Transcript CONTROLLING WATER POLLUTION

Sewage and
Organic Wastes
TREN 3P14: Sustainable
Integrated Waste Management
David T. Brown
Water Pollutants
• toxics
• nutrients
• anthropogenic
origin (e.g. industrial
• suspended matter
• pathogens
operations)
• thermal pollution
• dissolved gases • natural origin (e.g.
effluent, municipal
sewage, tourism
silt, mineral nutrients,
wild animal wastes)
Significant concern in the tourism industry
• Water quality
• Water quantity
• Aesthetic
concerns
• Disease and
pathogens
• Local equity
issues
Controlling Water
Pollution
• Upstream:
•
before the problem occurs
Downstream:
after the problem occurs
Upstream Methods of
Controlling Water Pollution
• process modification in industry:
elimination of pollutants and toxics
• avoidance of direct discharge into:
– water bodies
– storm sewers
– sanitary sewers
• identification of storm drains (e.g.
Yellow Fish Road project)
Upstream Methods of
Controlling Water Pollution
• decoupling of storm and sanitary
sewers
• runoff control:
– increasing absorptive surfaces
– avoiding erosion
– maintaining streambank and shoreline
vegetation
• legislation and regulation: guidelines
and laws establishing limits on
discharge
S
E
W
A
G
E
Neolithic revolution
• small towns and settlements ->
human excreta control generally nonproblematic
S
E
W
A
G
E
“In days of old
When knights were bold
And toilets weren’t invented
They’d leave their loads
Upon the roads
And walk away contented.”
S
E
W
A
G
E
Post - Neolithic revolution:
Large towns and cities ->
human waste control became a problem
high-density living required
technologies for handling human
wastes in urban areas:
• chamber pots and open gutters
• pit privies / trench latrines/ outhouses
• septic systems and variants
• centralized sewage collection and
treatment systems
"Our excreta--not wastes,
but misplaced resources-end up destroying food
chains, food supply and
water quality in rivers and
oceans....How did it come
to pass that we devised
such an enormously
wasteful and expensive
system to solve a simple
problem?“
- Sim van der Ryn,
‘The Toilet Papers’ (1978)
Downstream Methods of
Managing Sewage: Small scale
• Temporary /
short term:
–
–
–
–
packing it out
single-use holes
pit privies
trench latrines
Meyer, Kathleen. 1989.
How to shit in the woods :
an environmentally sound approach
to a lost art. Ten Speed Press, Berkeley, Calif.
Downstream Methods of
Managing Sewage: Small scale
• Long-term
–
–
–
–
–
outhouses
settling ponds
septic tanks
septic fields
composting toilets
van der Ryn, Sim. 1978 (republished and revised 1999). The
Toilet Papers: Recycling Waste and Conserving Water. Chelsea
Green Publishing, Vermont. Online edition available at
www.brocku.ca/tren/courses/tren3p14/2006/ToiletPapers.pdf
Tourism operations:
Tourism operations:
Tourism operations:
Land-based wastewater treatment: Surface spray
Land-based wastewater treatment: Overland flow
Land-based wastewater treatment:
Subsurface infiltration
Downstream Methods of
Sewage Treatment: Large Scale
Downstream Methods of
Sewage Treatment
• domestic sewage treatment:
– preliminary: screening and removal of
large contaminants
– primary: straining and settling of solids
– secondary: removal of biodegradable
organic matter and nutrients
– tertiary: removal of residual dissolved
nutrients and pollutants
Downstream Methods of
Sewage Treatment
• effluent treatment processes:
– mechanical: filtering, gravity separation
– chemical: flocculation, coagulation
– biological: microbes or macrophytes
aerobic or anaerobic
– disinfection: chlorination, ozonation, etc.
(pathogen control)
Downstream Methods of
Sewage Treatment
• ‘physical plant’/ ‘engineered’ approach
(usually centralized, large scale)
• ‘constructed wetland’ approach (centralized or
decentralized, large or small scale)
Primary Sewage Treatment
GRIT
SETTLING CHLORINATION
BAR
TANK
TANK
SCREEN CHAMBER
outflow
Raw sewage
Sludge
SLUDGE
DIGESTER
SLUDGE
DRYING
BED
Secondary Sewage Treatment
GRIT
SETTLING AERATION SETTLING
BAR
TANK
TANK
TANK 2
SCREEN CHAMBER
Raw sewage
CHLORINATION
TANK
Methane
SLUDGE
DIGESTER
outflow
Air
pump
SLUDGE
DRYING
BED
Activated sludge
Constructed Wetland
Constructed Wetland
EXPERIMENTAL CELLS
S.W.A.M.P.
(SEWAGE WASTE AMENDMENT MARSH PROJECT)
Niagara on the Lake, Ontario
Constructed Wetland
EXPERIMENTAL CELLS
Constructed Wetland
macrophytes
Cattails and Water Hyacinth
Large scale
constructed wetland
Saha Pat Industrial Park, Laem Chabang, Thailand
Settling tank
Saha Pat Industrial Park, Laem Chabang, Thailand
Sludge dewatering
and drying
Saha Pat Industrial Park, Laem Chabang, Thailand
Aeration pond
Saha Pat Industrial Park, Laem Chabang, Thailand
Outflow into
constructed
wetland
Saha Pat Industrial Park, Laem Chabang, Thailand
Large scale
constructed wetland
Saha Pat Industrial Park, Laem Chabang, Thailand
Waterless toilet technologies
Clivus Multrum
composting toilet
• converts human
and organic
wastes into
odourless
compost
Waterless toilet technologies
•
•
•
•
•
Scalable
Waterless
Low energy
Suitable for remote areas
Now CSA approved
Water and Legislation
• multijurisdictional:
•
federal, provincial, and municipal areas of
responsibility
multifaceted:
laws and regulations deal with
– conservation and management of water
resources; protection of aquatic life
– pollution and liquid discharge
– drinking water standards
Federal Water Legislation
(in areas of federal jurisdiction)
Canadian Environmental Protection Act
(CEPA) : regulates the release of specified toxic
substances, the concentration of nutrients in
products (e.g. nitrates, phosphates); national
regulations for pulp and paper mill effluents
Fisheries Act: forbids the depositing of
deleterious substances in any waters frequented by
fish; regulates aquatic toxicity testing; regulates
pulp and paper mill effluents and requires
monitoring of effects on fish habitat
Provincial Water Legislation
Ontario Water Resources Act: Section 30(1)
prohibits the discharge of any material into any
water body, shoreline, or bank that may impair the
quality of the water
Environmental Protection Act (EPA) :
Subsection 14: prohibits discharge of any
contaminant into the natural environment that
causes or is likely to cause an adverse effect
Water Quality Guidelines, Policies,
and Objectives:
• cover water quality for many types of water
•
uses and aquatic environments (e.g. water
storage structures, sewage plant discharge,
drinking water quality objectives and treatment
requirements, etc.)
legally enforceable when incorporated into a
Certificate of Approval or a Control Order
Banned and Phased-Out Chemicals:
• primary and secondary lists of substances to
be banned, phased out, or reduced in use due
to their persistence in water or aquatic
systems
• Drinking Water: Municipalities are
responsible for conforming to provincial water
quality and treatment guidelines for drinking
water from surface and ground sources
MISA
(Municipal, Industrial
Strategy for Abatement)
• program aimed at the virtual elimination of
persistent toxic contaminants from all
discharges into Ontario waterways
• dealt with direct dischargers (into surface
waters, e.g. sewage treatment plants, certain
industries) and indirect dischargers (into
municipal sewer systems).
Objectives:
• identify and measure toxic substances
in discharges
• increase emphasis on control technlogy
• pollution prevention and reduction in
multi-media transfer of pollutants
• strengthen abatement and enforcement
mechanisms -> eventual virtual
elimination of persistent toxic
substances
• Municipal-Industrial Strategy for
Abatement Advisory Committee was
eliminated by Harris government, and
MISA program severely weakened.
• Avenues for both public input and multistakeholder input to government decisionmaking were removed.
Starting in 1995, the Harris Government
weakened or revoked nearly every
environmental protection law in Ontario
and numerous regulations under these
laws.
• Every aspect of environmental protection
was affected, including controls on air
pollution, water pollution, pesticides, waste
disposal and recycling, urban sprawl, energy
use and climate change, natural heritage and
biodiversity protection, mining, and forestry.
DETAILS:
• Canadian Environmental Law Association
(http://www.cela.ca/):
Environmental Deregulation in Ontario - 1996-2000
http://62.44.8.131/coreprograms/detail.shtml?x=1780
Municipal Water Legislation
Discharges to Sewers: Municipal sewer use
by-laws regulate substances which can be
discharged to sanitary, combined, or storm
sewers. Based on MOE Model Sewer Use Bylaw.
In absence of municipal by-laws, the Ontario Clean
Water Agency regulated these parameters.
Harris Government Bill 107 promoted
privatization of municipal water and sewer
infrastructure without voter assent.
Budgets for monitoring and regulation were
slashed.
Walkerton
• E. Coli contamination of municipal water supply
from cattle manure results in hundreds of
illnesses and seven deaths, including two-year
old child
• Tragedy deemed preventable
• Incompetent management by Koebel brothers
(managers of water supply), lack of adequate
water testing, excessive budget cutbacks and
deregulation all identified as factors in tragedy
Further Details:
• The Walkerton Tragedy:
http://www.canoe.ca/EcoliTragedy/
• Walkerton Flash presentation:
http://www.canoe.ca/EcoliTragedy/Walkerton.swf
• Walkerton Inquiry report:
http://www.attorneygeneral.jus.gov.on.ca/english/about/pubs/walkerton/part1/
2002: Tory government introduced
• Safe Drinking Water Act
• Sustainable Water and Sewage
Systems Act
to guard against another water tragedy
like Walkerton
http://www.ene.gov.on.ca/envision/water/sdwa/index.htm
• Act authorized the government to
implement key recommendations in
Walkerton inquiry report
• Acts criticized as inadequate, as source
contamination concerns not addressed
• Tories defeated in 2003
• Liberal government elected 2003
• Introduced Clean Water Act (Dec 2005)
Clean Water Act
(received Royal Assent on October 19, 2006)
• The Act ensures that 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, farmers,
industry, community groups and the
public all work together to meet
common goals.
•
http://www.e-laws.gov.on.ca/DBLaws/Source/Statutes/English/2006
Other related Ontario government initiatives:
• Watershed-based source
protection planning
• Revision of
Permits To Take Water
• Nutrient Management
• Groundwater Studies