knowledge
You have now discussed the terms concern, issue, threats and risks. As a group, apply your knowledge to the following cases.
Consider four scenarios – decide whether the scenario depicts a Threat, Risk, Issue or Concern. Discuss with a partner and then share with the group.
Activity 9A
- Scenario One: An outhouse built over a sinkhole.
Concern Issue Threat Risk
Why?
- Scenario Two: A barrel of PCBs in a thick concrete storage building.
Concern Issue Threat Risk
Why?
- Scenario Three: The ‘H20ligarchy Big Bottling Company’ extracting water from a local watercourse.
Concern Issue Threat Risk
Why?
- Scenario Four: A committee member with a large technical report tells a crowd, “You were right all along.”
Concern Issue Threat Risk
Why?
Activity 9B – Group Activity
Time permitting you may decide to apply your knowledge of threats, risks, concerns and issues by plugging in examples to this exercise. Your facilitator will provide you with examples of a threat, issue, risk or concern. Place the example in the table below. In a few words explain why you chose this category.
Concern or Issue? Threat or Risk?
Example:
Concern
Issue
Threat
Risk
Why did you feel that category was the appropriate one?
Example:
Concern
Issue
Threat
Risk
Why did you feel that category was the appropriate one?
Example:
Concern
Issue
Threat
Risk
Why did you feel that category was the appropriate one?
Example:
Concern
Issue
Threat
Risk
Why did you feel that category was the appropriate one?
Activity 10 – Group Activity
Title: Drinking Water Concerns in Ausable Bayfield Maitland Valley Drinking Water Source Protection Region
- Based on suggestions from your facilitator what are some examples – real or hypothetical – of drinking water concerns or potential drinking water issues in your region?
Drinking Water Concern
- Why do have to say ‘potential’ drinking water issues at this time? (Visit sourcewaterinfo.on.ca and consult assessment reports to find examples, if any, of drinking water issues).
Unit 2 – Water Quality Threats Analysis in our Region
What is a Threats Inventory? How is a Threats Inventory conducted?
Activity 11 – Multimedia Presentation
Title: Learning from case studies
View a video of a well pump test in a case study.
- What is the vulnerable area in this case?
- What is the threat in this case, a chemical or a pathogen?
- Describe how there was risk in this case.
- Has the threat been realized?
Activity 12 Lecture – Multimedia Presentation
Title: Evaluation of Threats
We have identified some of the potential water quality threats in our region.
When assessing water quality threats there are many considerations:
The relationship between the threat and threat data with vulnerable areas and vulnerability
Past and present land uses
Hazard levels
Whether the threat should enter the risk assessment stream
Influence on baseflow contributions
Potential interception Loss
View a presentation from the Ontario Ministry of the Environment, Conservation and Parks about threats.
Consult the list of 22 prescribed drinking water threats and the Tables of Circumstances at ontario.ca
- What do we mean when we say we are ‘scoping’ or ‘connecting’ threats data to vulnerable areas?
- What do we mean when we say we are ‘aggregating’ threats?
Unit Three – Drinking Water Threats Analysis – After Inventory and Evaluation
Activity 13 – Presentation – Title: Rating hazard levels
- What is the definition of a ‘hazard level’?
- What is the formula for risk? _________ rating X_________________ score = _____
- There are two assessment processes for two contaminant categories. What are
they?
a) __________________________________________________
b) __________________________________________________
Activity 14 – Personal Reflection
Title: What have I learned so far?
Imagine that a secondary school student asked you three things you have learned about drinking water source protection so far. What would you tell them?
1)
2)
3)
More Help
Logging and Linking: Next steps, continuing questions, unresolved issues
SECTION TWO – Priming the Pump
Notes, Definitions, Fact sheets
Analyzing Threats to Water Quality
“It doesn’t take much gasoline from a gas station or leachate from a landfill to contaminate quite a lot of water.”
Those are the words of a university professor in Ontario, speaking decades ago.
The words are as true today as the day they were spoken.
Canadians may consider themselves ‘water-rich.’ However, many other countries felt they had water riches and they have since gone past the stage where contaminants are merely potential threats. A recent study by the government of the Czech Republic found that three quarters of surface water is “severely polluted” and one third is so contaminated there are no fish. [SOURCE: Marq de Villiers, Water: The Fate of our Most Precious Resource, McClelland and Stewart, 2003, page 89.]
Drinking Water Threats and Human Activity
What kind of water quality threats are we talking about? Here are some of the possible threats:
Water-borne pathogens
Pesticides
Chemicals (including organic solvents and dense non-aqueous phase liquids or DNAPLs)
Pharmaceutical and Personal Care Products (PPCPs)
Municipal waste water
Algae, turbidity etc.
Others . . .
There may be activities associated with contaminant threats that would allow their direct introduction into a source of drinking water. These could include:
Sewage/Wastewater Treatment Plant discharge
Sewage Treatment Plant effluent
Sewage Treatment Plant bypasses.
Industrial effluent.
Residential – household hazardous waste, PCP, fertilizers and pesticide use, etc.
Others . . .
The potential pollution could be ‘point source’ or ‘non-point source’ pollution:
Point source pollution – such as from industrial discharges or wastewater treatment plants – is when there is contamination originating from a definite source.
Non-point source pollution, on the other hand, comes from a number of different (diffuse) sources. It can be carried over the ground surface or through the ground by snowmelt or rainwater.
Our counties and municipalities, industries and businesses, farms and property owners, and organizations are involved in many activities. Some of those activities could pose contaminant threats.
These are some of them:
Stormwater management systems
Cemeteries
Septage application
Hazardous waste disposal
Liquid industrial waste
Biosolid application
Storage and application of nutrients – manure; pesticides; fertilizer
Winter control – Snow storage, road salt application and de-icing
Fertilizer application
Pesticide/herbicide application
Historical activities – contaminated lands
Landfill
Accident threats can be associated with contaminant threats (Storage of
Potential Contaminants):
DNAPLs (dense non-aqueous phase liquids)
Organic solvents
Pesticides
Fertilizers
Fuels and hydrocarbons
Unit 2 – Approaching Drinking Water Threats in our Region
Drinking Water Threats and Risks; Concerns and Issues
Anyone who has ever been in any kind of relationship knows that one person can say one thing and another person can hear quite another.
For that reason, it’s important we establish what is meant by words like
‘threat’ or ‘risk’; ‘concern’ or ‘issue.’
Each of these terms can have quite different meanings depending upon who is using them.
As you learn more about drinking water source protection planning in Ontario you will encounter these words:
1) Drinking Water Concern
2) Drinking Water Issue
3) Drinking Water Threat
4) Drinking Water Risk
They seem like simple enough words – and we probably could each come up with our own definitions of what they mean in terms of protecting our drinking water.
However, in terms of source protection planning, these words have very definite meanings and they are important concepts in relation to the work of committees and working groups.
We may all come into the drinking water source protection planning process with our own ideas of what we mean by concern, issue, threat or risk. It’s important that when providing science-based input on water quality and water quantity in our local watersheds that we understand the terms as they relate to drinking
water source protection planning in Ontario. The official definition of these words will come from the latest guidance modules and documents of the Province of Ontario through the Ministry of the Environment, Conservation and Parks (MECP).
The following definitions are based on guidance modules (Visit ontario.ca for current definitions).
The Clean Water Act, 2006 in Ontario establishes the following minimum objectives for the Assessment Reports:
a) Identify all the watersheds in the source protection area
b) Characterize the quality and quantity of water in each watershed
c) Set out a water budget for each watershed, which describes how water enters and leaves the watershed and describes the groundwater and surface water flows in the watershed and how water is used
d) Identify all significant groundwater recharge areas and highly vulnerable aquifers that are in the source protection area
e) Identify all surface water intake protection zones and wellhead protection areas that are in the source protection area
f) Describe the drinking water issues relating to the quality and quantity of water in each of the vulnerable areas identified under clauses (d) and (e)
g) List activities that are or would be drinking water threats, and conditions that result from past activities and that are drinking water threats
h) Identify the areas where an activity listed under clause (g) is or would be a significant drinking water threat, and the areas where a condition listed under clause (g) is a significant drinking water threat
The Assessment Reports include detailed local information in support of each of the above objectives.
Is it a concern or an issue? Is it a threat (low or moderate) or a risk (significant drinking water threat activity)?
A thesaurus will tell you there are many synonyms for these words – between eight and 15, in fact. But, our job is to find a common language to help us work together and plan together to protect the sources of our water.
These are the concepts we will be dealing with:
Drinking water threat
Drinking water risk
Drinking water concern
Drinking water issue
We can sum these concepts up in three words or less:
Drinking water threat: Potential pollution source
Drinking water risk: Measures pollution probability
Drinking water concern: Potential study topic
Drinking water issue: Contamination is present
There are, of course, more in-depth definitions as part of the assessment
reports.
Drinking Water Threat
A Drinking Water Threat is an existing activity, possible future activity or existing condition that results from a past activity,
a) that adversely affects or has the potential to adversely affect the quality or quantity of any water that is or may be used as a source of drinking water, or;
(b) that results in or has the potential to result in the raw water supply of an existing or planned drinking-water system failing to meet any standards
prescribed by the regulations . . . and includes an activity or condition that is prescribed by the regulations as a drinking water threat.
Anything that threatens, to any degree, the quantity or quality of drinking water is a drinking water threat.
For the list of 22 prescribed activities or conditions identified in Ontario that could pose a threat to drinking water sources visit: Threat activities and conditions.
Drinking Water Risk
A threat won’t necessarily contaminate drinking water sources but if that threat exists in a vulnerable area where a pathway can connect the contaminant and a water source then we have a risk.
A risk arises when there is a real and imminent possibility that the contaminant will materialize in a drinking water source. When a vulnerable area and pathway is present a threat ‘graduates’ into a risk. In this case, graduation is not a good thing.
A ‘threat’ becomes a ‘risk’ when preferential pathways create ‘shortcuts’ between a threat and drinking water – therefore creating risk.
A preferential pathway is any structure of land alteration or condition resulting from a naturally-occurring process or human activity which would increase the probability of a contaminant reaching a drinking water source.
When a threat activity is significant the risk of that activity is greater.
Drinking Water Concern
A drinking water concern is a possible threat that has yet to be substantiated by monitoring or other verification methods. Therefore, it has not yet been confirmed as an issue.
An issue is an identified and acknowledged threat to ground and surface water through previous study or historical proof. Drinking water concerns, on the other hand, may be identified through consultations with the public, stakeholder groups and technical experts such as water treatment plant operators, for example. You may have many concerns – and just because there isn’t a scientific document demonstrating a need to act at this time doesn’t mean your concern isn’t valid. As part of a science-based process, however, it is important to focus attention on issues – those situations where there is a demonstrated need to act now.
Drinking Water Issue
If a scientific study demonstrates that the concern can be substantiated, then it then becomes an issue. What is an ‘issue’ is in terms of water quality and drinking water source protection planning? A drinking water issue is a substantiated condition related to the quality of water that interferes, or that can reasonably be predicted to interfere in the near term with the use of a drinking water source if rising trends continue [Draft Guidance Module, October 2006].
Issues occur at the surface water intake or at the well, although issues may also be identified a distance away from the point of extraction (e.g., monitoring wells).
When we talk about threats we are talking about potential contaminants.
Contaminants could be chemicals or pathogens – a pathogen is a disease-causing organism.
Be careful not to confuse a ‘contaminant of concern’ with a ‘concern.’ A ‘contaminant of concern’ is a chemical or pathogen that is or may be graduated from a drinking water threat. A ‘concern’ in source protection planning, however, is something different. A drinking water concern is a purported drinking water issue that has not been substantiated by monitoring, or other verification methods; identified through consultations with the public, stakeholder groups, and technical experts (e.g. water treatment plant operators).
A drinking water issue, on the other hand, is a substantiated (through scientific means) condition relating to the quality of water that interferes or
is anticipated to soon interfere with the use of a drinking water source by a municipal residential system or designated system. Therefore, a ‘concern’
becomes an ‘issue’ when it is substantiated by science. That doesn’t mean that concerns aren’t valid or important – but it does mean they have to be documented and studied further.
A drinking water threat may “graduate” – a contaminant may move from its location on the ground to a home in our drinking water. In this case
‘graduation’ isn’t a good thing – it means a ‘threat’ has gone beyond a threat, and beyond a risk, and has become an issue.
Constructed Preferential Pathways are like 400 series highways – they are human-made ways for things to travel faster: in this case, it is chemical and
pathogenic contaminants that move more quickly into our watercourses and ground water. A constructed preferential pathway is a ‘shortcut,’ through which a contaminant can more easily enter a source of drinking water.
A sinkhole is a naturally-occurring pathway through which nutrients could enter groundwater quickly and without filtration. Excavations or wells are examples of constructed preferential pathways to groundwater.
Aggregate Risks are multiple risks in a municipal water supply protection areas that are considered together relative to the overall risk to drinking water sources.
These are a lot of terms and concepts thrown in your direction in a short time but the same terms will be revisited and used routinely in future modules so it is important to be confident in their meaning. Feel free to speak with staff if you have any questions.
Unit 3 – Drinking Water Threats Analysis
After the threats in an area have been inventoried and evaluated, a threats analysis can commence.
Introducing the Threats Analysis Process
We will be asked to ‘scope’ threats – create an inventory of the threats that exist in our study area.
We are also required to rate hazard levels.
A hazard rating is a scientifically-determined numeric value which represents the relative potential for a particular contaminant of concern to impact drinking water sources at concentrations significant enough to cause human illness.
A vulnerability score is assigned to vulnerable areas in the Source Protection Region and refers to the comparative likelihood of a contaminant of concern reaching an intake.
We combine the hazard level and vulnerability score and we have an indication of the ‘risk.’
Hazard Rating x Vulnerability Score = Risk
There are two assessment processes for two contaminant categories:
1) Chemical and;
2 Pathogen– A pathogen is a bacterium or living organism that causes disease, illness or death, e. g., E. coli O157:H7, a subgroup of E. coli, that produces verotoxins that cause hemorrhagic colitis and, in some cases, life-threatening hemolytic uremic syndrome (HUS).
[E. coli – There are numerous strains of Escherichia coli. Some are found in the human gastrointestinal tract. Others are responsible for diarrhea or other diseases, including illness and sometimes death. Testing for E. coli is often done as an indicator of other organisms which may be present.]
SECTION THREE
Handouts, additional readings, field learning assignments, findings
Reading, Listening and Viewing Resources:
Ontario Ministry of the Environment, Conservation and Parks Technical Guidance Modules
Ontario Ministry of the Environment, Conservation and Parks animated Illustrations depicting how contaminants can migrate from their source into a drinking water supply
Environment Canada. 2001. Threats to Sources of Drinking Water and Aquatic Ecosystem Health in Canada. National Water Research Institute, Burlington, Ontario. NWRI
Scientific Assessment Report Series, No. 1, 72 pp., ISSN 1499-5905; no. 1; Minister of Public Works and Government Services, Canada, 2001
Watershed Science Centre and Province of Ontario. Innovations in Water Management: Surface Water Quality Threat Assessment Method Using Landscape-Based Indexing, Watershed Science Centre, 2005.
Self-assessment on learning goals
Participation Pie
Think for a minute about how you have contributed to participation in the group.
Has your contribution been very high, high or moderate?
Consult the Participation Pie.
Put a check mark beside the piece of the pie that best represents your participation so far.
If you’re comfortable with your participation in the group, then great. If you feel you would like to take a larger role then let the facilitator know after the session or with a brief note.
Mark each box with a . . . plus sign + (Yes, True), a minus sign – (No, Not True) or a question mark ? (Uncertain).
I have:
__ . . .formed a clear appreciation of the nature and extent of potential future threats to our drinking water sources.
__ . . . acquired an understanding of the concepts and analytical processes associated with water quality threats.
__ . . . learned the definition of E. coli.
__ . . . learned the role of E. coli as an indicator of poor water quality and the potential for other pathogens to be present.
__ . . . learned about different types of E. coli and how they can impact human health.
__ . . . learned some of the chemical threats faced in our planning region.
__ . . . expanded my knowledge of vulnerable areas in our region such as Wellhead Protection Areas and pathways/shortcuts which could allow contaminants to reach our drinking water sources.
__ . . . acquired a better grasp of how water quality threats fit into the context of the drinking water source protection planning process.
Field Learning Assignment
Use the space here to record findings from your field learning assignment.
Select an item with which you are directly familiar (e.g., if you sit on a
landfill site board choose ‘landfill,’ if you are a homeowner who uses
pesticides choose ‘pesticide,’ if you own a service station choose ‘hazardous
waste disposal,’ etc.).
Stormwater management
Hazardous waste disposal
Fertilizer application
Cemeteries
Landfill
Septage application
Liquid industrial waste
Biosolid application
Manure/nutrient application
Fertilizer application
Septic waste disposal
Pesticide/herbicide application
Historical industrial activities (e.g., tannery)
Contaminated lands
Other …
After selecting from this list, do some research and/or thinking and/or interviewing (e.g., with someone in the field) in order to answer the following three questions:
1) What potential threat would this pose for water sources?
2) What measures, if any, are undertaken to reduce this threat?
3) What further measures, if any, could be taken to reduce this threat?
A suggested field trip for this module would be to a Water Treatment Plant or Wastewater Treatment Plant.
Information here is provisional, subject to change, and posted for local information and education purposes. For current information visit Ontario.ca and sourcewaterinfo.on.ca. We would like to acknowledge the support of the Government of Ontario. Such support does not indicate endorsement of the contents of this material.
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