The CAWT's Dr. Gordon Balch's presentation to the Ontario Association of Sewage Industry Services (OASIS) from October 2014. Treatment Options for Wastewaters Collected from On-Site Systems

1. Treatment Options for
Wastewaters Collected from On-
Site Systems
Gordon Balch
Centre for Alternative Wastewater Treatment, Fleming College,
Lindsay,

2. Disposal Challenges
2
• Regulatory oversight / requirements
increasing
– post Walkerton
– Ont. Environ Protection Act, Ont. Clean Water Act,
etc.
• Complexity of wastewater increasing
– Pharmaceuticals and personal care products
• Increasing number of wastewater sources
– Petroleum, agra-farms, aquaculture, etc.
• Treatment Costs Increasing

3.  only 2.5% of global water
is drinkable
 of this nearly ¾ is locked
away in ice and snow
 only a small fraction if
readily available for human
use
Global
Perspective
3

4. 1st everything
(1,385 km diameter)
2nd groundwater, fresh
surface water
(272.8 km diameter)
3rd fresh water in lakes
and rivers
(56.2 km diameter)Source: Scientific American
Global
Water
Supply

5.  Water use growing
twice as fast as
population growth
 world’s 6 billion people
are drawing from 54% of
all water resources
(rivers, lakes, aquifers)
Water Use Trends
5

6. North America
Wastewater Infrastructure Deficit
6
• Wastewater
infrastructure deficit
in 2 Provinces and 8
US states is $10
billion
• $90 billion needed in
next 10 y (2007) to
replace and upgrade
Canada wide
Great Lakes Commission – 2007 report

7. Aging municipal
infrastructure
7
When Bigger Isn’t Better: Decentralized Wastewater
Treatment Systems (Environ. Commission 2009)
• Small or rural communities in Ontario faced
with:
– Increasing population
– Climate change
– Stricter environmental regulations
• A call for decentralized systems

8. Waste Generation from DWWTs
8
• 1980 USA census – 3.8
trillion L per year to vadose
zone (US EPA 1987)
• 25-30% of households in
USA are served by septic
systems (Bremer & Harter
2012)
• 22% of Canadians utilize
on-site systems
(Richardson & Fulton 2009)
Septic system leachate represents the largest
unregulated source of wastewater

9. Increasing complexity of
wastewaters
9
• Consumption of pharmaceuticals $16 million in Canada
(2000)
– double digit growth (nearly doubling 2000-2005) Morgan
2004 & 2005
• Estrogen example (2007) Richardson & Fulton 2009
– dispensed 1,700 kg of synthetic estrogen compounds
• 760 kg diverted to wastewater (½ to WWTPs; ½ to
on-site)
– excreted 960 kg endogenous estrogen compounds
• ½ to WWTPs; ½ to on-site
– WWTPs (75% degraded) ; on-site (zero degradation)
– Mass of estrogens released via on-site equivalent to
release from WWTPs

10. Impediment to Decentralized
Systems
10
• DWWT have historically been poorly understood and
managed
• Regulatory agencies need scientifically sound third party
validation
• Need new more advanced systems to treat a greater
complexity of wastewater matrices

11. What Wastewater Disposal Options
Exist?
11
• Options depend on source of
wastewater and regulatory
requirements
• Most treatment options are best
suited for liquids with final disposal
via absorption into ground
• Solids have fewer options at this
time
• Primary focus of talk on treatment
of liquids (all options to treat liquids
need some form of solids
separation)

12. Liquid disposal options
12
• Decentralized systems typically dispose of the primary
treated wastewater to soil absorption systems rather than
release to surface waters
• There are several options for disposal to soils, including:
– Sandfilters (open, buried, recirculating)
– Spray and drip irrigation
– Mounded systems
– Evaporation systems

13. Alternative Treatment Systems
13
Number of treatment options is increasing
to accommodate
• Complexity of waste stream
• Volume of waste generation
• Replacement of older technology found to be
inadequate
• Mitigate environmental impacts

14. Future Trends in Treatment
14
• New twist on old
methods
– Constructed
wetlands,
– lagoon systems
• Biofilm
Technologies
– Fixed films
• Advanced Systems
– ozonation

15. Constructed Wetlands
15
Many
different
configuration
Designed for
different
wastes
Passive, low
maintenance

16. Hybridized Constructed
Wetlands
16
• Growing trend towards combining different types of
CWs
• Can treat complex wastewater
• Large wastewater volumes

17. Continuous Stirred Tank
Reactor
17
Blue Frog™ (base unit) is an efficient mixer and
passive aerator that provides up to 7 mm gallons
per day flows and has the ability to layer the
treated water
• helps to better mix lagoon
systems
• Aids in sludge digestion

18. Continuous Stirred Tank
Reactor
18

19. Hog Farm
19
Location: Western Oklahoma
 Farrowing operation with 6,600 sows
 Total of 14 feet of sludge was remediated in-situ over a one year period

20. BioCord Floating Islands (fixed
film)
20
Absorbed
by plants
and biofilm
Nitrogen Gas
to atmosphere
Phosphorus
removal however is
limited to what
plants can
accumulate during
growth
Phosphorus
Nitrogen

21. Waterloo Biofilter
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There are different configuration depending on
the wastewater constituents and desired
treatment level

22. Fixed Film Bioreactor
- rotating contact reactor -
22
• Biofilm grown on several discs stacked in a row
• Only half of disc rotates through effluent

23. Fixed Film Bioreactor
- rotating contact reactor -
23
Rotation ensure oxygenation for bacteria

24. Moving Bed Biofilm Reactor
24
• High BOD, NH4
+, NO2/NO3, potential to add a P removal media that is regenerative
• Relatively small foot print
• Chamber 1: BOD Chamber 2: organic solids & N oxidation Chamber 3: NO3
removal

25. Advanced On-Site Treatment
25
• Ozone
• Pressure differentials
• Poly-filter
• Granulated activated carbon
filter
• Nutrients (N & P)
• TSS
• BOD
• Pathogens
• PPCPs

26. Results: Selected PPCPs (ppt)
26
0 200 400 600 800 1000
Levonargestrel
Progesterone
Medroxyprogesterone
Aspartame
Diclofenac
Carbamazepine
Trimethoprim
Sulfamethoxazole
Influent Effluent
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
Concentration (ng L-1) Mean ± SD

27. Summary
• Need is great
• Expect greater demand for on-site
treatment
• More research needed to increase options
for solids
• Greater effort needed for verification of
emerging environmental technologies
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28. Questions
“You cannot get through a single day without having an impact on the
world around you. What you do makes a difference, and you have to
decide what kind of difference you want to make.” — Jane Goodall
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