SURFACE DRAINAGE SYSTEM

Sedimentation and turbidity of adjacent water bodies

• erosion control measures

• buffers and setbacks

• sediment traps

• staging work

• bio-engineering techniques

After site grading and during construction on slopes and channels

Collect sediment before entering drainage channel

During biologically critical periods

Ponding effects on adjacent properties due to natural drainage disruption

• appropriate use of culverts, porous backfill and tile drains

• apply natural channel design principles

In new construction projects and expansion

Streambank erosion from diversion, construction or channelization of watercourse

• erosion control measures

• bio-engineering techniques

River crossings, drainage outlets

Contamination of surface waters through runoff, spills, leaks and disinfection activities

• provision for spill control

• fast accurate reporting of spill

• spill containment

• stockpile materials or devices for spill control

• avoid adverse soil conditions

• monitor facility for leaks

• implement disinfection tech­niques in concert with fisheries requirements

• pollution prevention and source control by best management land use practices and best management stormwater practices.

• buffers and setbacks

• install check dams on drainage swales

As a general practice and particularly in vicinity of water bodies, wetlands

Blasting exposes rocks containing soluble minerals that could potentially contaminate surface water supply, i.e. sulfate, lead, arsenic

• subsurface investigation, i.e. geochemical analysis of bedrock

•   avoid blasting in areas containing toxic materials

Areas of shallow soil over relevant bedrock type (normally occurring in Canadian Shield)

Changes in volume of surface runoff

• use design measures to minimize increase in surface runoff

New impervious surfaces

Changes in flood storage capacity by placing fill and structures in floodplain

• avoid placing fill and structures in floodplain or compensate

•   flood and fill permits from Local Conservation Authority

Construction within river valleys. Disposal of excess fill.

GROUNDWATER

Through blasting, expose rocks containing soluble minerals that could potentially contaminate groundwater, e.g. sulfate, lead, arsenic

• subsurface investigation, i.e. geochemical analysis of bedrock

•   avoid blasting in areas containing toxic minerals

Areas of shallow soil over bedrock. Rock cuts and excavations.

Interference of shallow aquifers and springs

• hydrogeologic investigation to identify such areas in advance

•   develop alternatives to avoid impacts

Excavations

Reduce groundwater quantity through construction dewatering

• locate construction activities

• away from groundwater users and water bearing formations (soils) where possible

•   proper dewatering techniques

•   seasonal constraints on construction

Depletion or lowering of shallow aquifers and springs by groundwater utilization

Spills or leaks resulting in contamination of groundwater supply

• construction refuelling precautions

•   land filling precautions

• operation and storage precautions

Near watercourses and on site generally. Areas of high infiltration capability.

Drainage of wetland areas resulting in a reduced groundwater contribution to surface waterbodies

• avoid wetland areas

• utilize appropriate backfill material, i.e. high permeable backfill is unsuitable

Trenching, excavation, placing fill, dewatering

Reduced surface water recharge to

groundwater particularly in soils

• restrict extent of impervious surfaces in zones of high

Subsurface barriers, e.g., foundations, areas of impervious

Interference with groundwater movement

• maintenance of the existing groundwater regime through engineering design

Excavations, drainage, construction, dewatering, e.g. in roadbeds, foundations and trenches

Contaminations of adjacent wells through runoff from construction

• erosion and sediment control

• locate projects appropriately

• setbacks

Construction adjacent to well sites and exposed acquifers

FISH, AQUATIC WILDLIFE AND VEGETATION

Introduction of warmer water from ponds into colder surface watercourse

• appropriate selection of ponding site

• pond design

•   infiltrate into groundwater system

•   planting to provide shade

Dewatering of trench and excavations. Sediment traps. Extend detention ponds.

Modification or removal of aquatic habitat; displacement of plants and animals

• stage work to non-critical times

•   restore stream substrate

•   choose suitable site for stream diversions

•   seasonal constraints

During construction, e.g. river crossings, dewatering of excavations

Reduced water quality of nearby surface water having value as wildlife habitat

• provisions for spill control

•   fast and accurate reporting of spill

•   spill containment

•   stockpile materials or devices for spill control

•   avoid adverse soil conditions

•   minimize tree removal

•   buffers and setbacks

Storm sewers, ditches, diversions and by-passing

Timing effects of construction on spawning, nesting and breeding periods

• staging of work to avoid spawning and breeding periods

•   seasonal constraints for cold and warmwater systems

For stream crossings and diversions

Lowering of water table resulting in reduced contribution to streams and stress of riparian vegetation

• design to maintain existing groundwater flows

• restrict extent of impervious surfaces in zones of high infiltration

Dewatering of trenches, excavations and aquifers. Areas of newly created impervious surfaces.

Increased nutrient loading of existing habitats

• buffers and setbacks

•   provisions for spill control

•   land filling precautions

Near watercourses and on site generally.

Drainage of wetland areas causing mortality or stress to animals and possible changes in species composition

• maintain existing groundwater regime

•   avoid wetland areas

•   utilize appropriate backfill material,

Trenching or excavating

Siltation to surface watercourses resulting in “smothered” plants and animals due to the deposition of silt and increased turbidity of surface watercourses

• utilize suitable backfill material

•   trench drainage should be discharged to settling areas before being permitted to enter surface waterbodies

•   erosion control measures

•   staging of work

Road bed and ditch construction. Storm sewer outfalls. Erodible soils, stockpiles.

Stress on biological communities

• consider the carrying capacity of the local natural environment

• avoid sensitive periods such a breeding seasons

Municipal infrastructure is necessary to service projected municipal / population growth. This increases stress on recreational and natural resources.

Tree removal will affect the amount of sunlight reaching waters and affect plan productivity and increase watercourse temperatures

• avoid tree removal near surface waterbodies

• restoration planting

Stream crossings

TERRESTRIAL VEGETATION AND WILDLIFE

Introduction of exotic plant species through erosion control restoration

• restoration planting

• use annuals which later die out

•   use indigenous (native) species only

On slopes and other areas to control

erosion. In any distribution area requiring restoration work.

Changes in vegetative composition as a result of loss of topsoil and subsoil or mixing

• restore site by replacing soils in preconstruction horizons

Trenching or excavating

Removal or disturbance of significant trees and/or ground flora

• review status of species

•   avoid these areas

•   employ tree protection measures

During site grading and construction phase of any project

New or increased exposure of forest edge with resultant effects of windthrow, leading to loss of habitat for wildlife

• avoid woodlots and similar areas

•   pre-stress woodlots

•   restore edges

During site grading and construction phase of any project

Mortality / stress due to changes in soil moisture conditions, resulting in loss of wildlife habitat

• minimum fragmentation of forest habitat

•   avoid poorly drained areas

•   use of appropriate roadbed and backfill materials

•   revegetation using indigenous species able to survive new conditions

During construction of roadbed and storm sewers

HERITAGE RESOURCES

Deterioration of sites, structures or landscapes having archaeological, historical or architectural values, as a result of environmental changes

• avoid where possible

• employ necessary steps to decrease harmful environmental impacts such as vibration, alterations of water table, etc.

Where appropriate with respect to archaeological, historical or architectural resources

Unwanted increase in public access and potential vandalism

• fence off area of concern

•   prevent public access

Where appropriate with respect to archaeological heritage resource

Threatened viability of, or opportunity for, retention of sites having heritage value

• avoid these areas

•   record or salvage information on features to be lost

Where appropriate with respect to significance of the heritage recourse

Unavoidable alteration to or destruction of heritage structures or archaeological sites

• record or salvage information on features to be lost

Where appropriate with respect to significance of the heritage resource

Disruption of quiet enjoyment

• staging of construction to cause least disruption

•   employ noise and dust control measures

As general practice.

AGRICULTURAL

Soil contamination by chemicals

• minimize use of de-icing materials

•   establish and enforce chemical handling standards

•   provide for emergency clean-up and soils replacement

As general practice.

Loss of productive farmland

• avoid prime agricultural areas

•   direct where possible to non-agricultural designations

•   locate and design facilities so as to minimize land requirements and construction disturbance

•   rehabilitate disturbed areas

In agricultural and rural areas.

Disruption of field access

• minimize severance of farm properties

•   provide alternative access points at critical times

In agricultural and rural areas.

Disturbance of livestock by noise and dust during construction

• employ noise and dust control measures

In agricultural and rural areas.

Disruption of tile and surface drainage systems

• stage construction work

•   restore tile and surface drainage system

In agricultural and rural areas.

Loss of biosolids use as fertilizer

• improve biosolids quality

In agricultural and rural areas.

Decrease in groundwater

• design to minimize dewatering effects

•   provide recharge

In agricultural and rural areas.

Facilities inconsistent with or disrupt character of prime agricultural area

• avoid prime agricultural areas

•   avoid major capital infrastructure, i.e. barns, dryers, etc.

•   comply with MDS

In agricultural and rural areas.

Climate change on which crops including specialty crops depend

• avoid and design facilities so as to not adversely disrupt the micro-climate (cold air drainage) on which crops depend

In agricultural and rural areas Specialty crop designation in Municipal Official Plans.

Effects of physical changes in operation due to property loss

• compensation

In agricultural and rural areas.

Loss of infrastructure

• avoid major capital investments in infrastructure

•   avoid major livestock facilities

In agricultural and rural areas.

RESIDENTIAL, INSTITUTIONAL, COMMERCIAL AND INDUSTRIAL

Disruption of pedestrian movements between adjacent uses

• maintain continuity of pedestrian walkway system as much as possible

•   provide walkway strips to adjacent residential areas

As general practice. Where suitable.

Disruption of tourism facilities

• stage construction

•   employ noise and dust control measures

•   provide crosswalks and sidewalks at access points

As general practice. Where suitable.

Facilities inconsistent with or which disrupt character of area

• preserve existing amenities as much as possible

•   design and site structures to blend with adjacent building forms and materials

•   site grading; utilize berms or other screening devices

As general practice. Where suitable.

Temporary disruption during construction and/or inconvenience to users of adjacent properties and building

• notify public agencies and adjacent owners of construction scheduling

•   prepare emergency program to ensure quick resolution of servicing problems

•   consult with public agency and/or adjacent landowners regarding temporary access routes

•   schedule construction so as to minimize period of disruption in proximity of adjacent uses and structures

•   ensure access for emergency response vehicles / personnel

•   apply noise and vibration control measures (use quieter equipment, maintain equipment properly)

Where substantial inconvenience or disruption to adjacent uses would be experienced and where measures would substantially reduce effects.

As general practice.

Removal of residences and other buildings

• co-ordinate removal program to minimize inconvenience

•   carry out heritage assessment as appropriate

As general practice.

OUTDOOR RECREATION

Temporary disruption of open space

activities during construction

• employ noise and dust control

     measures

•   staging of construction to cause least disruption

In areas within or adjacent to public

open space.

Effects of physical changes in layout of recreational uses due to property loss

• compensate by providing facilities elsewhere

In areas within or adjacent to public open space.

SOILS GEOLOGY

Erosion by wind, water and ice

• restoration planting

•   stage work

•   avoid highly erodible soils

•   stabilize slopes

•   compaction

•   chemical stabilizers

•   gravel blankets

•   seeding

•   sodding

•   toe drainage

Erodible soils in excavations, cut and fill areas.

Stockpiles, cut slopes.

Slumping of encroached slopes

• avoid potentially unstable slopes

•   mechanical stabilization methods

•   revegetation (only effective once the root infrastructure has developed)

•   restrict dewatering near slopes

•   engineering design to control potential slumping

Steep slopes.

Cut slopes.

Removal of the toe of a slope during construction.

Dewatering.

Rockfall hazard

• buffer zone

•   initiate rockfall at potential failures

Blasting.

Steep weathered slopes.

Loss of aggregate and mineral resources

• avoid sites of aggregate and mineral reserves

•   extract aggregate and minerals prior to construction

Zones of economic aggregate and mineral occurrence.

Contamination of soils by petro­chemicals, etc.

• remedial measures to avoid spills and leaks

•   contingency plan for clean-up

During construction.

Mixing of topsoil with subsoil

• stripping and stockpiling of topsoil separate from subsoil

Generally in areas of undisturbed soils.

TOPOGRAPHY / LANDFORMS

“Scarring” of significant landscape features

• avoid significant features

Designation of significant feature, i.e. landmark.

CLIMATIC FEATURES

Drought, increased flooding, changes in water levels, increases in surface water runoff due to extreme weather events and climate change

Consider the following:

• Design associated drainage and storm ponds to manage extreme weather events 
• Use of pervious pavement or reduce impervious pavement and other low impact development methodologies to manage or reduce storm water runoff and on-site flow control
• Increase elevations of structures over waterways
• Increased capacity of sewer and treatment systems to accommodate additional flows
• Monitoring and adaptive management to manage flow rates
• Artificial destratification to manage evaporation
• Stormwater runoff to roadside ditches and/or grassed swales
• Back-up features and infrastructure for upset conditions and emergency response procedures (e.g. standby power for water and waste water facilities)
• Water conservation and efficiency through leakage/loss detection and prevention in distribution system

Construction in close proximity to buildings or activity areas

Cracked concrete during freeze thaw cycles; deterioration of roadway/structures sooner than anticipated

Consider using materials resilient to freeze-thaw effect and salting, and survive higher temperatures

Design and construction

PUBLIC HEALTH

Exhaust emissions from construction equipment and vehicles

• minimize operation on site, control location on site

Where adjacent uses or natural vegetation could be adversely affected

Effects on groundwater elevation of existing subsurface sewage disposal systems (e.g. septic systems)

• monitor groundwater levels and, if necessary, take appropriate action

Where appropriate

Groundwater contamination

• construction refuelling precautions

•   fill design and operation precautions

•   precautions in operation and storage facilities

•   containment of leachate maintenance facilities

On site generally.

Effects of emergency by-passing of sewage

• contact potentially affected government agencies and public downstream within 24 hours of by-pass event

In all cases.

OPERTIONAL AND CONSTRUCTION NOISE

Proximity to noise sensitive land uses (e.g. hospitals); insufficient setbacks;’ road grades (steep hills); high traffic volumes; poor road surface; stopping / starting of truck traffic; operation of construction equipment

• relocate major roads away from sensitive land uses, divert traffic

•   reduce grades of hills

•   use appropriate asphalt surface to reduce tire noise

•   institute truck prohibitions

•   construct noise barriers

•   modify speed limits

•   proper maintenance of equipment

As general practice. Construction in urban areas.