This glossary is for local use with the local drinking water source protection active learning program at protectwater.ca. This glossary is for local information purposes, the information is provisional, and it is subject to change, and it is not for legal purposes.
Protect Water – Active Learning Program for Drinking Water Source Protection – Glossary
Ausable Bayfield Maitland Valley (ABMV) Drinking Water Source Protection Region (SPR)
List of Abbreviations and Acronyms
ABCA – Ausable Bayfield Conservation Authority
ABMV – Ausable Bayfield Maitland Valley Drinking Water Source Protection Region
ANSI – Area of Natural and Scientific Interest AO – Aesthetic objective
BMP – Best management practice
BOD – Biological oxygen demand
CA – Conservation authority
CLI – Canada Land Inventory
CO – Conservation Ontario
CWA – Clean Water Act, 2006
DFO – Department of Fisheries and Oceans Canada
DNAPL – Dense non-aqueous phase liquid
DWSP – Drinking water source protection
ECC – Environment and Climate Change Canada
GAWSER – Guelph All-Weather Sequential-Events Runoff Model
GIS – Geographic information systems
GPS – Global positioning systems
GUDI – Groundwater under the direct influence of surface water
GVA – Groundwater vulnerability analysis
HLH – Healthy Lake Huron – Clean Water, Clean Beaches Partnership (Lake Huron Southeast Shores Initiative)
HRU – Hydrological response unit
HVA – Highly vulnerable aquifer
ISI – Intrinsic susceptibility index
IPZ – Intake protection zone
LaMP – Lakewide Management Plans
MECP – Ontario Ministry of the Environment, Conservation and Parks
MMAH – Ontario Ministry of Municipal Affairs and Housing
MNRF – Ontario Ministry of Natural Resources and Forestry
MTO – Ontario Ministry of Transportation
MVCA – Maitland Valley Conservation Authority
ODWS – Ontario Drinking Water Standards
ODWSP – Ontario Drinking Water Stewardship Program
OMAFRA – Ontario Ministry of Agriculture, Food and Rural Affairs
MOHLTC – Ontario Ministry of Health and Long Term Care
OMNRF – Ontario Ministry of Natural Resources and Forestry
OMTO – Ontario Ministry of Transportation
OPG – Ontario Power Generation
PCB – Polychlorinated biphenyls
PGMN – Provincial Groundwater Monitoring Network
PPB – Parts per billion
PTTW – Permit to take water
PWQMN – Provincial Water Quality Monitoring Network
PWQO – Provincial water quality objective(s)
RAP – Remedial action plans
SGRA – Significant groundwater recharge area
SP – Source protection
SPA – Source protection area
SPA – Source protection authority
SPC – Source protection committee
SPP – Source protection plan
SPP – Source protection planning
SPR – Source protection region
STP – Sewage treatment plant
SWAT – Surface to well advection time
SWOOP – Southwestern Ontario ortho-photography
SWP – Source Water Protection
SWVA – Surface water vulnerability analysis
TDS – Total dissolved solids
TOT – Time of travel
WHPA – Wellhead protection area
WWIS – Water Well Information System
WWTP – Wastewater treatment plant
The ABCs of Protecting Drinking Water Sources
For current information visit Ontario.ca.
An abandoned, or deserted, well may have been replaced by another source of drinking water. Abandoned wells can provide pathways for surface water to contaminate groundwater sources – for this reason they should be properly decommissioned and capped. A well may have been abandoned because it is dry, contains non-potable water, was discontinued, has not been properly maintained, was constructed poorly, or is susceptible to contamination.
Abiotic means not relating to living things.
A drinking water threat activity, under the Ontario Clean Water Act, 2006 and associated regulations, is one of 22 activities (or conditions) listed at Ontario.ca. An activity is one or a series of related processes, natural or anthropogenic (human activities) that take place in a geographical area and may be related to a particular land use.
The conversion of land, not previously forested, to forested land through human activities such as planting and seeding.
Aggregate risks are multiple risks in a municipal water supply protection area that are considered together relative to the overall risk to drinking water sources.
An agro-ecosystem is an agricultural system that incorporates a natural community of plants and animals in a physical environment on land where crops are grown or domestic animals are raised.
Some algal blooms are toxic. Algal blooms such as blue-green algae can be harmful to human health and aquatic systems. An algal bloom is rapid and prolific growth of small aquatic plants on the surface of rivers and lakes. This is often a result of excessive nutrients. Read also ‘Eutrophication.’
Ambient water is the natural concentration of water quality constituents prior to mixing of either point or non-point source load of contaminants.
Aquatic means growing or living in water.
A saturated formation that does not yield water in usable quantities is called an aquiclude. This saturated geologic unit is not capable of transmitting significant quantities of water under ordinary conditions.
An aquifer acts more like a sponge than a river. The water in an aquifer is called groundwater. An aquifer is an underground rock formation or structure that carries water. It is the saturated underground. The aquifer provides enough usable water to support a spring or well, when tapped, and it is an underground formation of permeable rock or loose material. This natural layer is a water-bearing, porous geologic formation that includes permeable materials such as soil, rock, sand, limestone, sandstone, and gravel as well as water. An aquifer is an underground area of porous, permeable soil or rock – almost like a sponge – that has enough water inside it to support a well.
Shallow aquifers exist in the overburden, the sedimentary rock and soil above bedrock.
Bedrock aquifers are found in the bedrock itself, under overburden.
A water-bearing layer (or several layers) of rock or sediment capable of yielding supplies of water; typically consists of unconsolidated deposits of sandstone, limestone or granite, and can be classified as confined, unconfined, or perched.
Read also ‘Confined Aquifer,’ ‘Unconfined Aquifer,’ and ‘Perched Aquifer.’
Aquifer Vulnerability Index (AVI)
An Aquifer Vulnerability Index (AVI) is a numerical indicator of an aquifer’s intrinsic or inherent vulnerability susceptibility to contamination expressed as a function of the thickness and permeability of overlying layers.
An aquitard is a layer of geological material that prevents or slows down the transmission of water in a confined aquifer. It is a confining bed and/or formation composed of rock or sediment that slows but does not prevent the flow of water to or from an adjacent aquifer. It does not readily yield water to wells or springs, but stores groundwater. It is a layer of geologic material with little to no permeability or hydraulic conductivity that functions as a container for an aquifer. Water does not rapidly pass through this layer or the rate of movement is extremely slow. Read also ‘Confining layer.’
Area of Natural and Scientific Interest (ANSI)
An ANSI (Area of Natural and Scientific Interest) is an area of land and water containing natural landscapes or features that have been identified as having values related to protection, scientific study, or education.
Artesian Aquifer – Read ‘Confined Aquifer’
Attenuation is flow that is lessened or weakened, or the severity reduced.
Ausable Bayfield Maitland Valley Drinking Water Source Protection (ABMV) Region
The Ausable Bayfield Maitland Valley Drinking Water Source Protection Region is a partnership of the Ausable Bayfield and Maitland Valley conservation authorities, in their roles, under the Ontario Clean Water Act, 2006 as source protection authorities. The source protection authorities support the creation and implementation of source protection plan(s), developed locally by stakeholders on the source protection committee (SPC) and approved by the Province of Ontario.
Average Maximum Water Velocity
Average Maximum Water Velocity is the average highest speed of a surface water body.
Bank stability is the ability of a stream bank to resist change.
Baseflow is the water that flows into a stream through the subsurface. Baseflow is the amount of water in a watercourse that comes from groundwater. It is the sustained flow (amount of water) in a stream that comes from groundwater discharge or seepage. Groundwater flows underground until the water table intersects the land surface and the flowing water becomes surface water in the form of springs, streams/rivers, lakes and wetlands. Baseflow is the continual contribution of groundwater to watercourses and is important for maintaining flow in streams and rivers between rainstorms and in winter conditions.
Basin is the area drained by a river or a watershed with a common outlet. Also, read ‘Watershed.’
Bedrock is the solid rock underlying unconsolidated surface material. Solid or fractured rock is usually underlying unconsolidated geologic materials; bedrock may be exposed at the land surface.
Shallow aquifers exist in the overburden, the sedimentary rock and soil above bedrock, whereas bedrock aquifers are found in the bedrock itself, beneath whatever overburden is present.
Bedrock geology is the study of the solid rock underlying unconsolidated surface material. It also refers to description of bedrock types.
Benthic means occurring at the bed or base of watercourses (e.g., streams, rivers, and other bodies of water such as lakes, oceans and seas).
Benthic invertebrates are small aquatic organisms that live in stream sediments and are a good indicator of water quality and stream health. Benthic invertebrate assemblages are reflective of not only water chemistry, but also substrate (i.e., stream bottom) conditions (Lammert and Allan 1999; Richards et al. 1993; de March 1976). Substrate conditions vary across watersheds and therefore efforts were made to be as consistent as possible when sampling benthic sites. Sampling sites for the Watershed Report Card process were of the highest quality substrate that supports the best possible invertebrate communities. Benthic invertebrate scores indicate that animals that are tolerant to organic pollution dominated the communities. Common species that were found in the Ausable Bayfield Conservation Authority (ABCA) watersheds include worms, riffle beetles and some insects that are tolerant to nutrient enriched conditions. Sites in the Middle Ausable and Mud Creek watersheds appeared to be more degraded than most other sites in this area. Benthic invertebrates are small animals, without backbones, that live in stream sediments. Visit abca.ca for current Watershed Report Card information.
Benthic macroinvertebrates are commonly used as indicators of aquatic environmental quality. ‘Benthic’ refers to the bottom of lakes and rivers whereas ‘macro’ refers to the subset of larger or visible invertebrates: generally ¼ to ½ mm in length. Invertebrates are animals without backbones such as insects, crustaceans, molluscs, and worms.
The benthic region is the bottom of a body of water, supporting the benthos.
Benthos is the plant and animal life whose habitat is the bottom of a body of water.
A berm is a narrow shelf or ledge that can be used at the bottom of a slope to reinforce and stabilize it against slumping and erosion or to direct overland flow. A berm can be a linear mound of earth, or raised barrier, that separates two areas.
Best management practices (BMPs)
Best management practices (BMPs) are proven, practical and affordable ways to conserve soil, water, and other natural resources. Best management practices – or beneficial management practices – are structural, non-structural and managerial techniques that are recognized to be the most effective and practical means to control pollutants yet are compatible with the productive use of the resource to which they are applied. BMPs are used in both urban and rural areas.
Biochemical Oxygen Demand (BOD)
Biochemical Oxygen Demand is a measurement used to assess the rate at which water is deoxygenated. High BOD general corresponds to water containing high amounts of organic pollution.
Biochemical oxygen demand (BOD)
Biochemical oxygen demand (BOD) is a measure of the quantity of oxygen used by micro-organisms (e.g., aerobic bacteria) in the decomposition (oxidation) of organic solids. It is a measurement used to assess the rate at which water is deoxygenated. High BOD general corresponds to water containing high amounts of organic pollution.
Bioengineering is the application of biological science to engineering principles. The use of living or organic plant material to achieve engineering solutions.
Biological diversity is the variability among organisms and the ecological complexes of which they are a part.
Biomass is the amount of living matter, usually measured per unit area or volume of habitat. Biosphere The biosphere is all living organisms (plant and animal life).
Biotic is relating to or caused by living beings.
Biotransformation is the conversion of a substance into other components by organisms; includes ‘biodegradation.’
A bluff occurs where those actions of the shoreline formed in non-cohesive or cohesive sediments where the land rises steeply away from the water such that the elevation of the top of the slope above the base or toe of the slope is greater than a set amount (for instance, two metres and the average slope angle exceeds 1:3 or 18 degrees).
Bogs are peat-covered areas or peat-filled depressions with a high water table and a surface carpet of mosses, chiefly sphagnum. The water table is at or near the surface in the spring, and slightly below during the remainder of the year. The mosses often form raised hummocks, separated by low, wet interstices. The bog surface is often raised, or, if flat or level with the surrounding wetlands, it is virtually isolated from mineral soil waters. Hence, the surface bog waters and peat are strongly acid and upper peat layers are extremely deficient in mineral nutrients. The surface of the bog may often be raised above the surrounding terrain. Bogs are isolated from mineral-rich soil waters, therefore nutrient input is from atmospheric deposition. They are strongly acidic and nutrient poor. Peat is usually greater than 40 centimetres deep. Groundcover is usually moss, Sphagnum spp. and ericaceous shrubs and may be treed or treeless.
Bog water is derived from groundwater or precipitation.
The broader landscape is the watershed or drinking water source protection study area. It applies to regional rather than local aquifer vulnerability assessments usually using an indices method of vulnerability assessment.
Campylobacter jejuni is the most common type of Campylobacter bacteria that causes human illness. It is often found in feces of cattle, swine, sheep, goats, fowl, and wildlife, including birds and deer. Most human infections are caused by the ingestion of contaminated foods, usually undercooked poultry.
Campylobacter jejuni can also be passed to humans through unpasteurized milk, direct contact with animals, person-to-person transmission, and water.
Carbon sequestration is a process by which carbon is removed from the environment and held within, for example, a wetland.
The southernmost part of the Province of Ontario, generally considered to lie south of a line drawn between Toronto and Grand Bend. It contains more endangered and rare species of plants and animals than any other part of Canada.
Catchment Area – Read ‘Watershed’
The area between the banks of a stream where water normally flows.
Channel capacity is the ability of a watercourse at a given cross-section to convey flows of water, or how much water can be carried at a particular place. Floods occur when the channel capacity is exceeded.
The smooth realignment and regarding of a creek or stream bed; implies modification of the watercourse to increase channel capacity; channelized banks are usually reinforced with stone or concrete rip-rap.
A chemical is a substance used in conjunction with, or associated with, a land use activity or a particular entity, and with the potential to adversely affect water quality. Chemicals include some ingredients in solvents, fuels, fertilizers, pesticides, and similar products. They may be found in factories, storage depots, gasoline stations, farms, institutional operations, municipalities, homes, or other sites.
Chloride is a naturally occurring element that can be found at high concentrations (i.e., greater than the drinking water quality standards) under natural circumstances. The concentration of chloride in groundwater can be related to the type of rock the groundwater is coming from. Typically sedimentary rocks (e.g., evaporates) have higher concentrations of chloride.
Climate is the average weather conditions of a place or region throughout many seasons and years compared to weather which can be day to day.
“Climate change is a change in the “average weather” that a given region experiences. Average weather includes all the features we associate with the weather such as temperature, wind patterns and precipitation. When we speak of climate change on a global scale, we are referring to changes in the climate of the Earth as a whole. The rate and magnitude of global climate changes over the long term have many implications for ecosystems as well as human activities.”– Natural Resources Canada
Climate change is a significant shift in long-term average weather patterns, which can include changes in temperature, precipitation and wind patterns.
Changes to our climate last for an extended period of time and can reflect a combination of natural and human impacts. There is broad agreement in the scientific community that human activities are playing a major role in affecting the chemical composition of the atmosphere through the build-up of greenhouse gases, such as carbon dioxide, that trap heat and reflect it back to the Earth’s surface – resulting in changes to our climate, including a rise in global mean temperatures.
Climate variability, or ‘climatic variability,’ refers to temporal variations of the atmosphere for periods of time longer than those associated with normal weather events. The term ‘natural climate variability’ is used to identify climate variations not attributable to or influenced by human activity. Climate variability refers to the normal ups and downs (warm periods, cool periods, wet periods, dry periods). Climate variability may be in the form of cycles, major floods (25 year) and major droughts (30 years). Climate change may amplify these extremes.
Cold water, or coldwater, is water with a temperature of about 14 degrees C. This thermal habitat is typically considered ideal for brook and brown trout.
Coliform – Go to ‘Total Coliform’ and ‘Fecal Coliform’
Bacteria found only in human and animal wastes; presence in a river indicates pollution by sewage or runoff. Coliforms are bacteria found only in human and animal wastes. Presence in a river may indicate pollution by sewage or runoff.
Some coliforms are threats to human health and they can also be indicators of the presence of other pathogen contaminants.
Conceptual Water Budget
A Conceptual Water Budget is a written description of the overall flow system dynamics for each watershed in the source protection area taking into consideration surface water and groundwater features, land cover (e.g. proportion of urban vs. rural uses), human-made structures (e.g. dams, channel diversions, water crossings), and water takings.
Conductivity is the quality or power of conducting or transmitting.
Confined aquifer is also commonly called an artesian aquifer. A confined aquifer is bounded above and perhaps below by layers of geological material that do not transmit water readily. It is the saturated formation between impermeable layers that restrict movement of water vertically into or out of the saturated formation. In this layer, water is confined under pressure, similar to water in a pipeline. Drilling a well into this type of aquifer is similar to puncturing a pressurized pipeline. If the pressure is great enough, the well will flow, and this is called a flowing artesian well. A confined aquifer is an aquifer that is bounded above, and perhaps below, by layers of geological material that don’t easily transmit water. Read also ‘Aquitard.’
Conservation is the wise use of natural resources including the protection of natural or human-made resources and landscapes for later use.
A conservation authority is a natural resource management agency, guided by a board of directors made up of local municipal representatives, having jurisdiction in a watershed area and operated in accordance with the Conservation Authorities Act. Conservation authorities are local watershed management agencies that deliver services and programs that protect and manage water and other natural resources in partnership with government, landowners and other organizations. They have legal responsibilities and powers under the Conservation Authorities Act, Clean Water Act, and other legislation. A community-based environmental protection agency.
Conservation lands are lands which are considered to be regionally significant, such as valleys or environmentally sensitive areas, and are best managed by a public agency to retain their natural characteristics.
A conservation strategy is an overall policy and development statement covering all aspects of a conservation authority’s work. Thirty-four people from the Ausable Bayfield community took part in a year-long project that resulted in a Conservation Strategy for this watershed area, including a new vision, mission, motto/tagline, logo, and long-term actions to create a healthy watershed. Visit abca.ca for a copy of the Conservation Strategy.
The umbrella organization that represents Ontario’s 36 conservation authorities.
Constructed preferential pathway
A constructed preferential pathway may bypass natural protective geologic layers above an aquifer (e.g., improperly constructed well, pits and quarries). An aquifer’s vulnerability may increase due to land uses or a feature that disturbs the surface or enhances flow.
A contaminant is an undesirable substance that makes water unfit for a given use when found in sufficient concentration. Pathogens and chemicals, including organic solvents and dense non-aqueous phase liquids (DNAPLs), are types of substances that can contaminate water.
Contaminant of Concern
A Contaminant of Concern is a chemical or pathogen that is, or may be, discharged from a drinking water threat – a chemical or pathogen that is or may become a drinking water threat as identified by the Ontario Ministry of the Environment, Conservation and Parks.
Contamination is the mixing of harmful elements, compounds or microorganisms with surface or groundwater. Contamination can occur naturally (e.g., an aquifer flowing through mineral deposits that contain heavy metals) or through human activity (e.g., sewer water flowing into a river). Nutrients, such as nitrogen and phosphorus, can also cause water contamination when they are present in excessive amounts.
Contiguous means having contact with, or touching along, a boundary or point.
Pollution can be transported through a stream corridor – a corridor is a long, narrow area centered on river or other watercourse along a line.
A large pipe or tube that allows water to flow under a road or driveway.
Cumulative (water quality) effects
Cumulative (water quality) effects are the consequence of multiple threats sources, in space and time, which affect the quality of drinking water sources.
The force of moving water.
A barrier set across a river to control the flow of water. A dam is a structure used to hold back water.
Data gaps indicate the lack of site-specific information for a geological area and/or specific type of information.
Decommissioned wells are capped, plugged and sealed in compliance with regulatory requirements by the Ontario Ministry of the Environment, Conservation and Parks (MECP). Decommissioning a well can prevent contamination by closing a potential pathway by which surface water can contaminate groundwater.
A designated system is a drinking water system that is included in a Terms of Reference (ToR), pursuant to resolution passed by a municipal council under subsection 8(3) of the Ontario Clean Water Act, 2006.
Developed / Developable
Developed / Developable reference to the useable portion of a parcel of land that meets the regulatory zoning provisions, particularly those pertaining to defining the area of occupation for buildings, structures, facilities and infrastructure.
Discharge is the flow of surface water in a stream or canal, or the outflow of groundwater to a well, ditch or spring. It is the volume of water in cubic metres per second (m3/s) running in a watercourse. Discharge, with reference to stream flow, is the quantity of water that passes a given point in a unit of time. It can be measured in cubic metres per second or cubic feet per second (CFS). [Source: Leet, L. Don. 1982. Physical Geology, 6th Edition. Englewood Cliffs, NJ: Prentice-Hall. Read also, ‘Local Discharge’
A discharge area is an area where water leaves the saturated zone across the water table surface. It is an area where groundwater emerges at the surface and where upward pressure or hydraulic head moves groundwater towards the surface to escape as a spring, seep, or base flow of a stream.
A distribution system prevents the intrusion of contaminants and ensures appropriate chlorine residual throughout the system.
A diversion is a redirection of water from one drainage or watercourse to another. Diversions of the Ausable River The Ausable River has had two diversions. The first, ‘The Cut,’ was dug in the 1870s. This channel south of Pinery Provincial Park bypassed the original loop through Grand Bend and drained shallow lagoons in the Thedford Marsh. In 1892, the second diversion routed Parkhill Creek, the remaining flow in the loop, straight west to Lake Huron at Grand Bend. The two diversions isolated the original Ausable River between Grand Bend and ‘The Cut,’ restricting the Old Ausable Channel to local drainage.
Diversions of the Ausable River
The Ausable River has two main diversions of water flow. The first, The Cut, was dug in the 1870s. This channel south of Pinery Provincial Park bypassed the original loop through Grand Bend and drained shallow lagoons in the Thedford Marsh. In 1892, the second diversion routed Parkhill Creek, the remaining flow in the loop, straight west to Lake Huron at Grand Bend. The two diversions isolated Pinery Provincial Park’s portion of the original Ausable (the Old Ausable Channel), restricting it to local drainage.
Drainage Area – Go to ‘Watershed’
Drainage Density is the length of watercourse per unit drainage area.
Drainage System (under the Drainage Act)
Drainage System (under the Drainage Act) is a drain constructed by any means, including works necessary to regulate the water table or water level. This broad definition allows for features to be included in drainage systems to restore wetlands while still protecting the agricultural interests of the private landowners.
Drained means a condition in which the level or volume of groundwater or surface water has been reduced or eliminated from an area by artificial means.
A drilled well usually 10 inches or less in diameter, drilled with a drilling rig and cased with steel or plastic pipe. Drilled wells can be of varying depth.
Drinking Water Concern
A drinking water concern is a possible drinking water issue that has not at this time been substantiated by monitoring, or other verification methods.
Concerns may be identified through consultations with the public, stakeholder groups, and technical experts (e.g. water treatment plant operators).
Drinking Water Issue
A drinking water issue is a scientifically substantiated condition relating to the quality of quantity 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.
Drinking Water Risk
A drinking water risk is the likelihood of a drinking water threat activity:
a) Rendering an existing or planned drinking water source impaired, unusable or unsustainable, or;
(b) Compromising the effectiveness of a drinking water treatment process, resulting in the potential for adverse human health effects.
Drinking Water Risk Assessment
Drinking Water Risk Assessment is an assessment of risks prepared in accordance with the regulations and the rules. 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;
There are assessments of threats – the number and type of threat activities, documented in the assessment reports. There are also ‘risk assessments’ that are done to verify vulnerability mapping.
Drinking Water Source Protection
Drinking water source protection is the first barrier of defence in a multi-barrier approach to keep municipal sources of raw water as clean as possible and to lower the risk that contaminants will get through and affect the treatment system. It provides an additional barrier of protection to municipal sources of drinking water. Drinking water source protection and source water protection are used interchangeably but source water protection is often used to apply to all watershed-wide efforts to protect water sources (all water, everywhere) while drinking water source protection is used to refer to the focus on protection of municipal drinking water sources by managing land use activities in the most vulnerable areas such as municipal wellhead protection areas. While source water protection includes voluntary efforts to protect water throughout the watershed, drinking water source protection planning includes Part IV tools under the Ontario Clean Water Act, 2006 including risk management plans and prohibition of some activities in some cases in some areas.
Drinking Water Source Protection Planning
Drinking water source protection planning is defined under the Ontario Clean Water Act, 2006. It involves developing and implementing a plan to manage land uses and potential contaminants in vulnerable areas around municipal sources of drinking water. To be effective, drinking water source protection should be directed at identified threats and risks to the drinking water source.
Drinking Water Threat
A drinking water threat has the same meaning as in the Ontario Clean Water Act, 2006. It is an existing or possibly future activity or existing condition that results from a past activity that:
a) 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 respecting the quality or quantity of water and includes an activity or condition that is prescribed by the regulations as a drinking water threat. A Drinking Water Threat may be classified as a significant threat to drinking water if, according to a risk assessment, it poses or has the potential to pose a significant risk (i.e., it is one of the 22 prescribed threat activities or conditions; it is in a vulnerable area where the vulnerability score is high enough; and it meets the circumstances – e.g., quantities – in the Tables of Threats and Circumstances).
Drinking Water Threat Assessment, Tier One
Drinking Water Threat Assessment, Tier One is a preliminary examination of a drinking water threat based on readily accessible information.
Drinking Water Threat Assessment, Tier Two
Drinking Water Threat Assessment, Tier Two is an advanced examination of a drinking water threat through assessing more detailed information, interviews and perhaps, when warranted, additional monitoring, modeling and studies.
E. coli – Go to ‘Escherichia coli’
Ecological is about the pattern and relationship between organisms and their environment.
Ecology is an interdependent community of plants and animals living in a recognizable area. Humans are a major part of most ecosystems.
An ecosystem is an interacting system of living organisms and their environment.
It is the natural community of plants and animals within a particular physical environment, linked by a flow of materials throughout the non-living (abiotic) as well as the living (biotic) section of the system.
The ecosystem approach is a holistic way of planning and managing natural resources; it means that the consequences of an action (including the cumulative effect of many small actions) on all other parts of the ecosystem will be considered and evaluated before the action is undertaken.
Elevation is the height of a portion of the Earth’s surface in relation to its surroundings.
Enhancement is to add to, or to make greater; for example, to add additional water to a wetland, in order to make greater its environmental functionality.
An entity is one or a series of related objects, natural or anthropogenic, that may be related to a specific process. Examples: storage tank, bird colony, abandoned well, mine tailing, natural radiation source.
Entrain is to draw in and transport through water.
Episodic is made up of separate loosely connected episodes.
Escherichia coli (E. coli)
Fecal coliform and Escherichia coli (E. coli) are bacteria. Escherichia coli are bacteria that normally inhabit the large intestines of humans and other mammals. Most E. coli bacteria are harmless to healthy humans and do not cause disease. However, some forms of E. coli cause disease through the intestines. More than 2,300 people became ill and seven people died when the drinking water system in Walkerton, Ontario became contaminated in May of 2000. The well system was contaminated with deadly bacteria: primarily Escherichia coli O157:H7.1 as well as Campylobacter jejuni. Studies on E. coli O157:H7 in various soil types show that these pathogens survive at least 10 to 25 weeks. Escherichia coli are bacteria found in the gut of warm-blooded animals – and in the waste of humans and animals. Their presence in water indicates fecal contamination, a threat to human health and the potential that water may have other disease-causing organisms. 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.
E. coli O157:H7, a subgroup of E. coli, produces verotoxins that cause hemorrhagic colitis and, in some cases, hemolytic uremic syndrome (HUS). HUS is life-threatening. A person infected with E. coli O157:H7 can experience intestinal disease marked by diarrhea usually lasting about four days or more.
Bloody diarrhea often occurs 24 hours after someone gets the illness. The infected person may experience severe abdominal pain. E. coli O157:H7 infection can have very serious consquences to the elderly and to children under five years of age.
Verotoxins produced by E. coli O157:H7 can cause acute kidney failure, anemia, and low platelet counts, according to the Report of the Walkerton Inquiry. Verotoxin produced by E. coli O157:H7 can also affect small blood vessels in the brain. For more information visit this link:
Effluent is the discharge of a pollutant in a liquid form, often from a pipe into a stream or river.
Emergency Procedures and Plans
Emergency Procedures and Plans are responses to emergency and adverse conditions that are thorough and effective to prevent health problems.
Enhancement is to add to, or to make greater. For example, to add additional water to a wetland, in order to make greater its environmental functionality, would be an enhancement.
Environmental Farm Plan (EFP)
Environmental Farm Plans are assessments voluntarily prepared by agricultural producers in order to highlight their farm’s environmental strengths, identify areas of environmental concern, and set realistic action plans with timetables to improve environmental conditions. Environmental cost-share programs are available to assist in implementing projects.
Environmentally Significant Area (ESA)
Ausable Bayfield Conservation defines Environmentally Significant Areas as areas of woodlots that contain some wetland features that play an important role in supporting significant plant or animal species and/or serving hydrological functions. A site may also be significant if it supports a remnant or a threatened species of flora or fauna.
Erosion is the movement of soil by wind, water or ice. Erosion is the wearing away of the land by the action of water, wind or glacial ice. It is a physical process causing the deterioration and transport of soil surfaces and river channel materials by the force of flowing water or wind, ice or other geological agents, including such processes as gravitational creep. Geological erosion is naturally occurring erosion over long periods of time.
Eutrophication is generally associated with increased plant productivity due to increased nutrient presence, mainly phosphorus, and sometimes nitrate concentrations in lakes, streams, rivers or other water bodies. Excessive nutrient enrichment, or eutrophication, takes place when a large amount of nutrients are released into a water body, causing excessive aquatic plant growth. The nutrient phosphorus often has the greatest effect on eutrophication as it tends to be more limited in the environment. Some environments are nitrogen deficient and may be more influenced by changing nitrogen levels. Too much plant growth can turn a lake into a bog or even land. Release of nutrients from human activities such as from fertilizers can lead to eutrophication. This can harm fish and other organisms that live in lakes. These aquatic species face depleted oxygen levels as plants decompose. Sources such as runoff can contribute to the presence of phosphorous or nitrates. Nutrients can contribute to the growth of algae, weeds or other nuisance plants. The growth of algae, or algal blooms, lowers dissolved oxygen in the water. Other organisms can die as plants decompose. This can also affect the number of species and the number of animals within a species.
Read also ‘Eutrophic conditions’
Eutrophic conditions are when water is oxygen-starved. This occurs when water becomes nutrient rich which causes algae blooms and other micro-organisms to increase. These micro-organisms use oxygen in their life cycle, and decrease the available oxygen in the water for other organisms (e.g., fish).
Eutrophic lakes are lakes that are rich in nutrients and organic materials, therefore highly productive for plant growth. These lakes are often shallow and seasonally deficient in oxygen in the hypolimnion.
The process by which water turns into a gas and goes to the sky. Evaporation is the process by which water or other liquids change from liquid to vapour; evaporation can return infiltrated water to the atmosphere from upper soil layers before it reaches groundwater or surface water, and occur from leaf surfaces (interception), water bodies (lakes, streams, wetlands, oceans), and small puddled depressions in the landscape.
Evapotranspiration is the combined loss of water from a given area and during a specific period of time by evaporation from the soil surface and by transpiration from plants.
An event is an occurrence of an incident (isolated or frequent) with the potential to promote the introduction of a threat into the environment. An event can be intentional, as in the case of licensed discharge or accidental, as in the case of a spill.
Existing Drinking Water Source
An Existing Drinking Water Source is the aquifer or surface water body from which municipal residential systems or other designated systems currently obtain their drinking water. This includes the aquifer or surface water body from which back-up wells or intakes for municipal residential systems or other designated systems obtain their drinking water when their current source is unavailable or an emergency occurs.
Exposure is the extent to which a contaminant or pathogen reaches a water resource. Exposure, like a drinking water threat, can be quantified based on the intensity, frequency, duration and scale. The degree of exposure will differ from that of a drinking water threat dependent on the nature of the pathway or barrier between the source (threat) and the target (receptor) and is largely dependent on the vulnerability of the resource.
Family Biotic Index (FBI)
A Family Biotic Index (FBI) is an index used to provide an evaluation of stream health based on pollution tolerance scores for families of benthic macroinvertebrates. Family Biotic Index (FBI) summarizes the numbers and types of these animals in a sediment sample. Values reflect stream health, ranging from 1 (healthy) to 10 (degraded).
Sources of total and fecal coliform in groundwater can include runoff (whether residential, agricultural, commercial or industrial), effluent from septic systems or sewage discharges and infiltration of domestic or wild animal fecal matter. Poor well maintenance and construction (particularly shallow dug wells) can also increase the risk of bacteria and other harmful organisms getting into a well water supply. Fecal coliform and Escherichia coli (E. coli) are types of bacteria.
Fens are peatlands characterized by surface layers of poorly to moderately decomposed peat, often with well-decomposed peat near the base. The waters and peat in fens are less acid than in bogs, and often are relatively nutrient rich and minerotrophic since they receive water through groundwater discharge from adjacent uplands. Fens usually develop in situations of restricted drainage where oxygen saturation is relatively low and mineral supply is restricted.
Usually very slow internal drainage occurs through seepage down very low gradient slopes, although sheet surface flow may occur during spring melt or periods of heavy precipitation or if a major local or regional aquifer discharges into the wetland. Some fen wetlands develop directly on limestone rock where minerotrophic waters are emerging through constant groundwater discharge.
Fill is the rubble, earth, rocks or other imported material that is used to raise or alter the existing elevation.
The overflowing of water in a river onto the flood plain. A flood is an overflow or inundation that comes from a river or other body of water and causes or threatens damage. It can be any relatively high streamflow overtopping the natural or artificial banks in any reach of a stream. It is also a relatively high flow as measured by either gauge height or discharge quantity.
Flood pulse is the peak flow during a flooding event.
A flood plain is a plain bordering a river, which has been formed from deposits of sediment carried down the river. When a river rises and overflows its banks, the water spreads over the flood plain. A flood plain is the flat land beside a watercourse that becomes covered by water from time to time. It is also referred to as “the the river’s living space.” A flood plain is the area bordering a river. It has been formed from deposits of sediment carried down the river. When a river rises and overflows its banks, the water spreads over the flood plain. A flood plain is a strip of relatively level land bordering a stream or river. It is built of sediment carried by the stream and dropped when the water has flooded the area. It is called a water flood plain if it is overflowed in times of high water, or a fossil flood plain if it is beyond the reach of the highest flood.
Flood warning system
The flood warming system is a service provided by conservation authorities to member municipalities forewarning of potential flooding situations.
Floodway is the channel of a river and those parts of the adjacent flood plain which are required to carry and discharge flood water.
Flow is the volumetric rate of water discharged from a source, given in volume with respect to time. Measured in cubic metres per second. Read also ‘Discharge.’
Flow regime is the pattern of how water levels change in a stream.
Flow stability is determined by measuring the ratio of surface discharge to groundwater discharge on an annual basis.
Fluvial is relating to a stream or river.
Forest conditions include percentage of forest cover and forest interior. Forest conditions relate to the health and extent of a forest based on ecological indicators and other parameters including assessment by professionals and community stakeholders.
Forest cover is the percentage of a watershed or source protection area that is forested. For recommended forest cover, read Environment and Climate Change Canada’s How Much Habitat is Enough?
Forest interior is the portion of a woodlot which remains when a 100-metre buffer is removed from the inside perimeter (e.g., 100 metres from the outside edge). It is the area inside a woodlot that some bird species need for breeding.
Forest interior is the percentage of a watershed with forest cover that is at least 100 metres from the forest’s edge. For more information visit Environment and Climate Change Canada.
Forest management is the intelligent use and control of the forest and its products for a specific purpose; may be for wood production, wildlife habitat, maple syrup, nature trails or any combination of these uses and others.
A great increase in the amount of water in a stream caused by heavy rains or melting snow, usually in the spring.
Fresh water is water with less than 1,000 milligrams per litre (mg/L) of dissolved solids. More than 500 milligrams per litre is undesirable as a drinking water source or for many industrial uses.
A function is an ecological role for human benefit.
Future Municipal Water Supply Areas
A Future Municipal Water Supply Area is an area corresponding to a wellhead protection area or a surface water intake protection zone, or an aquifer or groundwater area identified for future municipal water supply infrastructure (either a well or a surface water intake pipe).
Geographic Information Systems (GIS)
A geographic information system (GIS) is a computer-based system that has the capability to input, store, retrieve, manipulate, analyze, and output geographically referenced data. GIS, or Geographic Information System(s), is an electronic map-based database management system which uses a spatial reference system for analysis and mapping purposes.
Geology is the science of the composition, structure and history of the Earth. This includes the study of the material that makes up the planet the forces which act upon these materials and the structures which are formed from this relationship. It is the study of science dealing with the origin, history, materials and structure of the earth, together with the forces and processes operating to produce change within and on the earth.
The nth root of the product of all the members of the set, where n is the number of members. The geometric mean is useful to determine typical conditions.
Geomorphology is the scientific study of the origin of land, riverine and ocean features on the Earth surface. Great Lakes The Great Lakes are the five large lakes located in Canada and the United States of America: Lake Ontario; Lake Superior; Lake Huron, Lake Michigan; and Lake Erie.
Glaciation is the covering of an area or the action on that area, by an ice sheet or by glaciers.
Goals are high-level achievements for which to aim (e.g. to protect drinking water sources). Provides an opportunity to add value statements.
A gradient is the rate or regular graded ascent or descent.
Granular is having a texture composed of small particles.
The Great Lakes are the five (large) lakes located in Canada and United States: Lake Ontario, Lake Superior, Lake Huron, Lake Erie and Lake Michigan.
Great Lakes connecting channels
Great Lakes connecting channels are the large rivers that connect the Great Lakes (e.g. St. Clair River, St. Lawrence River).
Ground Water – Go to ‘Groundwater’
Groundwater is the water found underground in the soil, wells, porous rocks, and subsurface reservoirs and channels. Groundwater is water found in the spaces between soil particles and cracks in rocks beneath the earth’s surface (usually located in aquifers a natural reservoir below the earth’s surface in an aquifer). Groundwater is a natural resource that is used for drinking, recreation, industry, growing crops, and other human needs. Groundwater is subsurface water that occurs beneath the water table in soils and geological formations that are fully saturated.
Groundwater is subsurface water occurring below the water table in fully saturated soils and geological formations.
Present almost everywhere underground.
Found in the spaces between particles of rock and soil, in crevices and cracks in rock.
Usually within 100 metres of the surface (at greater depths the spaces are smaller, therefore there is less water)
It is the water below the water table contained in void spaces (pore spaces between rock and soil particles, or bedrock fractures). It is water occurring in the zone of saturation in an aquifer or soil.
The groundwater barrier describes rock or artificial material with a relatively low permeability that occurs (or is placed) below ground surface, where it impedes the movement of groundwater and thus may cause a pronounced difference in the hydraulic head on opposite sides of the barrier.
The groundwater basin is the underground area from which groundwater drains. The basins could be separated by geologic or hydrologic boundaries.
Groundwater flow is the rate of groundwater movement through the subsurface.
Groundwater flow varies in the rate of flow from slow to slower. (Sometimes it is relatively fast in limestone geology).
Groundwater recharge is the inflow of water to a groundwater reservoir from the surface. Infiltration of precipitation and its movement to the water table is one form of natural recharge.
Groundwater discharge is the function of a wetland to accept subsurface water and hold it for release over long periods of time.
Groundwater divide is the boundary between two adjacent groundwater basins, which is represented by a high point in the water table.
Groundwater recharge is the inflow of water to a ground water reservoir from the surface. Infiltration of precipitation and its movement to the water table is one form of natural recharge.
Groundwater recharge area
A groundwater recharge area is an area where an aquifer is replenished from:
(a) Natural processes, such as the infiltration of rainfall and snowmelt and the seepage of surface water from lakes, streams and wetlands;
(b) From human interventions, such as the use of stormwater management systems, and;
(c) whose recharge rate exceeds a specified threshold.
A significant groundwater recharge area is one of four vulnerable areas identified in Ontario’s Clean Water Act, 2006.
Read also ‘significant groundwater recharge area (SGRA).’
Groundwater table is the meeting point between the groundwater and the unsaturated layer above it.
Groundwater vulnerability is the probability of contaminants travelling to a specified region in the groundwater system after introduction at some location above the uppermost aquifer. Guideline (Water Quality) Acceptable concentrations of substances in water that is used for drinking, recreational activities, agricultural uses and the protection of aquatic life.
Habitat is an environmental area where an organism lives and the place where it is usually found. It includes the food, water, shelter, cover and other elements of the environment that living organisms need to survive.
A source of danger or risk, especially to one’s personal safety. In drinking water source protection, a hazard may be a contaminant such as a pathogen or chemical threat.
A hazard rating is a scientifically-determined numeric value which represents the relative potential for a contaminant of concern to impact drinking water sources at concentrations significant enough to cause human illness. The numeric value which represents the relative potential for a contaminant of concern to impact drinking water sources at concentrations significant enough to cause human illness.
Headwater is the source waters of a stream or river.
Highly Vulnerable Aquifer (HVA)
A highly vulnerable aquifer (HVA) is an aquifer that can be easily changed or affected by contamination from both human activities and natural process as a result of:
a) Its intrinsic susceptibility, as a function of the thickness and permeability of overlaying layers, or;
b) By preferential pathways to the aquifer.
Hydric soil is characterized by an abundance of moisture and much reduced oxygen levels, to the extent that the soil supports water-tolerant vegetation.
Hydrogeology is the study of the movement and interactions of groundwater in geological materials.
Driven by the sun, the hydrologic or water cycle converts solar energy into energy that performs the main transport functions in ecosystems. Water cycles throughout the oceans, the atmosphere, the soil, bodies of fresh surface water and living organisms. The main processes are evaporation, precipitation and condensation, infiltration to soil and groundwater, flow to vegetation or to streams and other water bodies, and then either transpiration from plants into the air or runoff via rivers to the oceans. These processes purify the Earth’s supply of water, reshape the Earth itself by erosion, drive other biogeochemical cycles, and redistribute the elements necessary for life. The hydrologic cycle is a key part of the global climate system and provides the condition and basis for all life. The cycle of water movement from the atmosphere to the earth and return to the atmosphere through various stages, such as precipitation, interception, runoff, infiltration, percolation, storage, evaporation, and transpiration.
Hydrology is the study of the Earth’s water, particularly of water on and under the ground before it reaches the ocean or before it evaporates into the air.
Hydro-period is the seasonal pattern of the water level of a wetland that is a hydrologic signature of each wetland type. It defines the rise and fall of a wetland’s surface and subsurface water.
Hydrophytic plants are vegetation adapted to growing in water or in hydric soils.
A life-threatening condition in which a person’s deep body temperature is lowered by exposure to cold air or water.
Ice – Black, Grey, or Blue
Dark areas of ice that are thin and weak spots.
Imminent Threat to Health
A contaminant of concern that can affect human health in a short period of time is an Imminent Threat to Health.
Impact is often considered the consequence or effect. The impact should be measurable and based on an agreed set of parameters. In the case of drinking water source protection, the parameters may be an acceptable list of standards which identify maximum raw water levels of contaminants and pathogens of concern. In the case of water quantity, the levels may relate to a minimum annual flow, piezometric head or lake level.
Impermeable means not allowing water to pass through.
Impervious is a term denoting the resistance to penetration by water or plant roots. Indicator (Ecological) Indicators are measures that provide information about the state or condition of a watershed and provide a means to assess progress towards an objective or target. Watershed health indicators include surface water quality, forest conditions, and groundwater quality.
Infiltration is the movement of water into soil pores from the ground surface.
Inflow is the water that flows into a lake, reservoir or forebay.
An inland lake is a body of standing water, usually fresh water, larger than a pool or pond or a body of water filling a depression in the earth’s surface.
An inland river is a creek, stream, brook and any similar watercourse inland from the Great Lakes that is not a connecting channel between two Great Lakes.
Intake Protection Zone (IPZ)
A surface water intake protection zone (IPZ) means the area of land and water that contributes source water to a drinking water system intake within a specified distance, period of flow time (for example, two hours). A surface water intake protection zone is one of four types of vulnerable areas identified in the Ontario Clean Water Act, 2006. Intake protection zone means the area of land and water that contributes source water to a drinking water system intake within a specified distance, period of flow time (for example, two hours), and/or watershed area. River and lake intakes can be contaminated when dangerous materials are spilled into the water or on nearby land and make their way to the intake. Intake protection zones are areas where dangerous materials may get to an intake so quickly the operators of the municipal water treatment plant may not have enough time to shut down the intake before the pollutant reaches it.
A surface water intake protection zone is the area of land and water upstream of an intake defined in accordance with a specific response time to an upstream event. (The main purpose is to permit response to spill situations, which result from accident or storm events and which may cause a spike in contamination concentrations.) An intake protection zone is a ring or rings, which are not necessarily regular in shape, surrounding municipal drinking water intakes from surface water sources. The two main surface water intakes in the Ausable Bayfield and Maitland Valley watersheds, or source protection areas, are the Lake Huron Primary Water Supply intake at Port Blake (near Grand Bend) and at Goderich.
Integrated watershed management
Integrated watershed or resource management is management of natural resources (water, trees, soil, wildlife) in a comprehensive, coordinated, cost-effective way; usually done on a watershed basis with the goal of ensuring that the resource base does not deteriorate.
Interflow is the runoff infiltrating into the surface soil and moving toward streams as shallow, perched ground water above the main groundwater level. [SOURCE: Atlas of Water Resources in the Black Hills Area, South Dakota].
Intermittent means that which stops and begins again, pausing at intervals. An intermittent stream is a watercourse that does not flow permanently year-round.
Intrinsic Vulnerability is the potential for the movement of a contaminant(s) through the subsurface based on the properties of natural geological materials.
Invertebrates are animals lacking a spinal column.
Leachate is a liquid formed by water percolating through contaminated soil or soluble waste as in a landfill site.
Loam is a rich soil containing sand, silt, and clay.
Karst topography is the name given to an area underlain by rocks such as limestone and is characterized by caves, sinkholes, and depressions.
Knowledge gaps refer to a lack of referenced materials or expertise to assess certain characteristics of the specific watershed or source protection area or region that can be adequately described without tabular or spatial data.
A landform defines the physical shape of the landscape and the materials based on how the geologic material was deposited by glaciers.
A land use is a particular use of space at or near the Earth’s surface with associated activities, substances and events related to the particular land use designation.
Liaising is refining logistics around gathering data and information
Local discharge is water discharging to a watercourse that originates nearby. The water moves through the upper layers of the groundwater system.
Read also, ‘Discharge’
Lowflow is the flow that exists in a stream channel in dry conditions. Lowflow is reduced water flows that exist in a stream channel in dry conditions.
Macroinvertebrates are animals lacking a spinal column that are visible with the unaided eye.
Marshes are wet areas periodically inundated with standing or slowly moving water, and/or permanently inundated areas characterized by robust emergents, and to a lesser extent, anchored floating plants and submergents. Surface water levels may fluctuate seasonally, with declining levels exposing drawdown zones of matted vegetation or mud flats. Standing or slow-moving water with emergent plants covering greater than 25 per cent. Permanently flooded, intermittently exposed, or seasonally flooded. Nutrient-rich water generally remains within the rooting zone for most of the growing season. Substrate is mineral soil or well-decomposed sedimentary organic material, often held together by a root mat.
A meander is a curve in the course of a river which continually swings from side to side.
Meandering is a curve in the course of a river which continually swings from side to side.
A meltwater channel is the path of drainage and leftover sedimentary deposits from ice or snow melt.
A model in drinking water source protection planning is an assembly of concepts in the form of mathematical equations or statistical terms that portrays a behavior of an object, process or natural phenomenon.
Model calibration is the process for generating information over the life cycle of the project that helps to determine whether a model and its analytical results are of a quality sufficient to serve as the basis of a decision.
Model evaluation is a comparison of model results with numerical data independently derived from experiments or observations of the environment.
Model validation is a test of a model with known input and output information that is used to adjust or estimate factors for which data are not available.
Model verification is the examination (normally performed by the model developers) of the numerical technique in the computer code to ascertain that it truly represents the conceptual model and that there are no inherent numerical problems with obtaining a solution.
Monitoring is periodic evaluation of a site or process to determine success in achieving goals.
Monitoring and management
A monitoring and management system from source to tap is monitored and managed by trained personnel in accordance with legislation, standards, policies and guidelines. Problems are detected early so that corrective action can be taken quickly. Automatic control systems are being incorporated into the water systems.
Moraine is an accumulation of earth and stones carried by a glacier which is usually deposited into a high point like a ridge. Moraine is the debris or rock fragments brought down with the movement of a glacier.
The mouth marks the end of a watercourse at a body of water, usually a lake or the sea.
Multi-barrier approach to safe drinking water
The multi-barrier approach to safe drinking water is a key approach to ensure clean, safe and secure drinking water. The method is to implement multiple barriers throughout the drinking water system from source to tap. No single barrier is 100 per cent effective so multiple barriers are required to minimize the risk that drinking water could become contaminated.
Ontario’s barriers of defence protecting drinking water include source water protection (drinking water source protection for zones around municipal wells and intakes as well as broader source water protection programs across larger areas); the Three Ts – Training of water operators, Treatment of water, Testing of water; water distribution; and inspection).
Source water protection – including drinking water source protection planning for municipal drinking water systems – is the first barrier of defence.
Other barriers include the three Ts:
- Training of water operators;
as well as distribution; and monitoring.
Municipal Residential System
Municipal residential systems are all municipal drinking-water systems that serve or are planned to serve a major residential development (i.e. six or more private residences).
Naturalize is to make a part of the physical environment natural, free from conventional characteristics.
Naturally-occurring processes occur in nature and that are the result of human activity. For example, erosion along a stream that provides a source of drinking water or the leaching of naturally occurring metals found in bedrock into groundwater.
Natural preferential pathways
Natural preferential pathways include fractured bedrock and Karst (sinkhole) topography. Such characteristics increase the intrinsic vulnerability of an aquifer.
Nitrate (NO3) is a chemical formed when nitrogen from ammonia (NH3), ammonium (NH4) and other nitrogen sources combine with oxygenated water. An important plant nutrient and type of inorganic fertilizer (most highly oxidized phase in the nitrogen cycle). In water, the major sources of nitrates are septic tanks, livestock feed lots and fertilizers. Nitrate (NO3) is a chemical formed when nitrogen from ammonia (NH3), ammonium (NH4) and other nitrogen sources combine with oxygenated water. An important plant nutrient and type of inorganic fertilizer (most highly oxidized phase in the nitrogen cycle). In rural water bodies, major sources of nitrates may include septic tanks, livestock wastes, and fertilizers.
Nitrite (NO2) is a product in the first step of the two-step process of conversion of ammonium (NH4) to nitrate (NO3). Nitrite + Nitrate Nitrogen occurs naturally in rocks and groundwater. The forms of nitrogen found in water include nitrite (NO2) and nitrate (NO3-). The concentration of nitrogen in groundwater can be significantly increased by anthropogenic activities such as applications of excessive amounts of fertilizer and manure, and leaky septic systems. Nitrite is unstable in aerated water and is generally considered to be an indicator of pollution through improper disposal of sewage or organic waste. Nitrite (NO2) is a product in the first step of the two-step process of conversion of ammonium (NH4) to nitrate (NO3).
Non-point source pollution
Non-point source (NPS) pollution, unlike pollution from industrial and sewage/wastewater treatment plants, for example, comes from many sources. A source of pollutants from a wide geographic area, such as stormwater runoff and stream bank erosion which can impair the quality of surface and groundwater sources of drinking water. Non-point source pollution occurs when precipitation runs off lawns, streets, parking lots, fields, backyards, roads, driveways, and other surfaces. As this runoff moves across the land surface, it picks up soil particles and pollutants. Pollution of the water from numerous locations that are hard to identify as non-point source, like runoff over a parking lot or field, or atmospheric deposition. Rainfall or snowmelt moves over and through the ground and this moving runoff picks up and carries natural, animal and human-made pollutants. The runoff then carries the pollutants into watercourses (lakes, rivers, coastal waters, etc.), wetlands, and underground sources of drinking water. A non-point source of pollutants comes from a wide geographic area, such as manure runoff, stream bank erosion, and stormwater runoff, and threatens the quality of surface and groundwater sources of drinking water.
Non-renewable resources are resources that are not capable of being replaced by natural ecological cycles or sound management practices within the timeframe of a human life.
Nutrients are materials such as fertilizer, manure, compost, sewage biosolids, and pulp and paper biosolids, that can be applied to land for the purpose of improving the growing of agricultural crops or for the purpose of a prescribed use. Nutrients are elements or chemicals (particularly phosphorus) that stimulate the growth of aquatic plants and may lead to eutrophication. A nutrient is something that nourishes and promotes growth. It is possible to have too many nutrients in an ecosystem, which can result in an unhealthy imbalance or overgrowth of certain species. A nutrient is something that nourishes and promotes growth – it may be manure or chemical or other product. It is possible to have too many nutrients in an ecosystem, which can result in an unhealthy imbalance or overgrowth of certain species.
Ontario Ministry of the Environment, Conservation and Parks (MECP)
The Ontario Ministry of the Environment, Conservation and Parks (MECP) is the provincial ministry that is spearheading drinking water source protection in Ontario. The Minister of the Environment introduced the Clean Water Act, 2006 in December, 2005. It was passed the next year and regulations bringing the Act into full force were approved the next year. The Act ensures communities are able to identify potential risks to their supply of drinking water, and take action to reduce or eliminate these risks. Municipalities, conservation authorities, landowners, business people, institutional people, agricultural producers, industry, commerce, and the public work together to meet common goals. For more information on the Ontario Ministry of the Environment, Conservation and Parks and the Ontario Clean Water Act, 2006 visit Ontario.ca.
Organic matter is related to, or derived from, living organisms.
Overburden is unconsolidated geologic material above the bedrock. It is used to describe the soil and other material that lies above a specific geologic feature.
Outflow is the flow out of or through a waterpower facility, control structure, pond, reservoir or lake.
Outwash is sediments deposited by glacial meltwater creating stratified layers of gravel, sand and fines. The terms fluvial and outwash are used interchangeably. Outwash sand Outwash sand is sand drift, which becomes deposited by meltwater streams.
An oxbow is a crescent-shaped lake or slough formed in an abandoned stream bend that has become separate from the main stream by a change in its course.
A parcel is a conveyable property, in accordance with the provisions of the Land Titles Act. The parcel is the smallest geographic scale at which risk assessment and risk management are conducted.
Parts per billion (ppb)
Parts per billion (ppb) is a measure of the amount of dissolved matter in a solution in terms of a ratio between the number of parts of matter to a billion parts of total volume; equivalent to microgram per litre in water or one part per billion = one microgram per litre (µg /l).
Parts per million (ppm)
Parts per million (ppm) is a measure of the amount of dissolved matter in a solution in terms of a ratio between the number of parts of matter to a million parts of total volume; equivalent to milligram per litre in water or one part per million = one milligram per litre.
A pathogen is a bacterial or virus that is dangerous to human health. It can found in human or animal waste. Human pathogens can be found in septic tanks. Manure contains animal pathogens. A pathogen is an organism capable of producing disease. A pathogen is a bacterium or living organism that causes disease, illness or death.
Read also ‘E. coli.’
Preferential pathways are 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 water.
Pathways – Read also ‘natural preferential pathway’ and ‘constructed preferential pathway’
Perched aquifers occur where groundwater is perched above unsaturated formations as a result of a discontinuous impermeable layer. They also occur in formations where weathered layers or ancient soils have created impermeable zones. Wells drilled into these aquifers have been known to go dry because the water is mined.
Percolation is the downward movement of water in the ground through porous soil and cracked or loosely-packed rock. Percolation is the actual movement of subsurface water either horizontally or vertically; lateral movement of water in the soil subsurface toward a nearby surface drainage feature (e.g., stream) or vertical movement through the soil to the groundwater zone.
Permeable is a porous surface through which water passes quickly.
Permeability is the quality of having pores or openings that allow liquids to pass through. the property or capacity of a soil or rock for transmitting a fluid, usually water; the rate at which a fluid can move through a medium. The definition only considers the properties of the soil or rock, not the fluid.
Read also ‘Hydraulic conductivity.’
Pesticides are chemicals including insecticides, fungicides, and herbicides that are used to kill living organisms. pH pH is a numerical measure of acidity, or hydrogen ion activity used to express acidity or alkalinity. Neutral value is pH 7.0, values below pH 7.0 are acid, and above pH 7.0 are alkaline.
Phosphorus is a non-toxic pollutant that is an essential nutrient but in excessive amounts it leads to eutrophication of a water system. Phosphorus accumulates along the entire length of a river from a variety of point and non-point sources.
Read also ‘Total phosphorus.’
Physiography is the study or description of landforms.
Planned Drinking Water Source
A Planned Drinking Water Source is the drinking water source (e.g., aquifer or surface water body) from which planned municipal residential systems or other planned designated systems are projected to obtain their drinking water from in the future and for which specific wellhead protection areas (WHPAs) and surface water intake protection zones (IPZs) have been identified.
A plume is a pattern of contaminant concentrations created by the movement of water. The spill/source site is the highest concentration, and the concentration decreases away from the source. Read ‘contaminant plume’ and ‘pollution plume.’ A pollution plume is a pattern of contaminant concentrations created by the movement of water – an area of a stream or aquifer containing degraded water resulting from migration of a pollutant. Contaminants spread in the direction of the water movement. The spill/source site has the highest concentration, the concentration decreases as the plume moves away from the source.
Point source pollution
Point source pollution is a source of contamination that originates in an identifiable location. Point-source pollution comes from a distinct source, such as an industrial discharge pipe, underground storage tank, septic system, or spills. An example of a source of pollutants would be a municipal treatment plant or an industrial facility, often by way of a pipe. A point source of pollution is a single, identifiable source of pollution, whether that be water, air, noise, light or thermal pollution. It may come from a municipal treatment plant or an industrial facility, often by way of a pipe. When waste is discharged to the receiving waters from a pipe or drain, from an identifiable source such as a wastewater treatment plant or industrial discharge, then that contamination originates from a definite source.
For more information visit the Victoria EPA site.
Poorly-drained soils are saturated at or near the surface during a sufficient part of the year such that field crops cannot be grown without drainage.
Porosity is the ratio of the volume of void or air spaces in a rock or sediment to the total volume of the rock or sediment.
Porous is having ‘pores’ or ‘holes’ – allowing liquid or gas to pass through.
Potable water is water that is safe for drinking.
Precipitation is the deposits of water, in either liquid or solid form, which reach the Earth from the atmosphere. It includes rain, sleet, snow and hail. Precipitation is moisture falling from the atmosphere in the form of rain, snow, sleet or hail. Reforestation The planting of trees, saplings or seedlings on land that has been cleared of trees in the past.
Preferential pathways are 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.
Productivity is the rate of production, especially of food or solar energy by producer organisms.
Raw water is water in its natural state, prior to any treatment – not the same as ‘pure’ water which does not exist in nature.
Raw water is water that is in a drinking-water system or in plumbing that has not been treated in accordance with,
(a) the prescribed standards and requirements that apply to the system, or;
(b) such additional treatment requirements that are imposed by the license or approval for the system.
Raw water supply
Raw water supply is water outside a drinking-water system that is a source of water for the system.
A receptor is the exposed target in danger of incurring a potential impact. An example would be any aquifer or surface water body used for drinking water consumption.
Recharge is, according to the Dictionary of Mining, Mineral and Related Terms:
a. The processes by which water is absorbed and added to the zone of saturation, either directly into an aquifer or indirectly by way of another formation; also, the quantity of water so added.
b. Putting water brought from elsewhere into a body of groundwater to augment groundwater supply.
A Recharge Area is an area where water enters a saturated zone at the water table surface.
Read also, ‘Groundwater Recharge Area’ and ‘Significant Groundwater Recharge Area (SGRA).’
A Regional Discharge is water that has traveled deep beneath the ground through the saturated zone and resurfaces at the water table.
Regulated Areas are those areas for which conservation authorities delineate and restrict land uses by making regulations under subsection 28(1) of the Conservation Authorities Act. This subsection applies to watercourses, streams, lakes, valleys, flood plains, and wetlands in Ontario. Provincially approved standards and methodologies for delineating Regulated Areas are outlined in draft guidance documents prepared by Conservation Ontario in cooperation with the Ontario Ministry of the Natural Resources and Forestry.
Renewable resources are resources that are capable of being replaced through ecological processes or sound management practices.
Reserve amounts are minimum flows in streams that are required for the maintenance of the ecology of the ecosystem.
Response factors are typical factors affecting the response include dilution, rate of discharge, absorption, and degradation of the contaminant or pathogen in question. Because of the nature of the water resource, certain contaminants and pathogens may not have an impact (see definition), great enough to warrant concern or responsive action. The level of impact may not effectively degrade the water resource and therefore would not require a mitigative action.
Restoration is changing existing function and structure of wetland habitat so that it is similar to historical conditions.
A return period is the frequency in which a flow event in a stream is likely to repeat itself.
A riffle/pool system is a riverine system that alternates cycles of shallow broken water (riffle) and deeper still water (pool).
The riparian area is the area that lies as a transition zone between upland areas (such as fields) and other areas (such as streams, wetlands, lakes, rivers, etc.) The zone is intermittently inundated and usually supports wet meadow, marshy or swampy vegetation.
Risk is the likelihood of a drinking water threat activity:
(a) rendering an existing or planned drinking water source impaired, unusable or unsustainable, or;
(b) compromising the effectiveness of a drinking water treatment process, resulting in the potential for adverse human health effects.
Read also, ‘Drinking Water Risk.’
Risk Assessment – Read ‘Drinking Water Risk Assessment’
Risk Management Plan
A risk management plan means a plan for reducing a risk prepared in accordance with the regulations and the rules.
A risk management plan is generally negotiated between a person doing an activity (such as storing home heating oil)and a municipal risk management official.
The risk management plan (RMP) regulates those activities, in protection areas around municipal wells, that pose a significant drinking water threat to drinking water sources.
The risk management plan includes best management practices and other measures designed to ensure that risks to the municipal drinking water source are reduced or eliminated.
For example, if fuel stored at a service station was a significant threat to drinking water, a risk management official would work with the gas station owner. Together, they would develop a risk management plan to reduce the chance of spills from an underground tank.
The risk management plan may be simple and straightforward in cases where best management practices are already in place.
The plans can be amended as activities and operations change over time.
Talk to staff in the region or to your risk management official to find out more.
Riverine is relating to or resembling a river.
Runoff, or run-off, is water that moves over land rather than being absorbed into the ground. Runoff is greatest after heavy rains or snowmelts, and can pick up and transport contaminants from landfills, farms, sewers, industrial or commercial operations, institutional, residential, municipal, streets and parking lots, or other sources.
Saturated Soil is soil that is full of moisture.
Saturated Zone – Go to ‘Zone of Saturation’
Scale is a graduated series or scheme of rank or order.
Security of well or intake infrastructure
Security of well or intake infrastructure is an evaluation of structures/measures that are in place or are needed to protect a municipal groundwater supply well or surface water intake from potential contamination from external sources.
Sediment is material deposited by water, wind or glaciers. Fragmented organic or inorganic material derived from the weathering of soil, alluvial and rock materials. It is removed by erosion and transported by water, wind, ice and gravity.
Sedimentary bedrock is rock formed of mechanical, chemical or organic sediment such as rock formed from sediment transported from elsewhere, by chemical precipitation from solution or from inorganic remains of living organisms.
The deposition of sediment from a state of suspension in water or air. 75th percentile The 75th percentile represents the value below which 75 per cent of the values occur. This value is used as opposed to a median value (50th percentile) to account for the tendency of Provincial Water Quality Monitoring Network samples to be collected during dry weather periods.
Semi-Quantitative describes an approach or methodology that uses measurable or ranked data, derived from both quantitative and qualitative assessments, to produce numerical values to articulate results.
Semi-Quantitative Risk Analysis
Semi-Quantitative Risk Analysis describes an approach or methodology that uses measurable or ranked data, derived from both quantitative and qualitative assessments, to produce numerical values to articulate results.
Sensitivity analysis evaluates the effect of changes in input values or assumptions on a model’s results.
Severity is the degree to which an impact is measured compared to an idealized value of some parameter of concern. In the case of water quality, the severity may relate to degree of measurable exceedence of some contaminant or pathogen. In the case of water quantity, deviation from some measurable parameter (e.g. minimum annual flow, piezometric head or lake level) must also be established.
Significant Drinking Water Threat
A significant threat to municipal drinking water sources is a drinking water threat activity that, based on activity circumstances, poses or has the potential to pose a significant risk.
Visit Ontario.ca for the list of 22 activities that can pose a threat to drinking water sources as well as the Tables of Threats and Circumstances which outline in what areas, quantities, and other circumstances an activity is considered a significant drinking water threats (SDWT).
Significant Hydrologic Features
Significant Hydrologic Features are:
(a) A permanent or intermittent stream,
(c) kettle lakes and their surface catchment areas,
(d) seepage areas and springs, and;
(e) aquifers and recharge areas that have been identified as significant by the Ontario Ministry of Natural Resources and Forestry (MNRF), using evaluation procedures established by that Ministry, as amended from time to time.
Significant Groundwater Recharge Areas (SGRAs)
A significant groundwater recharge area (SGRA) is one of the four types of vulnerable areas identified in the Ontario Clean Water Act, 2006.
Significant recharge areas account for the bulk of water flow from surface to aquifer. A decline in the recharge rate can affect those surface water sources, which depend on local groundwater discharge. Cumulative loadings in recharge areas can impair aquifer water quality.
A sinkhole is sometimes defined as any depression in the surface of the ground, with or without collapse of the surrounding soil or rock, which provides a means through which surface water can enter the ground and therefore come in contact with groundwater. Sinkholes often allow this contact to occur quite rapidly and do little to filter any contaminants the surface water may contain. A sinkhole is a depression in the land surface resulting from the dissolution of the underlying soluble bedrock, and the subsequent collapse of overlying soil and rock. Essentially, dissolved bedrock creates a cave which eventually collapses, with soil moving into the bedrock and a large sinkhole depression sometimes forming on the surface. Sinkholes represent conduits where potentially unsafe surface waters have a higher potential to be quickly transmitted to the groundwater system. Sinkholes are circular or elliptical closed depressions. A property owner may view sinkholes as naturally forming holes that occasionally open up. Some people see sinkholes as sites for dumping trash without thinking of the potential impact on groundwater sources. In urban areas, the sudden appearance of a sinkhole is a hazard that can disrupt utility services, hamper transportation, and cause severe damage to nearby structures. Sinkholes are generally depressions on the surface of the land where water can collect and seep into the groundwater. Sinkholes are typical features of karst regions (Karst topography is the name given to an area underlain by rocks such as limestone and is characterized by caves, sinkholes, and depressions), and provide a direct pathway for surface water to move into the subsurface. The run-off that enters through sinkholes is not filtered as it joins the groundwater system. Sinkholes occur singly, or in groups in close proximity to one another. Sinkholes range from less than a metre to more than thirty metres in depth. Not all topographical depressions are sinkholes. Sinkholes are circular or elliptical closed depressions in the surface, usually formed by the dissolution of underlying soluble bedrock, allowing surface water to enter the groundwater. Sinkholes can allow this contact to occur rapidly and do little to filter contaminants in the surface water. A sinkhole is a depression in the surface of the ground, with or without collapse of the surrounding soil or rock, which provides a means through which surface water can enter the ground and therefore come in contact with groundwater. Sinkholes often allow this contact to occur quite rapidly and do little to filter any contaminants the surface water may contain. A sinkhole is a depression in the surface of the ground, with or without collapse of the surrounding soil or rock, which provides a means through which surface water can enter the ground and therefore come in contact with groundwater.
Site level is the most refined scale at which technical assessment of hydrological and hydrogeological conditions can be conducted. These assessments may contribute to water budgets, vulnerability assessments, and issues evaluation.
Slope is the ground that forms a natural or artificial incline.
Source protection – Go to ‘drinking water source protection.’
Slope is ground that forms a natural or artificial incline.
Source Protection Authority
Generally, the Source Protection Authority (SPA) follows the same structure as the current Conservation Authority Board of Directors, which is made up of members appointed by municipal councils. The geographic area of each authority will cover the watershed. There are 11 source protection planning regions in Ontario and eight stand-alone Source Protection Areas. In the case of Source Protection Regions, one Source Protection Authority is designated the lead and co-ordinates the efforts of the authorities across each region. This lead authority will establish the Source Protection Committee for the region, and provides support to the committee during the development of the Terms of Reference (ToR), Assessment Report and the Source Protection Plans (SPP). The Ausable Bayfield and Maitland Valley conservation authorities work in partnership through a Joint Management Committee model.
Source Protection Committee
Local Source Protection Committees (SPCs) prepared Terms of Reference (ToR); Assessment Reports; and Source Protection Plans (SPPs). The committee has worked since 2007 to identify, assess and address risks to drinking water within municipal wellhead and intake protection zones. The committee has broad sectoral representation from throughout the source protection planning region, including 1/3 Municipalities, 1/3 Economic (Agriculture, Industry/Manufacturing, Commerce/Small Business/Tourism) and 1/3 Other Representation (Environmental, Health, Community, Property/Landowner/Cottage/Beachfront). First Nations, Health, Ministry, and Source Protection Authority have also attended meetings in non-voting liaison capacities.
Source Protection Plans
Once the risks to drinking water sources were identified, the Source Protection Committee (SPC) worked with groups in the community to come up with source protection plans (SPP) for each source protection area to address these risks. Broad consultation involved municipalities, property owners, agricultural producers, industry, businesses, community groups, public health officials, First Nations, and the public in coming up with workable, effective solutions.
Source Protection Plans (SPPs)
Source protection plans (SPPs) have been created locally by local stakeholders on Source Protection Committees (SPCs); this process was facilitated by conservation authorities, in their roles as source protection authorities, making sure that Source Protection Committees (SPCs) had the technical knowledge to ensure that plans are science-based. The plans are approved by the Province of Ontario.
Source Protection Planning (SP)
Source protection planning is the creation of local, watershed-based plans for the protection of the quality and quantity of drinking water sources, now and in the future.
Source tracking is a method of identifying sources of contamination which impact water – the contaminants which might be tracked could be bacteria or fecal matter, for instance.
Source Water Protection
Source water protection is any action taken to prevent the pollution of drinking water sources, including groundwater, lakes, rivers, and streams. Source Water Protection is often used to refer to broad, voluntary, watershed-wide efforts to protect surface water sources such as lakes, rivers and streams, and groundwater sources from contamination or overuse. It is the first step in the multi-barrier approach to protecting drinking water and it can include voluntary stewardship efforts by individuals, landowners and businesses in a watershed. Other barriers include water testing and monitoring, reliable water treatment and distribution systems and training of water managers and staff. By comparison, when we talk about drinking water source protection as outlined in the Ontario Clean Water Act, 2006, that source protection is a very focused planning effort appropriately targeted at protection of water sources in the most vulnerable areas near municipal drinking water sources. ‘Source Water Protection’ and ‘Source Protection’ are terms that are often used interchangeably but in terms of Source Protection Planning we tend to refer to ‘Source Protection’ as the targeted efforts to protect municipal drinking water in the most vulnerable areas while ‘Source Water Protection’ refers to much broader umbrella efforts to protect all water sources and that is beyond the focus of policies, for significant threats to drinking water (SDWTs), that require action from certain people doing certain activities in certain circumstances in certain zones (such as wellhead protection areas).
Spawn is the mass of eggs deposited by fish, amphibians, mollusks, crustaceans and like animals. Spawn can be to produce and deposit eggs or sperm directly into the water, as fish do; to produce in large number. To spawn is to produce and deposit eggs in the reproductive process (particularly in aquatic animals).
Species at risk (SAR)
Species that are at risk of extinction, extirpation or endangerment globally or within a jurisdiction or region.
A spillway is the valley that results when glacial meltwater cuts into the landscape. Spillways are often composed of sand and gravel.
A measure of how spread out the values in a data set are. If the data points are all close to the mean, then the standard deviation is close to zero. If many data points are far from the mean, then the standard deviation is far from zero.
Watershed stewardship is the responsible care of our natural resources and wildlife on a watershed basis. It is essential to balance human and economic needs against the needs of our natural environment. We all need a vibrant environment in order to ensure that we have plenty of clean water and a healthy ecosystem. As caretakers of our environment, we need to continue to develop and implement stewardship practices that protect and restore natural resources. More than $1 million was spent at homes, farms, businesses, and other properties in the Maitland Valley and Ausable Bayfield source protection areas, between 2007 and 2013, to support stewardship projects near municipal wells. This funding was from the Province of Ontario through the Ontario Drinking Water Stewardship Program (ODWSP).
Stratigraphy is the geology that deals with the origin, composition, distribution and succession of layers of the Earth.
A stream is a body of water flowing on the surface of the Earth.
The discharge that occurs in a natural channel. Although the term ‘discharge’ can be applied to the flow of a canal, the word ‘streamflow’ uniquely describes the discharge in a surface stream course. The term ‘streamflow’ is more general than the term ‘runoff’, and may be applied to discharge whether or not it is affected by diversion or regulation.
Study Area – Go to ‘Broader landscape’
A substrate is the base on which an organism lives. A stream substrate is the material that is at the bottom of the stream.
A subwatershed is an area that is drained by an individual tributary into the main watercourse of a watershed.
Surface to Aquifer Advection Time (SAAT)
Surface to Aquifer Advection Time (SAAT) is the average time required by a water “particle” to travel from a point at the surface to the aquifer of concern. The SAAT is approximated by using the vertical component of the advective velocity integrated over the vertical distance and the average porosity.
Surface to Well Advection Time (SWAT)
Surface to Well Advection Time (SWAT) is the average time required by a water “particle” to travel from a point at the ground surface to the well, including both vertical and horizontal movement.
Surface water is the water that is present on the surface of the Earth‚ and may occur as rivers, lakes, wetlands, ponds, etc. It is water on the earth’s surface exposed to the atmosphere (e.g., rivers, lakes, streams, ponds, reservoirs, etc.).
Surface water intake
Drinking at least eight glasses of water a day is a fair definition of water intake, but not for students of drinking water source protection. Our definition is: A surface water intake is an important feature of the surface-water collection works employed to withdraw water from a body of water. The raw water collection facilities generally consist of an intake structure located in the water, an intake conduit, and a pumping station to convey the water to a treatment facility. The intake is designed to prevent the access of debris, fish and other objects.
Surface Water Intake Protection Zone (IPZ)
Surface water intake protection zone (IPZ) is the contiguous area of land and water immediately surrounding a surface water intake, which includes: the distance from the intake; a minimum travel time of the water associated with the intake of a municipal residential system or other designated system, based on the minimum response time for the water treatment plant operator to respond to adverse conditions or an emergency; the remaining watershed area upstream of the minimum travel time area (also referred to as the Total Water Contributing Area) – applicable to inland water courses and inland lakes only.
Read also ‘intake protection zone’ or ‘IPZ.’
Surface Water Quality
Water quality relates to the chemical, physical, and biological content of water. The quality of surface water sources can be affected by nature patterns, geographic features, wildlife, and land uses.
Surface Water Vulnerability Analysis
Surface Water Vulnerability Analysis has a dual purpose:
- To map or delineate intake protection zones (IPZs), and;
- to assign Vulnerability Scores to the zones.
The mapping and scores are used in Water Quality Risk Assessment.
Surficial Geology deals with the study and description of the forms on the outer layer of the Earth.
Swamps are wooded wetlands with 25 per cent cover or more of trees or tall shrubs. Swamps are standing, to gently flowing, waters that occur seasonally or persist for long periods on the surface. Many swamps are characteristically flooded in spring, with dry relict pools apparent later in the season.
Targets, in the context of draft technical guidance documents, are detailed goals that are often expressed as numeric goals (e.g., to reduce contaminant X in this aquifer by X per cent by 2112).
Terms of Reference (ToR)
The Terms of Reference (ToR) were defined by the Source Protection Committee (SPC), following guidance by the Ontario Ministry of the Environment, Conservation and Parks (MECP), and were accepted by the lead Source Protection Authority (SPA). The Terms of Reference outline all the steps to be taken to develop and implement the plans to protect drinking water sources.
Terrestrial is living on or growing on land.
Thermal regime is the characteristic behaviour and pattern of temperature.
Till is tough, unstratified clay loaded with stones originating from finely ground rock particles that were deposited by glacial activity.
Time of Travel (TOT)
Time of Travel (TOT) is an estimate of the time required for a particle of water to move in the saturated zone from a specific point in an aquifer into the well intake.
Tolerance of a Water Supply System
Tolerance of a Water Supply System is a measure of the ability to sustain required pumping levels even during exposure events.
Topography is a detailed description or representation of the features, both natural and artificial, or an area. Also the physical and natural features of an area, and their structural relationships.
Total phosphorus refers to the total amount of phosphorus, in a sample.
Phosphorus is an element that enhances plant growth and contributes to excess algae, low oxygen in streams and lakes. Total phosphorus is a nutrient that enhances plant growth and contributes to excess algae and low oxygen in streams.
Read also ‘Phosphorus.’
There are many unit treatment processes used to remove or inactivate contaminants.
A tributary is a stream or river that flows into another body of water. It is a stream that contributes its water to another stream or body of water. A tributary is a segment of a watercourse that joins with the main branch.
Turbidity is the cloudy appearance of water caused by the presence of tiny particles. High levels of turbidity may interfere with proper water treatment and monitoring.
Uncertainty analysis investigates the effects of lack of knowledge and other potential sources of error in the model.
An uncertainty score addresses known gaps in data/information about, or deficiencies in methods of assessment for, threats and/or vulnerability. It reflects the degree of confidence in the semi-quantitative data used to calculate risk.
An unconfined aquifer is an aquifer for which the upper boundary is the water table. An unconfined aquifer, or water table aquifer, is the saturated formation in which the upper surface fluctuates with the addition or removal of water. The upper surface of an unconfined aquifer is the water table that we talked about previously. Water, contained in an unconfined aquifer is free to move laterally in response to differences in the water table elevations. Unconfined aquifers are also often shallow. Wells constructed into them have a greater potential for contamination than wells constructed into the deeper or confined aquifers.
The unsaturated zone is directly below the surface and contains some water. In the unsaturated zone, water and air fill the voids between soil or rock particles. In summary, the area between the land surface and the water table in which the pore spaces are only partially filled with water is the unsaturated zone. It is also called the ‘zone of aeration’ or ‘vadose zone.’ Soil pore space also typically contains air or other gases. The subsurface zone above the water table in which pore spaces are only partially filled with water. Water in this zone is called soil moisture.
The expansion of the proportion of total population or area in urban areas.
Vadose Zone – Read ‘Unsaturated Zone’
A valley is a long, narrow depression on a the Earth’s surface, usually with a fairly regular downward slope. A river or stream usually flows through it.
Valuation of the Supply
Valuation of the Supply is an evaluation of the importance of a particular municipal well or intake to the whole municipal drinking water supply. For example, where there are multiple supplies, value may be smaller, versus asingle supply where value may be greater.
The word vulnerability describes how easily a well or intake can become polluted with a dangerous material. Researchers have studied each municipal well and intake to determine how vulnerable they are.
Vulnerability Analysis – Read ‘Surface Water Vulnerability Analysis’
A vulnerability score is assigned to drinking water intake zones and refers to the comparative likelihood of a contaminant of concern reaching an intake.
Vulnerable areas under the Ontario Clean Water Act, 2006 are:
(a) A significant groundwater recharge area;
(b) A highly vulnerable aquifer;
(c) A surface water intake protection zone, or;
(d) A wellhead protection area.
Water-borne disease is an infectious illness associated with the ingestion of water from a water system that is deficient in treatment.
The movement of water within the hydrologic cycle can be described through a water budget or water balance. A water budget is the summation of inputs, outputs, and net changes to a particular water resource system over a fixed period. It is a tool that when used properly allows the user to determine the source and quantity of water flowing through a system. From a groundwater perspective the key components of a water budget are:
- Contribution to baseflow
- Deeper groundwater flow outside the study area
- Groundwater taking.
Water contaminants are any physical, chemical, biological, or radiological substance or matter that has an adverse effect on water.
Read also, ‘contaminants’
Water control structure
A water control structure is an engineered structure designed to hold back water and mimic a natural water regime that promotes wetland restoration, without affecting adjacent agricultural practices.
A channel in which a flow of water occurs.
The process of water movement from the ground to the sky and back. Water Cycle is the continuous movement of water from the oceans to the atmosphere (by evaporation), from the atmosphere to the land by condensation and precipitation, and from the land back to the lake (via stream flow).
Read also, ‘Hydrologic cycle’
Water quality indicator
A water quality indicator is an entity that provides information on the condition and quality of water through its life cycle patterns. Water quality can also be determined through non-living sources, like chemical sampling.
An area of land that drains into a river or lake. A watershed is an area that is drained by a river or stream and its tributaries to a body of water such as a lake or ocean. It is often referred to as a drainage area, basin or catchment area for a watercourse.
A watershed is the area of land that contributes water to a lake, river, or stream. A watershed is an area of land that is drained by a river or a stream, and its tributaries, to a body of water such as a lake or ocean. It is often referred to as a drainage area, basin or catchment area for a watercourse. The area of land that drains water in a given region is known as a watershed. A watershed can be thought of as bathroom sink. Any rain or snow that falls within the sink-bowl runs down the sides of the sink and into the drain, which can also be thought of as a water supply intake such as a well or surface water intake pipe. Watersheds are based on natural boundaries, created by natural features of the land. They do not follow municipal, provincial or even national borders.
Watershed is an area that is drained by a river and its tributaries.
Watershed means the area of land that contributes water to a lake, etc.
A watershed assessment is a process for evaluating how well a watershed is working. A watershed-based assessment provides a comprehensive evaluation of conditions and trends in the entire watershed and can be used to:
- Characterize watershed conditions and trends in water quality
- Determine causes of existing and future water quality problems
- Aid in the development, prioritization, and implementation of an overall watershed management program to prevent or correct the identified water quality problems
- Establish a baseline and assess progress of overall watershed management activities or effectiveness of pollution prevention and control practices
- Provide data to verify watershed conditions
- Educate and inform the public.
Watershed management is the first and most fundamental step in a multiple-barrier approach to protecting drinking water. Healthy, functioning watersheds naturally filter pollutants and moderate water quantity by slowing surface runoff and increasing the infiltration of water into the soil. The result is less flooding and soil erosion, cleaner water downstream, and greater groundwater reserves. Watershed management is a multifaceted discipline that involves conservation and restoration, land use monitoring, proactive land use regulations, on-site field inspections, education, planning, and emergency spill response.
Caring for our water, land, air and biodiversity on a watershed basis recognizing that everything is connected in a watershed and is affected by natural and human activities.
More than $1 million was spent on projects to protect water – at homes, farms, businesses, and other properties in the Ausable Bayfield Maitland Valley Source Protection Region – through the Ontario Drinking Water Stewardship Program (ODWSP) of the Ontario Clean Water Act, 2006.
The water table is the surface below which the soil is saturated with water.
The point where the unsaturated zone meets the zone of saturation is known as the water table. Water table levels fluctuate naturally throughout the year based on seasonal variations and are the reason why some wells go dry in the summer. In addition, the depth to the water table varies. For example, in (select an area in the watershed or community) the water table is “x” metres below the surface. The water table is the surface below which the soil is saturated with water.
Any body of water flowing into another body of water.
A water well is a hole in the Earth’s surface used to obtain water from an aquifer. For a bored well, an earth auger is used to bore a hole to carry earth to the surface. The casing is usually steel, concrete or plastic pipe. Modern dug wells are dug by power equipment and typically are lined with concrete tile.
Dug and bored wells have a large diameter and expose a large area to the aquifer. These wells are able to obtain water from less-permeable materials such as very fine sand, silt, or clay. Drilled wells are constructed by either percussion or rotary-drilling machines. Drilled wells that penetrate unconsolidated material require installation of casing and a screen to prevent inflow of sediment and collapse. A flowing, or Artesian, well is completed in a confined aquifer that has a water level higher than the ground surface at the location of the well. This causes water to flow out of the well.
Source: Ontario Ministry of Agriculture, Food and Rural Affairs
Also read ‘Well’ entry.
Weathering is the disintegration of the Earth’s crust by exposure to the atmosphere, most importantly, rain.
A well is a hole in the Earth surface used to obtain water from an aquifer. For a bored well, an earth auger is used to bore a hole carry earth to the surface.
The casing is usually steel, concrete or plastic pipe. Modern dug wells are dug by power equipment and typically are lined with concrete tile. Dug and bored wells have a large diameter and expose a large area to the aquifer. These wells are able to obtain water from less-permeable materials such as very fine sand, silt, or clay. Drilled wells are constructed by either percussion or rotary-drilling machines. Drilled wells that penetrate unconsolidated material require installation of casing and a screen to prevent inflow of sediment and collapse. A flowing, or Artesian, well is completed in a confined aquifer that has a water level higher than the ground surface at the location of the well.
This causes water to flow out of the well.
Read also ‘Water Well.’
Well Capture Zone
A well capture zone is the area in the aquifer that will contribute water to a well in a certain time period. Often measured in days and years, the area at the ground surface is also included if the time period chosen is longer then the travel time for water in the aquifer and the groundwater recharge area is incorporated.
Wellhead protection area
A wellhead protection area (WHPA) is an area that is related to a wellhead and within which it is desirable to regulate or monitor drinking water threats. A wellhead protection area (WHPA) is one of four main types of vulnerable areas identified in the Ontario Clean Water Act, 2006. A wellhead protection area means an area that is related to a wellhead and within which it is desirable to regulate or monitor drinking water threats. The surface and underground area surrounding a water well, or well field, that supplies a municipal residential system or other designated system through which contaminants are reasonably likely to move so as to eventually reach the water well or wells. Wellhead protection area means the surface and subsurface area surrounding a well that supplies a drinking water system, through which contaminants are reasonably likely to move so as to eventually reach the well. Wells draw water from underground areas called aquifers where water fills cracks in bedrock or spaces between grains of sand, gravel or dirt. Aquifers are replenished when water from rain and melting snow soaks into the ground. Sometimes, the water also carries pollutants. It can take years, or even decades, for water to reach a well. The speed depends on the characteristics of the soil and bedrock in the area. A wellhead protection area (WHPA) is the surface and subsurface area surrounding a water well or well field that supplies a municipal residential system or other designated system through which contaminants are reasonably likely to move so as to eventually reach the water well or wells. A municipal wellhead protection area (WHPA) is the area within which the municipal well’s groundwater sources are vulnerable to surface threats. The area includes the surface and the sub-surface.
A wetland is a type of habitat that has water in it for all or part of the year.
A wetland is land seasonally or permanently flooded by shallow water as well as land where the water table is close to the surface; presence of abundant water causes poorly drained soils, favouring dominance of either water-loving or water-tolerant plants. Wetlands are often areas with high biodiversity and may help to filter pollutants from water and provide species habitat. Wetlands are lands such as a swamp, marsh, bog or fen (not including land that is being used for agricultural purposes and no longer exhibits wetland characteristics) that,
(a) is seasonally or permanently covered by shallow water or has the water table close to or at the surface,
(b) has hydric soils and vegetation dominated by hydrophytic or water-tolerant plants, and
(c) has been further identified, by the Ontario Ministry of Natural Resources and Forestry or by any other person, according to evaluation procedures established by the Ontario Ministry of Natural Resources and Forestry, as amended from time to time.
The percentage of wetland cover is not part of the overall forest conditions grade. Wetland cover is the percentage of the watershed that is covered by wetlands which include swamps (treed and thicket), bogs, fens and marshes.
Wetland – Locally Significant Wetland (LSW)
A wetland which provides functions or exhibits characteristics that are pertinent to planning decisions, but has not been classified by the Ontario Ministry of Natural Resources and Forestry.
Wetland – Provincially Significant Wetland (PSW)
A wetland that has been identified and classified as provincially significant by the Ontario Ministry of Natural Resources and Forestry.
Wetland values are processes or attributes which are beneficial to society.
These tree plantings have reduced wind erosion and increased soil conservation.
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